Fixed currentPath docs, delegateNotify method default error arg

Fixed FTP crash on rucursive remove
Removed FoundationErrorEnum, Refactoed delegate progress routine
2017-08-29 01:40:15 +04:30 · 2017-08-28 00:06:02 +04:30 · 2017-08-27 13:48:29 +04:30 · 2017-08-24 15:08:22 +04:30 · 2017-08-24 08:36:11 +04:30 · 2017-08-23 23:21:17 +04:30
37 changed files with 6724 additions and 2955 deletions
@@ -12,14 +12,14 @@ env:
  - MACOS_SDK=macosx
  - TVOS_SDK=appletvsimulator
  matrix:
-    - DESTINATION="OS=10.2,name=iPad Air 2"        SCHEME="$IOS_FRAMEWORK_SCHEME"     SDK="$IOS_SDK"     RUN_TESTS="NO" BUILD_EXAMPLE="NO" POD_LINT="YES"
-    - DESTINATION="OS=9.0,name=iPhone 6"           SCHEME="$IOS_FRAMEWORK_SCHEME"     SDK="$IOS_SDK"     RUN_TESTS="NO" BUILD_EXAMPLE="NO" POD_LINT="NO"
-    - DESTINATION="OS=8.1,name=iPhone 4S"          SCHEME="$IOS_FRAMEWORK_SCHEME"     SDK="$IOS_SDK"     RUN_TESTS="NO" BUILD_EXAMPLE="NO" POD_LINT="NO"
+    - DESTINATION="OS=10.2,name=iPad Air 2"        SCHEME="$IOS_FRAMEWORK_SCHEME"     SDK="$IOS_SDK"     RUN_TESTS="NO" BUILD_EXAMPLE="NO" POD="NO" CARTHAGEDEPLOY="YES"
+    - DESTINATION="OS=9.0,name=iPhone 6"           SCHEME="$IOS_FRAMEWORK_SCHEME"     SDK="$IOS_SDK"     RUN_TESTS="NO" BUILD_EXAMPLE="NO" POD="YES"  CARTHAGEDEPLOY="NO"
+    - DESTINATION="OS=8.1,name=iPhone 4S"          SCHEME="$IOS_FRAMEWORK_SCHEME"     SDK="$IOS_SDK"     RUN_TESTS="NO" BUILD_EXAMPLE="NO" POD="NO"  CARTHAGEDEPLOY="NO"

-    - DESTINATION="OS=10.1,name=Apple TV 1080p"    SCHEME="$TVOS_FRAMEWORK_SCHEME"    SDK="$TVOS_SDK"    RUN_TESTS="NO" BUILD_EXAMPLE="NO"  POD_LINT="NO"
-    - DESTINATION="OS=10.0,name=Apple TV 1080p"    SCHEME="$TVOS_FRAMEWORK_SCHEME"    SDK="$TVOS_SDK"    RUN_TESTS="NO" BUILD_EXAMPLE="NO"  POD_LINT="NO"
+    - DESTINATION="OS=10.1,name=Apple TV 1080p"    SCHEME="$TVOS_FRAMEWORK_SCHEME"    SDK="$TVOS_SDK"    RUN_TESTS="NO" BUILD_EXAMPLE="NO" POD="NO"  CARTHAGEDEPLOY="NO"
+    # - DESTINATION="OS=10.0,name=Apple TV 1080p"    SCHEME="$TVOS_FRAMEWORK_SCHEME"    SDK="$TVOS_SDK"    RUN_TESTS="NO" BUILD_EXAMPLE="NO" POD="NO"  CARTHAGEDEPLOY="NO"

-    - DESTINATION="arch=x86_64"                    SCHEME="$MACOS_FRAMEWORK_SCHEME"   SDK="$MACOS_SDK"   RUN_TESTS="NO" BUILD_EXAMPLE="NO"  POD_LINT="NO"
+    - DESTINATION="arch=x86_64"                    SCHEME="$MACOS_FRAMEWORK_SCHEME"   SDK="$MACOS_SDK"   RUN_TESTS="NO" BUILD_EXAMPLE="NO" POD="NO"  CARTHAGEDEPLOY="NO"
 before_install:
  - gem install xcpretty --no-rdoc --no-ri --no-document --quiet
  - gem install cocoapods --no-rdoc --no-ri --no-document --quiet
@@ -29,11 +29,6 @@ script:
  - set -o pipefail
  - xcodebuild -version

-  # Run `pod lib lint` if specified
-  - if [ $POD_LINT == "YES" ]; then
-      pod lib lint;
-    fi
-
  # Build Example in Debug if specified
  - if [ $BUILD_EXAMPLE == "YES" ]; then
      xcodebuild -project "$WORKSPACE" -scheme "$EXAMPLE_SCHEME" -sdk "$SDK" -destination "$DESTINATION" -configuration Debug ONLY_ACTIVE_ARCH=NO build | xcpretty;
@@ -53,20 +48,34 @@ script:
      xcodebuild -project "$PROJECT" -scheme "$SCHEME" -sdk "$SDK" -destination "$DESTINATION" -configuration Release ONLY_ACTIVE_ARCH=NO build | xcpretty;
    fi

-# after_success:
+  # Run `pod lib lint` if specified
+  - if [ $POD == "YES" ]; then
+      pod lib lint --quick;
+    fi
+
+after_success:
+  # Run `pod trunk push` if specified
+  - if [ $POD == "YES" ] && [ -n "$TRAVIS_TAG" ]; then
+      pod trunk push --allow-warnings;
+    fi
+
 #   - bash <(curl -s https://codecov.io/bash)
 before_deploy:
-  - brew update
-  - brew outdated carthage || brew upgrade carthage
-  - carthage version
-  - carthage build --no-skip-current --verbose
-  - carthage archive $PROJECTNAME
+  - if [ $CARTHAGEDEPLOY == "YES" ] && [ -n "$TRAVIS_TAG" ]; then
+      brew update;
+      brew outdated carthage || brew upgrade carthage;
+      carthage version;
+      carthage build --no-skip-current --verbose;
+      carthage archive $PROJECTNAME;
+    fi

 deploy:
  provider: releases
-  api_key: $GITHUBTOKEN
+  api_key: "$GITHUBTOKEN"
  file: $FRAMEWORK_NAME.zip
  skip_cleanup: true
  on:
-    repo: amosavian/$PROJECTNAME
-    tags: true
+    # repo: amosavian/$PROJECTNAME
+    repo: amosavian/FileProvider
+    tags: true
+    condition: "$CARTHAGEDEPLOY = YES"
@@ -1,5 +1,5 @@
 #
-#  Be sure to run `pod spec lint FileProvider.podspec' to ensure this is a
+#  Be sure to run `pod spec lint FilesProvider.podspec' to ensure this is a
 #  valid spec and to remove all comments including this before submitting the spec.
 #
 #  To learn more about Podspec attributes see http://docs.cocoapods.org/specification.html
@@ -15,9 +15,9 @@ Pod::Spec.new do |s|
  #  summary should be tweet-length, and the description more in depth.
  #

-  s.name         = "FileProvider"
-  s.version      = "0.12.5"
-  s.summary      = "FileManager replacement for Local and Remote (WebDAV/Dropbox/OneDrive/SMB2) files on iOS and macOS."
+  s.name         = "FilesProvider"
+  s.version      = "0.20.1"
+  s.summary      = "FileManager replacement for Local and Remote (WebDAV/FTP/Dropbox/OneDrive/SMB2) files on iOS and macOS."

  # This description is used to generate tags and improve search results.
  #   * Think: What does it do? Why did you write it? What is the focus?
@@ -35,6 +35,15 @@
 		792572411DF23BDA006A1526 /* LocalHelper.swift in Sources */ = {isa = PBXBuildFile; fileRef = 792572401DF23BDA006A1526 /* LocalHelper.swift */; };
 		792572421DF23BDA006A1526 /* LocalHelper.swift in Sources */ = {isa = PBXBuildFile; fileRef = 792572401DF23BDA006A1526 /* LocalHelper.swift */; };
 		792572431DF23BDA006A1526 /* LocalHelper.swift in Sources */ = {isa = PBXBuildFile; fileRef = 792572401DF23BDA006A1526 /* LocalHelper.swift */; };
+		7936BC121E880F5700A6C81C /* FTPFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7936BC111E880F5700A6C81C /* FTPFileProvider.swift */; };
+		7936BC131E880F5700A6C81C /* FTPFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7936BC111E880F5700A6C81C /* FTPFileProvider.swift */; };
+		7936BC141E880F5700A6C81C /* FTPFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7936BC111E880F5700A6C81C /* FTPFileProvider.swift */; };
+		793CCE2A1F4B8C5C00BC8288 /* FoundationExtensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = 793CCE291F4B8C5C00BC8288 /* FoundationExtensions.swift */; };
+		793CCE2B1F4B8C5C00BC8288 /* FoundationExtensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = 793CCE291F4B8C5C00BC8288 /* FoundationExtensions.swift */; };
+		793CCE2C1F4B8C5C00BC8288 /* FoundationExtensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = 793CCE291F4B8C5C00BC8288 /* FoundationExtensions.swift */; };
+		793CCE2E1F4B8C7B00BC8288 /* HashMAC.swift in Sources */ = {isa = PBXBuildFile; fileRef = 793CCE2D1F4B8C7B00BC8288 /* HashMAC.swift */; };
+		793CCE2F1F4B8C7B00BC8288 /* HashMAC.swift in Sources */ = {isa = PBXBuildFile; fileRef = 793CCE2D1F4B8C7B00BC8288 /* HashMAC.swift */; };
+		793CCE301F4B8C7B00BC8288 /* HashMAC.swift in Sources */ = {isa = PBXBuildFile; fileRef = 793CCE2D1F4B8C7B00BC8288 /* HashMAC.swift */; };
 		79480FF61E3ABDD0007E7275 /* CloudFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 79480FF51E3ABDD0007E7275 /* CloudFileProvider.swift */; };
 		79480FF71E3ABDD0007E7275 /* CloudFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 79480FF51E3ABDD0007E7275 /* CloudFileProvider.swift */; };
 		79480FF81E3ABDD0007E7275 /* CloudFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 79480FF51E3ABDD0007E7275 /* CloudFileProvider.swift */; };
@@ -47,6 +56,10 @@
 		794C220E1D591A4B00EC49B8 /* SMB2QueryTypes.swift in Sources */ = {isa = PBXBuildFile; fileRef = 794C220D1D591A4B00EC49B8 /* SMB2QueryTypes.swift */; };
 		794C220F1D591A4B00EC49B8 /* SMB2QueryTypes.swift in Sources */ = {isa = PBXBuildFile; fileRef = 794C220D1D591A4B00EC49B8 /* SMB2QueryTypes.swift */; };
 		794C22101D591A4B00EC49B8 /* SMB2QueryTypes.swift in Sources */ = {isa = PBXBuildFile; fileRef = 794C220D1D591A4B00EC49B8 /* SMB2QueryTypes.swift */; };
+		7958155A1F478ED9003344DD /* HTTPFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 795815591F478ED9003344DD /* HTTPFileProvider.swift */; };
+		7958155B1F478ED9003344DD /* HTTPFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 795815591F478ED9003344DD /* HTTPFileProvider.swift */; };
+		7958155C1F478ED9003344DD /* HTTPFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 795815591F478ED9003344DD /* HTTPFileProvider.swift */; };
+		798654331E8874BC002FA550 /* FTPHelper.swift in Sources */ = {isa = PBXBuildFile; fileRef = 798654321E8874BC002FA550 /* FTPHelper.swift */; };
 		799396AA1D48C02300086753 /* DropboxFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 799396931D48C02300086753 /* DropboxFileProvider.swift */; };
 		799396AB1D48C02300086753 /* DropboxFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 799396931D48C02300086753 /* DropboxFileProvider.swift */; };
 		799396AC1D48C02300086753 /* DropboxFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 799396931D48C02300086753 /* DropboxFileProvider.swift */; };
@@ -109,12 +122,14 @@
 		79BD63BE1E2CC3C20035128C /* ImageIO.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 79BD63BD1E2CC3C20035128C /* ImageIO.framework */; };
 		79BD63C01E2CC3CD0035128C /* CoreGraphics.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 79BD63BF1E2CC3CD0035128C /* CoreGraphics.framework */; };
 		79BD63C21E2CC3D30035128C /* AVFoundation.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 79BD63C11E2CC3D30035128C /* AVFoundation.framework */; };
-		79BD63C51E2D17880035128C /* OneDriveFileProvide.swift in Sources */ = {isa = PBXBuildFile; fileRef = 79BD63C31E2D17880035128C /* OneDriveFileProvide.swift */; };
-		79BD63C61E2D17880035128C /* OneDriveFileProvide.swift in Sources */ = {isa = PBXBuildFile; fileRef = 79BD63C31E2D17880035128C /* OneDriveFileProvide.swift */; };
-		79BD63C71E2D17880035128C /* OneDriveFileProvide.swift in Sources */ = {isa = PBXBuildFile; fileRef = 79BD63C31E2D17880035128C /* OneDriveFileProvide.swift */; };
+		79BD63C51E2D17880035128C /* OneDriveFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 79BD63C31E2D17880035128C /* OneDriveFileProvider.swift */; };
+		79BD63C61E2D17880035128C /* OneDriveFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 79BD63C31E2D17880035128C /* OneDriveFileProvider.swift */; };
+		79BD63C71E2D17880035128C /* OneDriveFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 79BD63C31E2D17880035128C /* OneDriveFileProvider.swift */; };
 		79BD63C81E2D17880035128C /* OneDriveHelper.swift in Sources */ = {isa = PBXBuildFile; fileRef = 79BD63C41E2D17880035128C /* OneDriveHelper.swift */; };
 		79BD63C91E2D17880035128C /* OneDriveHelper.swift in Sources */ = {isa = PBXBuildFile; fileRef = 79BD63C41E2D17880035128C /* OneDriveHelper.swift */; };
 		79BD63CA1E2D17880035128C /* OneDriveHelper.swift in Sources */ = {isa = PBXBuildFile; fileRef = 79BD63C41E2D17880035128C /* OneDriveHelper.swift */; };
+		79F4678B1E8B80F200C91A85 /* FTPHelper.swift in Sources */ = {isa = PBXBuildFile; fileRef = 798654321E8874BC002FA550 /* FTPHelper.swift */; };
+		79F4678C1E8B80F200C91A85 /* FTPHelper.swift in Sources */ = {isa = PBXBuildFile; fileRef = 798654321E8874BC002FA550 /* FTPHelper.swift */; };
 		79F5745B1DFDB10B00179ABF /* FileObject.swift in Sources */ = {isa = PBXBuildFile; fileRef = 79F5745A1DFDB10A00179ABF /* FileObject.swift */; };
 		79F5745C1DFDB10B00179ABF /* FileObject.swift in Sources */ = {isa = PBXBuildFile; fileRef = 79F5745A1DFDB10A00179ABF /* FileObject.swift */; };
 		79F5745D1DFDB10B00179ABF /* FileObject.swift in Sources */ = {isa = PBXBuildFile; fileRef = 79F5745A1DFDB10A00179ABF /* FileObject.swift */; };
@@ -130,13 +145,18 @@
 		7924B1921D89DAE000589DB7 /* Parser.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Parser.swift; sourceTree = "<group>"; };
 		7924B1A81D89F79200589DB7 /* FPSStreamTask.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = FPSStreamTask.swift; sourceTree = "<group>"; };
 		792572401DF23BDA006A1526 /* LocalHelper.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = LocalHelper.swift; sourceTree = "<group>"; };
+		7936BC111E880F5700A6C81C /* FTPFileProvider.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = FTPFileProvider.swift; sourceTree = "<group>"; };
+		793CCE291F4B8C5C00BC8288 /* FoundationExtensions.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = FoundationExtensions.swift; sourceTree = "<group>"; };
+		793CCE2D1F4B8C7B00BC8288 /* HashMAC.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = HashMAC.swift; sourceTree = "<group>"; };
 		79480FF51E3ABDD0007E7275 /* CloudFileProvider.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = CloudFileProvider.swift; sourceTree = "<group>"; };
 		794C21FD1D58912A00EC49B8 /* DropboxHelper.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = DropboxHelper.swift; sourceTree = "<group>"; };
 		794C22091D5893F800EC49B8 /* SMB2Notification.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = SMB2Notification.swift; sourceTree = "<group>"; };
 		794C220D1D591A4B00EC49B8 /* SMB2QueryTypes.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = SMB2QueryTypes.swift; sourceTree = "<group>"; };
-		799396671D48B7F600086753 /* FileProvider.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = FileProvider.framework; sourceTree = BUILT_PRODUCTS_DIR; };
-		799396751D48B80D00086753 /* FileProvider.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = FileProvider.framework; sourceTree = BUILT_PRODUCTS_DIR; };
-		799396821D48B82700086753 /* FileProvider.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = FileProvider.framework; sourceTree = BUILT_PRODUCTS_DIR; };
+		795815591F478ED9003344DD /* HTTPFileProvider.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = HTTPFileProvider.swift; sourceTree = "<group>"; };
+		798654321E8874BC002FA550 /* FTPHelper.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = FTPHelper.swift; sourceTree = "<group>"; };
+		799396671D48B7F600086753 /* FilesProvider.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = FilesProvider.framework; sourceTree = BUILT_PRODUCTS_DIR; };
+		799396751D48B80D00086753 /* FilesProvider.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = FilesProvider.framework; sourceTree = BUILT_PRODUCTS_DIR; };
+		799396821D48B82700086753 /* FilesProvider.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = FilesProvider.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		7993968B1D48B8C700086753 /* Info-iOS.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = "Info-iOS.plist"; sourceTree = "<group>"; };
 		7993968C1D48B8C700086753 /* Info-MacOS.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = "Info-MacOS.plist"; sourceTree = "<group>"; };
 		7993968D1D48B8C700086753 /* Info-tvOS.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = "Info-tvOS.plist"; sourceTree = "<group>"; };
@@ -170,7 +190,7 @@
 		79BD63BD1E2CC3C20035128C /* ImageIO.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = ImageIO.framework; path = Platforms/AppleTVOS.platform/Developer/SDKs/AppleTVOS10.1.sdk/System/Library/Frameworks/ImageIO.framework; sourceTree = DEVELOPER_DIR; };
 		79BD63BF1E2CC3CD0035128C /* CoreGraphics.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = CoreGraphics.framework; path = Platforms/AppleTVOS.platform/Developer/SDKs/AppleTVOS10.1.sdk/System/Library/Frameworks/CoreGraphics.framework; sourceTree = DEVELOPER_DIR; };
 		79BD63C11E2CC3D30035128C /* AVFoundation.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = AVFoundation.framework; path = Platforms/AppleTVOS.platform/Developer/SDKs/AppleTVOS10.1.sdk/System/Library/Frameworks/AVFoundation.framework; sourceTree = DEVELOPER_DIR; };
-		79BD63C31E2D17880035128C /* OneDriveFileProvide.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = OneDriveFileProvide.swift; sourceTree = "<group>"; };
+		79BD63C31E2D17880035128C /* OneDriveFileProvider.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = OneDriveFileProvider.swift; sourceTree = "<group>"; };
 		79BD63C41E2D17880035128C /* OneDriveHelper.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = OneDriveHelper.swift; sourceTree = "<group>"; };
 		79F5745A1DFDB10A00179ABF /* FileObject.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = FileObject.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
@@ -243,6 +263,15 @@
 			path = AEXML;
 			sourceTree = "<group>";
 		};
+		793CCE281F4B8C3600BC8288 /* Extensions */ = {
+			isa = PBXGroup;
+			children = (
+				793CCE291F4B8C5C00BC8288 /* FoundationExtensions.swift */,
+				793CCE2D1F4B8C7B00BC8288 /* HashMAC.swift */,
+			);
+			path = Extensions;
+			sourceTree = "<group>";
+		};
 		7993965B1D48B7BF00086753 = {
 			isa = PBXGroup;
 			children = (
@@ -257,9 +286,9 @@
 		799396681D48B7F600086753 /* Products */ = {
 			isa = PBXGroup;
 			children = (
-				799396671D48B7F600086753 /* FileProvider.framework */,
-				799396751D48B80D00086753 /* FileProvider.framework */,
-				799396821D48B82700086753 /* FileProvider.framework */,
+				799396671D48B7F600086753 /* FilesProvider.framework */,
+				799396751D48B80D00086753 /* FilesProvider.framework */,
+				799396821D48B82700086753 /* FilesProvider.framework */,
 			);
 			name = Products;
 			sourceTree = "<group>";
@@ -278,6 +307,7 @@
 			isa = PBXGroup;
 			children = (
 				7924B18B1D89DAE000589DB7 /* AEXML */,
+				793CCE281F4B8C3600BC8288 /* Extensions */,
 				799396991D48C02300086753 /* SMBTypes */,
 				799396941D48C02300086753 /* FileProvider.h */,
 				799396951D48C02300086753 /* FileProvider.swift */,
@@ -286,15 +316,18 @@
 				792572401DF23BDA006A1526 /* LocalHelper.swift */,
 				79480FF51E3ABDD0007E7275 /* CloudFileProvider.swift */,
 				79BD638B1E2CC2300035128C /* ExtendedLocalFileProvider.swift */,
+				7924B1A81D89F79200589DB7 /* FPSStreamTask.swift */,
 				7902C0851D61B56D00564440 /* RemoteSession.swift */,
+				795815591F478ED9003344DD /* HTTPFileProvider.swift */,
 				799396931D48C02300086753 /* DropboxFileProvider.swift */,
 				794C21FD1D58912A00EC49B8 /* DropboxHelper.swift */,
-				79BD63C31E2D17880035128C /* OneDriveFileProvide.swift */,
+				79BD63C31E2D17880035128C /* OneDriveFileProvider.swift */,
 				79BD63C41E2D17880035128C /* OneDriveHelper.swift */,
-				7924B1A81D89F79200589DB7 /* FPSStreamTask.swift */,
+				799396A61D48C02300086753 /* WebDAVFileProvider.swift */,
+				7936BC111E880F5700A6C81C /* FTPFileProvider.swift */,
+				798654321E8874BC002FA550 /* FTPHelper.swift */,
 				799396971D48C02300086753 /* SMBClient.swift */,
 				799396981D48C02300086753 /* SMBFileProvider.swift */,
-				799396A61D48C02300086753 /* WebDAVFileProvider.swift */,
 			);
 			path = Sources;
 			sourceTree = "<group>";
@@ -353,9 +386,9 @@
 /* End PBXHeadersBuildPhase section */

 /* Begin PBXNativeTarget section */
-		799396661D48B7F600086753 /* FileProvider iOS */ = {
+		799396661D48B7F600086753 /* FilesProvider iOS */ = {
 			isa = PBXNativeTarget;
-			buildConfigurationList = 7993966F1D48B7F600086753 /* Build configuration list for PBXNativeTarget "FileProvider iOS" */;
+			buildConfigurationList = 7993966F1D48B7F600086753 /* Build configuration list for PBXNativeTarget "FilesProvider iOS" */;
 			buildPhases = (
 				799396621D48B7F600086753 /* Sources */,
 				799396631D48B7F600086753 /* Frameworks */,
@@ -366,14 +399,14 @@
 			);
 			dependencies = (
 			);
-			name = "FileProvider iOS";
+			name = "FilesProvider iOS";
 			productName = "FileProvider iOS";
-			productReference = 799396671D48B7F600086753 /* FileProvider.framework */;
+			productReference = 799396671D48B7F600086753 /* FilesProvider.framework */;
 			productType = "com.apple.product-type.framework";
 		};
-		799396741D48B80D00086753 /* FileProvider OSX */ = {
+		799396741D48B80D00086753 /* FilesProvider OSX */ = {
 			isa = PBXNativeTarget;
-			buildConfigurationList = 7993967A1D48B80D00086753 /* Build configuration list for PBXNativeTarget "FileProvider OSX" */;
+			buildConfigurationList = 7993967A1D48B80D00086753 /* Build configuration list for PBXNativeTarget "FilesProvider OSX" */;
 			buildPhases = (
 				799396701D48B80D00086753 /* Sources */,
 				799396711D48B80D00086753 /* Frameworks */,
@@ -384,14 +417,14 @@
 			);
 			dependencies = (
 			);
-			name = "FileProvider OSX";
+			name = "FilesProvider OSX";
 			productName = "FileProvider OSX";
-			productReference = 799396751D48B80D00086753 /* FileProvider.framework */;
+			productReference = 799396751D48B80D00086753 /* FilesProvider.framework */;
 			productType = "com.apple.product-type.framework";
 		};
-		799396811D48B82700086753 /* FileProvider tvOS */ = {
+		799396811D48B82700086753 /* FilesProvider tvOS */ = {
 			isa = PBXNativeTarget;
-			buildConfigurationList = 799396871D48B82700086753 /* Build configuration list for PBXNativeTarget "FileProvider tvOS" */;
+			buildConfigurationList = 799396871D48B82700086753 /* Build configuration list for PBXNativeTarget "FilesProvider tvOS" */;
 			buildPhases = (
 				7993967D1D48B82700086753 /* Sources */,
 				7993967E1D48B82700086753 /* Frameworks */,
@@ -402,9 +435,9 @@
 			);
 			dependencies = (
 			);
-			name = "FileProvider tvOS";
+			name = "FilesProvider tvOS";
 			productName = "FileProvider tvOS";
-			productReference = 799396821D48B82700086753 /* FileProvider.framework */;
+			productReference = 799396821D48B82700086753 /* FilesProvider.framework */;
 			productType = "com.apple.product-type.framework";
 		};
 /* End PBXNativeTarget section */
@@ -427,7 +460,7 @@
 					};
 				};
 			};
-			buildConfigurationList = 7993965F1D48B7BF00086753 /* Build configuration list for PBXProject "FileProvider" */;
+			buildConfigurationList = 7993965F1D48B7BF00086753 /* Build configuration list for PBXProject "FilesProvider" */;
 			compatibilityVersion = "Xcode 3.2";
 			developmentRegion = English;
 			hasScannedForEncodings = 0;
@@ -439,9 +472,9 @@
 			projectDirPath = "";
 			projectRoot = "";
 			targets = (
-				799396661D48B7F600086753 /* FileProvider iOS */,
-				799396741D48B80D00086753 /* FileProvider OSX */,
-				799396811D48B82700086753 /* FileProvider tvOS */,
+				799396661D48B7F600086753 /* FilesProvider iOS */,
+				799396741D48B80D00086753 /* FilesProvider OSX */,
+				799396811D48B82700086753 /* FilesProvider tvOS */,
 			);
 		};
 /* End PBXProject section */
@@ -479,12 +512,15 @@
 				799396D41D48C02300086753 /* SMB2Tree.swift in Sources */,
 				7924B1A21D89DAE000589DB7 /* Options.swift in Sources */,
 				792572411DF23BDA006A1526 /* LocalHelper.swift in Sources */,
+				7936BC121E880F5700A6C81C /* FTPFileProvider.swift in Sources */,
 				79480FF61E3ABDD0007E7275 /* CloudFileProvider.swift in Sources */,
 				79F5745B1DFDB10B00179ABF /* FileObject.swift in Sources */,
-				79BD63C51E2D17880035128C /* OneDriveFileProvide.swift in Sources */,
+				79BD63C51E2D17880035128C /* OneDriveFileProvider.swift in Sources */,
 				7924B1991D89DAE000589DB7 /* Element.swift in Sources */,
 				799396C81D48C02300086753 /* SMB2IOCtl.swift in Sources */,
 				799396D71D48C02300086753 /* SMB2Types.swift in Sources */,
+				7958155A1F478ED9003344DD /* HTTPFileProvider.swift in Sources */,
+				798654331E8874BC002FA550 /* FTPHelper.swift in Sources */,
 				7924B1B21D89FCDA00589DB7 /* FPSStreamTask.swift in Sources */,
 				799396C51D48C02300086753 /* SMB2FileOperation.swift in Sources */,
 				79BD63C81E2D17880035128C /* OneDriveHelper.swift in Sources */,
@@ -501,10 +537,12 @@
 				799396E01D48C02300086753 /* WebDAVFileProvider.swift in Sources */,
 				799396DA1D48C02300086753 /* SMBErrorType.swift in Sources */,
 				799396C21D48C02300086753 /* SMB2FileHandle.swift in Sources */,
+				793CCE2E1F4B8C7B00BC8288 /* HashMAC.swift in Sources */,
 				799396CB1D48C02300086753 /* SMB2Query.swift in Sources */,
 				799396AA1D48C02300086753 /* DropboxFileProvider.swift in Sources */,
 				79BD638C1E2CC2300035128C /* ExtendedLocalFileProvider.swift in Sources */,
 				7924B1B31D89FD6400589DB7 /* SMBClient.swift in Sources */,
+				793CCE2A1F4B8C5C00BC8288 /* FoundationExtensions.swift in Sources */,
 				7924B1A51D89DAE000589DB7 /* Parser.swift in Sources */,
 				799396B01D48C02300086753 /* FileProvider.swift in Sources */,
 				7924B19C1D89DAE000589DB7 /* Error.swift in Sources */,
@@ -519,12 +557,15 @@
 				799396D51D48C02300086753 /* SMB2Tree.swift in Sources */,
 				7924B1A31D89DAE000589DB7 /* Options.swift in Sources */,
 				792572421DF23BDA006A1526 /* LocalHelper.swift in Sources */,
+				7936BC131E880F5700A6C81C /* FTPFileProvider.swift in Sources */,
 				79480FF71E3ABDD0007E7275 /* CloudFileProvider.swift in Sources */,
 				79F5745C1DFDB10B00179ABF /* FileObject.swift in Sources */,
-				79BD63C61E2D17880035128C /* OneDriveFileProvide.swift in Sources */,
+				79BD63C61E2D17880035128C /* OneDriveFileProvider.swift in Sources */,
 				7924B1B01D89F7DE00589DB7 /* FPSStreamTask.swift in Sources */,
 				7924B19A1D89DAE000589DB7 /* Element.swift in Sources */,
 				799396C91D48C02300086753 /* SMB2IOCtl.swift in Sources */,
+				7958155B1F478ED9003344DD /* HTTPFileProvider.swift in Sources */,
+				79F4678B1E8B80F200C91A85 /* FTPHelper.swift in Sources */,
 				799396D81D48C02300086753 /* SMB2Types.swift in Sources */,
 				799396C61D48C02300086753 /* SMB2FileOperation.swift in Sources */,
 				79BD63C91E2D17880035128C /* OneDriveHelper.swift in Sources */,
@@ -541,10 +582,12 @@
 				799396E11D48C02300086753 /* WebDAVFileProvider.swift in Sources */,
 				799396DB1D48C02300086753 /* SMBErrorType.swift in Sources */,
 				799396C31D48C02300086753 /* SMB2FileHandle.swift in Sources */,
+				793CCE2F1F4B8C7B00BC8288 /* HashMAC.swift in Sources */,
 				799396CC1D48C02300086753 /* SMB2Query.swift in Sources */,
 				7924B1AD1D89F7D800589DB7 /* SMBClient.swift in Sources */,
 				79BD638D1E2CC2300035128C /* ExtendedLocalFileProvider.swift in Sources */,
 				799396AB1D48C02300086753 /* DropboxFileProvider.swift in Sources */,
+				793CCE2B1F4B8C5C00BC8288 /* FoundationExtensions.swift in Sources */,
 				7924B1A61D89DAE000589DB7 /* Parser.swift in Sources */,
 				799396B11D48C02300086753 /* FileProvider.swift in Sources */,
 				7924B19D1D89DAE000589DB7 /* Error.swift in Sources */,
@@ -559,12 +602,15 @@
 				799396D61D48C02300086753 /* SMB2Tree.swift in Sources */,
 				7924B1A41D89DAE000589DB7 /* Options.swift in Sources */,
 				792572431DF23BDA006A1526 /* LocalHelper.swift in Sources */,
+				7936BC141E880F5700A6C81C /* FTPFileProvider.swift in Sources */,
 				79480FF81E3ABDD0007E7275 /* CloudFileProvider.swift in Sources */,
 				79F5745D1DFDB10B00179ABF /* FileObject.swift in Sources */,
-				79BD63C71E2D17880035128C /* OneDriveFileProvide.swift in Sources */,
+				79BD63C71E2D17880035128C /* OneDriveFileProvider.swift in Sources */,
 				7924B1B11D89F7DF00589DB7 /* FPSStreamTask.swift in Sources */,
 				7924B19B1D89DAE000589DB7 /* Element.swift in Sources */,
 				799396CA1D48C02300086753 /* SMB2IOCtl.swift in Sources */,
+				7958155C1F478ED9003344DD /* HTTPFileProvider.swift in Sources */,
+				79F4678C1E8B80F200C91A85 /* FTPHelper.swift in Sources */,
 				799396D91D48C02300086753 /* SMB2Types.swift in Sources */,
 				799396C71D48C02300086753 /* SMB2FileOperation.swift in Sources */,
 				79BD63CA1E2D17880035128C /* OneDriveHelper.swift in Sources */,
@@ -581,10 +627,12 @@
 				799396E21D48C02300086753 /* WebDAVFileProvider.swift in Sources */,
 				799396DC1D48C02300086753 /* SMBErrorType.swift in Sources */,
 				799396C41D48C02300086753 /* SMB2FileHandle.swift in Sources */,
+				793CCE301F4B8C7B00BC8288 /* HashMAC.swift in Sources */,
 				799396CD1D48C02300086753 /* SMB2Query.swift in Sources */,
 				7924B1AE1D89F7D900589DB7 /* SMBClient.swift in Sources */,
 				79BD638E1E2CC2300035128C /* ExtendedLocalFileProvider.swift in Sources */,
 				799396AC1D48C02300086753 /* DropboxFileProvider.swift in Sources */,
+				793CCE2C1F4B8C5C00BC8288 /* FoundationExtensions.swift in Sources */,
 				7924B1A71D89DAE000589DB7 /* Parser.swift in Sources */,
 				799396B21D48C02300086753 /* FileProvider.swift in Sources */,
 				7924B19E1D89DAE000589DB7 /* Error.swift in Sources */,
@@ -597,7 +645,7 @@
 		799396601D48B7BF00086753 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
-				BUNDLE_VERSION_STRING = 0.12.5;
+				BUNDLE_VERSION_STRING = 0.20.1;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
 				CLANG_WARN_EMPTY_BODY = YES;
@@ -607,6 +655,7 @@
 				CLANG_WARN_SUSPICIOUS_MOVE = YES;
 				CLANG_WARN_UNREACHABLE_CODE = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
+				COPY_PHASE_STRIP = NO;
 				DEBUG_INFORMATION_FORMAT = dwarf;
 				ENABLE_BITCODE = YES;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
@@ -620,6 +669,7 @@
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
 				ONLY_ACTIVE_ARCH = YES;
+				PRODUCT_NAME = FilesProvider;
 				SWIFT_VERSION = 3.0;
 			};
 			name = Debug;
@@ -627,7 +677,7 @@
 		799396611D48B7BF00086753 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
-				BUNDLE_VERSION_STRING = 0.12.5;
+				BUNDLE_VERSION_STRING = 0.20.1;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
 				CLANG_WARN_EMPTY_BODY = YES;
@@ -647,6 +697,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
+				PRODUCT_NAME = FilesProvider;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
 				SWIFT_VERSION = 3.0;
 			};
@@ -657,7 +708,6 @@
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
 				APPLICATION_EXTENSION_API_ONLY = YES;
-				BUNDLE_VERSION_STRING = 0.8.2;
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_ENABLE_MODULES = YES;
 				CLANG_ENABLE_OBJC_ARC = YES;
@@ -694,8 +744,7 @@
 				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				MTL_ENABLE_DEBUG_INFO = YES;
-				PRODUCT_BUNDLE_IDENTIFIER = "com.mousavian.FileProvider-iOS";
-				PRODUCT_NAME = FileProvider;
+				PRODUCT_BUNDLE_IDENTIFIER = "com.mousavian.FilesProvider-iOS";
 				SDKROOT = iphoneos;
 				SKIP_INSTALL = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
@@ -710,7 +759,6 @@
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
 				APPLICATION_EXTENSION_API_ONLY = YES;
-				BUNDLE_VERSION_STRING = 0.8.2;
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_ENABLE_MODULES = YES;
 				CLANG_ENABLE_OBJC_ARC = YES;
@@ -742,8 +790,7 @@
 				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				MTL_ENABLE_DEBUG_INFO = NO;
-				PRODUCT_BUNDLE_IDENTIFIER = "com.mousavian.FileProvider-iOS";
-				PRODUCT_NAME = FileProvider;
+				PRODUCT_BUNDLE_IDENTIFIER = "com.mousavian.FilesProvider-iOS";
 				SDKROOT = iphoneos;
 				SKIP_INSTALL = YES;
 				TARGETED_DEVICE_FAMILY = "1,2";
@@ -799,8 +846,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks @loader_path/Frameworks";
 				MACOSX_DEPLOYMENT_TARGET = 10.10;
 				MTL_ENABLE_DEBUG_INFO = YES;
-				PRODUCT_BUNDLE_IDENTIFIER = "com.mousavian.FileProvider-OSX";
-				PRODUCT_NAME = FileProvider;
+				PRODUCT_BUNDLE_IDENTIFIER = "com.mousavian.FilesProvider-OSX";
 				SDKROOT = macosx;
 				SKIP_INSTALL = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
@@ -850,8 +896,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks @loader_path/Frameworks";
 				MACOSX_DEPLOYMENT_TARGET = 10.10;
 				MTL_ENABLE_DEBUG_INFO = NO;
-				PRODUCT_BUNDLE_IDENTIFIER = "com.mousavian.FileProvider-OSX";
-				PRODUCT_NAME = FileProvider;
+				PRODUCT_BUNDLE_IDENTIFIER = "com.mousavian.FilesProvider-OSX";
 				SDKROOT = macosx;
 				SKIP_INSTALL = YES;
 				VERSIONING_SYSTEM = "apple-generic";
@@ -902,8 +947,7 @@
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				MTL_ENABLE_DEBUG_INFO = YES;
-				PRODUCT_BUNDLE_IDENTIFIER = "com.mousavian.FileProvider-tvOS";
-				PRODUCT_NAME = FileProvider;
+				PRODUCT_BUNDLE_IDENTIFIER = "com.mousavian.FilesProvider-tvOS";
 				SDKROOT = appletvos;
 				SKIP_INSTALL = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
@@ -952,8 +996,7 @@
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				MTL_ENABLE_DEBUG_INFO = NO;
-				PRODUCT_BUNDLE_IDENTIFIER = "com.mousavian.FileProvider-tvOS";
-				PRODUCT_NAME = FileProvider;
+				PRODUCT_BUNDLE_IDENTIFIER = "com.mousavian.FilesProvider-tvOS";
 				SDKROOT = appletvos;
 				SKIP_INSTALL = YES;
 				TARGETED_DEVICE_FAMILY = 3;
@@ -967,7 +1010,7 @@
 /* End XCBuildConfiguration section */

 /* Begin XCConfigurationList section */
-		7993965F1D48B7BF00086753 /* Build configuration list for PBXProject "FileProvider" */ = {
+		7993965F1D48B7BF00086753 /* Build configuration list for PBXProject "FilesProvider" */ = {
 			isa = XCConfigurationList;
 			buildConfigurations = (
 				799396601D48B7BF00086753 /* Debug */,
@@ -976,7 +1019,7 @@
 			defaultConfigurationIsVisible = 0;
 			defaultConfigurationName = Release;
 		};
-		7993966F1D48B7F600086753 /* Build configuration list for PBXNativeTarget "FileProvider iOS" */ = {
+		7993966F1D48B7F600086753 /* Build configuration list for PBXNativeTarget "FilesProvider iOS" */ = {
 			isa = XCConfigurationList;
 			buildConfigurations = (
 				7993966D1D48B7F600086753 /* Debug */,
@@ -985,7 +1028,7 @@
 			defaultConfigurationIsVisible = 0;
 			defaultConfigurationName = Release;
 		};
-		7993967A1D48B80D00086753 /* Build configuration list for PBXNativeTarget "FileProvider OSX" */ = {
+		7993967A1D48B80D00086753 /* Build configuration list for PBXNativeTarget "FilesProvider OSX" */ = {
 			isa = XCConfigurationList;
 			buildConfigurations = (
 				7993967B1D48B80D00086753 /* Debug */,
@@ -994,7 +1037,7 @@
 			defaultConfigurationIsVisible = 0;
 			defaultConfigurationName = Release;
 		};
-		799396871D48B82700086753 /* Build configuration list for PBXNativeTarget "FileProvider tvOS" */ = {
+		799396871D48B82700086753 /* Build configuration list for PBXNativeTarget "FilesProvider tvOS" */ = {
 			isa = XCConfigurationList;
 			buildConfigurations = (
 				799396881D48B82700086753 /* Debug */,
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "0810"
+   LastUpgradeVersion = "0820"
   version = "1.3">
   <BuildAction
      parallelizeBuildables = "YES"
@@ -15,9 +15,9 @@
            <BuildableReference
               BuildableIdentifier = "primary"
               BlueprintIdentifier = "799396741D48B80D00086753"
-               BuildableName = "FileProvider.framework"
-               BlueprintName = "FileProvider OSX"
-               ReferencedContainer = "container:FileProvider.xcodeproj">
+               BuildableName = "FilesProvider.framework"
+               BlueprintName = "FilesProvider OSX"
+               ReferencedContainer = "container:FilesProvider.xcodeproj">
            </BuildableReference>
         </BuildActionEntry>
      </BuildActionEntries>
@@ -26,6 +26,7 @@
      buildConfiguration = "Debug"
      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      language = ""
      shouldUseLaunchSchemeArgsEnv = "YES">
      <Testables>
      </Testables>
@@ -36,6 +37,7 @@
      buildConfiguration = "Debug"
      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      language = ""
      launchStyle = "0"
      useCustomWorkingDirectory = "NO"
      ignoresPersistentStateOnLaunch = "NO"
@@ -46,9 +48,9 @@
         <BuildableReference
            BuildableIdentifier = "primary"
            BlueprintIdentifier = "799396741D48B80D00086753"
-            BuildableName = "FileProvider.framework"
-            BlueprintName = "FileProvider OSX"
-            ReferencedContainer = "container:FileProvider.xcodeproj">
+            BuildableName = "FilesProvider.framework"
+            BlueprintName = "FilesProvider OSX"
+            ReferencedContainer = "container:FilesProvider.xcodeproj">
         </BuildableReference>
      </MacroExpansion>
      <AdditionalOptions>
@@ -64,9 +66,9 @@
         <BuildableReference
            BuildableIdentifier = "primary"
            BlueprintIdentifier = "799396741D48B80D00086753"
-            BuildableName = "FileProvider.framework"
-            BlueprintName = "FileProvider OSX"
-            ReferencedContainer = "container:FileProvider.xcodeproj">
+            BuildableName = "FilesProvider.framework"
+            BlueprintName = "FilesProvider OSX"
+            ReferencedContainer = "container:FilesProvider.xcodeproj">
         </BuildableReference>
      </MacroExpansion>
   </ProfileAction>
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "0810"
+   LastUpgradeVersion = "0820"
   version = "1.3">
   <BuildAction
      parallelizeBuildables = "YES"
@@ -15,9 +15,9 @@
            <BuildableReference
               BuildableIdentifier = "primary"
               BlueprintIdentifier = "799396661D48B7F600086753"
-               BuildableName = "FileProvider.framework"
-               BlueprintName = "FileProvider iOS"
-               ReferencedContainer = "container:FileProvider.xcodeproj">
+               BuildableName = "FilesProvider.framework"
+               BlueprintName = "FilesProvider iOS"
+               ReferencedContainer = "container:FilesProvider.xcodeproj">
            </BuildableReference>
         </BuildActionEntry>
      </BuildActionEntries>
@@ -26,6 +26,7 @@
      buildConfiguration = "Debug"
      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      language = ""
      shouldUseLaunchSchemeArgsEnv = "YES">
      <Testables>
      </Testables>
@@ -36,6 +37,7 @@
      buildConfiguration = "Debug"
      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      language = ""
      launchStyle = "0"
      useCustomWorkingDirectory = "NO"
      ignoresPersistentStateOnLaunch = "NO"
@@ -46,9 +48,9 @@
         <BuildableReference
            BuildableIdentifier = "primary"
            BlueprintIdentifier = "799396661D48B7F600086753"
-            BuildableName = "FileProvider.framework"
-            BlueprintName = "FileProvider iOS"
-            ReferencedContainer = "container:FileProvider.xcodeproj">
+            BuildableName = "FilesProvider.framework"
+            BlueprintName = "FilesProvider iOS"
+            ReferencedContainer = "container:FilesProvider.xcodeproj">
         </BuildableReference>
      </MacroExpansion>
      <AdditionalOptions>
@@ -64,9 +66,9 @@
         <BuildableReference
            BuildableIdentifier = "primary"
            BlueprintIdentifier = "799396661D48B7F600086753"
-            BuildableName = "FileProvider.framework"
-            BlueprintName = "FileProvider iOS"
-            ReferencedContainer = "container:FileProvider.xcodeproj">
+            BuildableName = "FilesProvider.framework"
+            BlueprintName = "FilesProvider iOS"
+            ReferencedContainer = "container:FilesProvider.xcodeproj">
         </BuildableReference>
      </MacroExpansion>
   </ProfileAction>
@@ -15,9 +15,9 @@
            <BuildableReference
               BuildableIdentifier = "primary"
               BlueprintIdentifier = "799396811D48B82700086753"
-               BuildableName = "FileProvider.framework"
-               BlueprintName = "FileProvider tvOS"
-               ReferencedContainer = "container:FileProvider.xcodeproj">
+               BuildableName = "FilesProvider.framework"
+               BlueprintName = "FilesProvider tvOS"
+               ReferencedContainer = "container:FilesProvider.xcodeproj">
            </BuildableReference>
         </BuildActionEntry>
      </BuildActionEntries>
@@ -26,6 +26,7 @@
      buildConfiguration = "Debug"
      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      language = ""
      shouldUseLaunchSchemeArgsEnv = "YES">
      <Testables>
      </Testables>
@@ -36,6 +37,7 @@
      buildConfiguration = "Debug"
      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      language = ""
      launchStyle = "0"
      useCustomWorkingDirectory = "NO"
      ignoresPersistentStateOnLaunch = "NO"
@@ -46,9 +48,9 @@
         <BuildableReference
            BuildableIdentifier = "primary"
            BlueprintIdentifier = "799396811D48B82700086753"
-            BuildableName = "FileProvider.framework"
-            BlueprintName = "FileProvider tvOS"
-            ReferencedContainer = "container:FileProvider.xcodeproj">
+            BuildableName = "FilesProvider.framework"
+            BlueprintName = "FilesProvider tvOS"
+            ReferencedContainer = "container:FilesProvider.xcodeproj">
         </BuildableReference>
      </MacroExpansion>
      <AdditionalOptions>
@@ -64,9 +66,9 @@
         <BuildableReference
            BuildableIdentifier = "primary"
            BlueprintIdentifier = "799396811D48B82700086753"
-            BuildableName = "FileProvider.framework"
-            BlueprintName = "FileProvider tvOS"
-            ReferencedContainer = "container:FileProvider.xcodeproj">
+            BuildableName = "FilesProvider.framework"
+            BlueprintName = "FilesProvider tvOS"
+            ReferencedContainer = "container:FilesProvider.xcodeproj">
         </BuildableReference>
      </MacroExpansion>
   </ProfileAction>
@@ -1,5 +1,5 @@
 import PackageDescription

 let package = Package(
-    name: "FileProvider"
-)
+    name: "FilesProvider"
+)
@@ -1,63 +1,71 @@
-# FileProvider
+![File Provider](fileprovider.png)

 >This Swift library provide a swifty way to deal with local and remote files and directories in a unified way.

+<center>
+
 [![Swift Version][swift-image]][swift-url]
 [![Platform][platform-image]](#)
 [![License][license-image]][license-url]
-
-[![Release versin][release-image]][release-url]
-[![CocoaPods version](https://img.shields.io/cocoapods/v/FileProvider.svg)][cocoapods]
-[![Carthage compatible][carthage-image]](https://github.com/Carthage/Carthage)
-
 [![Build Status][travis-image]][travis-url]
 [![Codebeat Badge][codebeat-image]][codebeat-url]
-[![Cocoapods Docs][docs-image]][docs-url]
+
+[![Release version][release-image]][release-url]
+[![CocoaPods version](https://img.shields.io/cocoapods/v/FilesProvider.svg)][cocoapods]
+[![Carthage compatible][carthage-image]](https://github.com/Carthage/Carthage)
 [![Cocoapods Downloads][cocoapods-downloads]][cocoapods]
 [![Cocoapods Apps][cocoapods-apps]][cocoapods]

+Old Cocoapods repo stats:
+[![Cocoapods Downloads][cocoapods-downloads-old]][cocoapods-old]
+[![Cocoapods Apps][cocoapods-apps-old]][cocoapods-old]
+
+</center>
+
 <!--- 
+[![Cocoapods Doc][docs-image]][docs-url]
 [![codecov](https://codecov.io/gh/amosavian/FileProvider/branch/master/graph/badge.svg)](https://codecov.io/gh/amosavian/FileProvider) 
 ---> 

-This library provides implementaion of WebDav, Dropbox, OneDrive and SMB2 (incomplete) and local files.
+This library provides implementaion of WebDav, FTP, Dropbox, OneDrive and SMB2 (incomplete) and local files.

-All functions are async calls and it wont block your main thread.
-
-Local and WebDAV providers are fully tested and can be used in production environment.
+All functions do async calls and it wont block your main thread.

 ## Features

- [x] **LocalFileProvider** a wrapper around `FileManager` with some additions like searching and reading a portion of file.
- [x] **CloudFileProvider** A wrapper around app's ubiquitous container to iCloud Drive in iOS 8+ API.
- [x] **WebDAVFileProvider** WebDAV protocol is defacto file transmission standard, replaced FTP.
+- [x] **LocalFileProvider** a wrapper around `FileManager` with some additions like builtin coordinating, searching and reading a portion of file.
+- [x] **CloudFileProvider** A wrapper around app's ubiquitous container API of iCloud Drive.
+- [x] **WebDAVFileProvider** WebDAV protocol is defacto file transmission standard, supported by some cloud services like `ownCloud`, `Box.com` and `Yandex.disk`.
+- [x] **FTPFileProvider** While deprecated in 1990s due to serious security concerns, it's still in use on some Web hosts.
 - [x] **DropboxFileProvider** A wrapper around Dropbox Web API.
    * For now it has limitation in uploading files up to 150MB.
 - [x] **OneDriveFileProvider** A wrapper around OneDrive REST API, works with `onedrive.com` and compatible (business) servers.
    * For now it has limitation in uploading files up to 100MB.
- [ ] **GoogleFileProvider** A wrapper around Goodle Drive REST API.
 - [ ] **AmazonS3FileProvider** Amazon storage backend. Used by many sites.
+- [ ] **GoogleFileProvider** A wrapper around Goodle Drive REST API.
 - [ ] **SMBFileProvider** SMB2/3 introduced in 2006, which is a file and printer sharing protocol originated from Microsoft Windows and now is replacing AFP protocol on macOS.
    * Data types and some basic functions are implemented but *main interface is not implemented yet!*.
-    * SMB1/CIFS is deprecated and very tricky to be implemented.
- [ ] **FTPFileProvider** while deprecated in 1990s, it's still in use on some Web hosts.
+    * SMBv1/CIFS is insecure, deprecated and kinda tricky to be implemented due to strict memory allignment in Swift.

 ## Requirements

- **Swift 3**
+- **Swift 3.0 or higher**
 - iOS 8.0 , OSX 10.10
 - XCode 8.0

-Legacy version is available in swift-2 branch
+Legacy version is available in swift-2 branch.

 ## Installation

+### Important: this library has been renamed to avoid conflict in iOS 11, macOS 10.13 and Xcode 9.0. Please read issue [#53](https://github.com/amosavian/FileProvider/issues/53) to find more.
+
+
 ### Cocoapods / Carthage / Swift Package Manager

 Add this line to your pods file:

 ```ruby
-pod "FileProvider"
+pod "FilesProvider"
 ```

 Or add this to Cartfile:
@@ -69,7 +77,7 @@ github "amosavian/FileProvider"
 Or to use in Swift Package Manager add this line in `Dependencies`:

 ```swift
-.Package(url: "https://github.com/amosavian/FileProvider.git", majorVersion: 0, minorVersion: 12)
+.Package(url: "https://github.com/amosavian/FileProvider.git", majorVersion: 0)
 ```

 ### Manually
@@ -95,7 +103,7 @@ Then you can do either:

 * Copy Source folder to your project and Voila!

-* Drop FileProvider.xcodeproj to you Xcode workspace and add the framework to your Embeded Binaries in target.
+* Drop `FilesProvider.xcodeproj` to you Xcode workspace and add the framework to your Embeded Binaries in target.

 ## Usage

@@ -106,10 +114,12 @@ Each provider has a specific class which conforms to FileProvider protocol and s
 For LocalFileProvider if you want to deal with `Documents` folder

 ```	swift
+import FilesProvider
+
 let documentsProvider = LocalFileProvider()

 // Equals with:
-let documentsProvider = LocalFileProvider(directory: .documentDirectory, domainMask: = .userDomainMask)
+let documentsProvider = LocalFileProvider(for: .documentDirectory, in: .userDomainMask)

 // Equals with:
 let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
@@ -119,15 +129,19 @@ let documentsProvider = LocalFileProvider(baseURL: documentsURL)
 Also for using group shared container:

 ```swift
+import FilesProvider
+
 let documentsProvider = LocalFileProvider(sharedContainerId: "group.yourcompany.appContainer")
-// Replace your group identifier with string above
+// Replace your group identifier
 ```

 You can't change the base url later. and all paths are related to this base url by default.

-To initialize an iCloud Container provider use below code, This will automatically manager creating Documents folder in container:
+To initialize an iCloud Container provider look at [here](https://medium.com/ios-os-x-development/icloud-drive-documents-1a46b5706fe1) to see how to update project settings then use below code, This will automatically manager creating Documents folder in container:

 ```swift
+import FilesProvider
+
 let documentsProvider = CloudFileProvider(containerId: nil)
 ```

@@ -135,11 +149,13 @@ let documentsProvider = CloudFileProvider(containerId: nil)
 For remote file providers authentication may be necessary:

 ```	swift
+import FilesProvider
+
 let credential = URLCredential(user: "user", password: "pass", persistence: .permanent)
 let webdavProvider = WebDAVFileProvider(baseURL: URL(string: "http://www.example.com/dav")!, credential: credential)
 ```

-* In case you want to connect non-secure servers for WebDAV (http) in iOS 9+ / macOS 10.11+ you should disable App Transport Security (ATS) according to [this guide.](https://gist.github.com/mlynch/284699d676fe9ed0abfa)
+* In case you want to connect non-secure servers for WebDAV (http) or FTP in iOS 9+ / macOS 10.11+ you should disable App Transport Security (ATS) according to [this guide.](https://gist.github.com/mlynch/284699d676fe9ed0abfa)

 * For Dropbox & OneDrive, user is clientID and password is Token which both must be retrieved via [OAuth2 API of Dropbox](https://www.dropbox.com/developers/reference/oauth-guide). There are libraries like [p2/OAuth2](https://github.com/p2/OAuth2) or [OAuthSwift](https://github.com/OAuthSwift/OAuthSwift) which can facilate the procedure to retrieve token. The latter is easier to use and prefered.
 	
@@ -151,7 +167,7 @@ You can use `url(of:)` method if provider to get direct access url (local or rem

 For updating User interface please consider using delegate method instead of completion handlers. Delegate methods are guaranteed to run in main thread to avoid bugs.

-It's simply three method which indicated whether the operation failed, succeed and how much of operation has been done (suitable for uploading and downloading operations).
+There's simply three method which indicated whether the operation failed, succeed and how much of operation has been done (suitable for uploading and downloading operations).

 Your class should conforms `FileProviderDelegate` class:

@@ -160,7 +176,7 @@ override func viewDidLoad() {
 	documentsProvider.delegate = self as FileProviderDelegate
 }
 	
-func fileproviderSucceed(_ fileProvider: FileProviderOperations, operation: FileOperation) {
+func fileproviderSucceed(_ fileProvider: FileProviderOperations, operation: FileOperationType) {
 	switch operation {
 	case .copy(source: let source, destination: let dest):
 		print("\(source) copied to \(dest).")
@@ -171,7 +187,7 @@ func fileproviderSucceed(_ fileProvider: FileProviderOperations, operation: File
 	}
 }

-func fileproviderFailed(_ fileProvider: FileProviderOperations, operation: FileOperation) {
+func fileproviderFailed(_ fileProvider: FileProviderOperations, operation: FileOperationType) {
    switch operation {
 	case .copy(source: let source, destination: let dest):
 		print("copy of \(source) failed.")
@@ -182,7 +198,7 @@ func fileproviderFailed(_ fileProvider: FileProviderOperations, operation: FileO
 	}
 }
 	
-func fileproviderProgress(_ fileProvider: FileProviderOperations, operation: FileOperation, progress: Float) {
+func fileproviderProgress(_ fileProvider: FileProviderOperations, operation: FileOperationType, progress: Float) {
 	switch operation {
 	case .copy(source: let source, destination: let dest):
 		print("Copy\(source) to \(dest): \(progress * 100) completed.")
@@ -204,7 +220,7 @@ You can also implement `FileOperationDelegate` protocol to control behaviour of

 `fileProvider(shouldProceedAfterError:, operation:)` will be called if an error occured during file operations. Return `true` if you want to continue operation on next files or `false` if you want stop operation further. Default value is false if you don't implement delegate.

-**Note: these methods will be called for files in a directory and its subfolders recursively.**
+**Note: In `LocalFileProvider`, these methods will be called for files in a directory and its subfolders recursively.**

 ### Directory contents and file attributes

@@ -230,10 +246,10 @@ To get list of files in a directory:
 documentsProvider.contentsOfDirectory(path: "/", completionHandler: {
 	contents, error in
 	for file in contents {
-		print("Name: \(attributes.name)")
-		print("Size: \(attributes.size)")
-		print("Creation Date: \(attributes.creationDate)")
-		print("Modification Date: \(attributes.modifiedDate)")
+		print("Name: \(file.name)")
+		print("Size: \(file.size)")
+		print("Creation Date: \(file.creationDate)")
+		print("Modification Date: \(file.modifiedDate)")
 	}
 })
 ```
@@ -250,29 +266,21 @@ func storageProperties(completionHandler: { total, used in
 	
 * if this function is unavailable on provider or an error has been occurred, total space will be reported `-1` and used space `0`

-### Change current directory
-
-```swift
-documentsProvider.currentPath = "/New Folder"
-// now path is ~/Documents/New Folder
-```
-	
-You can then pass "" (empty string) to `contentsOfDirectory` method to list files in current directory.
-
 ### Creating File and Folders

 Creating new directory:

 ```swift
-documentsProvider.create(folder: "new folder", at: "/", completionHandler: nil)
+documentsProvider.create(folder: "new folder", at: "/", completionHandler: { error in
+    if let error = error {
+        // Error handling here
+    } else {
+        // The operation succeed
+    }
+})
 ```

-Creating new file from data:
-
-```swift
-let data = "hello world!".data(encoding: .utf8)
-documentsProvider.create(file: "newFile.txt", at: "/", contents: data, completionHandler: nil)
-```
+To create a file, use `writeContents(path:, content:, atomically:, completionHandler:)` method.

 ### Copy and Move/Rename Files

@@ -296,11 +304,9 @@ documentsProvider.moveItem(path: "new folder/old.txt", to: "new.txt", overwrite:
 documentsProvider.removeItem(path: "new.txt", completionHandler: nil)
 ```

-***Caution:*** This method will delete directories with all it's contents recursively.
-
 ### Fetching Contents of File

-There is two method for this purpose, one of them loads entire file into NSData and another can load a portion of file.
+There is two method for this purpose, one of them loads entire file into `Data` and another can load a portion of file.

 ```swift
 documentsProvider.contents(path: "old.txt", completionHandler: {
@@ -329,6 +335,33 @@ let data = "What's up Newyork!".data(encoding: .utf8)
 documentsProvider.writeContents(path: "old.txt", content: data, atomically: true, completionHandler: nil)
 ```

+### Copying Files to and From Local Storage
+
+There are two methods to download and upload files between provider's and local storage. These methods use `URLSessionDownloadTask` and `URLSessionUploadTask` classes and allows to use background session and provide progress via delegate.
+
+To upload a file:
+
+```swift
+let fileURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!.appendingPathComponent("image.jpg")
+documentsProvider.copyItem(localFile: fileURL, to: "/upload/image.jpg", overwrite: true, completionHandler: nil)
+```
+
+To download a file:
+
+```swift
+let fileURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!.appendingPathComponent("image.jpg")
+documentsProvider.copyItem(path: "/download/image.jpg", toLocalURL: fileURL, overwrite: true, completionHandler: nil)
+```
+
+* It's safe only to assume these methods **won't** handle directories to upload/download recursively. If you need, you can list directories, create directories on target and copy files using these methods.
+* FTP provider allows developer to either use apple implemented `URLSessionDownloadTask` or custom implemented method based on stream task via `useAppleImplementation` property. FTP protocol is not supported by background session.
+
+### Operation Progress
+
+Creating/Copying/Deleting/Searching functions return a `(NS)Progress`. It provides operation type, progress and a `.cancel()` method which allows you to cancel operation in midst. You can check `cancellable` property to check either you can cancel operation via this object or not.
+
+- **Note:** Progress reporting is not supported by native `(NS)FileManager` so `LocalFileProvider`.
+
 ### Undo Operations

 Providers conform to `FileProviderUndoable` can perform undo for **some** operations like moving/renaming, copying and creating (file or folder). **Now, only `LocalFileProvider` supports this feature.** To implement:
@@ -372,11 +405,9 @@ class ViewController: UIViewController
 }
 ```

-### Operation Handle
+### File Coordination

-Creating/Copying/Deleting functions return a `OperationHandle` for remote operations. It provides operation type, progress and a `.cancel()` method which allows you to cancel operation in midst.
-
-It's not supported by native `(NS)FileManager` so `LocalFileProvider`, but this functionality will be added to future `PosixFileProvider` class.
+`LocalFileProvider` and its descendents has a `isCoordinating` property. By setting this, provider will use `NSFileCoordinating` class to do all file operations. It's mandatory for iCloud, while recommended when using shared container or anywhere that simultaneous operations on a file/folder is common.

 ### Monitoring File Changes

@@ -384,12 +415,12 @@ You can monitor updates in some file system (Local and SMB2), there is three met

 ```swift
 // to register a new notification handler
-documentsProvider.registerNotifcation(path: provider.currentPath) {
+documentsProvider.registerNotifcation(path: "/") {
 	// calling functions to update UI 
 }
 	
 // To discontinue monitoring folders:
-documentsProvider.unregisterNotifcation(path: provider.currentPath)
+documentsProvider.unregisterNotifcation(path: "/")
 ```

 * **Please note** in LocalFileProvider it will also monitor changes in subfolders. This behaviour can varies according to file system specification.
@@ -405,9 +436,10 @@ To check either file thumbnail is supported or not and fetch thumbnail, use (and

 ```swift
 let path = "/newImage.jpg"
-let thumbSize = CGSize(width: 64, height: 64)
+let thumbSize = CGSize(width: 64, height: 64) // or nil which renders to default dimension of provider
 if documentsProvider.thumbnailOfFileSupported(path: path {
    documentsProvider.thumbnailOfFile(path: file.path, dimension: thumbSize, completionHandler: { (image, error) in
+        // Interacting with UI must be placed in main thread
        DispatchQueue.main.async {
            self.previewImage.image = image
        }
@@ -435,6 +467,13 @@ if documentsProvider..propertiesOfFile(path: file.path, completionHandler: { (pr

 We would love for you to contribute to **FileProvider**, check the `LICENSE` file for more info.

+Things you may consider to help us:
+
+- [ ] Implement request/response stack for `SMBClient`
+- [ ] Implement Test-case (`XCTest`)
+- [ ] Add Sample project for iOS
+- [ ] Add Sample project for macOS
+
 ## Projects in use

 * [EDM - Browse and Receive Files](https://itunes.apple.com/us/app/edm-browse-and-receive-files/id948397575?ls=1&mt=8)
@@ -444,16 +483,19 @@ If you used this library in your project, you can open an issue to inform us.

 ## Meta

-Amir-Abbas Mousavian  – [@amosavian](https://twitter.com/amosavian)
+Amir-Abbas Mousavian – [@amosavian](https://twitter.com/amosavian)
+
+Thanks to [Hootan Moradi](https://github.com/hoootan) for designing logo.

 Distributed under the MIT license. See `LICENSE` for more information.

 [https://github.com/amosavian/](https://github.com/amosavian/)

-[cocoapods]: https://cocoapods.org/pods/FileProvider
-[swift-image]: https://img.shields.io/badge/swift-3.0-orange.svg
+[cocoapods]: https://cocoapods.org/pods/FilesProvider
+[cocoapods-old]: https://cocoapods.org/pods/FileProvider
+[swift-image]: https://img.shields.io/badge/swift-3.0,%203.1-orange.svg
 [swift-url]: https://swift.org/
-[platform-image]: https://img.shields.io/cocoapods/p/FileProvider.svg
+[platform-image]: https://img.shields.io/cocoapods/p/FilesProvider.svg
 [license-image]: https://img.shields.io/github/license/amosavian/FileProvider.svg
 [license-url]: LICENSE
 [codebeat-image]: https://codebeat.co/badges/7b359f48-78eb-4647-ab22-56262a827517
@@ -463,7 +505,9 @@ Distributed under the MIT license. See `LICENSE` for more information.
 [release-url]: https://github.com/amosavian/FileProvider/releases
 [release-image]: https://img.shields.io/github/release/amosavian/FileProvider.svg
 [carthage-image]: https://img.shields.io/badge/Carthage-compatible-4BC51D.svg
-[cocoapods-downloads]: https://img.shields.io/cocoapods/dt/FileProvider.svg
-[cocoapods-apps]: https://img.shields.io/cocoapods/at/FileProvider.svg
-[docs-image]: https://img.shields.io/cocoapods/metrics/doc-percent/FileProvider.svg
-[docs-url]: http://cocoadocs.org/docsets/FileProvider/
+[cocoapods-downloads-old]: https://img.shields.io/cocoapods/dt/FileProvider.svg
+[cocoapods-apps-old]: https://img.shields.io/cocoapods/at/FileProvider.svg
+[cocoapods-downloads]: https://img.shields.io/cocoapods/dt/FilesProvider.svg
+[cocoapods-apps]: https://img.shields.io/cocoapods/at/FilesProvider.svg
+[docs-image]: https://img.shields.io/cocoapods/metrics/doc-percent/FilesProvider.svg
+[docs-url]: http://cocoadocs.org/docsets/FilesProvider/
@@ -0,0 +1,19 @@
+Copyright (c) 2014-2017 Marko Tadić <tadija@me.com> http://tadija.net
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
@@ -8,7 +8,15 @@

 import Foundation

-open class CloudFileProvider: LocalFileProvider {
+/**
+ Allows accessing to iCloud Drive stored files. Determine scope when initializing, to either access
+ to public documents folder or files stored as data.
+ 
+ To setup a functional iCloud container, please
+ [read this page](https://medium.com/ios-os-x-development/icloud-drive-documents-1a46b5706fe1).
+ */
+open class CloudFileProvider: LocalFileProvider, FileProviderSharing {
+    /// An string to identify type of provider.
    open override class var type: String { return "iCloudDrive" }
    
    /// Forces file operations to use `NSFileCoordinating`,
@@ -18,6 +26,7 @@ open class CloudFileProvider: LocalFileProvider {
            return true
        }
        set {
+            assert(true, "CloudFileProvider.isCoorinating can't be set")
            return
        }
    }
@@ -28,6 +37,9 @@ open class CloudFileProvider: LocalFileProvider {
    /// Scope of container, indicates user can manipulate data/files or not.
    open fileprivate(set) var scope: UbiquitousScope
    
+    /// Set this property to ignore initiations asserting to be on secondary thread
+    static open var asserting: Bool = true
+    
    /**
     Initializes the provider for the iCloud container associated with the specified identifier and 
     establishes access to that container.
@@ -40,8 +52,8 @@ open class CloudFileProvider: LocalFileProvider {
     - Parameter scope: Use `.documents` (default) to put documents that the user is allowed to access inside a Documents subdirectory. Otherwise use `.data` to store user-related data files that your app needs to share but that are not files you want the user to manipulate directly.
    */
    public init? (containerId: String?, scope: UbiquitousScope = .documents) {
-        assert(!Thread.isMainThread, "LocalFileProvider.init(containerId:) is not recommended to be executed on Main Thread.")
-        guard FileManager.default.ubiquityIdentityToken == nil else {
+        assert(!(CloudFileProvider.asserting && Thread.isMainThread), "CloudFileProvider.init(containerId:) is not recommended to be executed on Main Thread.")
+        guard FileManager.default.ubiquityIdentityToken != nil else {
            return nil
        }
        guard let ubiquityURL = FileManager.default.url(forUbiquityContainerIdentifier: containerId) else {
@@ -51,17 +63,22 @@ open class CloudFileProvider: LocalFileProvider {
        self.scope = scope
        let baseURL: URL
        if scope == .documents {
-            baseURL = ubiquityURL.standardized.appendingPathComponent("Documents/")
+            baseURL = ubiquityURL.appendingPathComponent("Documents/")
        } else {
-            baseURL = ubiquityURL.standardized
+            baseURL = ubiquityURL
        }
        
        super.init(baseURL: baseURL)
        self.isCoorinating = true
        
-        dispatch_queue = DispatchQueue(label: "FileProvider.\(type(of: self).type)", attributes: .concurrent)
+        #if swift(>=3.1)
+        let queueLabel = "FileProvider.\(Swift.type(of: self).type)"
+        #else
+        let queueLabel = "FileProvider.\(type(of: self).type)"
+        #endif
+        dispatch_queue = DispatchQueue(label: queueLabel, attributes: .concurrent)
        operation_queue = OperationQueue()
-        operation_queue.name = "FileProvider.\(type(of: self).type).Operation"
+        operation_queue.name = "\(queueLabel).Operation"
        
        fileManager.url(forUbiquityContainerIdentifier: containerId)
        opFileManager.url(forUbiquityContainerIdentifier: containerId)
@@ -69,16 +86,54 @@ open class CloudFileProvider: LocalFileProvider {
        try? fileManager.createDirectory(at: baseURL, withIntermediateDirectories: true)
    }
    
-    // FIXME: create runloop for dispatch_queue, start query on it
+    
+    public required convenience init?(coder aDecoder: NSCoder) {
+        guard let containerId = aDecoder.decodeObject(forKey: "containerId") as? String,
+            let scopeString = aDecoder.decodeObject(forKey: "scope") as? String,
+            let scope = UbiquitousScope(rawValue: scopeString) else {
+            return nil
+        }
+        self.init(containerId: containerId, scope: scope)
+        self.currentPath   = aDecoder.decodeObject(forKey: "currentPath") as? String ?? ""
+        self.isCoorinating = aDecoder.decodeBool(forKey: "isCoorinating")
+    }
+    
+    open override func encode(with aCoder: NSCoder) {
+        aCoder.encode(self.containerId, forKey: "containerId")
+        aCoder.encode(self.scope.rawValue, forKey: "scope")
+        aCoder.encode(self.currentPath, forKey: "currentPath")
+        aCoder.encode(self.isCoorinating, forKey: "isCoorinating")
+    }
+    
+    open override func copy(with zone: NSZone? = nil) -> Any {
+        let copy = CloudFileProvider(containerId: self.containerId, scope: self.scope)
+        copy?.currentPath = self.currentPath
+        copy?.delegate = self.delegate
+        copy?.fileOperationDelegate = self.fileOperationDelegate
+        return copy as Any
+    }
+    
+    /**
+     Returns an Array of `FileObject`s identifying the the directory entries via asynchronous completion handler.
+     
+     If the directory contains no entries or an error is occured, this method will return the empty array.
+     
+     - Parameter path: path to target directory. If empty, root will be iterated.
+     - Parameter completionHandler: a closure with result of directory entries or error.
+         `contents`: An array of `FileObject` identifying the the directory entries.
+         `error`: Error returned by system.
+     */
    open override func contentsOfDirectory(path: String, completionHandler: @escaping ((_ contents: [FileObject], _ error: Error?) -> Void)) {
+        // FIXME: create runloop for dispatch_queue, start query on it
        dispatch_queue.async {
            let pathURL = self.url(of: path)
            
            let query = NSMetadataQuery()
            query.predicate = NSPredicate(format: "%K BEGINSWITH %@", NSMetadataItemPathKey, pathURL.path)
+            query.valueListAttributes = [NSMetadataItemURLKey, NSMetadataItemFSNameKey, NSMetadataItemPathKey, NSMetadataItemFSSizeKey, NSMetadataItemContentTypeTreeKey, NSMetadataItemFSCreationDateKey, NSMetadataItemFSContentChangeDateKey]
            query.searchScopes = [self.scope.rawValue]
            var finishObserver: NSObjectProtocol?
-            finishObserver = NotificationCenter.default.addObserver(forName: NSNotification.Name.NSMetadataQueryDidFinishGathering, object: query, queue: nil, using: { (notification) in
+            finishObserver = NotificationCenter.default.addObserver(forName: .NSMetadataQueryDidFinishGathering, object: query, queue: nil, using: { (notification) in
                defer {
                    query.stop()
                    NotificationCenter.default.removeObserver(finishObserver!)
@@ -106,29 +161,46 @@ open class CloudFileProvider: LocalFileProvider {
                }
                
                query.stop()
-                completionHandler(contents, nil)
+                self.dispatch_queue.async {
+                    completionHandler(contents, nil)
+                }
+                
            })
            DispatchQueue.main.async {
                if !query.start() {
-                    completionHandler([], self.throwError(path, code: CocoaError.fileReadNoPermission))
+                    self.dispatch_queue.async {
+                        completionHandler([], self.throwError(path, code: CocoaError.fileReadNoPermission))
+                    }
                }
            }
        }
    }
    
+    /// Please don't rely this function to get iCloud drive total and remaining capacity
    /// - Important: iCloud Storage size and free space is unavailable, it returns local space
    open override func storageProperties(completionHandler: (@escaping (_ total: Int64, _ used: Int64) -> Void)) {
        super.storageProperties(completionHandler: completionHandler)
    }
    
+    /**
+     Returns a `FileObject` containing the attributes of the item (file, directory, symlink, etc.) at the path in question via asynchronous completion handler.
+     
+     If the directory contains no entries or an error is occured, this method will return the empty `FileObject`.
+     
+     - Parameter path: path to target directory. If empty, attributes of root will be returned.
+     - Parameter completionHandler: a closure with result of directory entries or error.
+         `attributes`: A `FileObject` containing the attributes of the item.
+         `error`: Error returned by system.
+     */
    open override func attributesOfItem(path: String, completionHandler: @escaping ((_ attributes: FileObject?, _ error: Error?) -> Void)) {
        dispatch_queue.async {
            let pathURL = self.url(of: path)
            let query = NSMetadataQuery()
            query.predicate = NSPredicate(format: "%K LIKE %@", NSMetadataItemPathKey, pathURL.path)
+            query.valueListAttributes = [NSMetadataItemURLKey, NSMetadataItemFSNameKey, NSMetadataItemPathKey, NSMetadataItemFSSizeKey, NSMetadataItemContentTypeTreeKey, NSMetadataItemFSCreationDateKey, NSMetadataItemFSContentChangeDateKey]
            query.searchScopes = [self.scope.rawValue]
            var finishObserver: NSObjectProtocol?
-            finishObserver = NotificationCenter.default.addObserver(forName: NSNotification.Name.NSMetadataQueryDidFinishGathering, object: query, queue: nil, using: { (notification) in
+            finishObserver = NotificationCenter.default.addObserver(forName: .NSMetadataQueryDidFinishGathering, object: query, queue: nil, using: { (notification) in
                defer {
                    query.stop()
                    NotificationCenter.default.removeObserver(finishObserver!)
@@ -138,145 +210,105 @@ open class CloudFileProvider: LocalFileProvider {
                
                guard let result = (query.results as? [NSMetadataItem])?.first, let attribs = result.values(forAttributes: [NSMetadataItemURLKey, NSMetadataItemFSNameKey, NSMetadataItemPathKey, NSMetadataItemFSSizeKey, NSMetadataItemContentTypeTreeKey, NSMetadataItemFSCreationDateKey, NSMetadataItemFSContentChangeDateKey]) else {
                    let error = self.throwError(path, code: CocoaError.fileNoSuchFile)
-                    completionHandler(nil, error)
+                    self.dispatch_queue.async {
+                        completionHandler(nil, error)
+                    }
                    return
                }
                
                if let file = self.mapFileObject(attributes: attribs) {
-                    completionHandler(file, nil)
+                    self.dispatch_queue.async {
+                        completionHandler(file, nil)
+                    }
                } else {
                    let noFileError = self.throwError(path, code: CocoaError.fileNoSuchFile)
-                    completionHandler(nil, noFileError)
+                    self.dispatch_queue.async {
+                        completionHandler(nil, noFileError)
+                    }
                }
            })
            DispatchQueue.main.async {
                if !query.start() {
-                    completionHandler(nil, self.throwError(path, code: CocoaError.fileReadNoPermission))
+                    self.dispatch_queue.async {
+                        completionHandler(nil, self.throwError(path, code: CocoaError.fileReadNoPermission))
+                    }
                }
            }
        }
    }
    
-    @discardableResult
-    open override func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        guard let r = super.create(folder: folderName, at: atPath, completionHandler: completionHandler) else { return nil }
-        return CloudOperationHandle(operationType: r.operationType, baseURL: self.baseURL)
-    }
-    
-    @discardableResult
-    open override func create(file fileName: String, at atPath: String, contents data: Data?, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        guard let r = super.create(file: fileName, at: atPath, contents: data, completionHandler: completionHandler) else { return nil }
-        return CloudOperationHandle(operationType: r.operationType, baseURL: self.baseURL)
-    }
-    
-    @discardableResult
-    open override func moveItem(path: String, to toPath: String, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        guard let r = super.moveItem(path: path, to: toPath, overwrite: overwrite, completionHandler: completionHandler) else { return nil }
-        return CloudOperationHandle(operationType: r.operationType, baseURL: self.baseURL)
-    }
-    
-    @discardableResult
-    open override func copyItem(path: String, to toPath: String, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        guard let r = super.copyItem(path: path, to: toPath, overwrite: overwrite, completionHandler: completionHandler) else { return nil }
-        return CloudOperationHandle(operationType: r.operationType, baseURL: self.baseURL)
-    }
-    
-    @discardableResult
-    open override func removeItem(path: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        guard let r = super.removeItem(path: path, completionHandler: completionHandler) else { return nil }
-        return CloudOperationHandle(operationType: r.operationType, baseURL: self.baseURL)
-    }
-    
-    @discardableResult
-    open override func copyItem(localFile: URL, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        // TODO: Make use of overwrite parameter
-        let opType = FileOperationType.copy(source: localFile.absoluteString, destination: toPath)
-        operation_queue.addOperation {
-            let tempFolder: URL
-            if #available(iOS 10.0, macOS 10.12, tvOS 10.0, *) {
-                tempFolder = FileManager.default.temporaryDirectory
+    /**
+     Search files inside directory using query asynchronously.
+     
+     - Note: For now only it's limited to file names. `query` parameter may take `NSPredicate` format in near future.
+     
+     - Parameters:
+         - path: location of directory to start search
+         - recursive: Searching subdirectories of path
+         - query: Simple string of file name to be search (for now).
+         - foundItemHandler: Closure which is called when a file is found
+         - completionHandler: Closure which will be called after finishing search. Returns an arry of `FileObject` or error if occured.
+     */
+    open override func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) -> Progress? {
+        
+        let mapDict: [String: String] = ["url": NSMetadataItemURLKey, "name": NSMetadataItemFSNameKey, "path": NSMetadataItemPathKey, "filesize": NSMetadataItemFSSizeKey, "modifiedDate": NSMetadataItemFSContentChangeDateKey, "creationDate": NSMetadataItemFSCreationDateKey, "contentType": NSMetadataItemContentTypeKey]
+        
+        func updateQueryKeys(_ queryComponent: NSPredicate) -> NSPredicate {
+            if let cQuery = queryComponent as? NSCompoundPredicate {
+                let newSub = cQuery.subpredicates.map { updateQueryKeys($0 as! NSPredicate) }
+                switch cQuery.compoundPredicateType {
+                case .and: return NSCompoundPredicate(andPredicateWithSubpredicates: newSub)
+                case .not: return NSCompoundPredicate(notPredicateWithSubpredicate: newSub.first!)
+                case .or:  return NSCompoundPredicate(orPredicateWithSubpredicates: newSub)
+                }
+            } else if let cQuery = queryComponent as? NSComparisonPredicate {
+                var newLeft = cQuery.leftExpression
+                var newRight = cQuery.rightExpression
+                if newLeft.expressionType == .keyPath, let newKey = mapDict[newLeft.keyPath] {
+                    newLeft = NSExpression(forKeyPath: newKey)
+                }
+                if newRight.expressionType == .keyPath, let newKey = mapDict[newRight.keyPath] {
+                    newRight = NSExpression(forKeyPath: newKey)
+                }
+                if newLeft.expressionType == .keyPath, newLeft.keyPath == "type" {
+                    newRight = NSExpression(forConstantValue: newRight.constantValue as? String == "directory" ? "public.directory": "public.data")
+                }
+                if newRight.expressionType == .keyPath, newRight.keyPath == "type" {
+                    newLeft = NSExpression(forConstantValue: newLeft.constantValue as? String == "directory" ? "public.directory": "public.data")
+                }
+                return NSComparisonPredicate(leftExpression: newLeft, rightExpression: newRight, modifier: cQuery.comparisonPredicateModifier, type: cQuery.predicateOperatorType, options: cQuery.options)
            } else {
-                tempFolder = URL(fileURLWithPath: NSTemporaryDirectory())
-            }
-            let tmpFile = tempFolder.appendingPathComponent(UUID().uuidString)
-            
-            do {
-                try self.opFileManager.copyItem(at: localFile, to: tmpFile)
-                let toUrl = self.url(of: toPath)
-                try self.opFileManager.setUbiquitous(true, itemAt: tmpFile, destinationURL: toUrl)
-                completionHandler?(nil)
-                DispatchQueue.main.async(execute: {
-                    self.delegate?.fileproviderSucceed(self, operation: opType)
-                })
-            } catch let e {
-                if self.opFileManager.fileExists(atPath: tmpFile.path) {
-                    try? self.opFileManager.removeItem(at: tmpFile)
-                }
-                completionHandler?(e)
-                DispatchQueue.main.async(execute: {
-                    self.delegate?.fileproviderFailed(self, operation: opType)
-                })
+                return queryComponent
            }
        }
-        return CloudOperationHandle(operationType: opType, baseURL: self.baseURL)
-    }
-    
-    @discardableResult
-    open override func copyItem(path: String, toLocalURL: URL, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.copy(source: path, destination: toLocalURL.absoluteString)
        
-        do {
-            try self.opFileManager.startDownloadingUbiquitousItem(at: self.url(of: path))
-        } catch let e {
-            completionHandler?(e)
-            DispatchQueue.main.async(execute: {
-                self.delegate?.fileproviderFailed(self, operation: opType)
-            })
-            return nil
-        }
+        let progress = Progress(parent: nil, userInfo: nil)
        
-        guard let r = super.copyItem(path: path, toLocalURL: toLocalURL, completionHandler: completionHandler) else { return nil }
-        return CloudOperationHandle(operationType: r.operationType, baseURL: self.baseURL)
-    }
-    
-    @discardableResult
-    open override func contents(path: String, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
-        guard let r = super.contents(path: path, completionHandler: completionHandler) else { return nil }
-        return CloudOperationHandle(operationType: r.operationType, baseURL: self.baseURL)
-    }
-    
-    @discardableResult
-    open override func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
-        guard let r = super.contents(path: path, offset: offset, length: length, completionHandler: completionHandler) else { return nil }
-        return CloudOperationHandle(operationType: r.operationType, baseURL: self.baseURL)
-    }
-    
-    @discardableResult
-    open override func writeContents(path: String, contents data: Data, atomically: Bool, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        guard let r = super.writeContents(path: path, contents: data, atomically: atomically, overwrite: overwrite, completionHandler: completionHandler) else { return nil }
-        return CloudOperationHandle(operationType: r.operationType, baseURL: self.baseURL)
-    }
-    
-    open override func searchFiles(path: String, recursive: Bool, query: String, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) {
        dispatch_queue.async {
            let pathURL = self.url(of: path)
-            let query = NSMetadataQuery()
-            query.predicate = NSPredicate(format: "(%K BEGINSWITH %@) && (%K LIKE %@)", NSMetadataItemPathKey, pathURL.path, NSMetadataItemFSNameKey, query)
-            query.searchScopes = [self.scope.rawValue]
+            progress.setUserInfoObject(pathURL, forKey: .fileURLKey)
+            let mdquery = NSMetadataQuery()
+            mdquery.predicate = NSPredicate(format: "(%K BEGINSWITH %@) && (\(updateQueryKeys(query).predicateFormat))", NSMetadataItemPathKey, pathURL.path)
+            mdquery.searchScopes = [self.scope.rawValue]
            
            var lastReportedCount = 0
            
+            progress.cancellationHandler = { [weak mdquery] in
+                mdquery?.stop()
+            }
+            
            if let foundItemHandler = foundItemHandler {
                var updateObserver: NSObjectProtocol?
                
-                updateObserver = NotificationCenter.default.addObserver(forName: .NSMetadataQueryGatheringProgress, object: query, queue: nil, using: { (notification) in
+                // FIXME: Remove this section as it won't work as expected on iCloud
+                updateObserver = NotificationCenter.default.addObserver(forName: .NSMetadataQueryGatheringProgress, object: mdquery, queue: nil, using: { (notification) in
                    
-                    query.disableUpdates()
+                    mdquery.disableUpdates()
                    
-                    guard query.resultCount > lastReportedCount else { return }
+                    guard mdquery.resultCount > lastReportedCount else { return }
                    
-                    for index in lastReportedCount..<query.resultCount {
-                        guard let attribs = (query.result(at: index) as? NSMetadataItem)?.values(forAttributes: [NSMetadataItemURLKey, NSMetadataItemFSNameKey, NSMetadataItemPathKey, NSMetadataItemFSSizeKey, NSMetadataItemContentTypeTreeKey, NSMetadataItemFSCreationDateKey, NSMetadataItemFSContentChangeDateKey]) else {
+                    for index in lastReportedCount..<mdquery.resultCount {
+                        guard let attribs = (mdquery.result(at: index) as? NSMetadataItem)?.values(forAttributes: [NSMetadataItemURLKey, NSMetadataItemFSNameKey, NSMetadataItemPathKey, NSMetadataItemFSSizeKey, NSMetadataItemContentTypeTreeKey, NSMetadataItemFSCreationDateKey, NSMetadataItemFSContentChangeDateKey]) else {
                            continue
                        }
                        
@@ -288,24 +320,25 @@ open class CloudFileProvider: LocalFileProvider {
                            foundItemHandler(file)
                        }
                    }
-                    lastReportedCount = query.resultCount
+                    lastReportedCount = mdquery.resultCount
+                    progress.totalUnitCount = Int64(lastReportedCount)
                    
-                    query.enableUpdates()
+                    mdquery.enableUpdates()
                })
            }
            
            var finishObserver: NSObjectProtocol?
-            finishObserver = NotificationCenter.default.addObserver(forName: .NSMetadataQueryDidFinishGathering, object: query, queue: nil, using: { (notification) in
+            finishObserver = NotificationCenter.default.addObserver(forName: .NSMetadataQueryDidFinishGathering, object: mdquery, queue: nil, using: { (notification) in
                defer {
-                    query.stop()
+                    mdquery.stop()
                    NotificationCenter.default.removeObserver(finishObserver!)
                }
                
-                guard let results = query.results as? [NSMetadataItem] else {
+                guard let results = mdquery.results as? [NSMetadataItem] else {
                    return
                }
                
-                query.disableUpdates()
+                mdquery.disableUpdates()
                
                var contents = [FileObject]()
                for result in results {
@@ -321,25 +354,224 @@ open class CloudFileProvider: LocalFileProvider {
                        contents.append(file)
                    }
                }
-                
-                completionHandler(contents, nil)
+                progress.completedUnitCount = Int64(contents.count)
+                self.dispatch_queue.async {
+                    completionHandler(contents, nil)
+                }
            })
            
            DispatchQueue.main.async {
-                if !query.start() {
-                    completionHandler([], self.throwError(path, code: CocoaError.fileReadNoPermission))
+                progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
+                if !mdquery.start() {
+                    self.dispatch_queue.async {
+                        completionHandler([], self.throwError(path, code: CocoaError.fileReadNoPermission))
+                    }
                }
            }
        }
+        
+        return progress
+    }
+    
+    open override func isReachable(completionHandler: @escaping (Bool) -> Void) {
+        dispatch_queue.async {
+            completionHandler(self.fileManager.ubiquityIdentityToken != nil)
+        }
+    }
+    
+    /**
+     Removes the file or directory at the specified path.
+     
+     - Important: Due to a bug (race condition?) in Apple API, it takes about 3-5 seconds to update containing folder
+       list and triggering notification registered for directory while completion handler will run almost immediately.
+       It's your responsibility to workaourd this bug/feature and mark file as deleted in your software.
+     
+     - Parameters:
+       - path: file or directory path.
+       - completionHandler: If an error parameter was provided, a presentable `Error` will be returned.
+     - Returns: A `Progress` object to get progress or cancel progress. Doesn't work on `CloudFileProvider`.
+     */
+    @discardableResult
+    open override func removeItem(path: String, completionHandler: SimpleCompletionHandler) -> Progress? {
+        return super.removeItem(path: path, completionHandler: completionHandler)
+    }
+    
+    /**
+     Uploads a file from local file url to designated path asynchronously.
+     Method will fail if source is not a local url with `file://` scheme.
+     
+     - Parameters:
+       - localFile: a file url to file.
+       - to: destination path of file, including file/directory name.
+       - overwrite: Destination file should be overwritten if file is already exists. **Default** is `false`.
+       - completionHandler: If an error parameter was provided, a presentable `Error` will be returned.
+     - Returns: A `Progress` object to get progress or cancel progress.
+     */
+    @discardableResult
+    open override func copyItem(localFile: URL, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> Progress? {
+        // TODO: Make use of overwrite parameter
+        let operation = FileOperationType.copy(source: localFile.absoluteString, destination: toPath)
+        let progress = Progress(parent: nil, userInfo: nil)
+        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+        progress.kind = .file
+        progress.isCancellable = false
+        progress.setUserInfoObject(localFile, forKey: .fileURLKey)
+        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
+        monitorFile(path: toPath, operation: operation, progress: progress)
+        operation_queue.addOperation {
+            let tempFolder: URL
+            if #available(iOS 10.0, macOS 10.12, tvOS 10.0, *) {
+                tempFolder = FileManager.default.temporaryDirectory
+            } else {
+                tempFolder = URL(fileURLWithPath: NSTemporaryDirectory())
+            }
+            let tmpFile = tempFolder.appendingPathComponent(UUID().uuidString)
+            
+            do {
+                try self.opFileManager.copyItem(at: localFile, to: tmpFile)
+                let toUrl = self.url(of: toPath)
+                try self.opFileManager.setUbiquitous(true, itemAt: tmpFile, destinationURL: toUrl)
+                completionHandler?(nil)
+                self.delegateNotify(operation)
+            } catch let e {
+                if self.opFileManager.fileExists(atPath: tmpFile.path) {
+                    try? self.opFileManager.removeItem(at: tmpFile)
+                }
+                completionHandler?(e)
+                self.delegateNotify(operation, error: e)
+            }
+        }
+        return progress
+    }
+    
+    /**
+     Download a file from `path` to designated local file url asynchronously.
+     Method will fail if destination is not a local url with `file://` scheme.
+     
+     - Parameters:
+       - path: original file or directory path.
+       - toLocalURL: destination local url of file, including file/directory name.
+       - completionHandler: If an error parameter was provided, a presentable `Error` will be returned.
+     - Returns: A `Progress` object to get progress or cancel progress.
+     */
+    @discardableResult
+    open override func copyItem(path: String, toLocalURL: URL, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let operation = FileOperationType.copy(source: path, destination: toLocalURL.absoluteString)
+        let progress = Progress(parent: nil, userInfo: nil)
+        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+        progress.kind = .file
+        progress.isCancellable = false
+        progress.setUserInfoObject(self.url(of: path), forKey: .fileURLKey)
+        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
+        monitorFile(path: path, operation: operation, progress: progress)
+        do {
+            try self.opFileManager.startDownloadingUbiquitousItem(at: self.url(of: path))
+        } catch let e {
+            completionHandler?(e)
+            self.delegateNotify(operation, error: e)
+            return nil
+        }
+        let _ = super.copyItem(path: path, toLocalURL: toLocalURL, completionHandler: completionHandler)
+        return progress
+    }
+    
+    /**
+     Retreives a `Data` object with the contents of the file asynchronously vis contents argument of completion handler.
+     If path specifies a directory, or if some other error occurs, data will be nil.
+     
+     - Parameters:
+       - path: Path of file.
+       - completionHandler: a closure with result of file contents or error.
+         `contents`: contents of file in a `Data` object.
+         `error`: Error returned by system.
+     - Returns: A `Progress` object to get progress or cancel progress.
+     */
+    @discardableResult
+    open override func contents(path: String, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> Progress? {
+        let operation = FileOperationType.fetch(path: path)
+        let progress = Progress(parent: nil, userInfo: nil)
+        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+        progress.kind = .file
+        progress.setUserInfoObject(self.url(of: path), forKey: .fileURLKey)
+        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
+        monitorFile(path: path, operation: operation, progress: progress)
+        _ = super.contents(path: path, completionHandler: completionHandler)
+        return progress
+    }
+    
+    /**
+     Retreives a `Data` object with a portion contents of the file asynchronously vis contents argument of completion handler.
+     If path specifies a directory, or if some other error occurs, data will be nil.
+     
+     - Parameters:
+       - path: Path of file.
+       - offset: First byte index which should be read. **Starts from 0.**
+       - length: Bytes count of data. Pass `-1` to read until the end of file.
+       - completionHandler: a closure with result of file contents or error.
+         `contents`: contents of file in a `Data` object.
+         `error`: Error returned by system.
+     - Returns: A `Progress` object to get progress or cancel progress.
+     */
+    @discardableResult
+    open override func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> Progress? {
+        let operation = FileOperationType.fetch(path: path)
+        let progress = Progress(parent: nil, userInfo: nil)
+        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+        progress.kind = .file
+        progress.setUserInfoObject(self.url(of: path), forKey: .fileURLKey)
+        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
+        monitorFile(path: path, operation: operation, progress: progress)
+        _ = super.contents(path: path, offset: offset, length: length, completionHandler: completionHandler)
+        return progress
+    }
+    
+    /**
+     Write the contents of the `Data` to a location asynchronously.
+     
+     - Parameters:
+       - path: Path of target file.
+       - contents: Data to be written into file.
+       - overwrite: Destination file should be overwritten if file is already exists. Default is `false`.
+       - atomically: data will be written to a temporary file before writing to final location. Default is `false`.
+       - completionHandler: If an error parameter was provided, a presentable `Error` will be returned.
+     - Returns: A `Progress` object to get progress or cancel progress. Doesn't work on `LocalFileProvider`.
+     */
+    @discardableResult
+    open override func writeContents(path: String, contents data: Data?, atomically: Bool, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let operation = FileOperationType.fetch(path: path)
+        let progress = Progress(parent: nil, userInfo: nil)
+        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+        progress.kind = .file
+        progress.setUserInfoObject(self.url(of: path), forKey: .fileURLKey)
+        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
+        monitorFile(path: path, operation: operation, progress: progress)
+        _ = super.writeContents(path: path, contents: data, atomically: atomically, overwrite: overwrite, completionHandler: completionHandler)
+        return progress
    }
    
    fileprivate var monitors = [String: (NSMetadataQuery, NSObjectProtocol)]()
    
+    /**
+     Starts monitoring a path and its subpaths, including files and folders, for any change,
+     including copy, move/rename, content changes, etc.
+     To avoid thread congestion, `evetHandler` will be triggered with 0.2 seconds interval,
+     and has a 0.25 second delay, to ensure it's called after updates.
+     
+     - Note: this functionality is available only in `LocalFileProvider` and `CloudFileProvider`.
+     - Note: `eventHandler` is not called on main thread, for updating UI. dispatch routine to main thread.
+     - Important: `eventHandler` may be called if file is changed in recursive subpaths of registered path.
+     This may cause negative impact on performance if a root path is being monitored.
+     
+     - Parameters:
+       - path: path of directory.
+       - eventHandler: Closure executed after change, on a secondary thread.
+     */
    open override func registerNotifcation(path: String, eventHandler: @escaping (() -> Void)) {
        self.unregisterNotifcation(path: path)
        let pathURL = self.url(of: path)
        let query = NSMetadataQuery()
        query.predicate = NSPredicate(format: "(%K BEGINSWITH %@)", NSMetadataItemPathKey, pathURL.path)
+        query.valueListAttributes = []
        query.searchScopes = [self.scope.rawValue]
        
        let updateObserver = NotificationCenter.default.addObserver(forName: .NSMetadataQueryDidUpdate, object: query, queue: nil, using: { (notification) in
@@ -358,6 +590,9 @@ open class CloudFileProvider: LocalFileProvider {
        }
    }
    
+    /// Stops monitoring the path.
+    ///
+    /// - Parameter path: path of directory.
    open override func unregisterNotifcation(path: String) {
        guard let (query, observer) = monitors[path] else {
            return
@@ -368,27 +603,22 @@ open class CloudFileProvider: LocalFileProvider {
        monitors.removeValue(forKey: path)
    }
    
+    /// Investigate either the path is registered for change notification or not.
+    ///
+    /// - Parameter path: path of directory.
+    /// - Returns: Directory is being monitored or not.
    open override func isRegisteredForNotification(path: String) -> Bool {
        return monitors[path] != nil
    }
    
-    open override func copy(with zone: NSZone? = nil) -> Any {
-        let copy = CloudFileProvider(containerId: self.containerId)
-        copy?.currentPath = self.currentPath
-        copy?.delegate = self.delegate
-        copy?.fileOperationDelegate = self.fileOperationDelegate
-        copy?.isPathRelative = self.isPathRelative
-        return copy as Any
-    }
-    
    fileprivate func mapFileObject(attributes attribs: [String: Any]) -> FileObject? {
-        guard let url = (attribs[NSMetadataItemURLKey] as? URL)?.standardized, let name = attribs[NSMetadataItemFSNameKey] as? String else {
+        guard let url = (attribs[NSMetadataItemURLKey] as? URL)?.standardizedFileURL, let name = attribs[NSMetadataItemFSNameKey] as? String else {
            return nil
        }
        
        let path = self.relativePathOf(url: url)
        let rpath = path.hasPrefix("/") ? path.substring(from: path.index(after: path.startIndex)) : path
-        let relativeUrl = URL(string: rpath, relativeTo: self.baseURL)
+        let relativeUrl = URL(string: rpath.addingPercentEncoding(withAllowedCharacters: .urlPathAllowed) ?? rpath, relativeTo: self.baseURL)
        let file = FileObject(url: relativeUrl ?? url, name: name, path: path)
        
        file.size = (attribs[NSMetadataItemFSSizeKey] as? NSNumber)?.int64Value ?? -1
@@ -401,8 +631,69 @@ open class CloudFileProvider: LocalFileProvider {
        return file
    }
    
-    /// Removes local copy of file, but spares cloud copy/
-    /// - Parameter path: Path of file or directory to be remoed from local
+    fileprivate func monitorFile(path: String, operation: FileOperationType, progress: Progress?) {
+        dispatch_queue.async {
+            let pathURL = self.url(of: path)
+            let size = pathURL.fileSize
+            progress?.totalUnitCount = size > 0 ? size : 0
+            let query = NSMetadataQuery()
+            query.predicate = NSPredicate(format: "%K LIKE %@", NSMetadataItemPathKey, pathURL.path)
+            query.valueListAttributes = [NSMetadataItemURLKey, NSMetadataItemFSNameKey, NSMetadataItemPathKey, NSMetadataUbiquitousItemPercentDownloadedKey, NSMetadataUbiquitousItemPercentUploadedKey, NSMetadataItemFSSizeKey]
+            query.searchScopes = [self.scope.rawValue]
+            var updateObserver: NSObjectProtocol?
+            updateObserver = NotificationCenter.default.addObserver(forName: .NSMetadataQueryDidUpdate, object: query, queue: nil, using: { (notification) in
+                query.disableUpdates()
+                
+                guard let item = (query.results as? [NSMetadataItem])?.first else {
+                    return
+                }
+                
+                if progress?.totalUnitCount == 0, let size = item.value(forAttribute: NSMetadataItemFSSizeKey) as? Int64 {
+                    progress?.totalUnitCount = size
+                }
+                let downloaded = item.value(forAttribute: NSMetadataUbiquitousItemPercentDownloadedKey) as? Double ?? 0
+                let uploaded = item.value(forAttribute: NSMetadataUbiquitousItemPercentUploadedKey) as? Double ?? 0
+                if (downloaded == 0 || downloaded == 100) && (uploaded > 0 && uploaded < 100) {
+                    progress?.completedUnitCount = Int64(uploaded / 100 * Double(progress?.totalUnitCount ?? 0))
+                    self.delegateNotify(operation, progress: uploaded / 100)
+                } else if (uploaded == 0 || uploaded == 100) && (downloaded > 0 && downloaded < 100) {
+                    progress?.completedUnitCount = Int64(downloaded / 100 * Double(progress?.totalUnitCount ?? 0))
+                    self.delegateNotify(operation, progress: downloaded / 100)
+                } else if uploaded == 100 || downloaded == 100 {
+                    progress?.completedUnitCount = progress?.totalUnitCount ?? 0
+                    query.stop()
+                    NotificationCenter.default.removeObserver(updateObserver!)
+                    self.delegateNotify(operation)
+                }
+                
+                query.enableUpdates()
+            })
+            
+            DispatchQueue.main.async {
+                progress?.setUserInfoObject(Date(), forKey: .startingTimeKey)
+                query.start()
+            }
+        }
+    }
+    
+    open func publicLink(to path: String, completionHandler: @escaping ((_ link: URL?, _ attribute: FileObject?, _ expiration: Date?, _ error: Error?) -> Void)) {
+        operation_queue.addOperation {
+            do {
+                var expiration: NSDate?
+                let url = try self.opFileManager.url(forPublishingUbiquitousItemAt: self.url(of: path), expiration: &expiration)
+                self.dispatch_queue.async {
+                    completionHandler(url, nil, expiration as Date?, nil)
+                }
+            } catch let e {
+                self.dispatch_queue.async {
+                    completionHandler(nil, nil, nil, e)
+                }
+            }
+        }
+    }
+    
+    /// Removes local copy of file, but spares cloud copy.
+    /// - Parameter path: Path of file or directory to be removed from local
    /// - Parameter completionHandler: If an error parameter was provided, a presentable `Error` will be returned.
    open func evictItem(path: String, completionHandler: SimpleCompletionHandler) {
        operation_queue.addOperation {
@@ -415,27 +706,34 @@ open class CloudFileProvider: LocalFileProvider {
        }
    }
    
-    /// Returns a pulic url with expiration date, can be shared with other people.
-    open func temporaryLink(to path: String, completionHandler: @escaping ((_ link: URL?, _ attribute: FileObject?, _ expiration: Date?, _ error: Error?) -> Void)) {
-        operation_queue.addOperation {
-            do {
-                var expiration: NSDate?
-                let url = try self.opFileManager.url(forPublishingUbiquitousItemAt: self.url(of: path), expiration: &expiration)
-                completionHandler(url, nil, expiration as Date?, nil)
-            } catch let e {
-                completionHandler(nil, nil, nil, e)
-            }
-        }
+    /// Returns current version of file on this device and all versions of files in user devices.
+    /// - Parameter path: Path of file or directory.
+    /// - Parameter completionHandler: Retrieve current version on this device and all versions available. `currentVersion` will be nil if file doesn't exist. If an error parameter was provided, a presentable `Error` will be returned.
+    func versionsOfItem(path: String, completionHandler: @escaping ((_ currentVersion: NSFileVersion?, _ versions: [NSFileVersion], _ error: Error?) -> Void)) {
+        NotImplemented()
+    }
+    
+    /// Resolves conflicts by selecting a version.
+    /// - Parameter path: Path of file or directory.
+    /// - Parameter version: Version than will be choose as main version. `nil` value indicates current version on this device will be selected.
+    /// - Parameter completionHandler: If an error parameter was provided, a presentable `Error` will be returned.
+    func selectVersionOfItem(path: String, version: NSFileVersion? = nil, completionHandler: SimpleCompletionHandler) {
+        NotImplemented()
    }
 }

+/// Scope of iCloud, wrapper for NSMetadataQueryUbiquitous...Scope constants
 public enum UbiquitousScope: RawRepresentable {
    /// Search all files not in the Documents directories of the app’s iCloud container directories.
    /// Use this scope to store user-related data files that your app needs to share 
    /// but that are not files you want the user to manipulate directly.
+    ///
+    /// Raw value is equivalent to `NSMetadataQueryUbiquitousDataScope`
    case data
    /// Search all files in the Documents directories of the app’s iCloud container directories.
    /// Put documents that the user is allowed to access inside a Documents subdirectory.
+    ///
+    /// Raw value is equivalent to `NSMetadataQueryUbiquitousDocumentsScope`
    case documents
    
    public typealias RawValue = String
@@ -461,89 +759,36 @@ public enum UbiquitousScope: RawRepresentable {
    }
 }

-open class CloudOperationHandle: OperationHandle {
-    public let baseURL: URL?
-    public let operationType: FileOperationType
+/*
+func getMetadataItem(url: URL) -> NSMetadataItem? {
+    let query = NSMetadataQuery()
+    query.predicate = NSPredicate(format: "(%K LIKE %@)", NSMetadataItemPathKey, url.path)
+    query.searchScopes = [NSMetadataQueryUbiquitousDocumentsScope, NSMetadataQueryUbiquitousDataScope]
    
-    init (operationType: FileOperationType, baseURL: URL?) {
-        self.baseURL = baseURL
-        self.operationType = operationType
-    }
+    var item: NSMetadataItem?
    
-    private var sourceURL: URL? {
-        guard let source = operationType.source, let baseURL = baseURL else { return nil }
-        return source.hasPrefix("file://") ? URL(fileURLWithPath: source) : baseURL.appendingPathComponent(source)
-    }
-    
-    private var destURL: URL? {
-        guard let dest = operationType.destination, let baseURL = baseURL else { return nil }
-        return dest.hasPrefix("file://") ? URL(fileURLWithPath: dest) : baseURL.appendingPathComponent(dest)
-    }
-    
-    open var bytesSoFar: Int64 {
-        assert(!Thread.isMainThread, "Don't run \(#function) method on main thread")
-        
-        guard let url = destURL ?? sourceURL, let item = CloudOperationHandle.getMetadataItem(url: url) else { return 0 }
-        let downloaded = item.value(forAttribute: NSMetadataUbiquitousItemPercentDownloadedKey) as? Double ?? 0
-        let uploaded = item.value(forAttribute: NSMetadataUbiquitousItemPercentUploadedKey) as? Double ?? 0
-        guard let size = item.value(forAttribute: NSMetadataItemFSSizeKey) as? Int64 else { return -1 }
-        if (downloaded == 0 || downloaded == 100) && (uploaded > 0 && uploaded < 100) {
-            return Int64(uploaded * (Double(size) / 100))
-        } else if (uploaded == 0 || uploaded == 100) && (downloaded > 0 && downloaded < 100) {
-            return Int64(downloaded * (Double(size) / 100))
-        } else if uploaded == 100 || downloaded == 100 {
-            return size
+    let group = DispatchGroup()
+    group.enter()
+    var finishObserver: NSObjectProtocol?
+    finishObserver = NotificationCenter.default.addObserver(forName: .NSMetadataQueryDidFinishGathering, object: query, queue: nil, using: { (notification) in
+        defer {
+            query.stop()
+            group.leave()
+            NotificationCenter.default.removeObserver(finishObserver!)
        }
-        return 0
-    }
-    
-    open var totalBytes: Int64 {
-        assert(!Thread.isMainThread, "Don't run \(#function) method on main thread")
-        guard let url = destURL ?? sourceURL, let item = CloudOperationHandle.getMetadataItem(url: url) else { return -1 }
-        return item.value(forAttribute: NSMetadataItemFSSizeKey) as? Int64 ?? -1
-    }
-    
-    open var inProgress: Bool {
-        guard let url = destURL ?? sourceURL, let item = CloudOperationHandle.getMetadataItem(url: url) else { return false }
-        let downloadStatus = item.value(forAttribute: NSMetadataUbiquitousItemDownloadingStatusKey) as? String ?? NSMetadataUbiquitousItemDownloadingStatusNotDownloaded
-        let isUploading = item.value(forAttribute: NSMetadataUbiquitousItemIsUploadingKey) as? Bool ?? false
-        return downloadStatus == NSMetadataUbiquitousItemDownloadingStatusCurrent || isUploading
-    }
-    
-    /// Not usable in local provider
-    open func cancel() -> Bool {
-        return false
-    }
-    
-    fileprivate static func getMetadataItem(url: URL) -> NSMetadataItem? {
-        let query = NSMetadataQuery()
-        query.predicate = NSPredicate(format: "(%K LIKE %@)", NSMetadataItemPathKey, url.path)
-        query.searchScopes = [NSMetadataQueryUbiquitousDocumentsScope, NSMetadataQueryUbiquitousDataScope]
        
-        var item: NSMetadataItem?
-        
-        let group = DispatchGroup()
-        group.enter()
-        var finishObserver: NSObjectProtocol?
-        finishObserver = NotificationCenter.default.addObserver(forName: .NSMetadataQueryDidFinishGathering, object: query, queue: nil, using: { (notification) in
-            defer {
-                query.stop()
-                group.leave()
-                NotificationCenter.default.removeObserver(finishObserver!)
-            }
-            
-            if query.resultCount > 0 {
-                item = query.result(at: 0) as? NSMetadataItem
-            }
-            
-            query.disableUpdates()
-            
-        })
-        
-        DispatchQueue.main.async {
-            query.start()
+        if query.resultCount > 0 {
+            item = query.result(at: 0) as? NSMetadataItem
        }
-        _ = group.wait(timeout: DispatchTime.now() + 30)
-        return item
+        
+        query.disableUpdates()
+        
+    })
+    
+    DispatchQueue.main.async {
+        query.start()
    }
+    _ = group.wait(timeout: .now() + 30)
+    return item
 }
+*/
@@ -10,43 +10,20 @@
 import Foundation
 import CoreGraphics

-open class DropboxFileProvider: FileProviderBasicRemote {
-    open class var type: String { return "DropBox" }
-    open let isPathRelative: Bool
-    open let baseURL: URL?
-    open var currentPath: String
+/**
+ Allows accessing to Dropbox stored files. This provider doesn't cache or save files internally, however you can
+ set `useCache` and `cache` properties to use Foundation `NSURLCache` system.
+ 
+ - Note: Uploading files and data are limited to 150MB, for now.
+ */
+open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
+    override open class var type: String { return "Dropbox" }
    
    /// Dropbox RPC API URL, which is equal with [https://api.dropboxapi.com/2/](https://api.dropboxapi.com/2/)
    open let apiURL: URL
    /// Dropbox contents download/upload API URL, which is equal with [https://content.dropboxapi.com/2/](https://content.dropboxapi.com/2/)
    open let contentURL: URL
    
-    open var dispatch_queue: DispatchQueue
-    open var operation_queue: OperationQueue {
-        willSet {
-            assert(_session == nil, "It's not effective to change dispatch_queue property after session is initialized.")
-        }
-    }
-    
-    open weak var delegate: FileProviderDelegate?
-    open let credential: URLCredential?
-    open private(set) var cache: URLCache?
-    public var useCache: Bool
-    public var validatingCache: Bool
-   
-    fileprivate var _session: URLSession?
-    fileprivate var sessionDelegate: SessionDelegate?
-    public var session: URLSession {
-        if _session == nil {
-            self.sessionDelegate = SessionDelegate(fileProvider: self, credential: credential)
-            let config = URLSessionConfiguration.default
-            config.urlCache = cache
-            config.requestCachePolicy = .returnCacheDataElseLoad
-            _session = URLSession(configuration: config, delegate: sessionDelegate as URLSessionDelegate?, delegateQueue: self.operation_queue)
-        }
-        return _session!
-    }
-    
    /**
     Initializer for Dropbox provider with given client ID and Token.
     These parameters must be retrieved via [OAuth2 API of Dropbox](https://www.dropbox.com/developers/reference/oauth-guide).
@@ -55,55 +32,53 @@ open class DropboxFileProvider: FileProviderBasicRemote {
     The latter is easier to use and prefered. Also you can use [auth0/Lock](https://github.com/auth0/Lock.iOS-OSX) which provides graphical user interface.
     
     - Parameter credential: a `URLCredential` object with Client ID set as `user` and Token set as `password`.
-     - Parameter cache: A URLCache to cache downloaded files and contents. If set to nil, URLCache.shared object will be used.
+     - Parameter cache: A URLCache to cache downloaded files and contents.
    */
    public init(credential: URLCredential?, cache: URLCache? = nil) {
-        self.baseURL = nil
-        self.isPathRelative = true
-        self.currentPath = ""
-        self.useCache = false
-        self.validatingCache = true
-        self.cache = cache
-        self.credential = credential
-        
        self.apiURL = URL(string: "https://api.dropboxapi.com/2/")!
        self.contentURL = URL(string: "https://content.dropboxapi.com/2/")!
-        
-        dispatch_queue = DispatchQueue(label: "FileProvider.\(type(of: self).type)", attributes: .concurrent)
-        operation_queue = OperationQueue()
-        operation_queue.name = "FileProvider.\(type(of: self).type).Operation"
-
+        super.init(baseURL: nil, credential: credential, cache: cache)
    }
    
-    deinit {
-        if fileProviderCancelTasksOnInvalidating {
-            _session?.invalidateAndCancel()
-        } else {
-            _session?.finishTasksAndInvalidate()
-        }
+    public required convenience init?(coder aDecoder: NSCoder) {
+        self.init(credential: aDecoder.decodeObject(forKey: "credential") as? URLCredential)
+        self.currentPath     = aDecoder.decodeObject(forKey: "currentPath") as? String ?? ""
+        self.useCache        = aDecoder.decodeBool(forKey: "useCache")
+        self.validatingCache = aDecoder.decodeBool(forKey: "validatingCache")
    }
    
-    open func contentsOfDirectory(path: String, completionHandler: @escaping ((_ contents: [FileObject], _ error: Error?) -> Void)) {
-        list(path) { (contents, cursor, error) in
+    override open func copy(with zone: NSZone? = nil) -> Any {
+        let copy = DropboxFileProvider(credential: self.credential, cache: self.cache)
+        copy.currentPath = self.currentPath
+        copy.delegate = self.delegate
+        copy.fileOperationDelegate = self.fileOperationDelegate
+        copy.useCache = self.useCache
+        copy.validatingCache = self.validatingCache
+        return copy
+    }
+    
+    open override func contentsOfDirectory(path: String, completionHandler: @escaping ((_ contents: [FileObject], _ error: Error?) -> Void)) {
+        let progress = Progress(parent: nil, userInfo: nil)
+        list(path, progress: progress) { (contents, cursor, error) in
            completionHandler(contents, error)
        }
    }
    
-    open func attributesOfItem(path: String, completionHandler: @escaping ((_ attributes: FileObject?, _ error: Error?) -> Void)) {
+    open override func attributesOfItem(path: String, completionHandler: @escaping ((_ attributes: FileObject?, _ error: Error?) -> Void)) {
        let url = URL(string: "files/get_metadata", relativeTo: apiURL)!
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
+        request.set(httpAuthentication: credential, with: .oAuth2)
+        request.set(httpContentType: .json)
        let requestDictionary: [String: AnyObject] = ["path": correctPath(path)! as NSString]
-        request.httpBody = dictionaryToJSON(requestDictionary)?.data(using: .utf8)
+        request.httpBody = Data(jsonDictionary: requestDictionary)
        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
            var serverError: FileProviderDropboxError?
            var fileObject: DropboxFileObject?
            if let response = response as? HTTPURLResponse {
                let code = FileProviderHTTPErrorCode(rawValue: response.statusCode)
                serverError = code != nil ? FileProviderDropboxError(code: code!, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8)) : nil
-                if let data = data, let jsonStr = String(data: data, encoding: .utf8), let json = jsonToDictionary(jsonStr), let file = DropboxFileObject(json: json) {
+                if let json = data?.deserializeJSON(), let file = DropboxFileObject(json: json) {
                    fileObject = file
                }
            }
@@ -112,15 +87,15 @@ open class DropboxFileProvider: FileProviderBasicRemote {
        task.resume()
    }
    
-    open func storageProperties(completionHandler: @escaping ((_ total: Int64, _ used: Int64) -> Void)) {
+    open override func storageProperties(completionHandler: @escaping ((_ total: Int64, _ used: Int64) -> Void)) {
        let url = URL(string: "users/get_space_usage", relativeTo: apiURL)!
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
+        request.set(httpAuthentication: credential, with: .oAuth2)
        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
            var totalSize: Int64 = -1
            var usedSize: Int64 = 0
-            if let data = data, let jsonStr = String(data: data, encoding: .utf8), let json = jsonToDictionary(jsonStr) {
+            if let json = data?.deserializeJSON() {
                totalSize = ((json["allocation"] as? NSDictionary)?["allocated"] as? NSNumber)?.int64Value ?? -1
                usedSize = (json["used"] as? NSNumber)?.int64Value ?? 0
            }
@@ -129,170 +104,128 @@ open class DropboxFileProvider: FileProviderBasicRemote {
        task.resume()
    }
    
-    open weak var fileOperationDelegate: FileOperationDelegate?
-}
-
-extension DropboxFileProvider: FileProviderOperations {
-    public func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let path = (atPath as NSString).appendingPathComponent(folderName) + "/"
-        return doOperation(.create(path: path), completionHandler: completionHandler)
-    }
-    
-    public func create(file fileName: String, at path: String, contents data: Data?, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let filePath = (path as NSString).appendingPathComponent(fileName)
-        return self.writeContents(path: filePath, contents: data ?? Data(), completionHandler: completionHandler)
-    }
-    
-    public func moveItem(path: String, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        return doOperation(.move(source: path, destination: toPath), completionHandler: completionHandler)
-    }
-    
-    public func copyItem(path: String, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        return doOperation(.copy(source: path, destination: toPath), completionHandler: completionHandler)
-    }
-    
-    public func removeItem(path: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        return doOperation(.remove(path: path), completionHandler: completionHandler)
-    }
-    
-    fileprivate func doOperation(_ operation: FileOperationType, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: operation) ?? true == true else {
-            return nil
+    open override func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) -> Progress? {
+        let progress = Progress(parent: nil, userInfo: nil)
+        var foundFiles = [DropboxFileObject]()
+        if let queryStr = query.findValue(forKey: "name", operator: .beginsWith) as? String {
+            // Dropbox only support searching for file names begin with query in non-enterprise accounts.
+            // We will use it if there is a `name BEGINSWITH[c] "query"` in predicate, then filter to form final result.
+            search(path, query: queryStr, progress: progress, foundItem: { (file) in
+                if query.evaluate(with: file.mapPredicate()) {
+                    foundFiles.append(file)
+                    foundItemHandler?(file)
+                }
+            }, completionHandler: { (error) in
+                completionHandler(foundFiles, error)
+            })
+        } else {
+            // Dropbox doesn't support searching attributes natively. The workaround is to fallback to listing all files
+            // and filter it locally. It may have a network burden in case there is many files in Dropbox, so please use it concisely.
+            list(path, recursive: true, progress: progress, progressHandler: { (files, _, error) in
+                for file in files where query.evaluate(with: file.mapPredicate()) {
+                    foundItemHandler?(file)
+                }
+            }, completionHandler: { (files, _, error) in
+                let predicatedFiles = files.filter { query.evaluate(with: $0.mapPredicate()) }
+                completionHandler(predicatedFiles, error)
+            })
        }
+        return progress
+    }
+    
+    override func request(for operation: FileOperationType, overwrite: Bool = false, attributes: [URLResourceKey : Any] = [:]) -> URLRequest {
+        // content operations
+        var request: URLRequest
+        switch operation {
+        case .copy(source: let source, destination: let dest) where dest.lowercased().hasPrefix("file://"):
+            let url = URL(string: "files/download", relativeTo: contentURL)!
+            request = URLRequest(url: url)
+            request.set(httpAuthentication: credential, with: .oAuth2)
+            request.set(dropboxArgKey: ["path": correctPath(source)! as NSString])
+        case .fetch(let path):
+            let url = URL(string: "files/download", relativeTo: contentURL)!
+            request = URLRequest(url: url)
+            request.set(httpAuthentication: credential, with: .oAuth2)
+            request.set(dropboxArgKey: ["path": correctPath(path)! as NSString])
+        case .copy(source: let source, destination: let dest) where source.lowercased().hasPrefix("file://"):
+            var requestDictionary = [String: AnyObject]()
+            let url: URL = URL(string: "files/upload", relativeTo: contentURL)!
+            requestDictionary["path"] = correctPath(dest) as NSString?
+            requestDictionary["mode"] = (overwrite ? "overwrite" : "add") as NSString
+            requestDictionary["client_modified"] = (attributes[.contentModificationDateKey] as? Date)?.format(with: .rfc3339) as NSString?
+            request = URLRequest(url: url)
+            request.httpMethod = "POST"
+            request.set(httpAuthentication: credential, with: .oAuth2)
+            request.set(httpContentType: .stream)
+            request.set(dropboxArgKey: requestDictionary)
+        case .modify(let path):
+            var requestDictionary = [String: AnyObject]()
+            let url: URL = URL(string: "files/upload", relativeTo: contentURL)!
+            requestDictionary["path"] = correctPath(path) as NSString?
+            requestDictionary["mode"] = (overwrite ? "overwrite" : "add") as NSString
+            requestDictionary["client_modified"] = (attributes[.contentModificationDateKey] as? Date)?.format(with: .rfc3339) as NSString?
+            request = URLRequest(url: url)
+            request.httpMethod = "POST"
+            request.set(httpAuthentication: credential, with: .oAuth2)
+            request.set(httpContentType: .stream)
+            request.set(dropboxArgKey: requestDictionary)
+        default:
+            return self.apiRequest(for: operation, overwrite: overwrite)
+        }
+        return request
+    }
+    
+    func apiRequest(for operation: FileOperationType, overwrite: Bool = false) -> URLRequest {
        let url: String
-        guard let sourcePath = operation.source else { return nil }
+        let sourcePath = operation.source
        let destPath = operation.destination
+        var requestDictionary = [String: AnyObject]()
        switch operation {
        case .create:
-            url = "files/create_folder"
+            url = "files/create_folder_v2"
+            
        case .copy:
-            url = "files/copy"
+            url = "files/copy_v2"
+            requestDictionary["allow_shared_folder"] = NSNumber(value: true)
        case .move:
-            url = "files/move"
+            url = "files/move_v2"
+            requestDictionary["allow_shared_folder"] = NSNumber(value: true)
        case .remove:
-            url = "files/delete"
+            url = "files/delete_v2"
        default: // modify, link, fetch
-            return nil
+            fatalError("Unimplemented operation \(operation.description) in \(#file)")
        }
        var request = URLRequest(url: URL(string: url, relativeTo: apiURL)!)
        request.httpMethod = "POST"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
-        var requestDictionary = [String: AnyObject]()
+        request.set(httpAuthentication: credential, with: .oAuth2)
+        request.set(httpContentType: .json)
        if let dest = correctPath(destPath) as NSString? {
            requestDictionary["from_path"] = correctPath(sourcePath) as NSString?
            requestDictionary["to_path"] = dest
        } else {
            requestDictionary["path"] = correctPath(sourcePath) as NSString?
        }
-        request.httpBody = dictionaryToJSON(requestDictionary)?.data(using: .utf8)
-        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
-            var serverError: FileProviderDropboxError?
-            if let response = response as? HTTPURLResponse, response.statusCode >= 300, let code = FileProviderHTTPErrorCode(rawValue: response.statusCode) {
-                 serverError = FileProviderDropboxError(code: code, path: sourcePath, errorDescription: String(data: data ?? Data(), encoding: .utf8))
-            }
-            completionHandler?(serverError ?? error)
-            self.delegateNotify(operation, error: serverError ?? error)
-        })
-        task.taskDescription = operation.json
-        task.resume()
-        return RemoteOperationHandle(operationType: operation, tasks: [task])
+        request.httpBody = Data(jsonDictionary: requestDictionary)
+        return request
    }
    
-    public func copyItem(localFile: URL, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.copy(source: localFile.absoluteString, destination: toPath)
-        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
-            return nil
-        }
-        return upload_simple(toPath, localFile: localFile, overwrite: overwrite, operation: opType, completionHandler: completionHandler)
+    override func serverError(with code: FileProviderHTTPErrorCode, path: String?, data: Data?) -> FileProviderHTTPError {
+        return FileProviderDropboxError(code: code, path: path ?? "", errorDescription: data.flatMap({ String(data: $0, encoding: .utf8) }))
    }
    
-    public func copyItem(path: String, toLocalURL destURL: URL, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.copy(source: path, destination: destURL.absoluteString)
-        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
-            return nil
-        }
-        let url = URL(string: "files/download", relativeTo: contentURL)!
-        var request = URLRequest(url: url)
-        request.httpMethod = "GET"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        let requestDictionary: [String: AnyObject] = ["path": path as NSString]
-        let requestJson = dictionaryToJSON(requestDictionary) ?? ""
-        request.setValue(requestJson, forHTTPHeaderField: "Dropbox-API-Arg")
-        let task = session.downloadTask(with: request, completionHandler: { (cacheURL, response, error) in
-            guard let cacheURL = cacheURL, let httpResponse = response as? HTTPURLResponse , httpResponse.statusCode < 300 else {
-                let code = FileProviderHTTPErrorCode(rawValue: (response as? HTTPURLResponse)?.statusCode ?? -1)
-                let errorData : Data? = nil //Data(contentsOf:cacheURL) // TODO: Figure out how to get error response data for the error description
-                let serverError : FileProviderDropboxError? = code != nil ? FileProviderDropboxError(code: code!, path: path, errorDescription: String(data: errorData ?? Data(), encoding: .utf8)) : nil
-                completionHandler?(serverError ?? error)
-                return
-            }
-            do {
-                try FileManager.default.moveItem(at: cacheURL, to: destURL)
-                completionHandler?(nil)
-            } catch let e {
-                completionHandler?(e)
-            }
-        })
-        task.taskDescription = opType.json
-        task.resume()
-        return RemoteOperationHandle(operationType: opType, tasks: [task])
-    }
-}
-
-extension DropboxFileProvider: FileProviderReadWrite {
-    public func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
-        if length == 0 || offset < 0 {
-            dispatch_queue.async {
-                completionHandler(Data(), nil)
-            }
+    override func upload_simple(_ targetPath: String, request: URLRequest, data: Data?, localFile: URL?, operation: FileOperationType, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let size = data?.count ?? Int((try? localFile?.resourceValues(forKeys: [.fileSizeKey]))??.fileSize ?? -1)
+        if size > 150 * 1024 * 1024 {
+            let error = FileProviderDropboxError(code: .payloadTooLarge, path: targetPath, errorDescription: nil)
+            completionHandler?(error)
+            self.delegateNotify(operation, error: error)
            return nil
        }
        
-        let opType = FileOperationType.fetch(path: path)
-        let url = URL(string: "files/download", relativeTo: contentURL)!
-        var request = URLRequest(url: url)
-        request.httpMethod = "GET"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        if length > 0 {
-            request.setValue("bytes=\(offset)-\(offset + length - 1)", forHTTPHeaderField: "Range")
-        } else if offset > 0 && length < 0 {
-            request.setValue("bytes=\(offset)-", forHTTPHeaderField: "Range")
-        }
-        let requestDictionary: [String: AnyObject] = ["path": correctPath(path)! as NSString]
-        request.setValue(dictionaryToJSON(requestDictionary), forHTTPHeaderField: "Dropbox-API-Arg")
-        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
-            var serverError: FileProviderDropboxError?
-            if let httpResponse = response as? HTTPURLResponse , httpResponse.statusCode >= 300, let code = FileProviderHTTPErrorCode(rawValue: httpResponse.statusCode) {
-                serverError = FileProviderDropboxError(code: code, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8))
-            }
-            let filedata = serverError ?? error == nil ? data : nil
-            completionHandler(filedata, serverError ?? error)
-        })
-        task.taskDescription = opType.json
-        task.resume()
-        return RemoteOperationHandle(operationType: opType, tasks: [task])
+        return super.upload_simple(targetPath, request: request, data: data, localFile: localFile, operation: operation, completionHandler: completionHandler)
    }
-    
-    public func writeContents(path: String, contents data: Data, atomically: Bool, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.modify(path: path)
-        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
-            return nil
-        }
-        // FIXME: remove 150MB restriction
-        return upload_simple(path, data: data, overwrite: overwrite, operation: opType, completionHandler: completionHandler)
-    }
-    
-    public func searchFiles(path: String, recursive: Bool, query: String, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) {
-        var foundFiles = [DropboxFileObject]()
-        search(path, query: query, foundItem: { (file) in
-            foundFiles.append(file)
-            foundItemHandler?(file)
-            }, completionHandler: { (error) in
-                completionHandler(foundFiles, error)
-        })
-    }
-    
+
+    /*
    fileprivate func registerNotifcation(path: String, eventHandler: (() -> Void)) {
        /* There is two ways to monitor folders changing in Dropbox. Either using webooks
         * which means you have to implement a server to translate it to push notifications
@@ -305,48 +238,17 @@ extension DropboxFileProvider: FileProviderReadWrite {
    fileprivate func unregisterNotifcation(path: String) {
        NotImplemented()
    }
-    
-    // TODO: Implement /get_account & /get_current_account
-}
-
-extension DropboxFileProvider {
-    /// *DEPRECATED:* Use `publicLink(to:, completionHandler: (URL?, DropboxFileObject?, Date?,  Error?))` function instead.
-    @available(*, deprecated, renamed: "publicLink(to:completionHandler:)", message: "Use publicLink(to:, completionHandler: (URL?, DropboxFileObject?, Date?,  Error?)) function instead.")
-    open func temporaryLink(to path: String, completionHandler: @escaping ((_ link: URL?, _ attribute: DropboxFileObject?, _ error: Error?) -> Void)) {
-        self.publicLink(to: path) { (url, file, _, error) in
-            completionHandler(url, file, error)
-        }
-    }
-    
-    /// *DEPRECATED:* Use `publicLink(to:, completionHandler: (URL?, DropboxFileObject?, Date?,  Error?))` function instead.
-    @available(*, deprecated, renamed: "publicLink(to:completionHandler:)", message: "Use publicLink(to:, completionHandler: (URL?, DropboxFileObject?, Date?,  Error?)) function instead.")
-    open func temporaryLink(to path: String, completionHandler: @escaping ((_ link: URL?, _ attribute: DropboxFileObject?, _ expiration: Date?, _ error: Error?) -> Void)) {
-        self.publicLink(to: path) { (url, file, expiration, error) in
-            completionHandler(url, file, expiration, error)
-        }
-    }
-    
-    /**
-     Genrates a public url to a file to be shared with other users and can be downloaded without authentication.
-     
-     - Important: URL will be available for a limitied time (4 hours according to Dropbox documentation).
-     
-     - Parameters:
-       - to: path of file, including file/directory name.
-       - completionHandler: a block with result of directory entries or error.
-         `link`: a url returned by Dropbox to share.
-         `attribute`: a `FileObject` containing the attributes of the item.
-         `expiration`: a `Date` object, determines when the public url will expires.
-         `error`: Error returned by Dropbox.
    */
-    open func publicLink(to path: String, completionHandler: @escaping ((_ link: URL?, _ attribute: DropboxFileObject?, _ expiration: Date?, _ error: Error?) -> Void)) {
+    // TODO: Implement /get_account & /get_current_account
+    
+    open func publicLink(to path: String, completionHandler: @escaping ((_ link: URL?, _ attribute: FileObject?, _ expiration: Date?, _ error: Error?) -> Void)) {
        let url = URL(string: "files/get_temporary_link", relativeTo: apiURL)!
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
+        request.set(httpAuthentication: credential, with: .oAuth2)
+        request.set(httpContentType: .json)
        let requestDictionary: [String: AnyObject] = ["path": correctPath(path)! as NSString]
-        request.httpBody = dictionaryToJSON(requestDictionary)?.data(using: .utf8)
+        request.httpBody = Data(jsonDictionary: requestDictionary)
        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
            var serverError: FileProviderDropboxError?
            var link: URL?
@@ -354,7 +256,7 @@ extension DropboxFileProvider {
            if let response = response as? HTTPURLResponse {
                let code = FileProviderHTTPErrorCode(rawValue: response.statusCode)
                serverError = code != nil ? FileProviderDropboxError(code: code!, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8)) : nil
-                if let data = data, let jsonStr = String(data: data, encoding: .utf8), let json = jsonToDictionary(jsonStr) {
+                if let json = data?.deserializeJSON() {
                    if let linkStr = json["link"] as? String {
                        link = URL(string: linkStr)
                    }
@@ -376,10 +278,10 @@ extension DropboxFileProvider {
     - Parameters:
       - remoteURL: a valid remote url to file.
       - to: Destination path of file, including file/directory name.
-       - completionHandler: a block with result of directory entries or error.
-         `jobId`: Job ID returned by Dropbox to monitor the copy/download progress.
-         `attribute`: A `FileObject` containing the attributes of the item.
-         `error`: Error returned by Dropbox.
+       - completionHandler: a closure with result of directory entries or error.
+         - `jobId`: Job ID returned by Dropbox to monitor the copy/download progress.
+         - `attribute`: A `FileObject` containing the attributes of the item.
+         - `error`: Error returned by Dropbox.
     */
    open func copyItem(remoteURL: URL, to toPath: String, completionHandler: @escaping ((_ jobId: String?, _ attribute: DropboxFileObject?, _ error: Error?) -> Void)) {
        if remoteURL.isFileURL {
@@ -389,10 +291,10 @@ extension DropboxFileProvider {
        let url = URL(string: "files/save_url", relativeTo: apiURL)!
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
+        request.set(httpAuthentication: credential, with: .oAuth2)
+        request.set(httpContentType: .json)
        let requestDictionary: [String: AnyObject] = ["path": correctPath(toPath)! as NSString, "url" : remoteURL.absoluteString as NSString]
-        request.httpBody = dictionaryToJSON(requestDictionary)?.data(using: .utf8)
+        request.httpBody = Data(jsonDictionary: requestDictionary)
        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
            var serverError: FileProviderDropboxError?
            var jobId: String?
@@ -400,7 +302,7 @@ extension DropboxFileProvider {
            if let response = response as? HTTPURLResponse {
                let code = FileProviderHTTPErrorCode(rawValue: response.statusCode)
                serverError = code != nil ? FileProviderDropboxError(code: code!, path: toPath, errorDescription: String(data: data ?? Data(), encoding: .utf8)) : nil
-                if let data = data, let jsonStr = String(data: data, encoding: .utf8), let json = jsonToDictionary(jsonStr) {
+                if let json = data?.deserializeJSON() {
                    jobId = json["async_job_id"] as? String
                    if let attribDic = json["metadata"] as? [String: AnyObject] {
                        fileObject = DropboxFileObject(json: attribDic)
@@ -424,10 +326,10 @@ extension DropboxFileProvider {
        let url = URL(string: "files/copy_reference/save", relativeTo: apiURL)!
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
+        request.set(httpAuthentication: credential, with: .oAuth2)
+        request.set(httpContentType: .json)
        let requestDictionary: [String: AnyObject] = ["path": correctPath(toPath)! as NSString, "copy_reference" : reference as NSString]
-        request.httpBody = dictionaryToJSON(requestDictionary)?.data(using: .utf8)
+        request.httpBody = Data(jsonDictionary: requestDictionary)
        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
            var serverError: FileProviderDropboxError?
            if let response = response as? HTTPURLResponse {
@@ -441,7 +343,7 @@ extension DropboxFileProvider {
 }

 extension DropboxFileProvider: ExtendedFileProvider {
-    public func thumbnailOfFileSupported(path: String) -> Bool {
+    open func thumbnailOfFileSupported(path: String) -> Bool {
        switch (path as NSString).pathExtension.lowercased() {
        case "jpg", "jpeg", "gif", "bmp", "png", "tif", "tiff":
            return true
@@ -456,7 +358,7 @@ extension DropboxFileProvider: ExtendedFileProvider {
        }
    }
    
-    public func propertiesOfFileSupported(path: String) -> Bool {
+    open func propertiesOfFileSupported(path: String) -> Bool {
        let fileExt = (path as NSString).pathExtension.lowercased()
        switch fileExt {
        case "jpg", "jpeg", "bmp", "gif", "png", "tif", "tiff":
@@ -471,42 +373,57 @@ extension DropboxFileProvider: ExtendedFileProvider {
    }
        
    /// Default value for dimension is 64x64, according to Dropbox documentation
-    public func thumbnailOfFile(path: String, dimension: CGSize?, completionHandler: @escaping ((_ image: ImageClass?, _ error: Error?) -> Void)) {
+    open func thumbnailOfFile(path: String, dimension: CGSize?, completionHandler: @escaping ((_ image: ImageClass?, _ error: Error?) -> Void)) {
        let url: URL
+        let thumbAPI: Bool
        switch (path as NSString).pathExtension.lowercased() {
        case "jpg", "jpeg", "gif", "bmp", "png", "tif", "tiff":
            url = URL(string: "files/get_thumbnail", relativeTo: contentURL)!
+            thumbAPI = true
        case "doc", "docx", "docm", "xls", "xlsx", "xlsm":
            fallthrough
        case  "ppt", "pps", "ppsx", "ppsm", "pptx", "pptm":
            fallthrough
        case "rtf":
            url = URL(string: "files/get_preview", relativeTo: contentURL)!
+            thumbAPI = false
        default:
            return
        }
        var request = URLRequest(url: url)
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
+        request.set(httpAuthentication: credential, with: .oAuth2)
        var requestDictionary: [String: AnyObject] = ["path": path as NSString]
-        requestDictionary["format"] = "jpeg" as NSString
-        if let dimension = dimension {
-            requestDictionary["size"] = "w\(Int(dimension.width))h\(Int(dimension.height))" as NSString
+        if thumbAPI {
+            requestDictionary["format"] = "jpeg" as NSString
+            let size: String
+            switch dimension?.height ?? 64 {
+            case 0...32:    size = "w32h32"
+            case 33...64:   size = "w64h64"
+            case 65...128:  size = "w128h128"
+            case 129...480: size = "w640h480"
+            default: size = "w1024h768"
+            }
+            requestDictionary["size"] = size as NSString
        }
-        request.setValue(dictionaryToJSON(requestDictionary), forHTTPHeaderField: "Dropbox-API-Arg")
+        request.set(dropboxArgKey: requestDictionary)
        let task = self.session.dataTask(with: request, completionHandler: { (data, response, error) in
            var image: ImageClass? = nil
-            if let r = response as? HTTPURLResponse, let result = r.allHeaderFields["Dropbox-API-Result"] as? String, let jsonResult = jsonToDictionary(result) {
+            if let r = response as? HTTPURLResponse, let result = r.allHeaderFields["Dropbox-API-Result"] as? String, let jsonResult = result.deserializeJSON() {
                if jsonResult["error"] != nil {
-                    completionHandler(nil, self.throwError(path, code: URLError.cannotDecodeRawData as FoundationErrorEnum))
+                    completionHandler(nil, self.throwError(path, code: URLError.cannotDecodeRawData))
                }
            }
            if let data = data {
-                if DropboxFileProvider.dataIsPDF(data) {
-                    image = DropboxFileProvider.convertToImage(pdfData: data)
+                if data.isPDF, let pageImage = DropboxFileProvider.convertToImage(pdfData: data) {
+                    image = pageImage
                } else if let contentType = (response as? HTTPURLResponse)?.allHeaderFields["Content-Type"] as? String, contentType.contains("text/html") {
                     // TODO: Implement converting html returned type of get_preview to image
-                } else {
-                    image = ImageClass(data: data)
+                } else if let fetchedimage = ImageClass(data: data){
+                    if let dimension = dimension {
+                        image = DropboxFileProvider.scaleDown(image: fetchedimage, toSize: dimension)
+                    } else {
+                        image = fetchedimage
+                    }
                }
            }
            completionHandler(image, error)
@@ -514,14 +431,14 @@ extension DropboxFileProvider: ExtendedFileProvider {
        task.resume()
    }
    
-    public func propertiesOfFile(path: String, completionHandler: @escaping ((_ propertiesDictionary: [String : Any], _ keys: [String], _ error: Error?) -> Void)) {
+    open func propertiesOfFile(path: String, completionHandler: @escaping ((_ propertiesDictionary: [String : Any], _ keys: [String], _ error: Error?) -> Void)) {
        let url = URL(string: "files/get_metadata", relativeTo: apiURL)!
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
+        request.set(httpAuthentication: credential, with: .oAuth2)
+        request.set(httpContentType: .json)
        let requestDictionary: [String: AnyObject] = ["path": correctPath(path)! as NSString, "include_media_info": NSNumber(value: true)]
-        request.httpBody = dictionaryToJSON(requestDictionary)?.data(using: .utf8)
+        request.httpBody = Data(jsonDictionary: requestDictionary)
        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
            var serverError: FileProviderDropboxError?
            var dic = [String: Any]()
@@ -529,7 +446,7 @@ extension DropboxFileProvider: ExtendedFileProvider {
            if let response = response as? HTTPURLResponse {
                let code = FileProviderHTTPErrorCode(rawValue: response.statusCode)
                serverError = code != nil ? FileProviderDropboxError(code: code!, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8)) : nil
-                if let data = data, let jsonStr = String(data: data, encoding: .utf8), let json = jsonToDictionary(jsonStr), let properties = json["media_info"] as? [String: Any] {
+                if let json = data?.deserializeJSON(), let properties = (json["media_info"] as? [String: Any])?["metadata"] as? [String: Any] {
                    (dic, keys) = self.mapMediaInfo(properties)
                }
            }
@@ -538,15 +455,3 @@ extension DropboxFileProvider: ExtendedFileProvider {
        task.resume()
    }
 }
-
-extension DropboxFileProvider: FileProvider {
-    open func copy(with zone: NSZone? = nil) -> Any {
-        let copy = DropboxFileProvider(credential: self.credential, cache: self.cache)
-        copy.currentPath = self.currentPath
-        copy.delegate = self.delegate
-        copy.fileOperationDelegate = self.fileOperationDelegate
-        copy.useCache = self.useCache
-        copy.validatingCache = self.validatingCache
-        return copy
-    }
-}
@@ -8,44 +8,50 @@

 import Foundation

+/// Error returned by Dropbox server when trying to access or do operations on a file or folder.
 public struct FileProviderDropboxError: FileProviderHTTPError {
    public let code: FileProviderHTTPErrorCode
    public let path: String
    public let errorDescription: String?
 }

+/// Containts path, url and attributes of a Dropbox file or resource.
 public final class DropboxFileObject: FileObject {
-    internal init(name: String, path: String) {
-        super.init(url: URL(string: path) ?? URL(string: "/")!, name: name, path: path)
-    }
-    
    internal convenience init? (jsonStr: String) {
-        guard let json = jsonToDictionary(jsonStr) else { return nil }
+        guard let json = jsonStr.deserializeJSON() else { return nil }
        self.init(json: json)
    }
    
-    internal convenience init? (json: [String: AnyObject]) {
+    internal init? (json: [String: AnyObject]) {
+        var json = json
+        if json["name"] == nil, let metadata = json["metadata"] as? [String: AnyObject] {
+            json = metadata
+        }
        guard let name = json["name"] as? String else { return nil }
        guard let path = json["path_display"] as? String else { return nil }
-        self.init(name: name, path: path)
+        super.init(url: nil, name: name, path: path)
        self.size = (json["size"] as? NSNumber)?.int64Value ?? -1
-        self.serverTime = resolve(dateString: json["server_modified"] as? String ?? "")
-        self.modifiedDate = resolve(dateString: json["client_modified"] as? String ?? "")
+        self.serverTime = Date(rfcString: json["server_modified"] as? String ?? "")
+        self.modifiedDate = Date(rfcString: json["client_modified"] as? String ?? "")
        self.type = (json[".tag"] as? String) == "folder" ? .directory : .regular
        self.isReadOnly = (json["sharing_info"]?["read_only"] as? NSNumber)?.boolValue ?? false
        self.id = json["id"] as? String
        self.rev = json["rev"] as? String
    }
    
+    /// The time contents of file has been modified on server, returns nil if not set
    open internal(set) var serverTime: Date? {
        get {
-            return allValues[.serverDate] as? Date
+            return allValues[.serverDateKey] as? Date
        }
        set {
-            allValues[.serverDate] = newValue
+            allValues[.serverDateKey] = newValue
        }
    }
    
+    /// The document identifier is a value assigned by the Dropbox to a file.
+    /// This value is used to identify the document regardless of where it is moved on a volume.
+    /// The identifier persists across system restarts.
    open internal(set) var id: String? {
        get {
            return allValues[.documentIdentifierKey] as? String
@@ -55,6 +61,8 @@ public final class DropboxFileObject: FileObject {
        }
    }
    
+    /// The revision of file, which changes when a file contents are modified.
+    /// Changes to attributes or other file metadata do not change the identifier.
    open internal(set) var rev: String? {
        get {
            return allValues[.generationIdentifierKey] as? String
@@ -65,9 +73,13 @@ public final class DropboxFileObject: FileObject {
    }
 }

- // codebeat:disable[ARITY]
+// codebeat:disable[ARITY]
 internal extension DropboxFileProvider {
-    func list(_ path: String, cursor: String? = nil, prevContents: [DropboxFileObject] = [], recursive: Bool = false, completionHandler: @escaping ((_ contents: [FileObject], _ cursor: String?, _ error: Error?) -> Void)) {
+    
+    
+    func list(_ path: String, cursor: String? = nil, prevContents: [DropboxFileObject] = [], recursive: Bool = false, session: URLSession? = nil, progress: Progress, progressHandler: ((_ contents: [FileObject], _ nextCursor: String?, _ error: Error?) -> Void)? = nil, completionHandler: @escaping ((_ contents: [FileObject], _ cursor: String?, _ error: Error?) -> Void)) {
+        if progress.isCancelled { return }
+        
        var requestDictionary = [String: AnyObject]()
        let url: URL
        if let cursor = cursor {
@@ -80,129 +92,74 @@ internal extension DropboxFileProvider {
        }
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
-        request.httpBody = dictionaryToJSON(requestDictionary)?.data(using: .utf8)
-        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
+        request.set(httpAuthentication: credential, with: .oAuth2)
+        request.set(httpContentType: .json)
+        request.httpBody = Data(jsonDictionary: requestDictionary)
+        let task = (session ?? self.session).dataTask(with: request, completionHandler: { (data, response, error) in
            var responseError: FileProviderDropboxError?
-            var files = prevContents
+            var files = [DropboxFileObject]()
            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
                responseError = FileProviderDropboxError(code: rCode, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8))
            }
-            if let data = data, let jsonStr = String(data: data, encoding: .utf8) {
-                let json = jsonToDictionary(jsonStr)
-                if let entries = json?["entries"] as? [AnyObject] , entries.count > 0 {
+            if let json = data?.deserializeJSON() {
+                if let entries = json["entries"] as? [AnyObject] , entries.count > 0 {
+                    files.reserveCapacity(entries.count)
                    for entry in entries {
                        if let entry = entry as? [String: AnyObject], let file = DropboxFileObject(json: entry) {
                            files.append(file)
+                            progress.totalUnitCount = Int64(files.count)
                        }
                    }
-                    let ncursor = json?["cursor"] as? String
-                    let hasmore = (json?["has_more"] as? NSNumber)?.boolValue ?? false
-                    if hasmore {
-                        self.list(path, cursor: ncursor, prevContents: files, completionHandler: completionHandler)
+                    let ncursor = json["cursor"] as? String
+                    let hasmore = (json["has_more"] as? NSNumber)?.boolValue ?? false
+                    if hasmore && !progress.isCancelled {
+                        progressHandler?(files, ncursor, responseError ?? error)
+                        self.list(path, cursor: ncursor, prevContents: prevContents + files, progress: progress, completionHandler: completionHandler)
                        return
                    }
                }
            }
-            completionHandler(files, nil, responseError ?? error)
+            progressHandler?(files, nil, responseError ?? error)
+            completionHandler(prevContents + files, nil, responseError ?? error)
        })
+        progress.cancellationHandler = { [weak task] in
+            task?.cancel()
+        }
+        progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
        task.taskDescription = FileOperationType.fetch(path: path).json
        task.resume()
    }
    
-    func upload_simple(_ targetPath: String, data: Data, modifiedDate: Date = Date(), overwrite: Bool, operation: FileOperationType, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        if data.count > 150 * 1024 * 1024 {
-            let error = FileProviderDropboxError(code: .payloadTooLarge, path: targetPath, errorDescription: nil)
-            completionHandler?(error)
-            self.delegateNotify(.create(path: targetPath), error: error)
-            return nil
-        }
-        var requestDictionary = [String: AnyObject]()
-        let url: URL
-        url = URL(string: "files/upload", relativeTo: contentURL)!
-        requestDictionary["path"] = correctPath(targetPath) as NSString?
-        requestDictionary["mode"] = (overwrite ? "overwrite" : "add") as NSString
-        requestDictionary["client_modified"] = rfc3339utc(of: modifiedDate) as NSString
-        var request = URLRequest(url: url)
-        request.httpMethod = "POST"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        request.setValue("application/octet-stream", forHTTPHeaderField: "Content-Type")
-        request.setValue(dictionaryToJSON(requestDictionary), forHTTPHeaderField: "Dropbox-API-Arg")
-        request.httpBody = data
-        let task = session.uploadTask(with: request, from: data, completionHandler: { (data, response, error) in
-            var responseError: FileProviderDropboxError?
-            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
-                responseError = FileProviderDropboxError(code: rCode, path: targetPath, errorDescription: String(data: data ?? Data(), encoding: .utf8))
-            }
-            completionHandler?(responseError ?? error)
-            self.delegateNotify(.create(path: targetPath), error: responseError ?? error)
-        })
-        task.taskDescription = operation.json
-        task.resume()
-        return RemoteOperationHandle(operationType: operation, tasks: [task])
-    }
-    
-    func upload_simple(_ targetPath: String, localFile: URL, modifiedDate: Date = Date(), overwrite: Bool, operation: FileOperationType, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let size = (try? localFile.resourceValues(forKeys: [.fileSizeKey]))?.fileSize ?? -1
-        if size > 150 * 1024 * 1024 {
-            let error = FileProviderDropboxError(code: .payloadTooLarge, path: targetPath, errorDescription: nil)
-            completionHandler?(error)
-            self.delegateNotify(.create(path: targetPath), error: error)
-            return nil
-        }
-        var requestDictionary = [String: AnyObject]()
-        let url: URL
-        url = URL(string: "files/upload", relativeTo: contentURL)!
-        requestDictionary["path"] = correctPath(targetPath) as NSString?
-        requestDictionary["mode"] = (overwrite ? "overwrite" : "add") as NSString
-        requestDictionary["client_modified"] = rfc3339utc(of: modifiedDate) as NSString
-        var request = URLRequest(url: url)
-        request.httpMethod = "POST"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        request.setValue("application/octet-stream", forHTTPHeaderField: "Content-Type")
-        request.setValue(dictionaryToJSON(requestDictionary), forHTTPHeaderField: "Dropbox-API-Arg")
-        let task = session.uploadTask(with: request, fromFile: localFile, completionHandler: { (data, response, error) in
-            var responseError: FileProviderDropboxError?
-            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
-                responseError = FileProviderDropboxError(code: rCode, path: targetPath, errorDescription: String(data: data ?? Data(), encoding: .utf8))
-            }
-            completionHandler?(responseError ?? error)
-            self.delegateNotify(.create(path: targetPath), error: responseError ?? error)
-        })
-        task.taskDescription = operation.json
-        task.resume()
-        return RemoteOperationHandle(operationType: operation, tasks: [task])
-    }
-    
-    func search(_ startPath: String = "", query: String, start: Int = 0, maxResultPerPage: Int = 25, maxResults: Int = -1, foundItem:@escaping ((_ file: DropboxFileObject) -> Void), completionHandler: @escaping ((_ error: Error?) -> Void)) {
+    func search(_ startPath: String = "", query: String, start: Int = 0, maxResultPerPage: Int = 25, maxResults: Int = -1, progress: Progress, foundItem:@escaping ((_ file: DropboxFileObject) -> Void), completionHandler: @escaping ((_ error: Error?) -> Void)) {
+        if progress.isCancelled { return }
+        
        let url = URL(string: "files/search", relativeTo: apiURL)!
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
+        request.set(httpAuthentication: credential, with: .oAuth2)
+        request.set(httpContentType: .json)
        var requestDictionary: [String: AnyObject] = ["path": startPath as NSString]
        requestDictionary["query"] = query as NSString
        requestDictionary["start"] = start as NSNumber
        requestDictionary["max_results"] = maxResultPerPage as NSNumber
-        request.httpBody = dictionaryToJSON(requestDictionary)?.data(using: .utf8)
+        request.httpBody = Data(jsonDictionary: requestDictionary)
        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
            var responseError: FileProviderDropboxError?
            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
                responseError = FileProviderDropboxError(code: rCode, path: startPath, errorDescription: String(data: data ?? Data(), encoding: .utf8))
            }
-            if let data = data, let jsonStr = String(data: data, encoding: .utf8) {
-                let json = jsonToDictionary(jsonStr)
-                if let entries = json?["matches"] as? [AnyObject] , entries.count > 0 {
+            if let json = data?.deserializeJSON() {
+                if let entries = json["matches"] as? [AnyObject] , entries.count > 0 {
                    for entry in entries {
                        if let entry = entry as? [String: AnyObject], let file = DropboxFileObject(json: entry) {
                            foundItem(file)
+                            progress.completedUnitCount += 1
                        }
                    }
-                    let rstart = json?["start"] as? Int
-                    let hasmore = (json?["more"] as? NSNumber)?.boolValue ?? false
-                    if hasmore, let rstart = rstart {
-                        self.search(startPath, query: query, start: rstart + entries.count, maxResultPerPage: maxResultPerPage, foundItem: foundItem, completionHandler: completionHandler)
+                    let rstart = json["start"] as? Int
+                    let hasmore = (json["more"] as? NSNumber)?.boolValue ?? false
+                    if hasmore && !progress.isCancelled, let rstart = rstart {
+                        self.search(startPath, query: query, start: rstart + entries.count, maxResultPerPage: maxResultPerPage, progress: progress, foundItem: foundItem, completionHandler: completionHandler)
                    } else {
                        completionHandler(responseError ?? error)
                    }
@@ -210,7 +167,11 @@ internal extension DropboxFileProvider {
                }
            }
            completionHandler(responseError ?? error)
-        }) 
+        })
+        progress.cancellationHandler = { [weak task] in
+            task?.cancel()
+        }
+        progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
        task.resume()
    }
 }
@@ -232,29 +193,19 @@ internal extension DropboxFileProvider {
            DropboxFileProvider.decimalFormatter.numberStyle = .decimal
            DropboxFileProvider.decimalFormatter.maximumFractionDigits = 5
            keys.append("Location")
-            let latStr = DropboxFileProvider.decimalFormatter.string(from: NSNumber(value: latitude))
-            let longStr = DropboxFileProvider.decimalFormatter.string(from: NSNumber(value: longitude))
+            let latStr = DropboxFileProvider.decimalFormatter.string(from: NSNumber(value: latitude))!
+            let longStr = DropboxFileProvider.decimalFormatter.string(from: NSNumber(value: longitude))!
            dic["Location"] = "\(latStr), \(longStr)"
        }
-        if let timeTakenStr = json["time_taken"] as? String, let timeTaken = resolve(dateString: timeTakenStr) {
+        if let timeTakenStr = json["time_taken"] as? String, let timeTaken = Date(rfcString: timeTakenStr) {
            keys.append("Date taken")
            DropboxFileProvider.dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
            dic["Date taken"] = DropboxFileProvider.dateFormatter.string(from: timeTaken)
        }
        if let duration = json["duration"] as? UInt64 {
            keys.append("Duration")
-            dic["Duration"] = DropboxFileProvider.formatshort(interval: TimeInterval(duration))
+            dic["Duration"] = TimeInterval(duration).formatshort
        }
        return (dic, keys)
    }
-    
-    func delegateNotify(_ operation: FileOperationType, error: Error?) {
-        DispatchQueue.main.async(execute: {
-            if error == nil {
-                self.delegate?.fileproviderSucceed(self, operation: operation)
-            } else {
-                self.delegate?.fileproviderFailed(self, operation: operation)
-            }
-        })
-    }
 }
@@ -10,15 +10,9 @@ import Foundation
 import ImageIO
 import CoreGraphics
 import AVFoundation
-#if os(iOS) || os(tvOS)
-import UIKit
-#elseif os(macOS)
-import Cocoa
-#endif

 extension LocalFileProvider: ExtendedFileProvider {
-    
-    public func thumbnailOfFileSupported(path: String) -> Bool {
+    open func thumbnailOfFileSupported(path: String) -> Bool {
        switch (path as NSString).pathExtension.lowercased() {
        case LocalFileInformationGenerator.imageThumbnailExtensions:
            return true
@@ -37,7 +31,7 @@ extension LocalFileProvider: ExtendedFileProvider {
        }
    }
    
-    public func propertiesOfFileSupported(path: String) -> Bool {
+    open func propertiesOfFileSupported(path: String) -> Bool {
        let fileExt = (path as NSString).pathExtension.lowercased()
        switch fileExt {
        case LocalFileInformationGenerator.imagePropertiesExtensions:
@@ -60,7 +54,7 @@ extension LocalFileProvider: ExtendedFileProvider {
        }
    }
    
-    public func thumbnailOfFile(path: String, dimension: CGSize? = nil, completionHandler: @escaping ((_ image: ImageClass?, _ error: Error?) -> Void)) {
+    open func thumbnailOfFile(path: String, dimension: CGSize? = nil, completionHandler: @escaping ((_ image: ImageClass?, _ error: Error?) -> Void)) {
        let dimension = dimension ?? CGSize(width: 64, height: 64)
        (dispatch_queue).async {
            var thumbnailImage: ImageClass? = nil
@@ -92,7 +86,7 @@ extension LocalFileProvider: ExtendedFileProvider {
        }
    }
    
-    public func propertiesOfFile(path: String, completionHandler: @escaping ((_ propertiesDictionary: [String: Any], _ keys: [String], _ error: Error?) -> Void)) {
+    open func propertiesOfFile(path: String, completionHandler: @escaping ((_ propertiesDictionary: [String: Any], _ keys: [String], _ error: Error?) -> Void)) {
        (dispatch_queue).async {
            let fileExt = (path as NSString).pathExtension.lowercased()
            var getter: ((_ fileURL: URL) -> (prop: [String: Any], keys: [String]))?
@@ -126,31 +120,90 @@ extension LocalFileProvider: ExtendedFileProvider {
    }
 }

+/// Holds supported file types and thumbnail/properties generator for specefied type of file
 public struct LocalFileInformationGenerator {
+    /// Image extensions supportes for thumbnail.
+    ///
+    /// Default: `["jpg", "jpeg", "gif", "bmp", "png", "tif", "tiff", "ico"]`
    static public var imageThumbnailExtensions: [String]  = ["jpg", "jpeg", "gif", "bmp", "png", "tif", "tiff", "ico"]
-    static public var audioThumbnailExtensions: [String]  = ["mp3", "aac", "m4a"]
-    static public var videoThumbnailExtensions: [String]  = ["mov", "mp4", "m4v", "mpg", "mpeg"]
-    static public var pdfThumbnailExtensions: [String]    = ["pdf"]
-    static public var officeThumbnailExtensions: [String] = []
-    static public var customThumbnailExtensions: [String] = []
    
+    /// Audio and music extensions supportes for thumbnail.
+    ///
+    /// Default: `["mp3", "aac", "m4a"]`
+    static public var audioThumbnailExtensions: [String]  = ["mp3", "aac", "m4a"]
+    
+    /// Video extensions supportes for thumbnail.
+    ///
+    /// Default: `["mov", "mp4", "m4v", "mpg", "mpeg"]`
+    static public var videoThumbnailExtensions: [String]  = ["mov", "mp4", "m4v", "mpg", "mpeg"]
+    
+    /// Portable document file extensions supportes for thumbnail.
+    ///
+    /// Default: `["pdf"]`
+    static public var pdfThumbnailExtensions: [String]    = ["pdf"]
+    
+    /// Office document extensions supportes for thumbnail.
+    ///
+    /// Default: `empty`
+    static public var officeThumbnailExtensions: [String] = []
+    
+    /// Custom document extensions supportes for thumbnail.
+    ///
+    /// Default: `empty`
+    static public var customThumbnailExtensions: [String] = []
+
+    
+    /// Image extensions supportes for properties.
+    ///
+    /// Default: `["jpg", "jpeg", "gif", "bmp", "png", "tif", "tiff"]`
    static public var imagePropertiesExtensions: [String]   = ["jpg", "jpeg", "bmp", "gif", "png", "tif", "tiff"]
+    
+    /// Audio and music extensions supportes for properties.
+    ///
+    /// Default: `["mp3", "aac", "m4a", "caf"]`
    static public var audioPropertiesExtensions: [String]   = ["mp3", "aac", "m4a", "caf"]
+    
+    /// Video extensions supportes for properties.
+    ///
+    /// Default: `["mp4", "mpg", "3gp", "mov", "avi"]`
    static public var videoPropertiesExtensions: [String]   = ["mp4", "mpg", "3gp", "mov", "avi"]
+    
+    /// Portable document file extensions supportes for properties.
+    ///
+    /// Default: `["pdf"]`
    static public var pdfPropertiesExtensions: [String]     = ["pdf"]
+    
+    /// Archive extensions (like zip) supportes for properties.
+    ///
+    /// Default: `empty`
    static public var archivePropertiesExtensions: [String] = []
+    
+    /// Office document extensions supportes for properties.
+    ///
+    /// Default: `empty`
    static public var officePropertiesExtensions: [String]  = []
+    
+    /// Custom document extensions supportes for properties.
+    ///
+    /// Default: `empty`
    static public var customPropertiesExtensions: [String]  = []
    
+    /// Thumbnail generator closure for image files.
    static public var imageThumbnail: (_ fileURL: URL) -> ImageClass? = { fileURL in
        return ImageClass(contentsOfFile: fileURL.path)
    }
    
+    /// Thumbnail generator closure for audio and music files.
    static public var audioThumbnail: (_ fileURL: URL) -> ImageClass? = { fileURL in
        let playerItem = AVPlayerItem(url: fileURL)
        let metadataList = playerItem.asset.commonMetadata
+        #if swift(>=4.0)
+        let commonKeyArtwork = AVMetadataKey.commonKeyArtwork
+        #else
+        let commonKeyArtwork = AVMetadataCommonKeyArtwork
+        #endif
        for item in metadataList {
-            if item.commonKey == AVMetadataCommonKeyArtwork {
+            if item.commonKey == commonKeyArtwork {
                if let data = item.dataValue {
                    return ImageClass(data: data)
                }
@@ -159,6 +212,7 @@ public struct LocalFileInformationGenerator {
        return nil
    }
    
+    /// Thumbnail generator closure for video files.
    static public var videoThumbnail: (_ fileURL: URL) -> ImageClass? = { fileURL in
        let asset = AVAsset(url: fileURL)
        let assetImgGenerate = AVAssetImageGenerator(asset: asset)
@@ -174,25 +228,30 @@ public struct LocalFileInformationGenerator {
        return nil
    }
    
+    /// Thumbnail generator closure for portable document files files.
    static public var pdfThumbnail: (_ fileURL: URL) -> ImageClass? = { fileURL in
-        guard let data = try? Data(contentsOf: fileURL) else { return nil }
-        return LocalFileProvider.convertToImage(pdfData: data)
+        return LocalFileProvider.convertToImage(pdfURL: fileURL)
    }
    
+    /// Thumbnail generator closure for office document files.
+    /// - Note: No default implementation is avaiable
    static public var officeThumbnail: (_ fileURL: URL) -> ImageClass? = { fileURL in
        return nil
    }
    
+    /// Thumbnail generator closure for custom type of files.
+    /// - Note: No default implementation is avaiable
    static public var customThumbnail: (_ fileURL: URL) -> ImageClass? = { fileURL in
        return nil
    }
    
+    /// Properties generator closure for image files.
    static public var imageProperties: ((_ fileURL: URL) -> (prop: [String: Any], keys: [String]))? = { fileURL in
        var dic = [String: Any]()
        var keys = [String]()
        
        func add(key: String, value: Any?) {
-            if let value = value {
+            if let value = value, !((value as? String)?.isEmpty ?? false) {
                keys.append(key)
                dic[key] = value
            }
@@ -227,31 +286,29 @@ public struct LocalFileInformationGenerator {
        add(key: "Device model", value: tiffDict[kCGImagePropertyTIFFModel as String])
        add(key: "Lens model", value: exifDict[kCGImagePropertyExifLensModel as String])
        add(key: "Artist", value: tiffDict[kCGImagePropertyTIFFArtist as String] as? String)
-        if let cr = tiffDict[kCGImagePropertyTIFFCopyright as String] as? String , !cr.isEmpty {
-            add(key: "Copyright", value: cr)
-
-        }
-        if let date = tiffDict[kCGImagePropertyTIFFDateTime as String] as? String , !date.isEmpty {
-            add(key: "Date taken", value: date)
-        }
+        add(key: "Copyright", value: tiffDict[kCGImagePropertyTIFFCopyright as String] as? String)
+        add(key: "Date taken", value: tiffDict[kCGImagePropertyTIFFDateTime as String] as? String)
+        
        if let latitude = tiffDict[kCGImagePropertyGPSLatitude as String] as? NSNumber, let longitude = tiffDict[kCGImagePropertyGPSLongitude as String] as? NSNumber {
            add(key: "Location", value: "\(latitude), \(longitude)")
        }
+        add(key: "Altitude", value: tiffDict[kCGImagePropertyGPSAltitude as String] as? NSNumber)
+        add(key: "Area", value: tiffDict[kCGImagePropertyGPSAreaInformation as String])
+        
        add(key: "Color space", value: imageDict[kCGImagePropertyColorModel as String])
        add(key: "Focal length", value: exifDict[kCGImagePropertyExifFocalLength as String])
        add(key: "F number", value: exifDict[kCGImagePropertyExifFNumber as String])
        add(key: "Exposure program", value: exifDict[kCGImagePropertyExifExposureProgram as String])
        
        if let exp = exifDict[kCGImagePropertyExifExposureTime as String] as? NSNumber {
-            let expfrac = simplify(Int64(exp.doubleValue * 10_000_000_000_000), 10_000_000_000_000)
+            let expfrac = simplify(Int64(exp.doubleValue * 1_163_962_800_000), 1_163_962_800_000)
            add(key: "Exposure time", value: "\(expfrac.newTop)/\(expfrac.newBottom)")
        }
-        if let iso = exifDict[kCGImagePropertyExifISOSpeedRatings as String] as? NSArray , iso.count > 0 {
-            add(key: "ISO speed", value: iso[0])
-        }
+        add(key: "ISO speed", value: (exifDict[kCGImagePropertyExifISOSpeedRatings as String] as? [NSNumber])?.first)
        return (dic, keys)
    }
    
+    /// Properties generator closure for audio and music files.
    static var audioProperties: ((_ fileURL: URL) -> (prop: [String: Any], keys: [String]))? = { fileURL in
        var dic = [String: Any]()
        var keys = [String]()
@@ -267,32 +324,39 @@ public struct LocalFileInformationGenerator {
            guard let key = key else {
                return nil
            }
-            guard let regex = try? NSRegularExpression(pattern: "([a-z])([A-Z])" , options: NSRegularExpression.Options()) else {
+            guard let regex = try? NSRegularExpression(pattern: "([a-z])([A-Z])" , options: []) else {
                return nil
            }
-            let newKey = regex.stringByReplacingMatches(in: key, options: NSRegularExpression.MatchingOptions(), range: NSMakeRange(0, (key as NSString).length) , withTemplate: "$1 $2")
+            let newKey = regex.stringByReplacingMatches(in: key, options: [], range: NSRange(location: 0, length: (key as NSString).length) , withTemplate: "$1 $2")
            return newKey.capitalized
        }
        
-        if FileManager.default.fileExists(atPath: fileURL.path) {
-            let playerItem = AVPlayerItem(url: fileURL)
-            let metadataList = playerItem.asset.commonMetadata
-            for item in metadataList {
-                if let description = makeDescription(item.commonKey) {
-                    if let value = item.stringValue {
-                        keys.append(description)
-                        dic[description] = value
-                    }
+        guard FileManager.default.fileExists(atPath: fileURL.path) else {
+            return (dic, keys)
+        }
+        let playerItem = AVPlayerItem(url: fileURL)
+        let metadataList = playerItem.asset.commonMetadata
+        for item in metadataList {
+            #if swift(>=4.0)
+                let commonKey = item.commonKey?.rawValue
+            #else
+                let commonKey = item.commonKey
+            #endif
+            if let description = makeDescription(commonKey) {
+                if let value = item.stringValue {
+                    keys.append(description)
+                    dic[description] = value
                }
            }
-            if let ap = try? AVAudioPlayer(contentsOf: fileURL) {
-                add(key: "Duration", value: LocalFileProvider.formatshort(interval: ap.duration))
-                add(key: "Bitrate", value: ap.settings[AVSampleRateKey] as? Int)
-            }
+        }
+        if let ap = try? AVAudioPlayer(contentsOf: fileURL) {
+            add(key: "Duration", value: ap.duration.formatshort)
+            add(key: "Bitrate", value: ap.settings[AVSampleRateKey] as? Int)
        }
        return (dic, keys)
    }
    
+    /// Properties generator closure for video files.
    static public var videoProperties: ((_ fileURL: URL) -> (prop: [String: Any], keys: [String]))? = { fileURL in
        var dic = [String: Any]()
        var keys = [String]()
@@ -313,21 +377,29 @@ public struct LocalFileInformationGenerator {
            }
        }
        let asset = AVURLAsset(url: fileURL, options: nil)
+        #if swift(>=4.0)
+        let videoTracks = asset.tracks(withMediaType: AVMediaType.video)
+        #else
        let videoTracks = asset.tracks(withMediaType: AVMediaTypeVideo)
-        if videoTracks.count > 0 {
+        #endif
+        if let videoTrack = videoTracks.first {
            var bitrate: Float = 0
-            let width = Int(videoTracks[0].naturalSize.width)
-            let height = Int(videoTracks[0].naturalSize.height)
+            let width = Int(videoTrack.naturalSize.width)
+            let height = Int(videoTrack.naturalSize.height)
            add(key: "Dimensions", value: "\(width)x\(height)")
            var duration: Int64 = 0
            for track in videoTracks {
                duration += track.timeRange.duration.timescale > 0 ? track.timeRange.duration.value / Int64(track.timeRange.duration.timescale) : 0
                bitrate += track.estimatedDataRate
            }
-            add(key: "Duration", value: LocalFileProvider.formatshort(interval: TimeInterval(duration)))
+            add(key: "Duration", value: TimeInterval(duration).formatshort)
            add(key: "Video Bitrate", value: "\(Int(ceil(bitrate / 1000))) kbps")
        }
+        #if swift(>=4.0)
+        let audioTracks = asset.tracks(withMediaType: AVMediaType.audio)
+        #else
        let audioTracks = asset.tracks(withMediaType: AVMediaTypeAudio)
+        #endif
        // dic["Audio channels"] = audioTracks.count
        var bitrate: Float = 0
        for track in audioTracks {
@@ -337,32 +409,53 @@ public struct LocalFileInformationGenerator {
        return (dic, keys)
    }
    
+    /// Properties generator closure for protable documents files.
    static public var pdfProperties: ((_ fileURL: URL) -> (prop: [String: Any], keys: [String]))? = { fileURL in
        var dic = [String: Any]()
        var keys = [String]()
        
        func add(key: String, value: Any?) {
-            if let value = value {
+            if let value = value, !((value as? String)?.isEmpty ?? false) {
                keys.append(key)
                dic[key] = value
            }
        }
        
        func getKey(_ key: String, from dict: CGPDFDictionaryRef) -> String? {
-            var cfValue: CGPDFStringRef? = nil
-            if (CGPDFDictionaryGetString(dict, key, &cfValue)), let value = CGPDFStringCopyTextString(cfValue!) {
+            var cfStrValue: CGPDFStringRef?
+            if (CGPDFDictionaryGetString(dict, key, &cfStrValue)), let value = cfStrValue.flatMap({ CGPDFStringCopyTextString($0) }) {
                return value as String
            }
+            var cfArrayValue: CGPDFArrayRef?
+            if (CGPDFDictionaryGetArray(dict, key, &cfArrayValue)), let cfArray = cfArrayValue {
+                var array = [String]()
+                for i in 0..<CGPDFArrayGetCount(cfArray) {
+                    var cfItemValue: CGPDFStringRef?
+                    if CGPDFArrayGetString(cfArray, i, &cfItemValue), let item = cfItemValue.flatMap({ CGPDFStringCopyTextString($0) }) {
+                        array.append(item as String)
+                    }
+                }
+                return array.joined(separator: ", ")
+            }
            return nil
        }
        
-        func convertDate(_ date: String) -> Date? {
-            var dateStr = date
+        func convertDate(_ date: String?) -> Date? {
+            guard let date = date else { return nil }
+            var dateStr = date.replacingOccurrences(of: "'", with: "")
            if dateStr.hasPrefix("D:") {
-                dateStr = date.substring(from: date.characters.index(date.startIndex, offsetBy: 2))
+                dateStr.characters.removeFirst(2)
            }
            let dateFormatter = DateFormatter()
-            dateFormatter.dateFormat = "yyyyMMddHHmmssTZD"
+            dateFormatter.dateFormat = "yyyyMMddHHmmssTZ"
+            if let result = dateFormatter.date(from: dateStr) {
+                return result
+            }
+            dateFormatter.dateFormat = "yyyyMMddHHmmssZZZZZ"
+            if let result = dateFormatter.date(from: dateStr) {
+                return result
+            }
+            dateFormatter.dateFormat = "yyyyMMddHHmmssZ"
            if let result = dateFormatter.date(from: dateStr) {
                return result
            }
@@ -373,48 +466,45 @@ public struct LocalFileInformationGenerator {
            return nil
        }
        
-        if let data = try? Data(contentsOf: fileURL), let provider = CGDataProvider(data: data as CFData), let reference = CGPDFDocument(provider), let dict = reference.info {
-            if let title = getKey("Title", from: dict), !title.isEmpty {
-                add(key: "Title", value: title)
-            }
-            if let author = getKey("Author", from: dict), !author.isEmpty {
-                add(key: "Author", value: author)
-            }
-            if let subject = getKey("Subject", from: dict), !subject.isEmpty {
-                add(key: "Subject", value: subject)
-            }
-            var majorVersion: Int32 = 0
-            var minorVersion: Int32 = 0
-            reference.getVersion(majorVersion: &majorVersion, minorVersion: &minorVersion)
-            if majorVersion > 0 {
-                add(key: "Version", value:  String(majorVersion) + "." + String(minorVersion))
-            }
-            add(key: "Pages", value: reference.numberOfPages)
-            
-            if reference.numberOfPages > 0, let pageRef = reference.page(at: 1) {
-                let size = pageRef.getBoxRect(CGPDFBox.mediaBox).size
-                add(key: "Resolution", value: "\(Int(size.width))x\(Int(size.height))")
-            }
-            if let creator = getKey("Creator", from: dict), !creator.isEmpty {
-                add(key: "Content creator", value: creator)
-            }
-            if let creationDateString = getKey("CreationDate", from: dict) {
-                add(key: "Creation date", value: convertDate(creationDateString))
-            }
-            if let modifiedDateString = getKey("ModDate", from: dict) {
-                add(key: "Modified date", value: convertDate(modifiedDateString))
-            }
-            add(key: "Security", value: reference.isEncrypted ? "Present" : "None")
-            add(key: "Allows printing", value: reference.allowsPrinting ? "Yes" : "No")
-            add(key: "Allows copying", value: reference.allowsCopying ? "Yes" : "No")
+        guard let provider = CGDataProvider(url: fileURL as CFURL), let reference = CGPDFDocument(provider), let dict = reference.info else {
+            return (dic, keys)
        }
+        add(key: "Title", value: getKey("Title", from: dict))
+        add(key: "Author", value: getKey("Author", from: dict))
+        add(key: "Subject", value: getKey("Subject", from: dict))
+        add(key: "Producer", value: getKey("Producer", from: dict))
+        add(key: "Keywords", value: getKey("Keywords", from: dict))
+        var majorVersion: Int32 = 0
+        var minorVersion: Int32 = 0
+        reference.getVersion(majorVersion: &majorVersion, minorVersion: &minorVersion)
+        if majorVersion > 0 {
+            add(key: "Version", value:  String(majorVersion) + "." + String(minorVersion))
+        }
+        add(key: "Pages", value: reference.numberOfPages)
+        
+        if reference.numberOfPages > 0, let pageRef = reference.page(at: 1) {
+            let size = pageRef.getBoxRect(CGPDFBox.mediaBox).size
+            add(key: "Resolution", value: "\(Int(size.width))x\(Int(size.height))")
+        }
+        add(key: "Content creator", value: getKey("Creator", from: dict))
+        add(key: "Creation date", value: convertDate(getKey("CreationDate", from: dict)))
+        add(key: "Modified date", value: convertDate(getKey("ModDate", from: dict)))
+        add(key: "Security", value: reference.isEncrypted)
+        add(key: "Allows printing", value: reference.allowsPrinting)
+        add(key: "Allows copying", value: reference.allowsCopying)
        return (dic, keys)
    }
    
+    /// Properties generator closure for video files.
+    /// - Note: No default implementation is avaiable
    static public var archiveProperties: ((_ fileURL: URL) -> (prop: [String: Any], keys: [String]))? = nil
    
+    /// Properties generator closure for office doument files.
+    /// - Note: No default implementation is avaiable
    static public var officeProperties: ((_ fileURL: URL) -> (prop: [String: Any], keys: [String]))? = nil
    
+    /// Properties generator closure for custom type of files.
+    /// - Note: No default implementation is avaiable
    static public var customProperties: ((_ fileURL: URL) -> (prop: [String: Any], keys: [String]))? = nil
 }

@@ -0,0 +1,478 @@
+//
+//  FileProviderExtensions.swift
+//  FileProvider
+//
+//  Created by Amir Abbas on 12/27/1395 AP.
+//
+//
+
+import Foundation
+
+public extension Array where Element: FileObject {
+    /// Returns a sorted array of `FileObject`s by criterias set in attributes.
+    public func sort(by type: FileObjectSorting.SortType, ascending: Bool = true, isDirectoriesFirst: Bool = false) -> [Element] {
+        let sorting = FileObjectSorting(type: type, ascending: ascending, isDirectoriesFirst: isDirectoriesFirst)
+        return sorting.sort(self) as! [Element]
+    }
+    
+    /// Sorts array of `FileObject`s by criterias set in attributes.
+    public mutating func sorted(by type: FileObjectSorting.SortType, ascending: Bool = true, isDirectoriesFirst: Bool = false) {
+        self = self.sort(by: type, ascending: ascending, isDirectoriesFirst: isDirectoriesFirst)
+    }
+}
+
+public extension Sequence where Iterator.Element == UInt8 {
+    func hexString() -> String {
+        return self.map{String(format: "%02X", $0)}.joined()
+    }
+}
+
+public extension URLFileResourceType {
+    /// **FileProvider** returns corresponding `URLFileResourceType` of a `FileAttributeType` value
+    public init(fileTypeValue: FileAttributeType) {
+        switch fileTypeValue {
+        case FileAttributeType.typeCharacterSpecial: self = .characterSpecial
+        case FileAttributeType.typeDirectory: self = .directory
+        case FileAttributeType.typeBlockSpecial: self = .blockSpecial
+        case FileAttributeType.typeRegular: self = .regular
+        case FileAttributeType.typeSymbolicLink: self = .symbolicLink
+        case FileAttributeType.typeSocket: self = .socket
+        case FileAttributeType.typeUnknown: self = .unknown
+        default: self = .unknown
+        }
+    }
+}
+
+public extension URLResourceKey {
+    /// **FileProvider** returns url of file object.
+    public static let fileURLKey = URLResourceKey(rawValue: "NSURLFileURLKey")
+    /// **FileProvider** returns modification date of file in server
+    public static let serverDateKey = URLResourceKey(rawValue: "NSURLServerDateKey")
+    /// **FileProvider** returns HTTP ETag string of remote resource
+    public static let entryTagKey = URLResourceKey(rawValue: "NSURLEntryTagKey")
+    /// **FileProvider** returns MIME type of file, if returned by server
+    public static let mimeTypeKey = URLResourceKey(rawValue: "NSURLMIMETypeIdentifierKey")
+    /// **FileProvider** returns either file is encrypted or not
+    public static let isEncryptedKey = URLResourceKey(rawValue: "NSURLIsEncryptedKey")
+}
+
+public extension ProgressUserInfoKey {
+    /// **FileProvider** returns associated `FileProviderOperationType`
+    public static let fileProvderOperationTypeKey = ProgressUserInfoKey("FilesProviderOperationTypeKey")
+    /// **FileProvider** returns start date/time of operation
+    public static let startingTimeKey = ProgressUserInfoKey("NSProgressStartingTimeKey")
+}
+
+internal extension URL {
+    var uw_scheme: String {
+        return self.scheme ?? ""
+    }
+    
+    var fileIsDirectory: Bool {
+        return (try? self.resourceValues(forKeys: [.isDirectoryKey]))?.isDirectory ?? false
+    }
+    
+    var fileSize: Int64 {
+        return Int64((try? self.resourceValues(forKeys: [.fileSizeKey]))?.fileSize ?? -1)
+    }
+    
+    var fileExists: Bool {
+        return self.isFileURL && FileManager.default.fileExists(atPath: self.path)
+    }
+}
+
+public extension URLRequest {
+    /// Defines HTTP Authentication method required to access
+    public enum AuthenticationType {
+        /// Basic method for authentication
+        case basic
+        /// Digest method for authentication
+        case digest
+        /// OAuth 1.0 method for authentication (OAuth)
+        case oAuth1
+        /// OAuth 2.0 method for authentication (Bearer)
+        case oAuth2
+    }
+}
+
+struct Quality<T> {
+    let value: T
+    let quality: Float
+    
+    var stringifed: String {
+        var representaion = String(describing: value)
+        let quality = min(1, max(self.quality, 0))
+        if let value = value as? Locale {
+            representaion = "\(value.identifier.replacingOccurrences(of: "_", with: "-"))"
+        }
+        if let value = value as? String.Encoding {
+            let cfEncoding = CFStringConvertNSStringEncodingToEncoding(value.rawValue)
+            representaion = CFStringConvertEncodingToIANACharSetName(cfEncoding) as String? ?? "*"
+        }
+        let qualityDesc = String(format: "%.1f", quality)
+        return "\(representaion); q=\(qualityDesc)"
+    }
+}
+
+internal extension URLRequest {
+    mutating func set(httpAuthentication credential: URLCredential?, with type: AuthenticationType) {
+        func base64(_ str: String) -> String {
+            let plainData = str.data(using: .utf8)
+            let base64String = plainData!.base64EncodedString(options: [])
+            return base64String
+        }
+        
+        guard let credential = credential else { return }
+        switch type {
+        case .basic:
+            let user = credential.user?.replacingOccurrences(of: ":", with: "") ?? ""
+            let pass = credential.password ?? ""
+            let authStr = "\(user):\(pass)"
+            if let base64Auth = authStr.data(using: .utf8)?.base64EncodedString() {
+                self.setValue("Basic \(base64Auth)", forHTTPHeaderField: "Authorization")
+            }
+        case .digest:
+            // handled by RemoteSessionDelegate
+            break
+        case .oAuth1:
+            if let oauth = credential.password {
+                self.setValue("OAuth \(oauth)", forHTTPHeaderField: "Authorization")
+            }
+        case .oAuth2:
+            if let bearer = credential.password {
+                self.setValue("Bearer \(bearer)", forHTTPHeaderField: "Authorization")
+            }
+        }
+    }
+    
+    mutating func set(httpAcceptCharset acceptCharset: String.Encoding) {
+        let cfEncoding = CFStringConvertNSStringEncodingToEncoding(acceptCharset.rawValue)
+        if let charsetString = CFStringConvertEncodingToIANACharSetName(cfEncoding) as String? {
+            self.addValue(charsetString, forHTTPHeaderField: "Accept-Charset")
+        }
+    }
+    
+    mutating func set(httpAcceptCharset acceptCharset: Quality<String.Encoding>) {
+        self.addValue(acceptCharset.stringifed, forHTTPHeaderField: "Accept-Charset")
+    }
+    
+    mutating func set(httpAcceptCharsets acceptCharsets: [String.Encoding]) {
+        self.setValue(nil, forHTTPHeaderField: "Accept-Charset")
+        for charset in acceptCharsets {
+            let cfEncoding = CFStringConvertNSStringEncodingToEncoding(charset.rawValue)
+            if let charsetString = CFStringConvertEncodingToIANACharSetName(cfEncoding) as String? {
+                self.addValue(charsetString, forHTTPHeaderField: "Accept-Charset")
+            }
+        }
+    }
+    
+    mutating func set(httpAcceptCharsets acceptCharsets: [Quality<String.Encoding>]) {
+        self.setValue(nil, forHTTPHeaderField: "Accept-Charset")
+        for charset in acceptCharsets.sorted(by: { $0.quality > $1.quality }) {
+            self.addValue(charset.stringifed, forHTTPHeaderField: "Accept-Charset")
+        }
+    }
+    
+    enum Encoding: String {
+        case all = "*"
+        case identity
+        case gzip
+        case deflate
+    }
+    
+    mutating func set(httpAcceptEncoding acceptEncoding: Encoding) {
+        self.addValue(acceptEncoding.rawValue, forHTTPHeaderField: "Accept-Encoding")
+    }
+    
+    mutating func set(httpAcceptEncoding acceptEncoding: Quality<Encoding>) {
+        self.addValue(acceptEncoding.stringifed, forHTTPHeaderField: "Accept-Encoding")
+    }
+    
+    mutating func set(httpAcceptEncodings acceptEncodings: [Encoding]) {
+        self.setValue(nil, forHTTPHeaderField: "Accept-Encoding")
+        for encoding in acceptEncodings {
+            self.addValue(encoding.rawValue, forHTTPHeaderField: "Accept-Encoding")
+        }
+    }
+    
+    mutating func set(httpAcceptEncodings acceptEncodings: [Quality<Encoding>]) {
+        self.setValue(nil, forHTTPHeaderField: "Accept-Encoding")
+        for encoding in acceptEncodings.sorted(by: { $0.quality > $1.quality }) {
+            self.addValue(encoding.stringifed, forHTTPHeaderField: "Accept-Encoding")
+        }
+    }
+    
+    mutating func set(httpAcceptLanguage acceptLanguage: Locale) {
+        let langCode = acceptLanguage.identifier.replacingOccurrences(of: "_", with: "-")
+        self.addValue(langCode, forHTTPHeaderField: "Accept-Language")
+    }
+    
+    mutating func set(httpAcceptLanguage acceptLanguage: Quality<Locale>) {
+        self.addValue(acceptLanguage.stringifed, forHTTPHeaderField: "Accept-Language")
+    }
+    
+    mutating func set(httpAcceptLanguages acceptLanguages: [Locale]) {
+        self.setValue(nil, forHTTPHeaderField: "Accept-Language")
+        for lang in acceptLanguages {
+            let langCode = lang.identifier.replacingOccurrences(of: "_", with: "-")
+            self.addValue(langCode, forHTTPHeaderField: "Accept-Language")
+        }
+    }
+    
+    mutating func set(httpAcceptLanguages acceptLanguages: [Quality<Locale>]) {
+        self.setValue(nil, forHTTPHeaderField: "Accept-Language")
+        for lang in acceptLanguages.sorted(by: { $0.quality > $1.quality} ) {
+            self.addValue(lang.stringifed, forHTTPHeaderField: "Accept-Language")
+        }
+    }
+    
+    mutating func set(httpRangeWithOffset offset: Int64, length: Int) {
+        if length > 0 {
+            self.setValue("bytes=\(offset)-\(offset + Int64(length) - 1)", forHTTPHeaderField: "Range")
+        } else if offset > 0 && length < 0 {
+            self.setValue("bytes=\(offset)-", forHTTPHeaderField: "Range")
+        }
+    }
+    
+    mutating func set(httpRange range: Range<Int>) {
+        let range = max(0, range.lowerBound)..<range.upperBound
+        if range.upperBound < Int.max && range.count > 0 {
+            self.setValue("bytes=\(range.lowerBound)-\(range.upperBound - 1)", forHTTPHeaderField: "Range")
+        } else if range.lowerBound > 0 {
+            self.setValue("bytes=\(range.lowerBound)-", forHTTPHeaderField: "Range")
+        }
+    }
+    
+    struct ContentMIMEType: RawRepresentable {
+        public var rawValue: String
+        public typealias RawValue = String
+        
+        public init(rawValue: String) {
+            self.rawValue = rawValue
+        }
+        
+        static let javascript = ContentMIMEType(rawValue: "application/javascript")
+        static let json = ContentMIMEType(rawValue: "application/json")
+        static let pdf = ContentMIMEType(rawValue: "application/pdf")
+        static let stream = ContentMIMEType(rawValue: "application/octet-stream")
+        static let zip = ContentMIMEType(rawValue: "application/zip")
+        
+        // Texts
+        static let css = ContentMIMEType(rawValue: "text/css")
+        static let html = ContentMIMEType(rawValue: "text/html")
+        static let plainText = ContentMIMEType(rawValue: "text/plain")
+        static let xml = ContentMIMEType(rawValue: "text/xml")
+        
+        // Images
+        static let gif = ContentMIMEType(rawValue: "image/gif")
+        static let jpeg = ContentMIMEType(rawValue: "image/jpeg")
+        static let png = ContentMIMEType(rawValue: "image/png")
+    }
+    
+    mutating func set(httpContentType contentType: ContentMIMEType, charset: String.Encoding? = nil) {
+        var parameter = ""
+        if let charset = charset {
+            let cfEncoding = CFStringConvertNSStringEncodingToEncoding(charset.rawValue)
+            if let charsetString = CFStringConvertEncodingToIANACharSetName(cfEncoding) as String? {
+                parameter = ";charset=" + charsetString
+            }
+        }
+        
+        self.setValue(contentType.rawValue + parameter, forHTTPHeaderField: "Content-Type")
+    }
+    
+    mutating func set(dropboxArgKey requestDictionary: [String: AnyObject]) {
+        guard let jsonData = try? JSONSerialization.data(withJSONObject: requestDictionary, options: []) else {
+            return
+        }
+        guard var jsonString = String(data: jsonData, encoding: .utf8) else { return }
+        jsonString = jsonString.asciiEscaped().replacingOccurrences(of: "\\/", with: "/")
+        
+        self.setValue(jsonString, forHTTPHeaderField: "Dropbox-API-Arg")
+    }
+}
+
+internal extension CharacterSet {
+    static let filePathAllowed = CharacterSet.urlPathAllowed.subtracting(CharacterSet(charactersIn: ":"))
+}
+
+internal extension Data {
+    internal var isPDF: Bool {
+        return self.count > 4 && self.scanString(length: 4, using: .ascii) == "%PDF"
+    }
+    
+    init? (jsonDictionary dictionary: [String: AnyObject]) {
+        guard let data = try? JSONSerialization.data(withJSONObject: dictionary, options: []) else {
+            return nil
+        }
+        self = data
+    }
+    
+    func deserializeJSON() -> [String: AnyObject]? {
+        if let dic = try? JSONSerialization.jsonObject(with: self, options: []) as? [String: AnyObject] {
+            return dic
+        }
+        return nil
+    }
+    
+    init<T>(value: T) {
+        var value = value
+        self = Data(buffer: UnsafeBufferPointer(start: &value, count: 1))
+    }
+    
+    func scanValue<T>() -> T? {
+        guard MemoryLayout<T>.size <= self.count else { return nil }
+        return self.withUnsafeBytes { $0.pointee }
+    }
+    
+    func scanValue<T>(start: Int) -> T? {
+        let length = MemoryLayout<T>.size
+        guard self.count >= start + length else { return nil }
+        return self.subdata(in: start..<start+length).withUnsafeBytes { $0.pointee }
+    }
+    
+    func scanString(start: Int = 0, length: Int, using encoding: String.Encoding = .utf8) -> String? {
+        guard self.count >= start + length else { return nil }
+        return String(data: self.subdata(in: start..<start+length), encoding: encoding)
+    }
+    
+    static func mapMemory<T, U>(from: T) -> U? {
+        guard MemoryLayout<T>.size >= MemoryLayout<U>.size else { return nil }
+        let data = Data(value: from)
+        return data.scanValue()
+    }
+}
+
+internal extension String {
+    init? (jsonDictionary: [String: AnyObject]) {
+        guard let data = Data(jsonDictionary: jsonDictionary) else {
+            return nil
+        }
+        self.init(data: data, encoding: .utf8)
+    }
+    
+    func deserializeJSON(using encoding: String.Encoding = .utf8) -> [String: AnyObject]? {
+        guard let data = self.data(using: encoding) else {
+            return nil
+        }
+        return data.deserializeJSON()
+    }
+    
+    func asciiEscaped() -> String {
+        var res = ""
+        for char in self.unicodeScalars {
+            let substring = String(char)
+            if substring.canBeConverted(to: .ascii) {
+                res.append(substring)
+            } else {
+                res = res.appendingFormat("\\u%04x", char.value)
+            }
+        }
+        return res
+    }
+}
+
+internal extension TimeInterval {
+    internal var formatshort: String {
+        var result = "0:00"
+        if self < TimeInterval(Int32.max) {
+            result = ""
+            var time = DateComponents()
+            time.hour   = Int(self / 3600)
+            time.minute = Int((self.truncatingRemainder(dividingBy: 3600)) / 60)
+            time.second = Int(self.truncatingRemainder(dividingBy: 60))
+            let formatter = NumberFormatter()
+            formatter.paddingCharacter = "0"
+            formatter.minimumIntegerDigits = 2
+            formatter.maximumFractionDigits = 0
+            let formatterFirst = NumberFormatter()
+            formatterFirst.maximumFractionDigits = 0
+            if time.hour! > 0 {
+                result = "\(formatterFirst.string(from: NSNumber(value: time.hour!))!):\(formatter.string(from: NSNumber(value: time.minute!))!):\(formatter.string(from: NSNumber(value: time.second!))!)"
+            } else {
+                result = "\(formatterFirst.string(from: NSNumber(value: time.minute!))!):\(formatter.string(from: NSNumber(value: time.second!))!)"
+            }
+        }
+        result = result.trimmingCharacters(in: CharacterSet(charactersIn: ": "))
+        return result
+    }
+}
+
+public extension Date {
+    /// Date formats used commonly in internet messaging defined by various RFCs.
+    public enum RFCStandards: String {
+        /// Date format defined by usenet, commonly used in old implementations.
+        case rfc850 = "EEEE',' dd'-'MMM'-'yy HH':'mm':'ss z"
+        /// Date format defined by RFC 1132 for http.
+        case rfc1123 = "EEE',' dd' 'MMM' 'yyyy HH':'mm':'ss z"
+        /// Date format defined by ISO 8601, also defined in RFC 3339. Used by Dropbox.
+        case iso8601 = "yyyy'-'MM'-'dd'T'HH':'mm':'ssZ"
+        /// Date string returned by asctime() function.
+        case asctime = "EEE MMM d HH':'mm':'ss yyyy"
+        
+        /// Equivalent to and defined by RFC 1123.
+        public static let http = RFCStandards.rfc1123
+        /// Equivalent to and defined by ISO 8610.
+        public static let rfc3339 = RFCStandards.iso8601
+        /// Equivalent to and defined by RFC 850.
+        public static let usenet = RFCStandards.rfc850
+        
+        // Sorted by commonness
+        fileprivate static let allValues: [RFCStandards] = [.rfc1123, .rfc850, .iso8601, .asctime]
+    }
+    
+    /// Checks date string against various RFC standards and returns `Date`.
+    public init?(rfcString: String) {
+        let dateFor: DateFormatter = DateFormatter()
+        dateFor.locale = Locale(identifier: "en_US")
+        
+        for standard in RFCStandards.allValues {
+            dateFor.dateFormat = standard.rawValue
+            if let date = dateFor.date(from: rfcString) {
+                self = date
+                return
+            }
+        }
+        
+        return nil
+    }
+    
+    /// Formats date according to RFCs standard.
+    public func format(with standard: RFCStandards, locale: Locale? = nil, timeZone: TimeZone? = nil) -> String {
+        let fm = DateFormatter()
+        fm.dateFormat = standard.rawValue
+        fm.timeZone = timeZone ?? TimeZone(identifier: "UTC")
+        fm.locale = locale ?? Locale(identifier: "en_US_POSIX")
+        return fm.string(from: self)
+    }
+}
+
+internal extension NSPredicate {
+    func findValue(forKey key: String?, operator op: NSComparisonPredicate.Operator? = nil) -> Any? {
+        let val = findAllValues(forKey: key).lazy.filter { (op == nil || $0.operator == op!) && !$0.not }
+        return val.first?.value
+    }
+    
+    func findAllValues(forKey key: String?) -> [(value: Any, operator: NSComparisonPredicate.Operator, not: Bool)] {
+        if let cQuery = self as? NSCompoundPredicate {
+            let find = cQuery.subpredicates.flatMap { ($0 as! NSPredicate).findAllValues(forKey: key) }
+            if cQuery.compoundPredicateType == .not {
+                return find.map { return ($0.value, $0.operator, !$0.not) }
+            }
+            return find
+        } else if let cQuery = self as? NSComparisonPredicate {
+            if cQuery.leftExpression.expressionType == .keyPath, key == nil || cQuery.leftExpression.keyPath == key!, let const = cQuery.rightExpression.constantValue {
+                return [(value: const, operator: cQuery.predicateOperatorType, false)]
+            }
+            if cQuery.rightExpression.expressionType == .keyPath, key == nil || cQuery.rightExpression.keyPath == key!, let const = cQuery.leftExpression.constantValue {
+                return [(value: const, operator: cQuery.predicateOperatorType, false)]
+            }
+            return []
+        } else {
+            return []
+        }
+    }
+}
+
+extension URLError.Code: FoundationErrorEnum {}
+extension CocoaError.Code: FoundationErrorEnum {}
@@ -0,0 +1,462 @@
+// Originally based on CryptoSwift by Marcin Krzyżanowski <marcin.krzyzanowski@gmail.com>
+// Copyright (C) 2014 Marcin Krzyżanowski <marcin.krzyzanowski@gmail.com>
+// This software is provided 'as-is', without any express or implied warranty.
+//
+// In no event will the authors be held liable for any damages arising from the use of this software.
+//
+// Permission is granted to anyone to use this software for any purpose,including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions:
+//
+// - The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation is required.
+// - Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+// - This notice may not be removed or altered from any source or binary distribution.
+
+import Foundation
+
+protocol SHA2Variant {
+    static var size: Int { get }
+    static var h: [UInt64] { get }
+    static var k: [UInt64] { get }
+    
+    static func resultingArray<T>(_ hh:[T]) -> ArraySlice<T>
+    static func calculate(_ message: [UInt8]) -> [UInt8]
+}
+
+protocol SHA2Variant32: SHA2Variant { }
+protocol SHA2Variant64: SHA2Variant { }
+
+extension SHA2Variant32 {
+    static func calculate(_ message: [UInt8]) -> [UInt8] {
+        var tmpMessage = message
+        
+        let len = 64
+        
+        // Step 1. Append Padding Bits
+        tmpMessage.append(0x80) // append one bit (UInt8 with one bit) to message
+        
+        // append "0" bit until message length in bits ≡ 448 (mod 512)
+        var msgLength = tmpMessage.count
+        var counter = 0
+        
+        while msgLength % len != (len - 8) {
+            counter += 1
+            msgLength += 1
+        }
+        
+        tmpMessage += [UInt8](repeating: 0, count: counter)
+        
+        // hash values
+        var hh = [UInt32]()
+        Self.h.forEach {(h) -> () in
+            hh.append(UInt32(h))
+        }
+        
+        // append message length, in a 64-bit big-endian integer. So now the message length is a multiple of 512 bits.
+        tmpMessage += arrayOfBytes(message.count * 8, length: 64 / 8)
+        
+        // Process the message in successive 512-bit chunks:
+        let chunkSizeBytes = 512 / 8 // 64
+        for chunk in BytesSequence(chunkSize: chunkSizeBytes, data: tmpMessage) {
+            // break chunk into sixteen 32-bit words M[j], 0 ≤ j ≤ 15, big-endian
+            // Extend the sixteen 32-bit words into sixty-four 32-bit words:
+            var M:[UInt32] = [UInt32](repeating: 0, count: Self.k.count)
+            for x in 0..<M.count {
+                switch (x) {
+                case 0...15:
+                    let start = chunk.startIndex + (x * MemoryLayout.size(ofValue: M[x]))
+                    let end = start + MemoryLayout.size(ofValue: M[x])
+                    let le = toUInt32Array(chunk[start..<end])[0]
+                    M[x] = le.bigEndian
+                    break
+                default:
+                    let s0 = rotateRight(M[x-15], n: 7) ^ rotateRight(M[x-15], n: 18) ^ (M[x-15] >> 3) //FIXME: n
+                    let s1 = rotateRight(M[x-2], n: 17) ^ rotateRight(M[x-2], n: 19) ^ (M[x-2] >> 10)
+                    M[x] = M[x-16] &+ s0 &+ M[x-7] &+ s1
+                    break
+                }
+            }
+            
+            var A = hh[0]
+            var B = hh[1]
+            var C = hh[2]
+            var D = hh[3]
+            var E = hh[4]
+            var F = hh[5]
+            var G = hh[6]
+            var H = hh[7]
+            
+            // Main loop
+            for j in 0..<Self.k.count {
+                let s0 = rotateRight(A,n: 2) ^ rotateRight(A,n: 13) ^ rotateRight(A,n: 22)
+                let maj = (A & B) ^ (A & C) ^ (B & C)
+                let t2 = s0 &+ maj
+                let s1 = rotateRight(E,n: 6) ^ rotateRight(E,n: 11) ^ rotateRight(E,n: 25)
+                let ch = (E & F) ^ ((~E) & G)
+                let t1 = H &+ s1 &+ ch &+ UInt32(Self.k[j]) &+ M[j]
+                
+                H = G
+                G = F
+                F = E
+                E = D &+ t1
+                D = C
+                C = B
+                B = A
+                A = t1 &+ t2
+            }
+            
+            hh[0] = (hh[0] &+ A)
+            hh[1] = (hh[1] &+ B)
+            hh[2] = (hh[2] &+ C)
+            hh[3] = (hh[3] &+ D)
+            hh[4] = (hh[4] &+ E)
+            hh[5] = (hh[5] &+ F)
+            hh[6] = (hh[6] &+ G)
+            hh[7] = (hh[7] &+ H)
+        }
+        
+        // Produce the final hash value (big-endian) as a 160 bit number:
+        var result = [UInt8]()
+        result.reserveCapacity(hh.count / 4)
+        Self.resultingArray(hh).forEach {
+            let item = $0.bigEndian
+            result += [UInt8(item & 0xff), UInt8((item >> 8) & 0xff), UInt8((item >> 16) & 0xff), UInt8((item >> 24) & 0xff)]
+        }
+        return result
+    }
+}
+
+extension SHA2Variant64 {
+    static func calculate(_ message: [UInt8]) -> [UInt8] {
+        var tmpMessage = message
+        
+        let len = 128
+        
+        // Step 1. Append Padding Bits
+        tmpMessage.append(0x80) // append one bit (UInt8 with one bit) to message
+        
+        // append "0" bit until message length in bits ≡ 448 (mod 512)
+        var msgLength = tmpMessage.count
+        var counter = 0
+        
+        while msgLength % len != (len - 8) {
+            counter += 1
+            msgLength += 1
+        }
+        
+        tmpMessage += [UInt8](repeating: 0, count: counter)
+        
+        // hash values
+        var hh = [UInt64]()
+        Self.h.forEach {(h) -> () in
+            hh.append(h)
+        }
+        
+        
+        // append message length, in a 64-bit big-endian integer. So now the message length is a multiple of 512 bits.
+        tmpMessage += arrayOfBytes(message.count * 8, length: 64 / 8)
+        
+        // Process the message in successive 1024-bit chunks:
+        let chunkSizeBytes = 1024 / 8 // 128
+        for chunk in BytesSequence(chunkSize: chunkSizeBytes, data: tmpMessage) {
+            // break chunk into sixteen 64-bit words M[j], 0 ≤ j ≤ 15, big-endian
+            // Extend the sixteen 64-bit words into eighty 64-bit words:
+            var M = [UInt64](repeating: 0, count: Self.k.count)
+            for x in 0..<M.count {
+                switch (x) {
+                case 0...15:
+                    let start = chunk.startIndex + (x * MemoryLayout.size(ofValue: M[x]))
+                    let end = start + MemoryLayout.size(ofValue: M[x])
+                    let le = toUInt64Array(chunk[start..<end])[0]
+                    M[x] = le.bigEndian
+                    break
+                default:
+                    let s0 = rotateRight(M[x-15], n: 1) ^ rotateRight(M[x-15], n: 8) ^ (M[x-15] >> 7)
+                    let s1 = rotateRight(M[x-2], n: 19) ^ rotateRight(M[x-2], n: 61) ^ (M[x-2] >> 6)
+                    M[x] = M[x-16] &+ s0 &+ M[x-7] &+ s1
+                    break
+                }
+            }
+            
+            var A = hh[0]
+            var B = hh[1]
+            var C = hh[2]
+            var D = hh[3]
+            var E = hh[4]
+            var F = hh[5]
+            var G = hh[6]
+            var H = hh[7]
+            
+            // Main loop
+            for j in 0..<Self.k.count {
+                let s0 = rotateRight(A,n: 28) ^ rotateRight(A,n: 34) ^ rotateRight(A,n: 39) //FIXME: n:
+                let maj = (A & B) ^ (A & C) ^ (B & C)
+                let t2 = s0 &+ maj
+                let s1 = rotateRight(E,n: 14) ^ rotateRight(E,n: 18) ^ rotateRight(E,n: 41)
+                let ch = (E & F) ^ ((~E) & G)
+                let t1 = H &+ s1 &+ ch &+ Self.k[j] &+ UInt64(M[j])
+                
+                H = G
+                G = F
+                F = E
+                E = D &+ t1
+                D = C
+                C = B
+                B = A
+                A = t1 &+ t2
+            }
+            
+            hh[0] = (hh[0] &+ A)
+            hh[1] = (hh[1] &+ B)
+            hh[2] = (hh[2] &+ C)
+            hh[3] = (hh[3] &+ D)
+            hh[4] = (hh[4] &+ E)
+            hh[5] = (hh[5] &+ F)
+            hh[6] = (hh[6] &+ G)
+            hh[7] = (hh[7] &+ H)
+        }
+        
+        // Produce the final hash value (big-endian)
+        var result = [UInt8]()
+        result.reserveCapacity(hh.count / 4)
+        Self.resultingArray(hh).forEach {
+            let item = $0.bigEndian
+            var partialResult = [UInt8]()
+            partialResult.reserveCapacity(8)
+            for i in 0..<8 {
+                let shift = UInt64(8 * i)
+                partialResult.append(UInt8((item >> shift) & 0xff))
+            }
+            result += partialResult
+        }
+        return result
+    }
+}
+
+final class SHA256 : SHA2Variant32 {
+    static let size = 64
+    static let h: [UInt64] = [0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19]
+    static let k: [UInt64] = [0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
+                                     0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
+                                     0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
+                                     0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
+                                     0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
+                                     0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
+                                     0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
+                                     0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2]
+    
+    static func resultingArray<T>(_ hh: [T]) -> ArraySlice<T> {
+        return ArraySlice(hh)
+    }
+}
+
+final class SHA384 : SHA2Variant64 {
+    static let size = 128
+    static let h: [UInt64] = [0xcbbb9d5dc1059ed8, 0x629a292a367cd507, 0x9159015a3070dd17, 0x152fecd8f70e5939, 0x67332667ffc00b31, 0x8eb44a8768581511, 0xdb0c2e0d64f98fa7, 0x47b5481dbefa4fa4]
+    static let k: [UInt64] = [0x428a2f98d728ae22, 0x7137449123ef65cd, 0xb5c0fbcfec4d3b2f, 0xe9b5dba58189dbbc, 0x3956c25bf348b538,
+                                     0x59f111f1b605d019, 0x923f82a4af194f9b, 0xab1c5ed5da6d8118, 0xd807aa98a3030242, 0x12835b0145706fbe,
+                                     0x243185be4ee4b28c, 0x550c7dc3d5ffb4e2, 0x72be5d74f27b896f, 0x80deb1fe3b1696b1, 0x9bdc06a725c71235,
+                                     0xc19bf174cf692694, 0xe49b69c19ef14ad2, 0xefbe4786384f25e3, 0x0fc19dc68b8cd5b5, 0x240ca1cc77ac9c65,
+                                     0x2de92c6f592b0275, 0x4a7484aa6ea6e483, 0x5cb0a9dcbd41fbd4, 0x76f988da831153b5, 0x983e5152ee66dfab,
+                                     0xa831c66d2db43210, 0xb00327c898fb213f, 0xbf597fc7beef0ee4, 0xc6e00bf33da88fc2, 0xd5a79147930aa725,
+                                     0x06ca6351e003826f, 0x142929670a0e6e70, 0x27b70a8546d22ffc, 0x2e1b21385c26c926, 0x4d2c6dfc5ac42aed,
+                                     0x53380d139d95b3df, 0x650a73548baf63de, 0x766a0abb3c77b2a8, 0x81c2c92e47edaee6, 0x92722c851482353b,
+                                     0xa2bfe8a14cf10364, 0xa81a664bbc423001, 0xc24b8b70d0f89791, 0xc76c51a30654be30, 0xd192e819d6ef5218,
+                                     0xd69906245565a910, 0xf40e35855771202a, 0x106aa07032bbd1b8, 0x19a4c116b8d2d0c8, 0x1e376c085141ab53,
+                                     0x2748774cdf8eeb99, 0x34b0bcb5e19b48a8, 0x391c0cb3c5c95a63, 0x4ed8aa4ae3418acb, 0x5b9cca4f7763e373,
+                                     0x682e6ff3d6b2b8a3, 0x748f82ee5defb2fc, 0x78a5636f43172f60, 0x84c87814a1f0ab72, 0x8cc702081a6439ec,
+                                     0x90befffa23631e28, 0xa4506cebde82bde9, 0xbef9a3f7b2c67915, 0xc67178f2e372532b, 0xca273eceea26619c,
+                                     0xd186b8c721c0c207, 0xeada7dd6cde0eb1e, 0xf57d4f7fee6ed178, 0x06f067aa72176fba, 0x0a637dc5a2c898a6,
+                                     0x113f9804bef90dae, 0x1b710b35131c471b, 0x28db77f523047d84, 0x32caab7b40c72493, 0x3c9ebe0a15c9bebc,
+                                     0x431d67c49c100d4c, 0x4cc5d4becb3e42b6, 0x597f299cfc657e2a, 0x5fcb6fab3ad6faec, 0x6c44198c4a475817]
+    
+    public static func resultingArray<T>(_ hh: [T]) -> ArraySlice<T> {
+        return hh[0..<6]
+    }
+}
+
+final class SHA512 : SHA2Variant64 {
+    static let size = 128
+    static let h: [UInt64] = [0x6a09e667f3bcc908, 0xbb67ae8584caa73b, 0x3c6ef372fe94f82b, 0xa54ff53a5f1d36f1, 0x510e527fade682d1, 0x9b05688c2b3e6c1f, 0x1f83d9abfb41bd6b, 0x5be0cd19137e2179]
+    static let k: [UInt64] = [0x428a2f98d728ae22, 0x7137449123ef65cd, 0xb5c0fbcfec4d3b2f, 0xe9b5dba58189dbbc, 0x3956c25bf348b538,
+                                     0x59f111f1b605d019, 0x923f82a4af194f9b, 0xab1c5ed5da6d8118, 0xd807aa98a3030242, 0x12835b0145706fbe,
+                                     0x243185be4ee4b28c, 0x550c7dc3d5ffb4e2, 0x72be5d74f27b896f, 0x80deb1fe3b1696b1, 0x9bdc06a725c71235,
+                                     0xc19bf174cf692694, 0xe49b69c19ef14ad2, 0xefbe4786384f25e3, 0x0fc19dc68b8cd5b5, 0x240ca1cc77ac9c65,
+                                     0x2de92c6f592b0275, 0x4a7484aa6ea6e483, 0x5cb0a9dcbd41fbd4, 0x76f988da831153b5, 0x983e5152ee66dfab,
+                                     0xa831c66d2db43210, 0xb00327c898fb213f, 0xbf597fc7beef0ee4, 0xc6e00bf33da88fc2, 0xd5a79147930aa725,
+                                     0x06ca6351e003826f, 0x142929670a0e6e70, 0x27b70a8546d22ffc, 0x2e1b21385c26c926, 0x4d2c6dfc5ac42aed,
+                                     0x53380d139d95b3df, 0x650a73548baf63de, 0x766a0abb3c77b2a8, 0x81c2c92e47edaee6, 0x92722c851482353b,
+                                     0xa2bfe8a14cf10364, 0xa81a664bbc423001, 0xc24b8b70d0f89791, 0xc76c51a30654be30, 0xd192e819d6ef5218,
+                                     0xd69906245565a910, 0xf40e35855771202a, 0x106aa07032bbd1b8, 0x19a4c116b8d2d0c8, 0x1e376c085141ab53,
+                                     0x2748774cdf8eeb99, 0x34b0bcb5e19b48a8, 0x391c0cb3c5c95a63, 0x4ed8aa4ae3418acb, 0x5b9cca4f7763e373,
+                                     0x682e6ff3d6b2b8a3, 0x748f82ee5defb2fc, 0x78a5636f43172f60, 0x84c87814a1f0ab72, 0x8cc702081a6439ec,
+                                     0x90befffa23631e28, 0xa4506cebde82bde9, 0xbef9a3f7b2c67915, 0xc67178f2e372532b, 0xca273eceea26619c,
+                                     0xd186b8c721c0c207, 0xeada7dd6cde0eb1e, 0xf57d4f7fee6ed178, 0x06f067aa72176fba, 0x0a637dc5a2c898a6,
+                                     0x113f9804bef90dae, 0x1b710b35131c471b, 0x28db77f523047d84, 0x32caab7b40c72493, 0x3c9ebe0a15c9bebc,
+                                     0x431d67c49c100d4c, 0x4cc5d4becb3e42b6, 0x597f299cfc657e2a, 0x5fcb6fab3ad6faec, 0x6c44198c4a475817]
+    
+    static func resultingArray<T>(_ hh: [T]) -> ArraySlice<T> {
+        return ArraySlice(hh)
+    }
+}
+
+final class SHA2<Variant: SHA2Variant> {
+    static var size: Int {
+        return Variant.size
+    }
+    
+    static func calculate(_ message: [UInt8]) -> [UInt8] {
+        return Variant.calculate(message)
+    }
+}
+
+final class HMAC<Variant: SHA2Variant> {
+    public static func authenticate(message:[UInt8], withKey key: [UInt8]) -> [UInt8] {
+        var key = key
+        
+        if (key.count > Variant.size) {
+            key = Variant.calculate(key)
+        }
+        
+        if (key.count < Variant.size) { // keys shorter than blocksize are zero-padded
+            key = key + [UInt8](repeating: 0, count: Variant.size - key.count)
+        }
+        
+        var opad = [UInt8](repeating: 0x5c, count: Variant.size)
+        for (idx, _) in key.enumerated() {
+            opad[idx] = key[idx] ^ opad[idx]
+        }
+        var ipad = [UInt8](repeating: 0x36, count: Variant.size)
+        for (idx, _) in key.enumerated() {
+            ipad[idx] = key[idx] ^ ipad[idx]
+        }
+        
+        let ipadAndMessageHash = Variant.calculate(ipad + message)
+        let finalHash = Variant.calculate(opad + ipadAndMessageHash);
+        
+        return finalHash
+    }
+    
+    static func authenticate(message: String, withKey key: [UInt8]) -> [UInt8] {
+        return authenticate(message: [UInt8](message.utf8), withKey: key)
+    }
+    
+    static func authenticate(message: Data, withKey key: Data) -> Data {
+        return Data(bytes: authenticate(message: Array(message), withKey: Array(key)))
+    }
+    
+    static func authenticate(message: String, withKey key: Data) -> Data {
+        return Data(bytes: authenticate(message: [UInt8](message.utf8), withKey: Array(key)))
+    }
+}
+
+fileprivate struct BytesSequence: Sequence {
+    let chunkSize: Int
+    let data: [UInt8]
+    
+    init(chunkSize: Int, data: [UInt8]) {
+        self.chunkSize = chunkSize
+        self.data = data
+    }
+    
+    func makeIterator() -> AnyIterator<ArraySlice<UInt8>> {
+        var offset:Int = 0
+        
+        return AnyIterator {
+            let end = Swift.min(self.chunkSize, self.data.count - offset)
+            let result = self.data[offset..<offset + end]
+            offset += result.count
+            return result.count > 0 ? result : nil
+        }
+    }
+}
+
+fileprivate func rotateRight(_ x:UInt16, n:UInt16) -> UInt16 {
+    return (x >> n) | (x << (16 - n))
+}
+
+fileprivate func rotateRight(_ x:UInt32, n:UInt32) -> UInt32 {
+    return (x >> n) | (x << (32 - n))
+}
+
+fileprivate func rotateRight(_ x:UInt64, n:UInt64) -> UInt64 {
+    return ((x >> n) | (x << (64 - n)))
+}
+
+fileprivate func toUInt32Array(_ slice: ArraySlice<UInt8>) -> Array<UInt32> {
+    var result = Array<UInt32>()
+    result.reserveCapacity(16)
+    
+    for idx in stride(from: slice.startIndex, to: slice.endIndex, by: MemoryLayout<UInt32>.size) {
+        let val1:UInt32 = (UInt32(slice[idx.advanced(by: 3)]) << 24)
+        let val2:UInt32 = (UInt32(slice[idx.advanced(by: 2)]) << 16)
+        let val3:UInt32 = (UInt32(slice[idx.advanced(by: 1)]) << 8)
+        let val4:UInt32 = UInt32(slice[idx])
+        let val:UInt32 = val1 | val2 | val3 | val4
+        result.append(val)
+    }
+    return result
+}
+
+fileprivate func toUInt64Array(_ slice: ArraySlice<UInt8>) -> Array<UInt64> {
+    var result = Array<UInt64>()
+    result.reserveCapacity(32)
+    for idx in stride(from: slice.startIndex, to: slice.endIndex, by: MemoryLayout<UInt64>.size) {
+        var val:UInt64 = 0
+        val |= UInt64(slice[idx.advanced(by: 7)]) << 56
+        val |= UInt64(slice[idx.advanced(by: 6)]) << 48
+        val |= UInt64(slice[idx.advanced(by: 5)]) << 40
+        val |= UInt64(slice[idx.advanced(by: 4)]) << 32
+        val |= UInt64(slice[idx.advanced(by: 3)]) << 24
+        val |= UInt64(slice[idx.advanced(by: 2)]) << 16
+        val |= UInt64(slice[idx.advanced(by: 1)]) << 8
+        val |= UInt64(slice[idx.advanced(by: 0)]) << 0
+        result.append(val)
+    }
+    return result
+}
+
+fileprivate func arrayOfBytes<T>(_ value:T, length:Int? = nil) -> [UInt8] {
+    let totalBytes = length ?? MemoryLayout<T>.size
+    
+    let valuePointer = UnsafeMutablePointer<T>.allocate(capacity: 1)
+    
+    valuePointer.pointee = value
+    
+    let bytesPointer = UnsafeMutableRawPointer(valuePointer).assumingMemoryBound(to: UInt8.self)
+    var bytes = [UInt8](repeating: 0, count: totalBytes)
+    for j in 0..<min(MemoryLayout<T>.size,totalBytes) {
+        bytes[totalBytes - 1 - j] = (bytesPointer + j).pointee
+    }
+    
+    valuePointer.deinitialize()
+    valuePointer.deallocate(capacity: 1)
+    
+    return bytes
+}
+
+public extension String {
+    public func fp_sha256() -> [UInt8] {
+        return SHA2<SHA256>.calculate([UInt8](self.utf8))
+    }
+    
+    public func fp_sha384() -> [UInt8] {
+        return SHA2<SHA384>.calculate([UInt8](self.utf8))
+    }
+    
+    public func fp_sha512() -> [UInt8] {
+        return SHA2<SHA512>.calculate([UInt8](self.utf8))
+    }
+}
+
+public extension Data {
+    public func fp_sha256() -> [UInt8] {
+        return SHA2<SHA256>.calculate(Array(self))
+    }
+    
+    public func fp_sha384() -> [UInt8] {
+        return SHA2<SHA384>.calculate(Array(self))
+    }
+    
+    public func fp_sha512() -> [UInt8] {
+        return SHA2<SHA512>.calculate(Array(self))
+    }
+}
@@ -0,0 +1,894 @@
+//
+//  FTPFileProvider.swift
+//  FileProvider
+//
+//  Created by Amir Abbas Mousavian.
+//  Copyright © 2017 Mousavian. Distributed under MIT license.
+//
+
+import Foundation
+
+/**
+ Allows accessing to FTP files and directories. This provider doesn't cache or save files internally.
+ It's a complete reimplementation and doesn't use CFNetwork deprecated API.
+ */
+open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, FileProviderReadWrite {
+    open class var type: String { return "FTP" }
+    open let baseURL: URL?
+    open var currentPath: String
+    
+    open var dispatch_queue: DispatchQueue
+    open var operation_queue: OperationQueue {
+        willSet {
+            assert(_session == nil, "It's not effective to change dispatch_queue property after session is initialized.")
+        }
+    }
+    
+    open weak var delegate: FileProviderDelegate?
+    open var credential: URLCredential? {
+        didSet {
+            sessionDelegate?.credential = self.credential
+        }
+    }
+    open private(set) var cache: URLCache?
+    public var useCache: Bool
+    public var validatingCache: Bool
+    
+    /// Determine either FTP session is in passive or active mode.
+    public let passiveMode: Bool
+    
+    /// Force to use URLSessionDownloadTask/URLSessionDataTask when possible
+    public var useAppleImplementation = true
+    
+    fileprivate var _session: URLSession?
+    internal var sessionDelegate: SessionDelegate?
+    public var session: URLSession {
+        get {
+            if _session == nil {
+                self.sessionDelegate = SessionDelegate(fileProvider: self)
+                let config = URLSessionConfiguration.default
+                config.urlCache = cache
+                config.requestCachePolicy = .returnCacheDataElseLoad
+                _session = URLSession(configuration: config, delegate: sessionDelegate as URLSessionDelegate?, delegateQueue: self.operation_queue)
+                _session?.sessionDescription = UUID().uuidString
+                initEmptySessionHandler(_session!.sessionDescription!)
+            }
+            return _session!
+        }
+        
+        set {
+            assert(newValue.delegate is SessionDelegate, "session instances should have a SessionDelegate instance as delegate.")
+            _session = newValue
+            if session.sessionDescription?.isEmpty ?? true {
+                _session?.sessionDescription = UUID().uuidString
+            }
+            self.sessionDelegate = newValue.delegate as? SessionDelegate
+            initEmptySessionHandler(_session!.sessionDescription!)
+        }
+    }
+    
+    /**
+     Initializer for FTP provider with given username and password.
+     
+     - Note: `passive` value should be set according to server settings and firewall presence.
+     
+     - Parameter baseURL: a url with `ftp://hostaddress/` format.
+     - Parameter passive: FTP server data connection, `true` means passive connection (data connection created by client)
+         and `false` means active connection (data connection created by server). Default is `true` (passive mode).
+     - Parameter credential: a `URLCredential` object contains user and password.
+     - Parameter cache: A URLCache to cache downloaded files and contents. (unimplemented for FTP and should be nil)
+     */
+    public init? (baseURL: URL, passive: Bool = true, credential: URLCredential? = nil, cache: URLCache? = nil) {
+        guard (baseURL.scheme ?? "ftp").lowercased().hasPrefix("ftp") else { return nil }
+        guard baseURL.host != nil else { return nil }
+        var urlComponents = URLComponents(url: baseURL, resolvingAgainstBaseURL: true)!
+        let defaultPort: Int = baseURL.scheme == "ftps" ? 990 : 21
+        urlComponents.port = urlComponents.port ?? defaultPort
+        urlComponents.scheme = urlComponents.scheme ?? "ftp"
+        
+        self.baseURL =  (urlComponents.url!.path.hasSuffix("/") ? urlComponents.url! : urlComponents.url!.appendingPathComponent("")).absoluteURL
+        self.passiveMode = passive
+        self.currentPath = ""
+        self.useCache = false
+        self.validatingCache = true
+        self.cache = cache
+        self.credential = credential
+        
+        #if swift(>=3.1)
+        let queueLabel = "FileProvider.\(Swift.type(of: self).type)"
+        #else
+        let queueLabel = "FileProvider.\(type(of: self).type)"
+        #endif
+        dispatch_queue = DispatchQueue(label: queueLabel, attributes: .concurrent)
+        operation_queue = OperationQueue()
+        operation_queue.name = "\(queueLabel).Operation"
+    }
+    
+    public required convenience init?(coder aDecoder: NSCoder) {
+        guard let baseURL = aDecoder.decodeObject(forKey: "baseURL") as? URL else { return nil }
+        self.init(baseURL: baseURL, passive: aDecoder.decodeBool(forKey: "passiveMode"), credential: aDecoder.decodeObject(forKey: "credential") as? URLCredential)
+        self.currentPath     = aDecoder.decodeObject(forKey: "currentPath") as? String ?? ""
+        self.useCache        = aDecoder.decodeBool(forKey: "useCache")
+        self.validatingCache = aDecoder.decodeBool(forKey: "validatingCache")
+        self.useAppleImplementation = aDecoder.decodeBool(forKey: "useAppleImplementation")
+    }
+    
+    public func encode(with aCoder: NSCoder) {
+        aCoder.encode(self.baseURL, forKey: "baseURL")
+        aCoder.encode(self.credential, forKey: "credential")
+        aCoder.encode(self.currentPath, forKey: "currentPath")
+        aCoder.encode(self.useCache, forKey: "useCache")
+        aCoder.encode(self.validatingCache, forKey: "validatingCache")
+        aCoder.encode(self.useAppleImplementation, forKey: "useAppleImplementation")
+        aCoder.encode(self.passiveMode, forKey: "passiveMode")
+    }
+    
+    public static var supportsSecureCoding: Bool {
+        return true
+    }
+    
+    open func copy(with zone: NSZone? = nil) -> Any {
+        let copy = FTPFileProvider(baseURL: self.baseURL!, credential: self.credential, cache: self.cache)!
+        copy.currentPath = self.currentPath
+        copy.delegate = self.delegate
+        copy.fileOperationDelegate = self.fileOperationDelegate
+        copy.useCache = self.useCache
+        copy.validatingCache = self.validatingCache
+        copy.useAppleImplementation = self.useAppleImplementation
+        return copy
+    }
+    
+    deinit {
+        if let sessionuuid = _session?.sessionDescription {
+            removeSessionHandler(for: sessionuuid)
+        }
+        
+        if fileProviderCancelTasksOnInvalidating {
+            _session?.invalidateAndCancel()
+        } else {
+            _session?.finishTasksAndInvalidate()
+        }
+    }
+    
+    internal var serverSupportsRFC3659: Bool = true
+    
+    open func contentsOfDirectory(path: String, completionHandler: @escaping (([FileObject], Error?) -> Void)) {
+        self.contentsOfDirectory(path: path, rfc3659enabled: serverSupportsRFC3659, completionHandler: completionHandler)
+    }
+    
+    /**
+     Returns an Array of `FileObject`s identifying the the directory entries via asynchronous completion handler.
+     
+     If the directory contains no entries or an error is occured, this method will return the empty array.
+     
+     - Parameter path: path to target directory. If empty, root will be iterated.
+     - Parameter rfc3659enabled: uses MLST command instead of old LIST to get files attributes, default is `true`.
+     - Parameter completionHandler: a closure with result of directory entries or error.
+         `contents`: An array of `FileObject` identifying the the directory entries.
+         `error`: Error returned by system.
+     */
+    open func contentsOfDirectory(path apath: String, rfc3659enabled: Bool , completionHandler: @escaping ((_ contents: [FileObject], _ error: Error?) -> Void)) {
+        let path = ftpPath(apath)
+        
+        let task = session.fpstreamTask(withHostName: baseURL!.host!, port: baseURL!.port!)
+        self.ftpLogin(task) { (error) in
+            if let error = error {
+                self.dispatch_queue.async {
+                    completionHandler([], error)
+                }
+                return
+            }
+            
+            self.ftpList(task, of: self.ftpPath(path), useMLST: rfc3659enabled, completionHandler: { (contents, error) in
+                defer {
+                    self.ftpQuit(task)
+                }
+                if let error = error {
+                    if ((error as NSError).domain == URLError.errorDomain && (error as NSError).code == URLError.unsupportedURL.rawValue) {
+                        self.contentsOfDirectory(path: path, rfc3659enabled: false, completionHandler: completionHandler)
+                        return
+                    }
+                    
+                    self.dispatch_queue.async {
+                        completionHandler([], error)
+                    }
+                    return
+                }
+                
+                
+                let files: [FileObject] = contents.flatMap {
+                    rfc3659enabled ? self.parseMLST($0, in: path) : self.parseUnixList($0, in: path)
+                }
+                
+                self.dispatch_queue.async {
+                    completionHandler(files, nil)
+                }
+            })
+        }
+    }
+    
+    open func attributesOfItem(path: String, completionHandler: @escaping ((FileObject?, Error?) -> Void)) {
+        self.attributesOfItem(path: path, rfc3659enabled: serverSupportsRFC3659, completionHandler: completionHandler)
+    }
+    
+    /**
+     Returns a `FileObject` containing the attributes of the item (file, directory, symlink, etc.) at the path in question via asynchronous completion handler.
+     
+     If the directory contains no entries or an error is occured, this method will return the empty `FileObject`.
+     
+     - Parameter path: path to target directory. If empty, attributes of root will be returned.
+     - Parameter rfc3659enabled: uses MLST command instead of old LIST to get files attributes, default is true.
+     - Parameter completionHandler: a closure with result of directory entries or error.
+         `attributes`: A `FileObject` containing the attributes of the item.
+         `error`: Error returned by system.
+     */
+    open func attributesOfItem(path apath: String, rfc3659enabled: Bool, completionHandler: @escaping ((_ attributes: FileObject?, _ error: Error?) -> Void)) {
+        let path = ftpPath(apath)
+        
+        let task = session.fpstreamTask(withHostName: baseURL!.host!, port: baseURL!.port!)
+        self.ftpLogin(task) { (error) in
+            if let error = error {
+                self.dispatch_queue.async {
+                    completionHandler(nil, error)
+                }
+                return
+            }
+            
+            let command = rfc3659enabled ? "MLST \(path)" : "LIST \(path)"
+            self.execute(command: command, on: task, completionHandler: { (response, error) in
+                defer {
+                    self.ftpQuit(task)
+                }
+                if let error = error {
+                    self.dispatch_queue.async {
+                        completionHandler(nil, error)
+                    }
+                    return
+                }
+                
+                guard let response = response, response.hasPrefix("250") || (response.hasPrefix("50") && rfc3659enabled) else {
+                    self.dispatch_queue.async {
+                        completionHandler(nil, self.throwError(path, code: URLError.badServerResponse))
+                    }
+                    return
+                }
+                
+                if response.hasPrefix("500") {
+                    self.serverSupportsRFC3659 = false
+                    self.attributesOfItem(path: path, rfc3659enabled: false, completionHandler: completionHandler)
+                }
+                
+                let lines = response.components(separatedBy: "\n").flatMap { $0.isEmpty ? nil : $0.trimmingCharacters(in: .whitespacesAndNewlines) }
+                guard lines.count > 2 else {
+                    self.dispatch_queue.async {
+                        completionHandler(nil, self.throwError(path, code: URLError.badServerResponse))
+                    }
+                    return
+                }
+                let file = rfc3659enabled ? self.parseMLST(lines[1], in: path) : self.parseUnixList(lines[1], in: path)
+                self.dispatch_queue.async {
+                    completionHandler(file, nil)
+                }
+            })
+        }
+    }
+    
+    open func storageProperties(completionHandler: @escaping ((_ total: Int64, _ used: Int64) -> Void)) {
+        dispatch_queue.async {
+            completionHandler(-1, 0)
+        }
+    }
+    
+    open func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) -> Progress? {
+        let progress = Progress(parent: nil, userInfo: nil)
+        if recursive {
+            return self.recursiveList(path: path, useMLST: true, foundItemsHandler: { items in
+                if let foundItemHandler = foundItemHandler {
+                    for item in items where query.evaluate(with: item.mapPredicate()) {
+                        foundItemHandler(item)
+                    }
+                    progress.totalUnitCount = Int64(items.count)
+                }
+            }, completionHandler: {files, error in
+                if let error = error {
+                    completionHandler([], error)
+                    return
+                }
+                
+                let foundFiles = files.filter { query.evaluate(with: $0.mapPredicate()) }
+                completionHandler(foundFiles, nil)
+            })
+        } else {
+            self.contentsOfDirectory(path: path, completionHandler: { (items, error) in
+                if let error = error {
+                    completionHandler([], error)
+                    return
+                }
+                
+                var result = [FileObject]()
+                for item in items where query.evaluate(with: item.mapPredicate()) {
+                    foundItemHandler?(item)
+                    result.append(item)
+                }
+                completionHandler(result, nil)
+            })
+        }
+        
+        return progress
+    }
+    
+    open func url(of path: String?) -> URL {
+        let path = (path ?? self.currentPath).trimmingCharacters(in: CharacterSet(charactersIn: "/ ")).addingPercentEncoding(withAllowedCharacters: .filePathAllowed) ?? (path ?? self.currentPath)
+        
+        var baseUrlComponent = URLComponents(url: self.baseURL!, resolvingAgainstBaseURL: true)
+        baseUrlComponent?.user = credential?.user
+        baseUrlComponent?.password = credential?.password
+        return URL(string: path, relativeTo: baseUrlComponent?.url ?? baseURL) ?? baseUrlComponent?.url ?? baseURL!
+    }
+    
+    open func relativePathOf(url: URL) -> String {
+        // check if url derieved from current base url
+        let relativePath = url.relativePath
+        if !relativePath.isEmpty, url.baseURL == self.baseURL {
+            return (relativePath.removingPercentEncoding ?? relativePath).replacingOccurrences(of: "/", with: "", options: .anchored)
+        }
+        
+        if !relativePath.isEmpty, self.baseURL == self.url(of: "/") {
+            return (relativePath.removingPercentEncoding ?? relativePath).replacingOccurrences(of: "/", with: "", options: .anchored)
+        }
+        
+        return relativePath.replacingOccurrences(of: "/", with: "", options: .anchored)
+    }
+    
+    open func isReachable(completionHandler: @escaping (Bool) -> Void) {
+        self.attributesOfItem(path: "/") { (file, error) in
+            completionHandler(file != nil)
+        }
+    }
+    
+    open weak var fileOperationDelegate: FileOperationDelegate?
+    
+    open func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let path = (atPath as NSString).appendingPathComponent(folderName) + "/"
+        return doOperation(.create(path: path), completionHandler: completionHandler)
+    }
+    
+    open func moveItem(path: String, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> Progress? {
+        return doOperation(.move(source: path, destination: toPath), completionHandler: completionHandler)
+    }
+    
+    open func copyItem(path: String, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> Progress? {
+        return doOperation(.copy(source: path, destination: toPath), completionHandler: completionHandler)
+    }
+    
+    open func removeItem(path: String, completionHandler: SimpleCompletionHandler) -> Progress? {
+        return doOperation(.remove(path: path), completionHandler: completionHandler)
+    }
+    
+    open func copyItem(localFile: URL, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> Progress? {
+        // check file is not a folder
+        guard (try? localFile.resourceValues(forKeys: [.fileResourceTypeKey]))?.fileResourceType ?? .unknown == .regular else {
+            dispatch_queue.async {
+                completionHandler?(self.throwError(localFile.path, code: URLError.fileIsDirectory))
+            }
+            return nil
+        }
+        
+        let operation = FileOperationType.copy(source: localFile.absoluteString, destination: toPath)
+        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: operation) ?? true == true else {
+            return nil
+        }
+        
+        let progress = Progress(totalUnitCount: 0)
+        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+        progress.kind = .file
+        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
+        
+        let task = session.fpstreamTask(withHostName: baseURL!.host!, port: baseURL!.port!)
+        self.ftpLogin(task) { (error) in
+            if let error = error {
+                self.dispatch_queue.async {
+                    completionHandler?(error)
+                    self.delegateNotify(operation, error: error)
+                }
+                return
+            }
+            
+            self.ftpStore(task, filePath: self.ftpPath(toPath), fromData: nil, fromFile: localFile, onTask: { task in
+                weak var weakTask = task
+                progress.cancellationHandler = {
+                    weakTask?.cancel()
+                }
+                progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
+            }, onProgress: { bytesSent, totalSent, expectedBytes in
+                progress.completedUnitCount = totalSent
+                self.delegateNotify(operation, progress: progress.fractionCompleted)
+            }, completionHandler: { (error) in
+                if error != nil {
+                    progress.cancel()
+                }
+                self.ftpQuit(task)
+                self.dispatch_queue.async {
+                    completionHandler?(error)
+                    self.delegateNotify(operation, error: error)
+                }
+            })
+        }
+        
+        return progress
+    }
+    
+    open func copyItem(path: String, toLocalURL destURL: URL, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let operation = FileOperationType.copy(source: path, destination: destURL.absoluteString)
+        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: operation) ?? true == true else {
+            return nil
+        }
+        var progress = Progress(totalUnitCount: 0)
+        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+        progress.kind = .file
+        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
+        
+        if self.useAppleImplementation {
+            self.attributesOfItem(path: path, completionHandler: { (file, error) in
+                if let error = error {
+                    self.dispatch_queue.async {
+                        completionHandler?(error)
+                        self.delegateNotify(operation, error: error)
+                    }
+                    return
+                }
+                
+                if file?.isDirectory ?? false {
+                    self.dispatch_queue.async {
+                        let error = self.throwError(path, code: URLError.fileIsDirectory)
+                        completionHandler?(error)
+                        self.delegateNotify(operation, error: error)
+                    }
+                    return
+                }
+                
+                progress.totalUnitCount = file?.size ?? 0
+                
+                let task = self.session.downloadTask(with: self.url(of: path))
+                completionHandlersForTasks[self.session.sessionDescription!]?[task.taskIdentifier] = completionHandler
+                downloadCompletionHandlersForTasks[self.session.sessionDescription!]?[task.taskIdentifier] = { tempURL in
+                    do {
+                        try FileManager.default.moveItem(at: tempURL, to: destURL)
+                        completionHandler?(nil)
+                    } catch let e {
+                        completionHandler?(e)
+                    }
+                }
+                task.taskDescription = operation.json
+                task.addObserver(self.sessionDelegate!, forKeyPath: #keyPath(URLSessionTask.countOfBytesReceived), options: .new, context: &progress)
+                task.addObserver(self.sessionDelegate!, forKeyPath: #keyPath(URLSessionTask.countOfBytesExpectedToReceive), options: .new, context: &progress)
+                progress.cancellationHandler = { [weak task] in
+                    task?.cancel()
+                }
+                progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
+                task.resume()
+            })
+        } else {
+            let task = session.fpstreamTask(withHostName: baseURL!.host!, port: baseURL!.port!)
+            self.ftpLogin(task) { (error) in
+                if let error = error {
+                    self.dispatch_queue.async {
+                        completionHandler?(error)
+                    }
+                    return
+                }
+                
+                self.ftpRetrieveFile(task, filePath: self.ftpPath(path), onTask: { task in
+                    weak var weakTask = task
+                    progress.cancellationHandler = {
+                        weakTask?.cancel()
+                    }
+                    progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
+                }, onProgress: { recevied, totalReceived, totalSize in
+                    progress.totalUnitCount = totalSize
+                    progress.completedUnitCount = totalReceived
+                    self.delegateNotify(operation, progress: progress.fractionCompleted)
+                }) { (tmpurl, error) in
+                    if let error = error {
+                        progress.cancel()
+                        self.dispatch_queue.async {
+                            completionHandler?(error)
+                            self.delegateNotify(operation, error: error)
+                        }
+                        return
+                    }
+                    
+                    if let tmpurl = tmpurl {
+                        try? FileManager.default.moveItem(at: tmpurl, to: destURL)
+                        self.dispatch_queue.async {
+                            completionHandler?(nil)
+                            self.delegateNotify(operation)
+                        }
+                    }
+                }
+            }
+        }
+        return progress
+    }
+    
+    open func contents(path: String, completionHandler: @escaping ((Data?, Error?) -> Void)) -> Progress? {
+        let operation = FileOperationType.fetch(path: path)
+        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: operation) ?? true == true else {
+            return nil
+        }
+        
+        if self.useAppleImplementation {
+            var progress = Progress(totalUnitCount: 0)
+            progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+            progress.kind = .file
+            progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
+            
+            let task = session.downloadTask(with: url(of: path))
+            completionHandlersForTasks[session.sessionDescription!]?[task.taskIdentifier] = { error in
+                if error != nil {
+                    progress.cancel()
+                }
+                completionHandler(nil, error)
+            }
+            downloadCompletionHandlersForTasks[session.sessionDescription!]?[task.taskIdentifier] = { tempURL in
+                do {
+                    let data = try Data(contentsOf: tempURL)
+                    completionHandler(data, nil)
+                } catch let e {
+                    completionHandler(nil, e)
+                }
+            }
+            task.taskDescription = operation.json
+            task.addObserver(sessionDelegate!, forKeyPath: #keyPath(URLSessionTask.countOfBytesReceived), options: .new, context: &progress)
+            task.addObserver(sessionDelegate!, forKeyPath: #keyPath(URLSessionTask.countOfBytesExpectedToReceive), options: .new, context: &progress)
+            progress.cancellationHandler = { [weak task] in
+                task?.cancel()
+            }
+            progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
+            task.resume()
+            return progress
+        } else {
+            return self.contents(path: path, offset: 0, length: -1, completionHandler: completionHandler)
+        }
+    }
+    
+    open func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> Progress? {
+        let operation = FileOperationType.fetch(path: path)
+        if length == 0 || offset < 0 {
+            dispatch_queue.async {
+                completionHandler(Data(), nil)
+                self.delegateNotify(operation)
+            }
+            return nil
+        }
+        let progress = Progress(totalUnitCount: 0)
+        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+        progress.kind = .file
+        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
+        
+        let task = session.fpstreamTask(withHostName: baseURL!.host!, port: baseURL!.port!)
+        self.ftpLogin(task) { (error) in
+            if let error = error {
+                self.dispatch_queue.async {
+                    completionHandler(nil, error)
+                }
+                return
+            }
+            
+            self.ftpRetrieveData(task, filePath: self.ftpPath(path), from: offset, length: length, onTask: { task in
+                weak var weakTask = task
+                progress.cancellationHandler = {
+                    weakTask?.cancel()
+                }
+                progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
+            }, onProgress: { recevied, totalReceived, totalSize in
+                progress.totalUnitCount = totalSize
+                progress.completedUnitCount = totalReceived
+                self.delegateNotify(operation, progress: progress.fractionCompleted)
+            }) { (data, error) in
+                if let error = error {
+                    progress.cancel()
+                    self.dispatch_queue.async {
+                        completionHandler(nil, error)
+                        self.delegateNotify(operation, error: error)
+                    }
+                    return
+                }
+                
+                if let data = data {
+                    self.dispatch_queue.async {
+                        completionHandler(data, nil)
+                        self.delegateNotify(operation)
+                    }
+                }
+            }
+        }
+        
+        return progress
+    }
+    
+    open func writeContents(path: String, contents data: Data?, atomically: Bool, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let operation = FileOperationType.modify(path: path)
+        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: operation) ?? true == true else {
+            return nil
+        }
+        
+        let progress = Progress(totalUnitCount: Int64(data?.count ?? 0))
+        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+        progress.kind = .file
+        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
+        
+        let task = session.fpstreamTask(withHostName: baseURL!.host!, port: baseURL!.port!)
+        self.ftpLogin(task) { (error) in
+            if let error = error {
+                self.dispatch_queue.async {
+                    completionHandler?(error)
+                    self.delegateNotify(operation, error: error)
+                }
+                return
+            }
+            
+            let storeHandler = {
+                self.ftpStore(task, filePath: self.ftpPath(path), fromData: data ?? Data(), fromFile: nil, onTask: { task in
+                    weak var weakTask = task
+                    progress.cancellationHandler = {
+                        weakTask?.cancel()
+                    }
+                    progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
+                }, onProgress: { bytesSent, totalSent, expectedBytes in
+                    progress.completedUnitCount = totalSent
+                    self.delegateNotify(operation, progress: progress.fractionCompleted)
+                }, completionHandler: { (error) in
+                    if error != nil {
+                        progress.cancel()
+                    }
+                    self.ftpQuit(task)
+                    self.dispatch_queue.async {
+                        completionHandler?(error)
+                        self.delegateNotify(operation, error: error)
+                    }
+                })
+            }
+            
+            if overwrite {
+                storeHandler()
+            } else {
+                self.attributesOfItem(path: path, completionHandler: { (file, erroe) in
+                    if file == nil {
+                        storeHandler()
+                    }
+                })
+            }
+        }
+        
+        return progress
+    }
+    
+    /**
+     Creates a symbolic link at the specified path that points to an item at the given path.
+     This method does not traverse symbolic links contained in destination path, making it possible
+     to create symbolic links to locations that do not yet exist.
+     Also, if the final path component is a symbolic link, that link is not followed.
+     
+     - Note: Many servers does't support this functionality.
+     
+     - Parameters:
+       - symbolicLink: The file path at which to create the new symbolic link. The last component of the path issued as the name of the link.
+       - withDestinationPath: The path that contains the item to be pointed to by the link. In other words, this is the destination of the link.
+       - completionHandler: If an error parameter was provided, a presentable `Error` will be returned.
+     */
+    open func create(symbolicLink path: String, withDestinationPath destPath: String, completionHandler: SimpleCompletionHandler) {
+        let operation = FileOperationType.link(link: path, target: destPath)
+        _=self.doOperation(operation, completionHandler: completionHandler)
+    }
+}
+
+extension FTPFileProvider {
+    fileprivate func doOperation(_ operation: FileOperationType, completionHandler: SimpleCompletionHandler) -> Progress? {
+        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: operation) ?? true == true else {
+            return nil
+        }
+        let sourcePath = operation.source
+        let destPath = operation.destination
+        
+        let command: String
+        switch operation {
+        case .create:
+            command = "MKD \(ftpPath(sourcePath))"
+        case .copy:
+            command = "SITE CPFR \(ftpPath(sourcePath))\r\nSITE CPTO \(ftpPath(destPath!))"
+        case .move:
+            command = "RNFR \(ftpPath(sourcePath))\r\nRNTO \(ftpPath(destPath!))"
+        case .remove:
+            command = "DELE \(ftpPath(sourcePath))"
+        case .link:
+            command = "SITE SYMLINK \(ftpPath(sourcePath)) \(ftpPath(destPath!))"
+        default: // modify, fetch
+            return nil
+        }
+        let progress = Progress(totalUnitCount: 1)
+        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+        progress.kind = .file
+        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
+        
+        let task = session.fpstreamTask(withHostName: baseURL!.host!, port: baseURL!.port!)
+        self.ftpLogin(task) { (error) in
+            if let error = error {
+                self.dispatch_queue.async {
+                    completionHandler?(error)
+                    self.delegateNotify(operation, error: error)
+                }
+                return
+            }
+            
+            self.execute(command: command, on: task, completionHandler: { (response, error) in
+                if let error = error {
+                    self.dispatch_queue.async {
+                        completionHandler?(error)
+                        self.delegateNotify(operation, error: error)
+                    }
+                    return
+                }
+                
+                guard let response = response else {
+                    self.dispatch_queue.async {
+                        completionHandler?(error)
+                        self.delegateNotify(operation, error: self.throwError(sourcePath, code: URLError.badServerResponse))
+                    }
+                    return
+                }
+                
+                let codes: [Int] = response.components(separatedBy: .newlines).flatMap({ $0.isEmpty ? nil : $0})
+                    .flatMap {
+                        let code = $0.components(separatedBy: .whitespaces).flatMap({ $0.isEmpty ? nil : $0}).first
+                        return code != nil ? Int(code!) : nil
+                }
+                
+                if codes.filter({ (450..<560).contains($0) }).count > 0 {
+                    let errorCode: URLError.Code
+                    switch operation {
+                    case .create:
+                        errorCode = URLError.cannotCreateFile
+                    case .modify:
+                        errorCode = URLError.cannotWriteToFile
+                    case .copy:
+                        self.fallbackCopy(operation, progress: progress, completionHandler: completionHandler)
+                        return
+                    case .move:
+                        errorCode = URLError.cannotMoveFile
+                    case .remove:
+                        self.fallbackRemove(operation, progress: progress, on: task, completionHandler: completionHandler)
+                        return
+                    case .link:
+                        errorCode = URLError.cannotWriteToFile
+                    default:
+                        errorCode = URLError.cannotOpenFile
+                    }
+                    let error = self.throwError(sourcePath, code: errorCode)
+                    progress.cancel()
+                    self.dispatch_queue.async {
+                        completionHandler?(error)
+                    }
+                    self.delegateNotify(operation, error: error)
+                    return
+                }
+                
+                progress.completedUnitCount = progress.totalUnitCount
+                self.dispatch_queue.async {
+                    completionHandler?(nil)
+                }
+                self.delegateNotify(operation)
+            })
+        }
+        
+        progress.cancellationHandler = { [weak task] in
+            task?.cancel()
+        }
+        progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
+        return progress
+    }
+    
+    private func fallbackCopy(_ operation: FileOperationType, progress: Progress, completionHandler: SimpleCompletionHandler) {
+        let sourcePath = operation.source
+        guard let destPath = operation.destination else { return }
+        
+        let localURL = URL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent(UUID().uuidString).appendingPathExtension("tmp")
+        
+        progress.becomeCurrent(withPendingUnitCount: 1)
+        _ = self.copyItem(path: sourcePath, toLocalURL: localURL) { (error) in
+            if let error = error {
+                self.dispatch_queue.async {
+                    completionHandler?(error)
+                    self.delegateNotify(operation, error: error)
+                }
+                return
+            }
+            
+            progress.becomeCurrent(withPendingUnitCount: 1)
+            _ = self.copyItem(localFile: localURL, to: destPath) { error in
+                completionHandler?(nil)
+                self.delegateNotify(operation)
+            }
+            progress.resignCurrent()
+        }
+        progress.resignCurrent()
+        return
+    }
+    
+    private func fallbackRemove(_ operation: FileOperationType, progress: Progress, on task: FileProviderStreamTask, completionHandler: SimpleCompletionHandler) {
+        let sourcePath = operation.source
+        
+        self.execute(command: "SITE RMDIR \(ftpPath(sourcePath))", on: task) { (response, error) in
+            if let error = error {
+                progress.cancel()
+                self.dispatch_queue.async {
+                    completionHandler?(error)
+                }
+                self.delegateNotify(operation, error: error)
+                return
+            }
+            
+            guard let response = response else {
+                progress.cancel()
+                let error = self.throwError(sourcePath, code: URLError.badServerResponse)
+                self.dispatch_queue.async {
+                    completionHandler?(error)
+                }
+                self.delegateNotify(operation, error: error)
+                return
+            }
+            
+            if response.hasPrefix("50") {
+                self.fallbackRecursiveRemove(operation, progress: progress, on: task, completionHandler: completionHandler)
+                return
+            }
+            
+            var error: Error?
+            if !response.hasPrefix("2") {
+                error = self.throwError(sourcePath, code: URLError.cannotRemoveFile)
+            }
+            self.dispatch_queue.async {
+                completionHandler?(error)
+            }
+            self.delegateNotify(operation, error: error)
+        }
+    }
+    
+    private func fallbackRecursiveRemove(_ operation: FileOperationType, progress: Progress, on task: FileProviderStreamTask, completionHandler: SimpleCompletionHandler) {
+        let sourcePath = operation.source
+        
+        _ = self.recursiveList(path: sourcePath, useMLST: true, completionHandler: { (contents, error) in
+            if let error = error {
+                self.dispatch_queue.async {
+                    completionHandler?(error)
+                    self.delegateNotify(operation, error: error)
+                }
+                return
+            }
+            
+            progress.becomeCurrent(withPendingUnitCount: 1)
+            let recursiveProgress = Progress(parent: progress, userInfo: nil)
+            recursiveProgress.totalUnitCount = Int64(contents.count)
+            let sortedContents = contents.sorted(by: {
+                $0.path.localizedStandardCompare($1.path) == .orderedDescending
+            })
+            progress.resignCurrent()
+            var command = ""
+            for file in sortedContents {
+                command += (file.isDirectory ? "RMD \(self.ftpPath(file.path))" : "DELE \(self.ftpPath(file.path))") + "\r\n"
+            }
+            command += "RMD \(self.ftpPath(sourcePath))"
+            
+            self.execute(command: command, on: task, completionHandler: { (response, error) in
+                recursiveProgress.completedUnitCount += 1
+                self.dispatch_queue.async {
+                    completionHandler?(error)
+                    self.delegateNotify(operation, error: error)
+                }
+                // TODO: Digest response
+            })
+        })
+    }
+}
+
+extension FTPFileProvider: FileProvider { }
@@ -0,0 +1,955 @@
+//
+//  FTPHelper.swift
+//  FileProvider
+//
+//  Created by Amir Abbas Mousavian.
+//  Copyright © 2017 Mousavian. Distributed under MIT license.
+//
+
+import Foundation
+
+internal extension FTPFileProvider {
+    func readDataUntilEOF(of task: FileProviderStreamTask, minLength: Int, receivedData: Data? = nil, timeout: TimeInterval, completionHandler: @escaping (_ data: Data?, _ errror:Error?) -> Void) {
+        task.readData(ofMinLength: minLength, maxLength: 65535, timeout: timeout) { (data, eof, error) in
+            if let error = error {
+                completionHandler(nil, error)
+                return
+            }
+            
+            var receivedData = receivedData
+            if let data = data {
+                if receivedData != nil {
+                    receivedData!.append(data)
+                } else {
+                    receivedData = data
+                }
+            }
+            
+            if eof {
+                completionHandler(receivedData, nil)
+            } else {
+                self.readDataUntilEOF(of: task, minLength: 0, receivedData: receivedData, timeout: timeout, completionHandler: completionHandler)
+            }
+            
+        }
+    }
+    
+    func execute(command: String, on task: FileProviderStreamTask, minLength: Int = 4, afterSend: ((_ error: Error?) -> Void)? = nil, completionHandler: @escaping (_ response: String?, _ error: Error?) -> Void) {
+        let timeout = session.configuration.timeoutIntervalForRequest
+        let terminalcommand = command + "\r\n"
+        task.write(terminalcommand.data(using: .utf8)!, timeout: timeout) { (error) in
+            if let error = error {
+                completionHandler(nil, error)
+                return
+            }
+            afterSend?(error)
+            
+            if task.state == .suspended {
+                task.resume()
+            }
+            
+            task.readData(ofMinLength: minLength, maxLength: 1024, timeout: timeout) { (data, eof, error) in
+                if let error = error {
+                    completionHandler(nil, error)
+                    return
+                }
+                
+                if let data = data, let response = String(data: data, encoding: .utf8) {
+                    completionHandler(response.trimmingCharacters(in: .whitespacesAndNewlines), nil)
+                } else {
+                    completionHandler(nil, self.throwError("", code: URLError.cannotParseResponse))
+                    return
+                }
+            }
+        }
+    }
+    
+    func ftpLogin(_ task: FileProviderStreamTask, completionHandler: @escaping (_ error: Error?) -> Void) {
+        let timeout = session.configuration.timeoutIntervalForRequest
+        if task.state == .suspended {
+            task.resume()
+        }
+        
+        var isSecure = false
+        // Implicit FTP Connection
+        if self.baseURL?.port == 990 || self.baseURL?.scheme == "ftps" {
+            task.startSecureConnection()
+            isSecure = true
+        }
+        
+        let credential = self.credential
+        
+        task.readData(ofMinLength: 4, maxLength: 2048, timeout: timeout) { (data, eof, error) in
+            if let error = error {
+                completionHandler(error)
+                return
+            }
+            
+            guard let data = data, let response = String(data: data, encoding: .utf8) else {
+                completionHandler(self.throwError("", code: URLError.cannotParseResponse))
+                return
+            }
+            
+            guard response.hasPrefix("22") else {
+                let error = FileProviderFTPError(message: response)
+                completionHandler(error)
+                return
+            }
+            
+            let loginHandle: () -> Void = {
+                self.execute(command: "USER \(credential?.user ?? "anonymous")", on: task) { (response, error) in
+                    if let error = error {
+                        completionHandler(error)
+                        return
+                    }
+                    
+                    guard let response = response else {
+                        completionHandler(self.throwError("", code: URLError.badServerResponse))
+                        return
+                    }
+                    
+                    // successfully logged in
+                    if response.hasPrefix("23") {
+                        completionHandler(nil)
+                        return
+                    }
+                    
+                    // needs password
+                    if FileProviderFTPError(message: response).code == 331 {
+                        self.execute(command: "PASS \(credential?.password ?? "fileprovider@")", on: task) { (response, error) in
+                            if response?.hasPrefix("23") ?? false {
+                                completionHandler(nil)
+                            } else {
+                                completionHandler(self.throwError("", code: URLError.userAuthenticationRequired))
+                            }
+                        }
+                        return
+                    }
+                    
+                    let error = FileProviderFTPError(message: response)
+                    completionHandler(error)
+                    return
+                }
+            }
+            
+            if !isSecure && self.baseURL?.scheme == "ftpes" {
+                // Explicit FTP Connection, by upgrading connection to FTP/SSL
+                self.execute(command: "AUTH TLS", on: task, minLength: 0, completionHandler: { (response, error) in
+                    if let error = error {
+                        completionHandler(error)
+                        return
+                    }
+                    
+                    if let response = response, response.hasPrefix("23") {
+                        task.startSecureConnection()
+                        isSecure = true
+                        self.execute(command: "PBSZ 0\r\nPROT P", on: task, completionHandler: { (response, error) in
+                            if let error = error {
+                                completionHandler(error)
+                                return
+                            }
+                            
+                            loginHandle()
+                        })
+                    }
+                })
+            } else if isSecure {
+                self.execute(command: "PBSZ 0\r\nPROT P", on: task, completionHandler: { (response, error) in
+                    if let error = error {
+                        completionHandler(error)
+                        return
+                    }
+                    
+                    loginHandle()
+                })
+            } else {
+                loginHandle()
+            }
+        }
+    }
+    
+    func ftpCwd(_ task: FileProviderStreamTask, to path: String, completionHandler: @escaping (_ error: Error?) -> Void) {
+        self.execute(command: "CWD \(path)", on: task) { (response, error) in
+            if let error = error {
+                completionHandler(error)
+                return
+            }
+            
+            guard let response = response else {
+                completionHandler(self.throwError(path, code: URLError.badServerResponse))
+                return
+            }
+            
+            // successfully logged in
+            if response.hasPrefix("25") {
+                completionHandler(nil)
+            }
+            // not logged in
+            else if response.hasPrefix("55") {
+                let error = FileProviderFTPError(message: response)
+                completionHandler(error)
+                return
+            }
+        }
+    }
+    
+    func ftpPassive(_ task: FileProviderStreamTask, completionHandler: @escaping (_ dataTask: FileProviderStreamTask?, _ error: Error?) -> Void) {
+        func trimmedNumber(_ s : String) -> String {
+            let characterSet = Set("+*#0123456789".characters)
+            return String(s.characters.lazy.filter(characterSet.contains))
+        }
+        
+        self.execute(command: "PASV", on: task) { (response, error) in
+            if let error = error {
+                completionHandler(nil, error)
+                return
+            }
+            
+            guard let response = response, let destString = response.components(separatedBy: " ").flatMap({ $0 }).last.flatMap({ String($0) }) else {
+                completionHandler(nil, self.throwError("", code: URLError.badServerResponse))
+                return
+            }
+            
+            let destArray = destString.components(separatedBy: ",").flatMap({ UInt32(trimmedNumber($0)) })
+            guard destArray.count == 6 else {
+                completionHandler(nil, self.throwError("", code: URLError.badServerResponse))
+                return
+            }
+            
+            // first 4 elements are ip, 2 next are port, as byte
+            var host = destArray.prefix(4).flatMap({ String($0) }).joined(separator: ".")
+            let port = Int(destArray[4] << 8 + destArray[5])
+            // IPv6 workaround
+            if host == "127.555.555.555" {
+                host = self.baseURL!.host!
+            }
+            
+            let passiveTask = self.session.fpstreamTask(withHostName: host, port: port)
+            passiveTask.resume()
+            if self.baseURL?.scheme == "ftps" || self.baseURL?.scheme == "ftpes" || self.baseURL?.port == 990 {
+                passiveTask.startSecureConnection()
+            }
+            completionHandler(passiveTask, nil)
+        }
+    }
+    
+    func ftpActive(_ task: FileProviderStreamTask, completionHandler: @escaping (_ dataTask: FileProviderStreamTask?, _ error: Error?) -> Void) {
+        let service = NetService(domain: "", type: "_tcp.", name: "", port: 0)
+        service.publish(options: .listenForConnections)
+        let startTime = Date()
+        while service.port < 1 && startTime.timeIntervalSinceNow > -self.session.configuration.timeoutIntervalForRequest {
+            usleep(100_000)
+        }
+        let activeTask = self.session.fpstreamTask(withNetService: service)
+        activeTask.resume()
+        if self.baseURL?.scheme == "ftps" || self.baseURL?.port == 990 {
+            activeTask.startSecureConnection()
+        }
+        
+        self.execute(command: "PORT \(service.port)", on: task) { (response, error) in
+            if let error = error {
+                activeTask.cancel()
+                completionHandler(nil, error)
+                return
+            }
+            
+            guard let response = response else {
+                activeTask.cancel()
+                completionHandler(nil, self.throwError("", code: URLError.badServerResponse))
+                return
+            }
+            
+            guard !response.hasPrefix("5") else {
+                activeTask.cancel()
+                completionHandler(nil, self.throwError("", code: URLError.cannotConnectToHost))
+                return
+            }
+            
+            completionHandler(activeTask, nil)
+        }
+    }
+    
+    func ftpDataConnect(_ task: FileProviderStreamTask, completionHandler: @escaping (_ dataTask: FileProviderStreamTask?, _ error: Error?) -> Void) {
+        if self.passiveMode {
+            self.ftpPassive(task, completionHandler: completionHandler)
+        } else {
+            dispatch_queue.async {
+                self.ftpActive(task, completionHandler: completionHandler)
+            }
+        }
+    }
+    
+    func ftpRest(_ task: FileProviderStreamTask, startPosition: Int64, completionHandler: @escaping (_ error: Error?) -> Void) {
+        self.execute(command: "REST \(startPosition)", on: task) { (response, error) in
+            if let error = error {
+                completionHandler(error)
+                return
+            }
+            
+            // Successful
+            guard let response = response else {
+                completionHandler(self.throwError("", code: URLError.badServerResponse))
+                return
+            }
+            
+            if response.hasPrefix("35") {
+                completionHandler(nil)
+            } else {
+                let error = FileProviderFTPError(message: response, path: "")
+                completionHandler(error)
+                return
+            }
+        }
+    }
+    
+    func ftpList(_ task: FileProviderStreamTask, of path: String, useMLST: Bool, completionHandler: @escaping (_ contents: [String], _ error: Error?) -> Void) {
+        self.ftpDataConnect(task) { (dataTask, error) in
+            if let error = error {
+                completionHandler([], error)
+                return
+            }
+            
+            guard let dataTask = dataTask else {
+                completionHandler([], self.throwError(path, code: URLError.badServerResponse))
+                return
+            }
+            
+            var success = false
+            let command = useMLST ? "MLSD \(path)" : "LIST \(path)"
+            self.execute(command: command, on: task, minLength: 20, afterSend: { error in
+                // starting passive task
+                let timeout = self.session.configuration.timeoutIntervalForRequest
+                
+                DispatchQueue.global().async {
+                    var finalData = Data()
+                    var eof = false
+                    var error: Error?
+                    while !eof {
+                        let group = DispatchGroup()
+                        group.enter()
+                        dataTask.readData(ofMinLength: 1, maxLength: 65535, timeout: timeout, completionHandler: { (data, seof, serror) in
+                            if let data = data {
+                                finalData.append(data)
+                            }
+                            eof = seof
+                            error = serror
+                            group.leave()
+                        })
+                        let waitResult = group.wait(timeout: .now() + timeout)
+                        
+                        if let error = error {
+                            if !((error as NSError).domain == URLError.errorDomain && (error as NSError).code == URLError.cancelled.rawValue) {
+                                completionHandler([], error)
+                            }
+                            return
+                        }
+                        
+                        if waitResult == .timedOut {
+                            completionHandler([], self.throwError(path, code: URLError.timedOut))
+                            return
+                        }
+                    }
+                    
+                    guard let response = String(data: finalData, encoding: .utf8) else {
+                        completionHandler([], self.throwError(path, code: URLError.badServerResponse))
+                        return
+                    }
+                    
+                    let contents: [String] = response.components(separatedBy: "\n").flatMap({ $0.trimmingCharacters(in: .whitespacesAndNewlines) })
+                    success = true
+                    completionHandler(contents, nil)
+                    return
+                }
+            }) { (response, error) in
+                if let error = error {
+                    completionHandler([], error)
+                    return
+                }
+                
+                guard let response = response else {
+                    completionHandler([], self.throwError(path, code: URLError.cannotParseResponse))
+                    return
+                }
+                
+                if response.hasPrefix("500") && useMLST {
+                    dataTask.cancel()
+                    self.serverSupportsRFC3659 = false
+                    completionHandler([], self.throwError(path, code: URLError.unsupportedURL))
+                    return
+                }
+                
+                if !success && !(response.hasPrefix("25") || response.hasPrefix("15")) {
+                    let error = FileProviderFTPError(message: response, path: path)
+                    self.dispatch_queue.async {
+                        completionHandler([], error)
+                    }
+                    return
+                }
+            }
+        }
+    }
+    
+    func recursiveList(path: String, useMLST: Bool, foundItemsHandler: ((_ contents: [FileObject]) -> Void)? = nil, completionHandler: @escaping (_ contents: [FileObject], _ error: Error?) -> Void) -> Progress? {
+        let progress = Progress(totalUnitCount: 0)
+        let queue = DispatchQueue(label: "\(self.type).recursiveList")
+        queue.async {
+            let group = DispatchGroup()
+            var result = [FileObject]()
+            var success = true
+            group.enter()
+            self.contentsOfDirectory(path: path, completionHandler: { (files, error) in
+                success = success && (error == nil)
+                if let error = error {
+                    completionHandler([], error)
+                    group.leave()
+                    return
+                }
+                
+                result.append(contentsOf: files)
+                progress.completedUnitCount = Int64(files.count)
+                foundItemsHandler?(files)
+                
+                let directories: [FileObject] = files.filter { $0.isDirectory }
+                progress.becomeCurrent(withPendingUnitCount: Int64(directories.count))
+                for dir in directories {
+                    group.enter()
+                    _=self.recursiveList(path: dir.path, useMLST: useMLST, foundItemsHandler: foundItemsHandler, completionHandler: { (contents, error) in
+                        success = success && (error == nil)
+                        if let error = error {
+                            completionHandler([], error)
+                            group.leave()
+                            return
+                        }
+                        
+                        foundItemsHandler?(files)
+                        result.append(contentsOf: contents)
+                        
+                        group.leave()
+                    })
+                }
+                progress.resignCurrent()
+                group.leave()
+            })
+            group.wait()
+            
+            if success {
+                self.dispatch_queue.async {
+                    completionHandler(result, nil)
+                }
+            }
+        }
+        return progress
+    }
+    
+    func ftpRetrieveData(_ task: FileProviderStreamTask, filePath: String, from position: Int64 = 0, length: Int = -1, onTask: ((_ task: FileProviderStreamTask) -> Void)?, onProgress: ((_ bytesReceived: Int64, _ totalReceived: Int64, _ expectedBytes: Int64) -> Void)?, completionHandler: @escaping (_ data: Data?, _ error: Error?) -> Void) {
+        
+        // Check cache
+        if useCache, let url = URL(string: filePath.addingPercentEncoding(withAllowedCharacters: .filePathAllowed) ?? filePath, relativeTo: self.baseURL!)?.absoluteURL, let cachedResponse = self.cache?.cachedResponse(for: URLRequest(url: url)), cachedResponse.data.count > 0 {
+            dispatch_queue.async {
+                completionHandler(cachedResponse.data, nil)
+            }
+            return
+        }
+        
+        self.attributesOfItem(path: filePath) { (file, error) in
+            let totalSize = file?.size ?? -1
+            // Retreive data from server
+            self.ftpDataConnect(task) { (dataTask, error) in
+                if let error = error {
+                    completionHandler(nil, error)
+                    return
+                }
+                
+                guard let dataTask = dataTask else {
+                    completionHandler(nil, self.throwError(filePath, code: URLError.badServerResponse))
+                    return
+                }
+                
+                // Send retreive command
+                let len = 19 /* TYPE response */ + 65 + String(position).characters.count /* REST Response */ + 53 + filePath.characters.count + String(totalSize).characters.count /* RETR open response */ + 26 /* RETR Transfer complete message. */
+                self.execute(command: "TYPE I" + "\r\n" + "REST \(position)" + "\r\n" + "RETR \(filePath)", on: task, minLength: len, afterSend: { error in
+                    // starting passive task
+                    onTask?(dataTask)
+                    
+                    let timeout = self.session.configuration.timeoutIntervalForRequest
+                    DispatchQueue.global().async {
+                        var finalData = Data()
+                        var eof = false
+                        var error: Error?
+                        while !eof {
+                            let group = DispatchGroup()
+                            group.enter()
+                            dataTask.readData(ofMinLength: 0, maxLength: 65535, timeout: timeout, completionHandler: { (data, seof, serror) in
+                                if let data = data {
+                                    finalData.append(data)
+                                    onProgress?(Int64(data.count), Int64(finalData.count), totalSize)
+                                }
+                                eof = seof || (length > 0 && finalData.count >= length)
+                                if length > 0 && finalData.count > length {
+                                    finalData.count = length
+                                }
+                                error = serror
+                                group.leave()
+                            })
+                            let waitResult = group.wait(timeout: .now() + timeout)
+                            
+                            if let error = error {
+                                completionHandler(nil, error)
+                                return
+                            }
+                            
+                            if waitResult == .timedOut {
+                                completionHandler(nil, self.throwError(filePath, code: URLError.timedOut))
+                                return
+                            }
+                        }
+                        
+                        if let url = URL(string: filePath.addingPercentEncoding(withAllowedCharacters: .filePathAllowed) ?? filePath, relativeTo: self.baseURL!)?.absoluteURL {
+                            let urlresponse = URLResponse(url: url, mimeType: nil, expectedContentLength: finalData.count, textEncodingName: nil)
+                            let cachedResponse = CachedURLResponse(response: urlresponse, data: finalData)
+                            let request = URLRequest(url: url)
+                            self.cache?.storeCachedResponse(cachedResponse, for: request)
+                        }
+                        
+                        completionHandler(finalData, nil)
+                        return
+                    }
+                }) { (response, error) in
+                    if let error = error {
+                        completionHandler(nil, error)
+                        return
+                    }
+                    
+                    guard let response = response else {
+                        completionHandler(nil, self.throwError(filePath, code: URLError.cannotParseResponse))
+                        return
+                    }
+                    
+                    if !(response.hasPrefix("1") || !response.hasPrefix("2")) {
+                        let error = FileProviderFTPError(message: response)
+                        
+                        self.dispatch_queue.async {
+                            completionHandler(nil, error)
+                        }
+                        return
+                    }
+                }
+            }
+        }
+    }
+    
+    func ftpRetrieveFile(_ task: FileProviderStreamTask, filePath: String, from position: Int64 = 0, length: Int = -1, onTask: ((_ task: FileProviderStreamTask) -> Void)?, onProgress: ((_ bytesReceived: Int64, _ totalReceived: Int64, _ expectedBytes: Int64) -> Void)?, completionHandler: @escaping (_ file: URL?, _ error: Error?) -> Void) {
+        let tempURL = URL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent(UUID().uuidString).appendingPathExtension("tmp")
+        
+        // Check cache
+        if useCache, let url = URL(string: filePath.addingPercentEncoding(withAllowedCharacters: .filePathAllowed) ?? filePath, relativeTo: self.baseURL!)?.absoluteURL, let cachedResponse = self.cache?.cachedResponse(for: URLRequest(url: url)), cachedResponse.data.count > 0 {
+            dispatch_queue.async {
+                do {
+                    try cachedResponse.data.write(to: tempURL)
+                    completionHandler(tempURL, nil)
+                } catch {
+                    completionHandler(nil, error)
+                }
+                try? FileManager.default.removeItem(at: tempURL)
+            }
+            return
+        }
+        
+        self.attributesOfItem(path: filePath) { (file, error) in
+            let totalSize = file?.size ?? -1
+            // Retreive data from server
+            self.ftpDataConnect(task) { (dataTask, error) in
+                if let error = error {
+                    completionHandler(nil, error)
+                    return
+                }
+                
+                guard let dataTask = dataTask else {
+                    completionHandler(nil, self.throwError(filePath, code: URLError.badServerResponse))
+                    return
+                }
+                
+                // Send retreive command
+                let len = 19 /* TYPE response */ + 65 + String(position).characters.count /* REST Response */ + 53 + filePath.characters.count + String(totalSize).characters.count /* RETR open response */ + 26 /* RETR Transfer complete message. */
+                self.execute(command: "TYPE I"  + "\r\n" + "REST \(position)" + "\r\n" + "RETR \(filePath)", on: task, minLength: len, afterSend: { error in
+                    // starting passive task
+                    onTask?(dataTask)
+                    
+                    let timeout = self.session.configuration.timeoutIntervalForRequest
+                    DispatchQueue.global().async {
+                        var finalData = Data()
+                        var eof = false
+                        var error: Error?
+                        while !eof {
+                            let group = DispatchGroup()
+                            group.enter()
+                            dataTask.readData(ofMinLength: 0, maxLength: 65535, timeout: timeout, completionHandler: { (data, seof, serror) in
+                                if let data = data {
+                                    finalData.append(data)
+                                    onProgress?(Int64(data.count), Int64(finalData.count), totalSize)
+                                }
+                                eof = seof || (length > 0 && finalData.count >= length)
+                                if length > 0 && finalData.count > length {
+                                    finalData.count = length
+                                }
+                                error = serror
+                                group.leave()
+                            })
+                            let waitResult = group.wait(timeout: .now() + timeout)
+                            
+                            if let error = error {
+                                completionHandler(nil, error)
+                                return
+                            }
+                            
+                            if waitResult == .timedOut {
+                                error = self.throwError("", code: URLError.timedOut)
+                                completionHandler(nil, error)
+                                return
+                            }
+                        }
+                        
+                        if let url = URL(string: filePath.addingPercentEncoding(withAllowedCharacters: .filePathAllowed) ?? filePath, relativeTo: self.baseURL!)?.absoluteURL {
+                            let urlresponse = URLResponse(url: url, mimeType: nil, expectedContentLength: finalData.count, textEncodingName: nil)
+                            let cachedResponse = CachedURLResponse(response: urlresponse, data: finalData)
+                            let request = URLRequest(url: url)
+                            self.cache?.storeCachedResponse(cachedResponse, for: request)
+                        }
+                        
+                        self.dispatch_queue.async {
+                            do {
+                                try finalData.write(to: tempURL)
+                                completionHandler(tempURL, nil)
+                            } catch {
+                                completionHandler(nil, error)
+                            }
+                            try? FileManager.default.removeItem(at: tempURL)
+                        }
+                        return
+                    }
+                }) { (response, error) in
+                    if let error = error {
+                        completionHandler(nil, error)
+                        return
+                    }
+                    
+                    guard let response = response else {
+                        completionHandler(nil, self.throwError(filePath, code: URLError.cannotParseResponse))
+                        return
+                    }
+                    
+                    if !(response.hasPrefix("1") || response.hasPrefix("2")) {
+                        let error = FileProviderFTPError(message: response)
+                        
+                        self.dispatch_queue.async {
+                            completionHandler(nil, error)
+                        }
+                        return
+                    }
+                }
+            }
+        }
+    }
+    
+    func ftpStore(_ task: FileProviderStreamTask, filePath: String, fromData: Data?, fromFile: URL?, onTask: ((_ task: FileProviderStreamTask) -> Void)?,  onProgress: ((_ bytesSent: Int64, _ totalSent: Int64, _ expectedBytes: Int64) -> Void)?, completionHandler: @escaping (_ error: Error?) -> Void) {
+        let timeout = self.session.configuration.timeoutIntervalForRequest
+        operation_queue.addOperation {
+            guard let size: Int64 = (fromData != nil ? Int64(fromData!.count) : nil) ?? fromFile?.fileSize else { return }
+            
+            var error: Error?
+            let chunkSize: Int
+            switch size {
+            case 0..<262_144: chunkSize = 32_768 // 0KB To 256KB, page size is 32KB
+            case 262_144..<1_048_576: chunkSize = 65_536 // 256KB To 1MB, page size is 64KB
+            case 1_048_576..<10_485_760: chunkSize = 131_072 // 1MB To 10MB, page size is 128KB
+            case 10_048_576..<33_554_432: chunkSize = 262_144 // 1MB To 10MB, page size is 256KB
+            default: chunkSize = 524_288 // Larger than 32MB, page size is 512KB
+            }
+            
+            var fileHandle: FileHandle?
+            if let file = fromFile {
+                fileHandle = FileHandle(forReadingAtPath: file.path)
+            }
+            defer {
+                fileHandle?.closeFile()
+            }
+            
+            var eof = false
+            var sent: Int64 = 0
+            
+            while !eof {
+                let subdata: Data
+                if let data = fromData {
+                    let endIndex = min(data.count, Int(sent) + chunkSize)
+                    eof = endIndex == data.count
+                    subdata = data.subdata(in: Int(sent)..<endIndex)
+                }else if let fileHandle = fileHandle {
+                    subdata = fileHandle.readData(ofLength: chunkSize)
+                    eof = Int64(fileHandle.offsetInFile) == size
+                } else {
+                    return
+                }
+                if subdata.count == 0 { continue }
+                
+                let group = DispatchGroup()
+                group.enter()
+                self.ftpStore(task, data: subdata, to: filePath, from: sent, onTask: onTask, completionHandler: { (serror) in
+                    error = serror
+                    sent += Int64(subdata.count)
+                    group.leave()
+                    onProgress?(Int64(subdata.count), sent, size)
+                })
+                let waitResult = group.wait(timeout: .now() + timeout)
+                
+                if waitResult == .timedOut {
+                    error = self.throwError(filePath, code: URLError.timedOut)
+                    completionHandler(error)
+                    return
+                }
+                if let error = error {
+                    completionHandler(error)
+                    return
+                }
+            }
+            completionHandler(nil)
+        }
+    }
+    
+    func ftpStore(_ task: FileProviderStreamTask, data: Data, to filePath: String, from position: Int64, onTask: ((_ task: FileProviderStreamTask) -> Void)?, completionHandler: @escaping (_ error: Error?) -> Void) {
+        self.ftpDataConnect(task) { (dataTask, error) in
+            if let error = error {
+                completionHandler(error)
+                return
+            }
+            
+            guard let dataTask = dataTask else {
+                completionHandler(self.throwError(filePath, code: URLError.badServerResponse))
+                return
+            }
+            
+            // Send retreive command
+            var success = false
+            let len = 19 /* TYPE response */ + 65 + String(position).characters.count /* REST Response */ + 44 + filePath.characters.count /* STOR open response */ + 10 /* RETR Transfer complete message. */
+            self.execute(command: "TYPE I"  + "\r\n" + "REST \(position)"  + "\r\n" + "STOR \(filePath)", on: task, minLength: len, afterSend: { error in
+                // starting passive task
+                let timeout = self.session.configuration.timeoutIntervalForRequest
+                if self.baseURL?.scheme == "ftps" || self.baseURL?.port == 990 {
+                    task.startSecureConnection()
+                }
+                onTask?(dataTask)
+                
+                if data.count == 0 { return }
+                
+                dataTask.write(data, timeout: timeout, completionHandler: { (error) in
+                    if let error = error {
+                        completionHandler(error)
+                        return
+                    }
+                    success = true
+                    
+                    dataTask.closeRead()
+                    dataTask.closeWrite()
+                })
+            }) { (response, error) in
+                guard success else { return }
+                
+                if let error = error {
+                    completionHandler(error)
+                    return
+                }
+                
+                guard let response = response else {
+                    completionHandler(self.throwError(filePath, code: URLError.cannotParseResponse))
+                    return
+                }
+                
+                if !(response.hasPrefix("1") || response.hasPrefix("2")) {
+                    let error = FileProviderFTPError(message: response)
+                    
+                    self.dispatch_queue.async {
+                        completionHandler(error)
+                    }
+                    return
+                }
+                
+                completionHandler(nil)
+            }
+        }
+    }
+    
+    func ftpQuit(_ task: FileProviderStreamTask) {
+        self.execute(command: "QUIT", on: task) { (_, _) in
+            //task.closeRead()
+            //task.closeWrite()
+        }
+    }
+    
+    func ftpPath(_ apath: String) -> String {
+        var path = apath.isEmpty ? self.currentPath : apath
+        
+        // path of base url should be concreted into file path!
+        path = baseURL!.appendingPathComponent(path).path
+        
+        // Fixing slashes
+        if !path.hasPrefix("/") {
+            path = "/" + path
+        }
+        if path.hasSuffix("/"){
+            path.characters.removeLast()
+        }
+        
+        if path.isEmpty {
+            path = "/"
+        }
+        
+        return path
+    }
+    
+    func parseUnixList(_ text: String, in path: String) -> FileObject? {
+        let gregorian = Calendar(identifier: .gregorian)
+        let nearDateFormatter = DateFormatter()
+        nearDateFormatter.calendar = gregorian
+        nearDateFormatter.locale = Locale(identifier: "en_US_POSIX")
+        nearDateFormatter.dateFormat = "MMM dd hh:ss yyyy"
+        let farDateFormatter = DateFormatter()
+        farDateFormatter.calendar = gregorian
+        farDateFormatter.locale = Locale(identifier: "en_US_POSIX")
+        farDateFormatter.dateFormat = "MMM dd yyyy"
+        let thisYear = gregorian.component(.year, from: Date())
+        
+        let components = text.components(separatedBy: " ").flatMap { $0.isEmpty ? nil : $0 }
+        guard components.count >= 9 else { return nil }
+        let posixPermission = components[0]
+        let linksCount = Int(components[1]) ?? 0
+        //let owner = components[2]
+        //let groupOwner = components[3]
+        let size = Int64(components[4]) ?? -1
+        let date = components[5..<8].joined(separator: " ")
+        let name = components[8..<components.count].joined(separator: " ")
+        
+        guard name != "." && name != ".." else { return nil }
+        var path = (path as NSString).appendingPathComponent(name)
+        if path.hasPrefix("/") {
+            path.characters.removeFirst()
+        }
+        
+        let file = FileObject(url: url(of: path), name: name, path: path)
+        switch String(posixPermission.characters.first!) {
+        case "d": file.type = .directory
+        case "l": file.type = .symbolicLink
+        default:  file.type = .regular
+        }
+        file.isReadOnly = !posixPermission.contains("w")
+        file.size = file.isDirectory ? -1 : size
+        file.allValues[.linkCountKey] = linksCount
+        
+        if let parsedDate = nearDateFormatter.date(from: date + " " + String(thisYear)) {
+            if parsedDate > Date() {
+                file.modifiedDate = gregorian.date(byAdding: .year, value: -1, to: parsedDate)
+            } else {
+                file.modifiedDate = parsedDate
+            }
+        } else if let parsedDate = farDateFormatter.date(from: date) {
+            file.modifiedDate = parsedDate
+        }
+        
+        return file
+    }
+    
+    func parseMLST(_ text: String, in path: String) -> FileObject? {
+        var components = text.components(separatedBy: ";").flatMap { $0.isEmpty ? nil : $0 }
+        guard components.count > 1 else { return nil }
+        
+        let nameOrPath = components.removeLast().trimmingCharacters(in: .whitespacesAndNewlines)
+        var correctedPath: String
+        let name: String
+        if nameOrPath.hasPrefix("/") {
+            correctedPath = nameOrPath.replacingOccurrences(of: baseURL!.path, with: "", options: .anchored)
+            name = (nameOrPath as NSString).lastPathComponent
+        } else {
+            name = nameOrPath
+            correctedPath = (path as NSString).appendingPathComponent(nameOrPath)
+        }
+        if correctedPath.hasPrefix("/") {
+            correctedPath.characters.removeFirst()
+        }
+        
+        var attributes = [String: String]()
+        for component in components {
+            let keyValue = component.components(separatedBy: "=") .flatMap { $0.isEmpty ? nil : $0 }
+            guard keyValue.count >= 2, !keyValue[0].isEmpty else { continue }
+            attributes[keyValue[0].lowercased()] = keyValue.dropFirst().joined(separator: "=")
+        }
+        
+        let file = FileObject(url: url(of: correctedPath), name: name, path: correctedPath)
+        let dateFormatter = DateFormatter()
+        dateFormatter.calendar = Calendar(identifier: .gregorian)
+        dateFormatter.locale = Locale(identifier: "en_US_POSIX")
+        dateFormatter.dateFormat = "yyyyMMddhhmmss"
+        for (key, attribute) in attributes {
+            switch key {
+            case "type":
+                switch attribute.lowercased() {
+                case "file": file.type = .regular
+                case "dir": file.type = .directory
+                case "link": file.type = .symbolicLink
+                case "os.unix=block": file.type = .blockSpecial
+                case "cdir", "pdir": return nil // . and .. files are redundant in listing
+                default: file.type = .unknown
+                }
+                
+            case "unique":
+                file.allValues[.fileResourceIdentifierKey] = attribute
+                
+            case "modify":
+                file.modifiedDate = dateFormatter.date(from: attribute)
+            
+            case "create":
+                file.creationDate = dateFormatter.date(from: attribute)
+                
+            case "perm":
+                file.allValues[.isReadableKey] = attribute.contains("r") || attribute.contains("l")
+                file.allValues[.isWritableKey] = attribute.contains("w") || attribute.contains("a")
+                
+            case "size":
+                file.size = Int64(attribute) ?? -1
+                
+            case "media-type":
+                file.allValues[.mimeTypeKey] = attribute
+                
+            default:
+                break
+            }
+        }
+        
+        return file
+    }
+}
+
+/// Contains error code and description returned by FTP/S provider.
+public struct FileProviderFTPError: Error {
+    /// HTTP status code returned for error by server.
+    public let code: Int
+    /// Path of file/folder casued that error
+    public let path: String
+    /// Contents returned by server as error description
+    public let errorDescription: String?
+    
+    init(code: Int, path: String, errorDescription: String?) {
+        self.code = code
+        self.path = path
+        self.errorDescription = errorDescription
+    }
+    
+    init(message response: String, path: String = "") {
+        let message = response.components(separatedBy: .newlines).last ?? "No Response"
+        let spaceIndex = message.characters.index(of: "-") ?? message.characters.index(of: " ") ?? message.startIndex
+        self.code = Int(message.substring(to: spaceIndex).trimmingCharacters(in: .whitespacesAndNewlines)) ?? -1
+        self.path = path
+        if code > 0 {
+            self.errorDescription = message.substring(from: spaceIndex).trimmingCharacters(in: .whitespacesAndNewlines)
+        } else {
+            self.errorDescription = message
+        }
+    }
+}
@@ -8,36 +8,37 @@

 import Foundation

-/// Containts path and attributes of a file or resource.
-open class FileObject {
+/// Containts path, url and attributes of a file or resource.
+open class FileObject: Equatable {
    /// A `Dictionary` contains file information,  using `URLResourceKey` keys.
    open internal(set) var allValues: [URLResourceKey: Any]
    
-    internal init(allValues: [URLResourceKey: Any]) {
+    public init(allValues: [URLResourceKey: Any]) {
        self.allValues = allValues
    }
    
-    internal init(url: URL, name: String, path: String) {
+    internal init(url: URL?, name: String, path: String) {
        self.allValues = [URLResourceKey: Any]()
-        self.url = url
+        if let url = url {
+            self.url = url
+        }
        self.name = name
        self.path = path
    }
    
-    /// url to access the resource, not supported by Dropbox provider
-    @available(*, deprecated, renamed: "url", message: "Use url.absoluteURL instead.")
-    open var absoluteURL: URL? {
-        return url?.absoluteURL
-    }
-    
    /// URL to access the resource, can be a relative URL against base URL.
    /// not supported by Dropbox provider.
-    open internal(set) var url: URL? {
+    open internal(set) var url: URL {
        get {
-            return allValues[.fileURL] as? URL
+            if let url = allValues[.fileURLKey] as? URL {
+                return url
+            } else {
+                let path = self.path.addingPercentEncoding(withAllowedCharacters: .filePathAllowed) ?? self.path
+                return URL(string: path) ?? URL(string: "/")!
+            }
        }
        set {
-            allValues[.fileURL] = newValue
+            allValues[.fileURLKey] = newValue
        }
    }
    
@@ -101,12 +102,6 @@ open class FileObject {
        }
    }
    
-    /// **OBSOLETED:** Use `type` property instead.
-    @available(*, obsoleted: 1.0, renamed: "type", message: "Use type property instead.")
-    open var fileType: URLFileResourceType? {
-        return self.type
-    }
-    
    /// File is hidden either because begining with dot or filesystem flags
    /// Setting this value on a file begining with dot has no effect
    open internal(set) var isHidden: Bool {
@@ -142,37 +137,74 @@ open class FileObject {
    open var isSymLink: Bool {
        return self.type == .symbolicLink
    }
-}
-
-internal func resolve(dateString: String) -> Date? {
-    let dateFor: DateFormatter = DateFormatter()
-    dateFor.locale = Locale(identifier: "en_US")
-    dateFor.dateFormat = "yyyy'-'MM'-'dd'T'HH':'mm':'ssZ"
-    if let rfc3339 = dateFor.date(from: dateString) {
-        return rfc3339
-    }
-    dateFor.dateFormat = "EEE',' dd' 'MMM' 'yyyy HH':'mm':'ss z"
-    if let rfc1123 = dateFor.date(from: dateString) {
-        return rfc1123
-    }
-    dateFor.dateFormat = "EEEE',' dd'-'MMM'-'yy HH':'mm':'ss z"
-    if let rfc850 = dateFor.date(from: dateString) {
-        return rfc850
-    }
-    dateFor.dateFormat = "EEE MMM d HH':'mm':'ss yyyy"
-    if let asctime = dateFor.date(from: dateString) {
-        return asctime
+    
+    /// Check `FileObject` equality
+    public static func ==(lhs: FileObject, rhs: FileObject) -> Bool {
+        if rhs === lhs  {
+            return true
+        }
+        #if swift(>=3.1)
+        if Swift.type(of: lhs) != Swift.type(of: rhs) {
+            return false
+        }
+        #else
+        if type(of: lhs) != type(of: rhs) {
+            return false
+        }
+        #endif
+        
+        if let rurl = rhs.allValues[.fileURLKey] as? URL, let lurl = lhs.allValues[.fileURLKey] as? URL {
+            return rurl == lurl
+        }
+        return rhs.path == lhs.path && rhs.size == lhs.size && rhs.modifiedDate == lhs.modifiedDate
    }
    
-    return nil
-}
-
-internal func rfc3339utc(of date:Date) -> String {
-    let fm = DateFormatter()
-    fm.dateFormat = "yyyy'-'MM'-'dd'T'HH':'mm':'ss'Z'"
-    fm.timeZone = TimeZone(identifier:"UTC")
-    fm.locale = Locale(identifier:"en_US_POSIX")
-    return fm.string(from:date)
+    internal func mapPredicate() -> [String: Any] {
+        let mapDict: [URLResourceKey: String] = [.fileURLKey: "url", .nameKey: "name", .pathKey: "path", .fileSizeKey: "filesize", .creationDateKey: "creationDate",
+                                                 .contentModificationDateKey: "modifiedDate", .isHiddenKey: "isHidden", .isWritableKey: "isWritable", .serverDateKey: "serverDate", .entryTagKey: "entryTag", .mimeTypeKey: "mimeType"]
+        let typeDict: [URLFileResourceType: String] = [.directory: "directory", .regular: "regular", .symbolicLink: "symbolicLink", .unknown: "unknown"]
+        var result = [String: Any]()
+        for (key, value) in allValues {
+            if let convertkey = mapDict[key] {
+                result[convertkey] = value
+            }
+        }
+        result["eTag"] = result["entryTag"]
+        result["isReadOnly"] = self.isReadOnly
+        result["isDirectory"] = self.isDirectory
+        result["isRegularFile"] = self.isRegularFile
+        result["isSymLink"] = self.isSymLink
+        result["type"] = typeDict[self.type ?? .unknown] ?? "unknown"
+        return result
+    }
+    
+    /// Converts macOS spotlight query for searching files to a query that can be used for `searchFiles()` method
+    static public func convertPredicate(fromSpotlight query: NSPredicate) -> NSPredicate {
+        let mapDict: [String: URLResourceKey] = [NSMetadataItemURLKey: .fileURLKey, NSMetadataItemFSNameKey: .nameKey, NSMetadataItemPathKey: .pathKey,
+                                                 NSMetadataItemFSSizeKey: .fileSizeKey, NSMetadataItemFSCreationDateKey: .creationDateKey,
+                                                 NSMetadataItemFSContentChangeDateKey: .contentModificationDateKey, "kMDItemFSInvisible": .isHiddenKey, "kMDItemFSIsWriteable": .isWritableKey, "kMDItemKind": .mimeTypeKey]
+        
+        if let cQuery = query as? NSCompoundPredicate {
+            let newSub = cQuery.subpredicates.map { convertPredicate(fromSpotlight: $0 as! NSPredicate) }
+            switch cQuery.compoundPredicateType {
+            case .and: return NSCompoundPredicate(andPredicateWithSubpredicates: newSub)
+            case .not: return NSCompoundPredicate(notPredicateWithSubpredicate: newSub[0])
+            case .or:  return NSCompoundPredicate(orPredicateWithSubpredicates: newSub)
+            }
+        } else if let cQuery = query as? NSComparisonPredicate {
+            var newLeft = cQuery.leftExpression
+            var newRight = cQuery.rightExpression
+            if newLeft.expressionType == .keyPath, let newKey = mapDict[newLeft.keyPath] {
+                newLeft = NSExpression(forKeyPath: newKey.rawValue)
+            }
+            if newRight.expressionType == .keyPath, let newKey = mapDict[newRight.keyPath] {
+                newRight = NSExpression(forKeyPath: newKey.rawValue)
+            }
+            return NSComparisonPredicate(leftExpression: newLeft, rightExpression: newRight, modifier: cQuery.comparisonPredicateModifier, type: cQuery.predicateOperatorType, options: cQuery.options)
+        } else {
+            return query
+        }
+    }
 }

 /// Sorting FileObject array by given criteria, **not thread-safe**
@@ -231,7 +263,7 @@ public struct FileObjectSorting {
        self.isDirectoriesFirst = isDirectoriesFirst
    }
    
-    /// Sorts array of `FileObject`s by criterias set in properties
+    /// Sorts array of `FileObject`s by criterias set in attributes.
    public func sort(_ files: [FileObject]) -> [FileObject] {
        return files.sorted {
            if isDirectoriesFirst {
@@ -267,61 +299,3 @@ public struct FileObjectSorting {
        }
    }
 }
-
-extension Array where Element: FileObject {
-    /// Returns a sorted array of `FileObject`s by criterias set in properties.
-    public func sort(by type: FileObjectSorting.SortType, ascending: Bool = true, isDirectoriesFirst: Bool = false) -> [Element] {
-        let sorting = FileObjectSorting(type: type, ascending: ascending, isDirectoriesFirst: isDirectoriesFirst)
-        return sorting.sort(self) as! [Element]
-    }
-    
-    /// Sorts array of `FileObject`s by criterias set in properties
-    public mutating func sorted(by type: FileObjectSorting.SortType, ascending: Bool = true, isDirectoriesFirst: Bool = false) {
-        self = self.sort(by: type, ascending: ascending, isDirectoriesFirst: isDirectoriesFirst)
-    }
-}
-
-extension URLFileResourceType {
-    public init(fileTypeValue: FileAttributeType) {
-        switch fileTypeValue {
-        case FileAttributeType.typeCharacterSpecial: self = .characterSpecial
-        case FileAttributeType.typeDirectory: self = .directory
-        case FileAttributeType.typeBlockSpecial: self = .blockSpecial
-        case FileAttributeType.typeRegular: self = .regular
-        case FileAttributeType.typeSymbolicLink: self = .symbolicLink
-        case FileAttributeType.typeSocket: self = .socket
-        case FileAttributeType.typeUnknown: self = .unknown
-        default: self = .unknown
-        }
-    }
-}
-
-internal extension URLResourceKey {
-    static let fileURL = URLResourceKey(rawValue: "NSURLFileURLKey")
-    static let serverDate = URLResourceKey(rawValue: "NSURLServerDateKey")
-    static let entryTag = URLResourceKey(rawValue: "NSURLEntryTagKey")
-    static let mimeType = URLResourceKey(rawValue: "NSURLMIMETypeIdentifierKey")
-}
-
-internal extension URL {
-    var uw_scheme: String {
-        return self.scheme ?? ""
-    }
-}
-
-internal func jsonToDictionary(_ jsonString: String) -> [String: AnyObject]? {
-    guard let data = jsonString.data(using: .utf8) else {
-        return nil
-    }
-    if let dic = try? JSONSerialization.jsonObject(with: data, options: JSONSerialization.ReadingOptions()) as? [String: AnyObject] {
-        return dic
-    }
-    return nil
-}
-
-internal func dictionaryToJSON(_ dictionary: [String: AnyObject]) -> String? {
-    if let data = try? JSONSerialization.data(withJSONObject: dictionary, options: JSONSerialization.WritingOptions()) {
-        return String(data: data, encoding: .utf8)
-    }
-    return nil
-}
@@ -0,0 +1,392 @@
+//
+//  HTTPFileProvider.swift
+//  FilesProvider
+//
+//  Created by Amir Abbas Mousavian.
+//  Copyright © 2017 Mousavian. Distributed under MIT license.
+//
+
+import Foundation
+
+/**
+ The abstract base class for all REST/Web based providers such as WebDAV, Dropbox, OneDrive, Google Drive, etc. and encapsulates basic
+ functionalitis such as downloading/uploading.
+ 
+ No instance of this class should (and can) be created. Use derivated classes instead. It leads to a crash with `fatalError()`.
+ */
+open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, FileProviderReadWrite {
+    open class var type: String { fatalError("HTTPFileProvider is an abstract class. Please implement \(#function) in subclass.") }
+    open let baseURL: URL?
+    open var currentPath: String
+    
+    open var dispatch_queue: DispatchQueue
+    open var operation_queue: OperationQueue {
+        willSet {
+            assert(_session == nil, "It's not effective to change dispatch_queue property after session is initialized.")
+        }
+    }
+    
+    open weak var delegate: FileProviderDelegate?
+    open var credential: URLCredential? {
+        didSet {
+            sessionDelegate?.credential = self.credential
+        }
+    }
+    open private(set) var cache: URLCache?
+    public var useCache: Bool
+    public var validatingCache: Bool
+    
+    fileprivate var _session: URLSession?
+    internal fileprivate(set) var sessionDelegate: SessionDelegate?
+    public var session: URLSession {
+        get {
+            if _session == nil {
+                self.sessionDelegate = SessionDelegate(fileProvider: self)
+                let config = URLSessionConfiguration.default
+                config.urlCache = cache
+                config.requestCachePolicy = .returnCacheDataElseLoad
+                _session = URLSession(configuration: config, delegate: sessionDelegate as URLSessionDelegate?, delegateQueue: self.operation_queue)
+                _session!.sessionDescription = UUID().uuidString
+                initEmptySessionHandler(_session!.sessionDescription!)
+            }
+            return _session!
+        }
+        
+        set {
+            assert(newValue.delegate is SessionDelegate, "session instances should have a SessionDelegate instance as delegate.")
+            _session = newValue
+            if session.sessionDescription?.isEmpty ?? true {
+                _session?.sessionDescription = UUID().uuidString
+            }
+            self.sessionDelegate = newValue.delegate as? SessionDelegate
+            initEmptySessionHandler(_session!.sessionDescription!)
+        }
+    }
+    
+    fileprivate var _longpollSession: URLSession?
+    /// This session has extended timeout up to 10 minutes, suitable for monitoring.
+    internal var longpollSession: URLSession {
+        if _longpollSession == nil {
+            let config = URLSessionConfiguration.default
+            config.timeoutIntervalForRequest = 600
+            _longpollSession = URLSession(configuration: config, delegate: nil, delegateQueue: nil)
+        }
+        return _longpollSession!
+    }
+    
+    /**
+     This is parent initializer for subclasses. Using this method on `HTTPFileProvider` will fail as `type` is not implemented.
+     
+     - Parameters:
+     - baseURL: Location of WebDAV server.
+     - credential: An `URLCredential` object with `user` and `password`.
+     - cache: A URLCache to cache downloaded files and contents.
+     */
+    public init(baseURL: URL?, credential: URLCredential?, cache: URLCache?) {
+        self.baseURL = baseURL
+        self.currentPath = ""
+        self.useCache = false
+        self.validatingCache = true
+        self.cache = cache
+        self.credential = credential
+        
+        #if swift(>=3.1)
+            let queueLabel = "FileProvider.\(Swift.type(of: self).type)"
+        #else
+            let queueLabel = "FileProvider.\(type(of: self).type)"
+        #endif
+        dispatch_queue = DispatchQueue(label: queueLabel, attributes: .concurrent)
+        operation_queue = OperationQueue()
+        operation_queue.name = "\(queueLabel).Operation"
+    }
+    
+    public required convenience init?(coder aDecoder: NSCoder) {
+        fatalError("HTTPFileProvider is an abstract class. Please implement \(#function) in subclass.")
+    }
+    
+    public func encode(with aCoder: NSCoder) {
+        aCoder.encode(self.baseURL, forKey: "baseURL")
+        aCoder.encode(self.credential, forKey: "credential")
+        aCoder.encode(self.currentPath, forKey: "currentPath")
+        aCoder.encode(self.useCache, forKey: "useCache")
+        aCoder.encode(self.validatingCache, forKey: "validatingCache")
+    }
+    
+    public static var supportsSecureCoding: Bool {
+        return true
+    }
+    
+    open func copy(with zone: NSZone? = nil) -> Any {
+        fatalError("HTTPFileProvider is an abstract class. Please implement \(#function) in subclass.")
+    }
+    
+    deinit {
+        if let sessionuuid = _session?.sessionDescription {
+            removeSessionHandler(for: sessionuuid)
+        }
+        
+        if fileProviderCancelTasksOnInvalidating {
+            _session?.invalidateAndCancel()
+        } else {
+            _session?.finishTasksAndInvalidate()
+        }
+    }
+    
+    open func contentsOfDirectory(path: String, completionHandler: @escaping ((_ contents: [FileObject], _ error: Error?) -> Void)) {
+        fatalError("HTTPFileProvider is an abstract class. Please implement \(#function) in subclass.")
+    }
+    
+    open func attributesOfItem(path: String, completionHandler: @escaping ((_ attributes: FileObject?, _ error: Error?) -> Void)) {
+        fatalError("HTTPFileProvider is an abstract class. Please implement \(#function) in subclass.")
+    }
+    
+    open func storageProperties(completionHandler: @escaping ((_ total: Int64, _ used: Int64) -> Void)) {
+        fatalError("HTTPFileProvider is an abstract class. Please implement \(#function) in subclass.")
+    }
+    
+    open func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) -> Progress? {
+        fatalError("HTTPFileProvider is an abstract class. Please implement \(#function) in subclass.")
+    }
+    
+    open func isReachable(completionHandler: @escaping (Bool) -> Void) {
+        self.storageProperties { total, _ in
+            completionHandler(total > 0)
+        }
+    }
+    
+    open weak var fileOperationDelegate: FileOperationDelegate?
+    
+    open func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let path = (atPath as NSString).appendingPathComponent(folderName) + "/"
+        return doOperation(.create(path: path), completionHandler: completionHandler)
+    }
+    
+    open func moveItem(path: String, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> Progress? {
+        return doOperation(.move(source: path, destination: toPath), completionHandler: completionHandler)
+    }
+    
+    open func copyItem(path: String, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> Progress? {
+        return doOperation(.copy(source: path, destination: toPath), completionHandler: completionHandler)
+    }
+    
+    open func removeItem(path: String, completionHandler: SimpleCompletionHandler) -> Progress? {
+        return doOperation(.remove(path: path), completionHandler: completionHandler)
+    }
+    
+    open func copyItem(localFile: URL, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> Progress? {
+        // check file is not a folder
+        guard (try? localFile.resourceValues(forKeys: [.fileResourceTypeKey]))?.fileResourceType ?? .unknown == .regular else {
+            dispatch_queue.async {
+                completionHandler?(self.throwError(localFile.path, code: URLError.fileIsDirectory))
+            }
+            return nil
+        }
+        
+        let operation = FileOperationType.copy(source: localFile.absoluteString, destination: toPath)
+        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: operation) ?? true == true else {
+            return nil
+        }
+        let request = self.request(for: operation, overwrite: overwrite)
+        return upload_simple(toPath, request: request, localFile: localFile, operation: operation, completionHandler: completionHandler)
+    }
+    
+    open func copyItem(path: String, toLocalURL destURL: URL, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let operation = FileOperationType.copy(source: path, destination: destURL.absoluteString)
+        let request = self.request(for: operation)
+        return self.download_simple(path: path, request: request, operation: operation, completionHandler: { [weak self] (tempURL, error) in
+            if let error = error {
+                completionHandler?(error)
+                self?.delegateNotify(operation, error: error)
+                return
+            }
+            
+            guard let tempURL = tempURL else {
+                completionHandler?(error)
+                self?.delegateNotify(operation, error: error)
+                return
+            }
+            
+            do {
+                try FileManager.default.moveItem(at: tempURL, to: destURL)
+                completionHandler?(nil)
+                self?.delegateNotify(operation)
+            } catch let e {
+                completionHandler?(e)
+                self?.delegateNotify(operation, error: e)
+            }
+        })
+    }
+    
+    open func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> Progress? {
+        if length == 0 || offset < 0 {
+            dispatch_queue.async {
+                completionHandler(Data(), nil)
+            }
+            return nil
+        }
+        
+        let operation = FileOperationType.fetch(path: path)
+        var request = self.request(for: operation)
+        request.set(httpRangeWithOffset: offset, length: length)
+        return self.download_simple(path: path, request: request, operation: operation, completionHandler: { (tempURL, error) in
+            if let error = error {
+                completionHandler(nil, error)
+                return
+            }
+            
+            guard let tempURL = tempURL else {
+                completionHandler(nil, error)
+                return
+            }
+            
+            do {
+                let data = try Data(contentsOf: tempURL)
+                completionHandler(data, nil)
+            } catch let e {
+                completionHandler(nil, e)
+            }
+        })
+    }
+    
+    public func writeContents(path: String, contents data: Data?, atomically: Bool, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let operation = FileOperationType.modify(path: path)
+        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: operation) ?? true == true else {
+            return nil
+        }
+        let request = self.request(for: operation, overwrite: overwrite, attributes: [.contentModificationDateKey: Date()])
+        return upload_simple(path, request: request, data: data ?? Data(), operation: operation, completionHandler: completionHandler)
+    }
+    
+    internal func request(for operation: FileOperationType, overwrite: Bool = false, attributes: [URLResourceKey: Any] = [:]) -> URLRequest {
+        fatalError("HTTPFileProvider is an abstract class. Please implement \(#function) in subclass.")
+    }
+    
+    internal func serverError(with code: FileProviderHTTPErrorCode, path: String?, data: Data?) -> FileProviderHTTPError {
+        fatalError("HTTPFileProvider is an abstract class. Please implement \(#function) in subclass.")
+    }
+    
+    internal func multiStatusHandler(source: String, data: Data, completionHandler: SimpleCompletionHandler) -> Void {
+        // WebDAV will override this function
+    }
+    
+    fileprivate func doOperation(_ operation: FileOperationType, completionHandler: SimpleCompletionHandler) -> Progress? {
+        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: operation) ?? true == true else {
+            return nil
+        }
+        
+        let progress = Progress(totalUnitCount: 1)
+        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+        progress.kind = .file
+        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
+        
+        let request = self.request(for: operation)
+        
+        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
+            var serverError: FileProviderHTTPError?
+            if let response = response as? HTTPURLResponse, response.statusCode >= 300, let code = FileProviderHTTPErrorCode(rawValue: response.statusCode) {
+                serverError = self.serverError(with: code, path: operation.source, data: data)
+            }
+            
+            if let response = response as? HTTPURLResponse, FileProviderHTTPErrorCode(rawValue: response.statusCode) == .multiStatus, let data = data {
+                self.multiStatusHandler(source: operation.source, data: data, completionHandler: completionHandler)
+            }
+            
+            if serverError == nil && error == nil {
+                progress.completedUnitCount = 1
+            } else {
+                progress.cancel()
+            }
+            completionHandler?(serverError ?? error)
+            self.delegateNotify(operation, error: serverError ?? error)
+        })
+        task.taskDescription = operation.json
+        progress.cancellationHandler = { [weak task] in
+            task?.cancel()
+        }
+        progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
+        task.resume()
+        return progress
+    }
+    
+    internal func upload_simple(_ targetPath: String, request: URLRequest, data: Data? = nil, localFile: URL? = nil, operation: FileOperationType, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let size = data?.count ?? Int((try? localFile?.resourceValues(forKeys: [.fileSizeKey]))??.fileSize ?? -1)
+        
+        var progress = Progress(parent: nil, userInfo: nil)
+        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+        progress.kind = .file
+        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
+        progress.totalUnitCount = Int64(size)
+        
+        let task: URLSessionUploadTask
+        if let data = data {
+            task = session.uploadTask(with: request, from: data)
+        } else if let localFile = localFile {
+            task = session.uploadTask(with: request, fromFile: localFile)
+        } else {
+            return nil
+        }
+        
+        completionHandlersForTasks[session.sessionDescription!]?[task.taskIdentifier] = { [weak self] error in
+            var responseError: FileProviderHTTPError?
+            if let code = (task.response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
+                // We can't fetch server result from delegate!
+                responseError = self?.serverError(with: rCode, path: targetPath, data: nil)
+            }
+            if !(responseError == nil && error == nil) {
+                progress.cancel()
+            }
+            completionHandler?(responseError ?? error)
+            self?.delegateNotify(operation, error: responseError ?? error)
+        }
+        task.taskDescription = operation.json
+        task.addObserver(sessionDelegate!, forKeyPath: #keyPath(URLSessionTask.countOfBytesSent), options: .new, context: &progress)
+        progress.cancellationHandler = { [weak task] in
+            task?.cancel()
+        }
+        progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
+        task.resume()
+        return progress
+    }
+    
+    internal func download_simple(path: String, request: URLRequest, operation: FileOperationType, completionHandler: @escaping ((_ tempURL: URL?, _ error: Error?) -> Void)) -> Progress? {
+        var progress = Progress(parent: nil, userInfo: nil)
+        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+        progress.kind = .file
+        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
+        
+        let task = session.downloadTask(with: request)
+        completionHandlersForTasks[session.sessionDescription!]?[task.taskIdentifier] = { error in
+            if error != nil {
+                progress.cancel()
+            }
+            completionHandler(nil, error)
+            self.delegateNotify(operation, error: error)
+        }
+        downloadCompletionHandlersForTasks[session.sessionDescription!]?[task.taskIdentifier] = { tempURL in
+            guard let httpResponse = task.response as? HTTPURLResponse , httpResponse.statusCode < 300 else {
+                let code = FileProviderHTTPErrorCode(rawValue: (task.response as? HTTPURLResponse)?.statusCode ?? -1)
+                let errorData : Data? = nil //Data(contentsOf:cacheURL) // TODO: Figure out how to get error response data for the error description
+                let serverError : FileProviderHTTPError? = code != nil ? self.serverError(with: code!, path: path, data: errorData) : nil
+                if serverError != nil {
+                    progress.cancel()
+                }
+                completionHandler(nil, serverError)
+                self.delegateNotify(operation)
+                return
+            }
+            
+            completionHandler(tempURL, nil)
+        }
+        task.taskDescription = operation.json
+        task.addObserver(sessionDelegate!, forKeyPath: #keyPath(URLSessionTask.countOfBytesReceived), options: .new, context: &progress)
+        task.addObserver(sessionDelegate!, forKeyPath: #keyPath(URLSessionTask.countOfBytesExpectedToReceive), options: .new, context: &progress)
+        progress.cancellationHandler = { [weak task] in
+            task?.cancel()
+        }
+        progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
+        task.resume()
+        return progress
+    }
+}
+
+extension HTTPFileProvider: FileProvider { }
@@ -8,17 +8,24 @@

 import Foundation

+/**
+ This provider class allows interacting with local files placed in user disk. It also allows an
+ easy way to use `NSFileCoordintaing` to coordinate read and write when neccessary.
+ 
+ it uses `FileManager` foundation class with some additions like searching and reading a portion of file.
+ */
 open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndoable {
    open class var type: String { return "Local" }
-    open var isPathRelative: Bool
    open fileprivate(set) var baseURL: URL?
    open var currentPath: String
    open var dispatch_queue: DispatchQueue
    open var operation_queue: OperationQueue
    open weak var delegate: FileProviderDelegate?
-    open internal(set) var credential: URLCredential?
-        
+    open var credential: URLCredential?
+    
+    /// Underlying `FileManager` object for listing and metadata fetching.
    open private(set) var fileManager = FileManager()
+    /// Underlying `FileManager` object for operationa like copying, moving, etc.
    open private(set) var opFileManager = FileManager()
    fileprivate var fileProviderManagerDelegate: LocalFileProviderManagerDelegate? = nil
    
@@ -40,10 +47,10 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
     default values are `directory: .documentDirectory, domainMask: .userDomainMask`.
     
     - Parameters:
-       - directory: The search path directory. The supported values are described in `FileManager.SearchPathDirectory`.
-       - domainMask: The file system domain to search. The value for this parameter is one or more of the constants described in `FileManager.SearchPathDomainMask`.
-    */
-    public convenience init (directory: FileManager.SearchPathDirectory = .documentDirectory, domainMask: FileManager.SearchPathDomainMask = .userDomainMask) {
+     - for: The search path directory. The supported values are described in `FileManager.SearchPathDirectory`.
+     - in: Base locations for directory to search. The value for this parameter is one or more of the constants described in `FileManager.SearchPathDomainMask`.
+     */
+    public convenience init (for directory: FileManager.SearchPathDirectory = .documentDirectory, in domainMask: FileManager.SearchPathDomainMask = .userDomainMask) {
        self.init(baseURL: FileManager.default.urls(for: directory, in: domainMask).first!)
    }
    
@@ -55,7 +62,7 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
     default values are `directory: .documentDirectory`.
    
     - Parameters:
-       - sharedContainerId: Same  with `App Group` identifier defined in project settings.
+       - sharedContainerId: Same with `App Group` identifier defined in project settings.
       - directory: The search path directory. The supported values are described in `FileManager.SearchPathDirectory`.
    */
    public convenience init? (sharedContainerId: String, directory: FileManager.SearchPathDirectory = .documentDirectory) {
@@ -63,7 +70,7 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
            return nil
        }
        
-        var finalBaseURL = baseURL
+        var finalBaseURL = baseURL.absoluteURL
        
        switch directory {
        case .documentDirectory:
@@ -73,12 +80,13 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
        case .cachesDirectory:
            finalBaseURL = baseURL.appendingPathComponent("Library/Caches")
        case .applicationSupportDirectory:
-            finalBaseURL = baseURL.appendingPathComponent("Library/Application%20support")
+            finalBaseURL = baseURL.appendingPathComponent("Library/Application support")
        default:
            break
        }
        
        self.init(baseURL: finalBaseURL)
+        self.isCoorinating = true
        
        try? fileManager.createDirectory(at: finalBaseURL, withIntermediateDirectories: true)
    }
@@ -90,25 +98,51 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
        guard baseURL.isFileURL else {
            fatalError("Cannot initialize a Local provider from remote URL.")
        }
-        self.baseURL = baseURL
-        self.isPathRelative = true
+        self.baseURL = (baseURL.absoluteString.hasSuffix("/") ? baseURL : baseURL.appendingPathComponent("")).absoluteURL
        self.currentPath = ""
        self.credential = nil
        self.isCoorinating = false
        
-        dispatch_queue = DispatchQueue(label: "FileProvider.\(type(of: self).type)", attributes: .concurrent)
+        #if swift(>=3.1)
+        let queueLabel = "FileProvider.\(Swift.type(of: self).type)"
+        #else
+        let queueLabel = "FileProvider.\(type(of: self).type)"
+        #endif
+        dispatch_queue = DispatchQueue(label: queueLabel, attributes: .concurrent)
        operation_queue = OperationQueue()
-        operation_queue.name = "FileProvider.\(type(of: self).type).Operation"
+        operation_queue.name = "\(queueLabel).Operation"
        
        fileProviderManagerDelegate = LocalFileProviderManagerDelegate(provider: self)
        opFileManager.delegate = fileProviderManagerDelegate
-        
    }
    
-    /// **DEPRECATED:** No longer is in use and overriding this method has no effect anymore.
-    @available(*, deprecated, message: "Overriding this method has no effect anymore.")
-    open class func defaultBaseURL() -> URL {
-        return FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
+    public required convenience init?(coder aDecoder: NSCoder) {
+        guard let baseURL = aDecoder.decodeObject(forKey: "baseURL") as? URL else {
+            return nil
+        }
+        self.init(baseURL: baseURL)
+        self.currentPath   = aDecoder.decodeObject(forKey: "currentPath") as? String ?? ""
+        self.isCoorinating = aDecoder.decodeBool(forKey: "isCoorinating")
+    }
+    
+    open func encode(with aCoder: NSCoder) {
+        aCoder.encode(self.baseURL, forKey: "currentPath")
+        aCoder.encode(self.currentPath, forKey: "currentPath")
+        aCoder.encode(self.isCoorinating, forKey: "isCoorinating")
+    }
+    
+    public static var supportsSecureCoding: Bool {
+        return true
+    }
+    
+    public func copy(with zone: NSZone? = nil) -> Any {
+        let copy = LocalFileProvider(baseURL: self.baseURL!)
+        copy.currentPath = self.currentPath
+        copy.undoManager = self.undoManager
+        copy.isCoorinating = self.isCoorinating
+        copy.delegate = self.delegate
+        copy.fileOperationDelegate = self.fileOperationDelegate
+        return copy
    }
    
    open func contentsOfDirectory(path: String, completionHandler: @escaping ((_ contents: [FileObject], _ error: Error?) -> Void)) {
@@ -126,6 +160,12 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
        }
    }
    
+    open func attributesOfItem(path: String, completionHandler: @escaping ((_ attributes: FileObject?, _ error: Error?) -> Void)) {
+        dispatch_queue.async {
+            completionHandler(LocalFileObject(fileWithPath: path, relativeTo: self.baseURL), nil)
+        }
+    }
+    
    open func storageProperties(completionHandler: (@escaping (_ total: Int64, _ used: Int64) -> Void)) {
        let values = try? baseURL?.resourceValues(forKeys: [.volumeTotalCapacityKey, .volumeAvailableCapacityKey])
        let totalSize = Int64(values??.volumeTotalCapacity ?? -1)
@@ -133,73 +173,114 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
        completionHandler(totalSize, totalSize - freeSize)
    }
    
-    open func attributesOfItem(path: String, completionHandler: @escaping ((_ attributes: FileObject?, _ error: Error?) -> Void)) {
+    open func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) -> Progress? {
+        let progress = Progress(parent: nil, userInfo: nil)
+        progress.setUserInfoObject(self.url(of: path), forKey: .fileURLKey)
+        
        dispatch_queue.async {
-            completionHandler(LocalFileObject(fileWithPath: path, relativeTo: self.baseURL), nil)
+            progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
+            let iterator = self.fileManager.enumerator(at: self.url(of: path), includingPropertiesForKeys: nil, options: recursive ? [] : [.skipsSubdirectoryDescendants, .skipsPackageDescendants]) { (url, e) -> Bool in
+                completionHandler([], e)
+                return true
+            }
+            var result = [LocalFileObject]()
+            while let fileURL = iterator?.nextObject() as? URL {
+                if progress.isCancelled {
+                    break
+                }
+                let path = self.relativePathOf(url: fileURL)
+                if let fileObject = LocalFileObject(fileWithPath: path, relativeTo: self.baseURL), query.evaluate(with: fileObject.mapPredicate()) {
+                    result.append(fileObject)
+                    progress.completedUnitCount = Int64(result.count)
+                    foundItemHandler?(fileObject)
+                }
+            }
+            completionHandler(result, nil)
+        }
+        
+        return progress
+    }
+    
+    open func isReachable(completionHandler: @escaping (Bool) -> Void) {
+        dispatch_queue.async {
+            completionHandler(self.fileManager.isReadableFile(atPath: self.baseURL!.path))
        }
    }
    
    open weak var fileOperationDelegate : FileOperationDelegate?
    
    @discardableResult
-    open func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.create(path: (atPath as NSString).appendingPathComponent(folderName) + "/")
-        return self.doOperation(opType, completionHandler: completionHandler)
+    open func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let operation = FileOperationType.create(path: (atPath as NSString).appendingPathComponent(folderName) + "/")
+        return self.doOperation(operation, completionHandler: completionHandler)
    }
    
    @discardableResult
-    open func create(file fileName: String, at atPath: String, contents data: Data?, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let fileName = fileName.trimmingCharacters(in: CharacterSet(charactersIn: "/"))
-        let path = (atPath as NSString).appendingPathComponent(fileName)
-        let opType = FileOperationType.create(path: path)
+    open func moveItem(path: String, to toPath: String, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let operation = FileOperationType.move(source: path, destination: toPath)
        
-        return self.doOperation(opType, data: data, atomically: true, completionHandler: completionHandler)
-    }
-    
-    @discardableResult
-    open func moveItem(path: String, to toPath: String, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.move(source: path, destination: toPath)
-
-        if !overwrite && self.fileManager.fileExists(atPath: self.url(of: toPath).path) {
-            completionHandler?(self.throwError(toPath, code: CocoaError.fileWriteFileExists as FoundationErrorEnum))
+        let fileExists = ((try? self.url(of: toPath).checkResourceIsReachable()) ?? false) ||
+            ((try? self.url(of: toPath).checkPromisedItemIsReachable()) ?? false)
+        if !overwrite && fileExists {
+            let e = self.throwError(toPath, code: CocoaError.fileWriteFileExists)
+            dispatch_queue.async {
+                completionHandler?(e)
+            }
+            self.delegateNotify(operation, error: e)
            return nil
        }
        
-        return self.doOperation(opType, completionHandler: completionHandler)
+        return self.doOperation(operation, completionHandler: completionHandler)
    }
    
    @discardableResult
-    open func copyItem(path: String, to toPath: String, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.copy(source: path, destination: toPath)
+    open func copyItem(path: String, to toPath: String, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let operation = FileOperationType.copy(source: path, destination: toPath)
        
-        if !overwrite && self.fileManager.fileExists(atPath: self.url(of: toPath).path) {
-            completionHandler?(self.throwError(toPath, code: CocoaError.fileWriteFileExists as FoundationErrorEnum))
+        let fileExists = ((try? self.url(of: toPath).checkResourceIsReachable()) ?? false) ||
+            ((try? self.url(of: toPath).checkPromisedItemIsReachable()) ?? false)
+        if !overwrite && fileExists {
+            let e = self.throwError(toPath, code: CocoaError.fileWriteFileExists)
+            dispatch_queue.async {
+                completionHandler?(e)
+            }
+            self.delegateNotify(operation, error: e)
            return nil
        }
        
-        return self.doOperation(opType, completionHandler: completionHandler)
+        return self.doOperation(operation, completionHandler: completionHandler)
    }
    
    @discardableResult
-    open func removeItem(path: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.remove(path: path)
-        return self.doOperation(opType, completionHandler: completionHandler)
+    open func removeItem(path: String, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let operation = FileOperationType.remove(path: path)
+        return self.doOperation(operation, completionHandler: completionHandler)
    }
    
    @discardableResult
-    open func copyItem(localFile: URL, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        // TODO: Make use of overwrite parameter
-        let opType = FileOperationType.copy(source: localFile.absoluteString, destination: toPath)
-        return self.doOperation(opType, completionHandler: completionHandler)
+    open func copyItem(localFile: URL, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let operation = FileOperationType.copy(source: localFile.absoluteString, destination: toPath)
+        
+        let fileExists = ((try? self.url(of: toPath).checkResourceIsReachable()) ?? false) ||
+            ((try? self.url(of: toPath).checkPromisedItemIsReachable()) ?? false)
+        if !overwrite && fileExists {
+            let e = self.throwError(toPath, code: CocoaError.fileWriteFileExists)
+            dispatch_queue.async {
+                completionHandler?(e)
+            }
+            self.delegateNotify(operation, error: e)
+            return nil
+        }
+        return self.doOperation(operation, forUploading: true, completionHandler: completionHandler)
    }
    
    @discardableResult
-    open func copyItem(path: String, toLocalURL: URL, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.copy(source: path, destination: toLocalURL.absoluteString)
-        return self.doOperation(opType, completionHandler: completionHandler)
+    open func copyItem(path: String, toLocalURL: URL, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let operation = FileOperationType.copy(source: path, destination: toLocalURL.absoluteString)
+        return self.doOperation(operation, completionHandler: completionHandler)
    }
    
-    dynamic func doSimpleOperation(_ box: UndoBox) {
+    @objc dynamic func doSimpleOperation(_ box: UndoBox) {
        guard let _ = self.undoManager else { return }
        _ = self.doOperation(box.undoOperation) { (_) in
            return
@@ -207,45 +288,71 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
    }
    
    @discardableResult
-    fileprivate func doOperation(_ opType: FileOperationType, data: Data? = nil, atomically: Bool = false, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        guard let sourcePath = opType.source else { return nil }
-        let destPath = opType.destination
-        let source: URL = sourcePath.hasPrefix("file://") ? URL(string: sourcePath)! : self.url(of: sourcePath)
-        let dest: URL?
+    fileprivate func doOperation(_ operation: FileOperationType, data: Data? = nil, atomically: Bool = false, forUploading: Bool = false, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let progress = Progress(parent: nil, userInfo: nil)
+        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+        progress.kind = .file
+        progress.isCancellable = false
+        progress.setUserInfoObject(Progress.FileOperationKind.receiving, forKey: .fileOperationKindKey)
+        func urlofpath(path: String) -> URL {
+            if path.hasPrefix("file://") {
+                let removedSchemePath = path.replacingOccurrences(of: "file://", with: "", options: .anchored)
+                let pDecodedPath = removedSchemePath.removingPercentEncoding ?? removedSchemePath
+                return URL(fileURLWithPath: pDecodedPath)
+            } else {
+                return self.url(of: path)
+            }
+        }
        
+        let sourcePath = operation.source
+        let destPath = operation.destination
+        let source: URL = urlofpath(path: sourcePath)
+        progress.setUserInfoObject(source, forKey: .fileURLKey)
+        
+        let dest: URL?
        if let destPath = destPath {
-            dest = destPath.hasPrefix("file://") ? URL(string: destPath)! : self.url(of: destPath)
+            dest = urlofpath(path: destPath)
        } else {
            dest = nil
        }
        
-        if let undoManager = self.undoManager, let undoOp = self.undoOperation(for: opType) {
-            let undoBox = UndoBox(provider: self, operation: opType, undoOperation: undoOp)
+        if let undoManager = self.undoManager, let undoOp = self.undoOperation(for: operation) {
+            let undoBox = UndoBox(provider: self, operation: operation, undoOperation: undoOp)
            undoManager.beginUndoGrouping()
            undoManager.registerUndo(withTarget: self, selector: #selector(LocalFileProvider.doSimpleOperation(_:)), object: undoBox)
-            undoManager.setActionName(opType.actionDescription)
+            undoManager.setActionName(operation.actionDescription)
            undoManager.endUndoGrouping()
        }
        
+        var successfulSecurityScopedResourceAccess = false
+        
        let operationHandler: (URL, URL?) -> Void = { source, dest in
-            let successfulSecurityScopedResourceAccess = source.startAccessingSecurityScopedResource()
            do {
-                switch opType {
+                progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
+                switch operation {
                case .create:
                    if sourcePath.hasSuffix("/") {
+                        progress.totalUnitCount = 1
                        try self.opFileManager.createDirectory(at: source, withIntermediateDirectories: true, attributes: [:])
                    } else {
-                        try data?.write(to: source, options: Data.WritingOptions.atomic)
+                        progress.totalUnitCount = Int64(data?.count ?? 0)
+                        try data?.write(to: source, options: .atomic)
                    }
                case .modify:
+                    progress.totalUnitCount = Int64(data?.count ?? 0)
                    try data?.write(to: source, options: atomically ? [.atomic] : [])
                case .copy:
                    guard let dest = dest else { return }
+                    progress.setUserInfoObject(Progress.FileOperationKind.copying, forKey: .fileOperationKindKey)
+                    progress.totalUnitCount = abs(source.fileSize)
                    try self.opFileManager.copyItem(at: source, to: dest)
                case .move:
+                    progress.setUserInfoObject(Progress.FileOperationKind.copying, forKey: .fileOperationKindKey)
                    guard let dest = dest else { return }
+                    progress.totalUnitCount = abs(source.fileSize)
                    try self.opFileManager.moveItem(at: source, to: dest)
                case.remove:
+                    progress.totalUnitCount = abs(source.fileSize)
                    try self.opFileManager.removeItem(at: source)
                default:
                    return
@@ -253,134 +360,178 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
                if successfulSecurityScopedResourceAccess {
                    source.stopAccessingSecurityScopedResource()
                }
-                
-                completionHandler?(nil)
-                DispatchQueue.main.async {
-                    self.delegate?.fileproviderSucceed(self, operation: opType)
+
+                progress.completedUnitCount = progress.totalUnitCount
+                self.dispatch_queue.async {
+                    completionHandler?(nil)
                }
+                self.delegateNotify(operation)
            } catch let e {
                if successfulSecurityScopedResourceAccess {
                    source.stopAccessingSecurityScopedResource()
                }
-                completionHandler?(e)
-                DispatchQueue.main.async {
-                    self.delegate?.fileproviderFailed(self, operation: opType)
+                progress.cancel()
+                self.dispatch_queue.async {
+                    completionHandler?(e)
                }
+                self.delegateNotify(operation, error: e)
            }
        }
        
        if isCoorinating {
+            successfulSecurityScopedResourceAccess = source.startAccessingSecurityScopedResource()
            var intents = [NSFileAccessIntent]()
-            
-            switch opType {
-            case .create, .remove, .modify:
+            switch operation {
+            case .create, .modify:
                intents.append(NSFileAccessIntent.writingIntent(with: source, options: .forReplacing))
            case .copy:
                guard let dest = dest else { return nil }
-                intents.append(NSFileAccessIntent.readingIntent(with: source, options: .withoutChanges))
+                intents.append(NSFileAccessIntent.readingIntent(with: source, options: forUploading ? .forUploading : .withoutChanges))
                intents.append(NSFileAccessIntent.writingIntent(with: dest, options: .forReplacing))
            case .move:
                guard let dest = dest else { return nil }
-                intents.append(NSFileAccessIntent.writingIntent(with: source, options: .forDeleting))
+                intents.append(NSFileAccessIntent.writingIntent(with: source, options: .forMoving))
                intents.append(NSFileAccessIntent.writingIntent(with: dest, options: .forReplacing))
+            case .remove:
+                intents.append(NSFileAccessIntent.writingIntent(with: source, options: .forDeleting))
            default:
                return nil
            }
-            self.coordinated(intents: intents, completionHandler: operationHandler, errorHandler: { error in
-                completionHandler?(error)
-                DispatchQueue.main.async {
-                    self.delegate?.fileproviderFailed(self, operation: opType)
+            self.coordinated(intents: intents, operationHandler: operationHandler, errorHandler: { error in
+                self.dispatch_queue.async {
+                    completionHandler?(error)
                }
+                self.delegateNotify(operation, error: error)
            })
        } else {
            operation_queue.addOperation {
                operationHandler(source, dest)
            }
        }
-        
-        return LocalOperationHandle(operationType: opType, baseURL: self.baseURL)
+        return progress
    }
    
    @discardableResult
-    open func contents(path: String, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
-        let opType = FileOperationType.fetch(path: path)
+    open func contents(path: String, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> Progress? {
+        let operation = FileOperationType.fetch(path: path)
        let url = self.url(of: path)
        
+        let progress = Progress(parent: nil, userInfo: nil)
+        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+        progress.kind = .file
+        progress.isCancellable = false
+        progress.setUserInfoObject(Progress.FileOperationKind.receiving, forKey: .fileOperationKindKey)
+        progress.setUserInfoObject(url, forKey: .fileURLKey)
+        progress.totalUnitCount = url.fileSize
+        
        let operationHandler: (URL) -> Void = { url in
+            progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
            do {
                let data = try Data(contentsOf: url)
-                completionHandler(data, nil)
+                progress.completedUnitCount = progress.totalUnitCount
+                self.dispatch_queue.async {
+                    completionHandler(data, nil)
+                }
+                self.delegateNotify(operation)
            } catch let e {
-                completionHandler(nil, e)
+                progress.cancel()
+                self.dispatch_queue.async {
+                    completionHandler(nil, e)
+                }
+                self.delegateNotify(operation, error: e)
            }
        }
        
        if isCoorinating {
            let intent = NSFileAccessIntent.readingIntent(with: url, options: .withoutChanges)
-            coordinated(intents: [intent], completionHandler: operationHandler, errorHandler: { error in
-                completionHandler(nil, error)
-                DispatchQueue.main.async {
-                    self.delegate?.fileproviderFailed(self, operation: opType)
+            coordinated(intents: [intent], operationHandler: operationHandler, errorHandler: { error in
+                self.dispatch_queue.async {
+                    completionHandler(nil, error)
                }
+                self.delegateNotify(operation, error: error)
            })
        } else {
            dispatch_queue.async {
                operationHandler(url)
            }
        }
-        
-        return LocalOperationHandle(operationType: opType, baseURL: self.baseURL)
+
+        return progress
    }
    
    @discardableResult
-    open func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
+    open func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> Progress? {
        if length == 0 || offset < 0 {
            dispatch_queue.async {
                completionHandler(Data(), nil)
            }
            return nil
        }
-        
+
        if offset == 0 && length < 0 {
            return self.contents(path: path, completionHandler: completionHandler)
        }
-        
-        let opType = FileOperationType.fetch(path: path)
+
+        let operation = FileOperationType.fetch(path: path)
        let url = self.url(of: path)
        
+        let progress = Progress(parent: nil, userInfo: nil)
+        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+        progress.kind = .file
+        progress.isCancellable = false
+        progress.setUserInfoObject(url, forKey: .fileURLKey)
+        progress.setUserInfoObject(Progress.FileOperationKind.receiving, forKey: .fileOperationKindKey)
+        
        let operationHandler: (URL) -> Void = { url in
            guard let handle = FileHandle(forReadingAtPath: url.path) else {
-                completionHandler(nil, self.throwError(path, code: CocoaError.fileNoSuchFile as FoundationErrorEnum))
+                self.dispatch_queue.async {
+                    let e = self.throwError(path, code: CocoaError.fileNoSuchFile)
+                    completionHandler(nil, e)
+                    self.delegateNotify(operation, error: e)
+                }
                return
            }
            
            defer {
                handle.closeFile()
            }
-            
+
            let size = LocalFileObject(fileWithURL: url)?.size ?? -1
+            progress.totalUnitCount = size
            guard size > offset else {
-                completionHandler(nil, self.throwError(path, code: CocoaError.fileReadTooLarge as FoundationErrorEnum))
+                progress.cancel()
+                self.dispatch_queue.async {
+                    let e = self.throwError(path, code: CocoaError.fileReadTooLarge)
+                    completionHandler(nil, e)
+                    self.delegateNotify(operation, error: e)
+                }
                return
            }
+            progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
            handle.seek(toFileOffset: UInt64(offset))
            guard Int64(handle.offsetInFile) == offset else {
-                completionHandler(nil, self.throwError(path, code: CocoaError.fileReadTooLarge as FoundationErrorEnum))
+                progress.cancel()
+                self.dispatch_queue.async {
+                    let e = self.throwError(path, code: CocoaError.fileReadTooLarge)
+                    completionHandler(nil, e)
+                    self.delegateNotify(operation, error: e)
+                }
                return
            }
            
            let data = handle.readData(ofLength: length)
-            
-            completionHandler(data, nil)
+            progress.completedUnitCount = progress.totalUnitCount
+            self.dispatch_queue.async {
+                completionHandler(data, nil)
+                self.delegateNotify(operation)
+            }
        }
        
        if isCoorinating {
            let intent = NSFileAccessIntent.readingIntent(with: url, options: .withoutChanges)
-            coordinated(intents: [intent], completionHandler: operationHandler, errorHandler: { error in
+            coordinated(intents: [intent], operationHandler: operationHandler, errorHandler: { error in
                completionHandler(nil, error)
-                DispatchQueue.main.async {
-                    self.delegate?.fileproviderFailed(self, operation: opType)
-                }
+                self.delegateNotify(operation, error: error)
            })
        } else {
            dispatch_queue.async {
@@ -388,33 +539,24 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
            }
        }
        
-        return LocalOperationHandle(operationType: opType, baseURL: self.baseURL)
+        return progress
    }
    
    @discardableResult
-    open func writeContents(path: String, contents data: Data, atomically: Bool, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.modify(path: path)
-        return self.doOperation(opType, data: data, atomically: atomically, completionHandler: completionHandler)
-    }
-    
-    open func searchFiles(path: String, recursive: Bool, query: String, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) {
-        dispatch_queue.async { 
-            let iterator = self.fileManager.enumerator(at: self.url(of: path), includingPropertiesForKeys: nil, options: recursive ? [] : [.skipsSubdirectoryDescendants, .skipsPackageDescendants]) { (url, e) -> Bool in
-                completionHandler([], e)
-                return true
+    open func writeContents(path: String, contents data: Data?, atomically: Bool, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let fileExists = ((try? self.url(of: path).checkResourceIsReachable()) ?? false) ||
+            ((try? self.url(of: path).checkPromisedItemIsReachable()) ?? false)
+        if !overwrite && fileExists {
+            let e = self.throwError(path, code: CocoaError.fileWriteFileExists)
+            dispatch_queue.async {
+                completionHandler?(e)
            }
-            var result = [LocalFileObject]()
-            while let fileURL = iterator?.nextObject() as? URL {
-                if fileURL.lastPathComponent.lowercased().contains(query.lowercased()) {
-                    let path = self.relativePathOf(url: fileURL)
-                    if let fileObject = LocalFileObject(fileWithPath: path, relativeTo: self.baseURL) {
-                        result.append(fileObject)
-                        foundItemHandler?(fileObject)
-                    }
-                }
-            }
-            completionHandler(result, nil)
+            self.delegateNotify(.modify(path: path), error: e)
+            return nil
        }
+        
+        let operation: FileOperationType = fileExists ? .modify(path: path) : .create(path: path)
+        return self.doOperation(operation, data: data ?? Data(), atomically: atomically, completionHandler: completionHandler)
    }
    
    fileprivate var monitors = [LocalFolderMonitor]()
@@ -422,7 +564,7 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
    open func registerNotifcation(path: String, eventHandler: @escaping (() -> Void)) {
        self.unregisterNotifcation(path: path)
        let dirurl = self.url(of: path)
-        let isdir = (try? dirurl.resourceValues(forKeys: [.isDirectoryKey]).isDirectory ?? false) ?? false
+        let isdir = (try? dirurl.resourceValues(forKeys: [.isDirectoryKey]))?.isDirectory ?? false
        if !isdir {
            return
        }
@@ -445,46 +587,30 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
    }
    
    open func isRegisteredForNotification(path: String) -> Bool {
-        return monitors.map( { self.relativePathOf(url: $0.url) } ).contains(path)
+        return monitors.map( { self.relativePathOf(url: $0.url) } ).contains(path.trimmingCharacters(in: CharacterSet(charactersIn: "/")))
    }
    
-    open func copy(with zone: NSZone? = nil) -> Any {
-        let copy = LocalFileProvider(baseURL: self.baseURL!)
-        copy.currentPath = self.currentPath
-        copy.delegate = self.delegate
-        copy.fileOperationDelegate = self.fileOperationDelegate
-        copy.isPathRelative = self.isPathRelative
-        copy.undoManager = self.undoManager
-        copy.isCoorinating = self.isCoorinating
-        return copy
-    }
-}
-
-public extension LocalFileProvider {
    /**
     Creates a symbolic link at the specified path that points to an item at the given path.
-     This method does not traverse symbolic links contained in destURL, making it possible 
-     to create symbolic links to locations that do not yet exist. 
-     Also, if the final path component in url is a symbolic link, that link is not followed.
+     This method does not traverse symbolic links contained in destination path, making it possible
+     to create symbolic links to locations that do not yet exist.
+     Also, if the final path component is a symbolic link, that link is not followed.
    
     - Parameters:
-       - path: The file path at which to create the new symbolic link. The last component of the path issued as the name of the link.
-       - destPath: The path that contains the item to be pointed to by the link. In other words, this is the destination of the link.
+       - symbolicLink: The file path at which to create the new symbolic link. The last component of the path issued as the name of the link.
+       - withDestinationPath: The path that contains the item to be pointed to by the link. In other words, this is the destination of the link.
       - completionHandler: If an error parameter was provided, a presentable `Error` will be returned.
    */
-    public func create(symbolicLink path: String, withDestinationPath destPath: String, completionHandler: SimpleCompletionHandler) {
+    open func create(symbolicLink path: String, withDestinationPath destPath: String, completionHandler: SimpleCompletionHandler) {
        operation_queue.addOperation {
+            let operation = FileOperationType.link(link: path, target: destPath)
            do {
                try self.opFileManager.createSymbolicLink(at: self.url(of: path), withDestinationURL: self.url(of: destPath))
                completionHandler?(nil)
-                DispatchQueue.main.async {
-                    self.delegate?.fileproviderSucceed(self, operation: .link(link: path, target: destPath))
-                }
+                self.delegateNotify(operation)
            } catch let e {
                completionHandler?(e)
-                DispatchQueue.main.async {
-                    self.delegate?.fileproviderFailed(self, operation: .link(link: path, target: destPath))
-                }
+                self.delegateNotify(operation, error: e)
            }
        }
    }
@@ -494,7 +620,7 @@ public extension LocalFileProvider {
    /// - Parameters:
    ///   - path: The path of a file or directory.
    ///   - completionHandler: Returns destination url of given symbolic link, or an `Error` object if it fails.
-    public func destination(ofSymbolicLink path: String, completionHandler: @escaping (_ url: URL?, _ error: Error?) -> Void) {
+    open func destination(ofSymbolicLink path: String, completionHandler: @escaping (_ url: URL?, _ error: Error?) -> Void) {
        dispatch_queue.async {
            do {
                let destPath = try self.opFileManager.destinationOfSymbolicLink(atPath: self.url(of: path).path)
@@ -508,30 +634,30 @@ public extension LocalFileProvider {
 }

 internal extension LocalFileProvider {
-    func coordinated(intents: [NSFileAccessIntent], completionHandler: @escaping (_ url: URL) -> Void, errorHandler: ((_ error: Error) -> Void)? = nil) {
+    func coordinated(intents: [NSFileAccessIntent], operationHandler: @escaping (_ url: URL) -> Void, errorHandler: ((_ error: Error) -> Void)? = nil) {
        let coordinator = NSFileCoordinator(filePresenter: nil)
        coordinator.coordinate(with: intents, queue: operation_queue) { (error) in
            if let error = error {
                errorHandler?(error)
                return
            }
-            completionHandler(intents[0].url)
+            operationHandler(intents.first!.url)
        }
    }
    
-    func coordinated(intents: [NSFileAccessIntent], moving: Bool = false, completionHandler: @escaping (_ sourceUrl: URL, _ destURL: URL?) -> Void, errorHandler:  ((_ error: Error) -> Void)? = nil) {
+    func coordinated(intents: [NSFileAccessIntent], moving: Bool = false, operationHandler: @escaping (_ sourceUrl: URL, _ destURL: URL?) -> Void, errorHandler:  ((_ error: Error) -> Void)? = nil) {
        let coordinator = NSFileCoordinator(filePresenter: nil)
        coordinator.coordinate(with: intents, queue: operation_queue) { (error) in
            if let error = error {
                errorHandler?(error)
                return
            }
-            let newSource: URL = intents[0].url
-            let newDest: URL? = intents.count > 1 ? intents[1].url : nil
+            guard let newSource: URL = intents.first?.url else { return }
+            let newDest: URL? = intents.dropFirst().first?.url
            if moving, let newDest = newDest {
                coordinator.item(at: newSource, willMoveTo: newDest)
            }
-            completionHandler(newSource, newDest)
+            operationHandler(newSource, newDest)
            if moving, let newDest = newDest {
                coordinator.item(at: newSource, didMoveTo: newDest)
            }
@@ -8,26 +8,26 @@

 import Foundation

+/// Containts path, url and attributes of a local file or resource.
 public final class LocalFileObject: FileObject {
-    internal override init(url: URL, name: String, path: String) {
+    internal override init(url: URL?, name: String, path: String) {
        super.init(url: url, name: name, path: path)
    }
    
+    /// Initiates a `LocalFileObject` with attributes of file in path.
    public convenience init? (fileWithPath path: String, relativeTo relativeURL: URL?) {
        var fileURL: URL?
-        var rpath = path.replacingOccurrences(of: relativeURL?.absoluteString  ?? "", with: "", options: .anchored)
-        if path.hasPrefix("/") {
-            rpath.remove(at: rpath.startIndex)
+        var rpath = path.replacingOccurrences(of: relativeURL?.path ?? "", with: "", options: .anchored)
+        if relativeURL != nil && rpath.hasPrefix("/") {
+            _=rpath.characters.removeFirst()
        }
-        if rpath.isEmpty {
-            fileURL = relativeURL
+        if #available(iOS 9.0, macOS 10.11, tvOS 9.0, *) {
+            fileURL = URL(fileURLWithPath: rpath, relativeTo: relativeURL)
        } else {
-            if #available(iOS 9.0, macOS 10.11, tvOS 9.0, *) {
-                fileURL = URL(fileURLWithPath: rpath, relativeTo: relativeURL)
-            } else {
-                fileURL = URL(string: rpath, relativeTo: relativeURL)
-            }
+            rpath = rpath.addingPercentEncoding(withAllowedCharacters: .urlPathAllowed) ?? rpath
+            fileURL = URL(string: rpath, relativeTo: relativeURL) ?? relativeURL
        }
+        
        if let fileURL = fileURL {
            self.init(fileWithURL: fileURL)
        } else {
@@ -35,9 +35,10 @@ public final class LocalFileObject: FileObject {
        }
    }
    
+    /// Initiates a `LocalFileObject` with attributes of file in url.
    public convenience init?(fileWithURL fileURL: URL) {
        do {
-            let values = try fileURL.resourceValues(forKeys: [.nameKey, .fileSizeKey, .fileAllocatedSizeKey, .creationDateKey, .contentModificationDateKey, .fileResourceTypeKey, .isHiddenKey, .isWritableKey, .typeIdentifierKey, .generationIdentifierKey, .documentIdentifierKey])
+            let values = try fileURL.resourceValues(forKeys: [.nameKey, .fileSizeKey, .totalFileSizeKey, .fileAllocatedSizeKey, .totalFileAllocatedSizeKey, .creationDateKey, .contentModificationDateKey, .fileResourceTypeKey, .isHiddenKey, .isWritableKey, .typeIdentifierKey, .generationIdentifierKey, .documentIdentifierKey])
            let path = fileURL.relativePath.hasPrefix("/") ? fileURL.relativePath : "/" + fileURL.relativePath
            
            self.init(url: fileURL, name: values.name ?? fileURL.lastPathComponent, path: path)
@@ -49,6 +50,7 @@ public final class LocalFileObject: FileObject {
        }
    }
    
+    /// The total size allocated on disk for the file
    open internal(set) var allocatedSize: Int64 {
        get {
            return allValues[.fileAllocatedSizeKey] as? Int64 ?? 0
@@ -58,6 +60,9 @@ public final class LocalFileObject: FileObject {
        }
    }
    
+    /// The document identifier is a value assigned by the kernel/system to a file or directory. 
+    /// This value is used to identify the document regardless of where it is moved on a volume. 
+    /// The identifier persists across system restarts.
    open internal(set) var id: Int? {
        get {
            return allValues[.documentIdentifierKey] as? Int
@@ -67,6 +72,8 @@ public final class LocalFileObject: FileObject {
        }
    }
    
+    /// The revision of file, which changes when a file contents are modified. 
+    /// Changes to attributes or other file metadata do not change the identifier.
    open var rev: String? {
        get {
            let data = allValues[.generationIdentifierKey] as? Data
@@ -87,18 +94,21 @@ internal final class LocalFolderMonitor {
    init(url: URL, handler: @escaping ()->Void) {
        self.url = url
        descriptor = open((url as NSURL).fileSystemRepresentation, O_EVTONLY)
-        source = DispatchSource.makeFileSystemObjectSource(fileDescriptor: descriptor, eventMask: DispatchSource.FileSystemEvent.write, queue: qq)
+        source = DispatchSource.makeFileSystemObjectSource(fileDescriptor: descriptor, eventMask: .write, queue: qq)
        // Folder monitoring is recursive and deep. Monitoring a root folder may be very costly
        // We have a 0.2 second delay to ensure we wont call handler 1000s times when there is
        // a huge file operation. This ensures app will work smoothly while this 250 milisec won't
        // affect user experince much
-        let main_handler: ()->Void = {
+        let main_handler: ()->Void = { [weak self] in
+            guard let `self` = self else { return }
            if Date().timeIntervalSinceReferenceDate < self.monitoredTime + 0.2 {
                return
            }
            self.monitoredTime = Date().timeIntervalSinceReferenceDate
-            DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 0.25, execute: {
+            self.source.suspend()
+            DispatchQueue.main.asyncAfter(deadline: .now() + 0.25, execute: {
                handler()
+                self.source.resume()
            })
        }
        source.setEventHandler(handler: main_handler)
@@ -207,104 +217,6 @@ internal class LocalFileProviderManagerDelegate: NSObject, FileManagerDelegate {
    }
 }

-open class LocalOperationHandle: OperationHandle {
-    public let baseURL: URL
-    public let operationType: FileOperationType
-    
-    init (operationType: FileOperationType, baseURL: URL?) {
-        self.baseURL = baseURL ?? URL(fileURLWithPath: "/")
-        self.operationType = operationType
-    }
-    
-    private var sourceURL: URL? {
-        guard let source = operationType.source else { return nil }
-        return source.hasPrefix("file://") ? URL(fileURLWithPath: source) : baseURL.appendingPathComponent(source)
-    }
-    
-    private var destURL: URL? {
-        guard let dest = operationType.destination else { return nil }
-        return dest.hasPrefix("file://") ? URL(fileURLWithPath: dest) : baseURL.appendingPathComponent(dest)
-    }
-    
-    /// Caution: may put pressure on CPU, may have latency
-    open var bytesSoFar: Int64 {
-        assert(!Thread.isMainThread, "Don't run \(#function) method on main thread")
-        switch operationType {
-        case .modify:
-            guard let url = sourceURL, url.isFileURL else { return 0 }
-            if url.fileIsDirectory {
-                return iterateDirectory(url, deep: true).totalsize
-            } else {
-                return url.fileSize
-            }
-        case .copy, .move:
-            guard let url = destURL, url.isFileURL else { return 0 }
-            if url.fileIsDirectory {
-                return iterateDirectory(url, deep: true).totalsize
-            } else {
-                return url.fileSize
-            }
-        default:
-            return 0
-        }
-        
-    }
-    
-    /// Caution: may put pressure on CPU, may have latency
-    open var totalBytes: Int64 {
-        assert(!Thread.isMainThread, "Don't run \(#function) method on main thread")
-        switch operationType {
-        case .copy, .move:
-            guard let url = sourceURL, url.isFileURL else { return 0 }
-            if url.fileIsDirectory {
-                return iterateDirectory(url, deep: true).totalsize
-            } else {
-                return url.fileSize
-            }
-        default:
-            return 0
-        }
-    }
-    
-    /// Not usable in local provider
-    open var inProgress: Bool {
-        return false
-    }
-    
-    /// Not usable in local provider
-    open func cancel() -> Bool{
-        return false
-    }
-    
-    func iterateDirectory(_ pathURL: URL, deep: Bool) -> (folders: Int, files: Int, totalsize: Int64) {
-        var folders = 0
-        var files = 0
-        var totalsize: Int64 = 0
-        let keys: [URLResourceKey] = [.isDirectoryKey, .fileSizeKey]
-        let enumOpt: FileManager.DirectoryEnumerationOptions = !deep ? [.skipsSubdirectoryDescendants, .skipsPackageDescendants] : []
-        
-        let fp = FileManager()
-        let filesList = fp.enumerator(at: pathURL, includingPropertiesForKeys: keys, options: enumOpt, errorHandler: nil)
-        while let fileURL = filesList?.nextObject() as? URL {
-            do {
-                let values = try fileURL.resourceValues(forKeys: [.isDirectoryKey, .fileSizeKey])
-                let isdir = values.isDirectory ?? false
-                let size = Int64(values.fileSize ?? 0)
-                if isdir {
-                    folders += 1
-                } else {
-                    files += 1
-                }
-                totalsize += size
-            } catch _ {
-            }
-        }
-        
-        return (folders, files, totalsize)
-        
-    }
-}
-
 class UndoBox: NSObject {
    weak var provider: FileProvideUndoable?
    let operation: FileOperationType
@@ -316,17 +228,3 @@ class UndoBox: NSObject {
        self.undoOperation = undoOperation
    }
 }
-
-internal extension URL {
-    var fileIsDirectory: Bool {
-        return (try? self.resourceValues(forKeys: [.isDirectoryKey]))?.isDirectory ?? false
-    }
-    
-    var fileSize: Int64 {
-        return Int64((try? self.resourceValues(forKeys: [.fileSizeKey]))?.fileSize ?? -1)
-    }
-    
-    var fileExists: Bool {
-        return self.isFileURL && FileManager.default.fileExists(atPath: self.path)
-    }
-}
@@ -1,418 +0,0 @@
-
-//
-//  OneDriveFileProvider.swift
-//  FileProvider
-//
-//  Created by Amir Abbas Mousavian.
-//  Copyright © 2017 Mousavian. Distributed under MIT license.
-//
-
-import Foundation
-import CoreGraphics
-
-open class OneDriveFileProvider: FileProviderBasicRemote {
-    open class var type: String { return "OneDrive" }
-    open let isPathRelative: Bool
-    open let baseURL: URL?
-    /// OneDrive server url, equals with unwrapped `baseURL`
-    open var serverURL: URL { return baseURL! }
-    /// Drive name for user, default is `root`. Changing its value will effect on new operations.
-    open var drive: String
-    /// Generated storage url from server url and drive name
-    open var driveURL: URL {
-        return URL(string: "/drive/\(drive):/", relativeTo: baseURL)!
-    }
-    open var currentPath: String
-    
-    open var dispatch_queue: DispatchQueue
-    open var operation_queue: OperationQueue {
-        willSet {
-            assert(_session == nil, "It's not effective to change dispatch_queue property after session is initialized.")
-        }
-    }
-    
-    open weak var delegate: FileProviderDelegate?
-    open let credential: URLCredential?
-    open private(set) var cache: URLCache?
-    public var useCache: Bool
-    public var validatingCache: Bool
-   
-    fileprivate var _session: URLSession?
-    fileprivate var sessionDelegate: SessionDelegate?
-    public var session: URLSession {
-        if _session == nil {
-            self.sessionDelegate = SessionDelegate(fileProvider: self, credential: credential)
-            let queue = OperationQueue()
-            //queue.underlyingQueue = dispatch_queue
-            let config = URLSessionConfiguration.default
-            config.urlCache = cache
-            config.requestCachePolicy = .returnCacheDataElseLoad
-            _session = URLSession(configuration: config, delegate: sessionDelegate as URLSessionDelegate?, delegateQueue: queue)
-        }
-        return _session!
-    }
-    
-    /**
-     Initializer for Onedrive provider with given client ID and Token.
-     These parameters must be retrieved via [Authentication for the OneDrive API](https://dev.onedrive.com/auth/readme.htm).
-     
-     There are libraries like [p2/OAuth2](https://github.com/p2/OAuth2) or [OAuthSwift](https://github.com/OAuthSwift/OAuthSwift) which can facilate the procedure to retrieve token.
-     The latter is easier to use and prefered. Also you can use [auth0/Lock](https://github.com/auth0/Lock.iOS-OSX) which provides graphical user interface.
-     
-     - Parameters:
-       - credential: a `URLCredential` object with Client ID set as `user` and Token set as `password`.
-       - serverURL: server url, Set it if you are trying to connect OneDrive Business server, otherwise leave it
-         `nil` to connect to OneDrive Personal uses.
-       - drive: drive name for user on server, default value is `root`.
-       - cache: A URLCache to cache downloaded files and contents. If set to nil, URLCache.shared object will be used.
-     */
-    public init(credential: URLCredential?, serverURL: URL? = nil, drive: String = "root", cache: URLCache? = nil) {
-        self.baseURL = (serverURL ?? URL(string: "https://api.onedrive.com/")!).appendingPathComponent("")
-        self.drive = drive
-        self.isPathRelative = true
-        self.currentPath = ""
-        self.useCache = false
-        self.validatingCache = true
-        self.cache = cache
-        self.credential = credential
-        dispatch_queue = DispatchQueue(label: "FileProvider.\(type(of: self).type)", attributes: .concurrent)
-        operation_queue = OperationQueue()
-        operation_queue.name = "FileProvider.\(type(of: self).type).Operation"
-    }
-    
-    deinit {
-        if fileProviderCancelTasksOnInvalidating {
-            _session?.invalidateAndCancel()
-        } else {
-            _session?.finishTasksAndInvalidate()
-        }
-    }
-    
-    open func contentsOfDirectory(path: String, completionHandler: @escaping ((_ contents: [FileObject], _ error: Error?) -> Void)) {
-        list(path) { (contents, cursor, error) in
-            completionHandler(contents, error)
-        }
-    }
-    
-    open func attributesOfItem(path: String, completionHandler: @escaping ((_ attributes: FileObject?, _ error: Error?) -> Void)) {
-        let url = URL(string: escaped(path: path), relativeTo: driveURL)!
-        var request = URLRequest(url: url)
-        request.httpMethod = "GET"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
-            var serverError: FileProviderOneDriveError?
-            var fileObject: OneDriveFileObject?
-            if let response = response as? HTTPURLResponse {
-                let code = FileProviderHTTPErrorCode(rawValue: response.statusCode)
-                serverError = code != nil ? FileProviderOneDriveError(code: code!, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8)) : nil
-                if let data = data, let jsonStr = String(data: data, encoding: .utf8), let json = jsonToDictionary(jsonStr), let file = OneDriveFileObject(baseURL: self.baseURL, drive: self.drive, json: json) {
-                    fileObject = file
-                }
-            }
-            completionHandler(fileObject, serverError ?? error)
-        }) 
-        task.resume()
-    }
-    
-    open func storageProperties(completionHandler: @escaping ((_ total: Int64, _ used: Int64) -> Void)) {
-        let url = URL(string: "/drive/root", relativeTo: baseURL)!
-        var request = URLRequest(url: url)
-        request.httpMethod = "GET"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
-            var totalSize: Int64 = -1
-            var usedSize: Int64 = 0
-            if let data = data, let jsonStr = String(data: data, encoding: .utf8), let json = jsonToDictionary(jsonStr) {
-                totalSize = (json["total"] as? NSNumber)?.int64Value ?? -1
-                usedSize = (json["used"] as? NSNumber)?.int64Value ?? 0
-            }
-            completionHandler(totalSize, usedSize)
-        }) 
-        task.resume()
-    }
-    
-    open weak var fileOperationDelegate: FileOperationDelegate?
-}
-
-extension OneDriveFileProvider: FileProviderOperations {
-    
-    
-    public func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let path = (atPath as NSString).appendingPathComponent(folderName) + "/"
-        return doOperation(.create(path: path), completionHandler: completionHandler)
-    }
-    
-    public func create(file fileName: String, at path: String, contents data: Data?, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let filePath = (path as NSString).appendingPathComponent(fileName)
-        return self.writeContents(path: filePath, contents: data ?? Data(), completionHandler: completionHandler)
-    }
-    
-    public func moveItem(path: String, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        return doOperation(.move(source: path, destination: toPath), completionHandler: completionHandler)
-    }
-    
-    public func copyItem(path: String, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        return doOperation(.copy(source: path, destination: toPath), completionHandler: completionHandler)
-    }
-    
-    public func removeItem(path: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        return doOperation(.remove(path: path), completionHandler: completionHandler)
-    }
-    
-    fileprivate func doOperation(_ operation: FileOperationType, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: operation) ?? true == true else {
-            return nil
-        }
-        guard let sourcePath = operation.source else { return nil }
-        let destPath = operation.destination
-        var request = URLRequest(url: URL(string: sourcePath, relativeTo: driveURL)!)
-        switch operation {
-        case .create:
-            request.httpMethod = "CREATE"
-        case .copy:
-            request.httpMethod = "POST"
-        case .move:
-            request.httpMethod = "PATCH"
-        case .remove:
-            request.httpMethod = "DELETE"
-        default: // modify, link, fetch
-            return nil
-        }
-        
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        var requestDictionary = [String: AnyObject]()
-        if let dest = correctPath(destPath) as NSString? {
-            request.setValue("application/json", forHTTPHeaderField: "Content-Type")
-            requestDictionary["parentReference"] = ("/drive/\(drive):" + dest.deletingLastPathComponent) as NSString
-            requestDictionary["name"] = dest.lastPathComponent as NSString
-            request.httpBody = dictionaryToJSON(requestDictionary)?.data(using: .utf8)
-        }
-        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
-            var serverError: FileProviderOneDriveError?
-            if let response = response as? HTTPURLResponse, response.statusCode >= 300, let code = FileProviderHTTPErrorCode(rawValue: response.statusCode) {
-                 serverError = FileProviderOneDriveError(code: code, path: sourcePath, errorDescription: String(data: data ?? Data(), encoding: .utf8))
-            }
-            completionHandler?(serverError ?? error)
-            self.delegateNotify(operation, error: serverError ?? error)
-        })
-        task.taskDescription = operation.json
-        task.resume()
-        return RemoteOperationHandle(operationType: operation, tasks: [task])
-    }
-    
-    public func copyItem(localFile: URL, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.copy(source: localFile.absoluteString, destination: toPath)
-        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
-            return nil
-        }
-        return upload_simple(toPath, localFile: localFile, overwrite: overwrite, operation: opType, completionHandler: completionHandler)
-    }
-    
-    public func copyItem(path: String, toLocalURL destURL: URL, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.copy(source: path, destination: destURL.absoluteString)
-        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
-            return nil
-        }
-        let url = URL(string: escaped(path: path) + ":/content", relativeTo: driveURL)!
-        var request = URLRequest(url: url)
-        request.httpMethod = "GET"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        let task = session.downloadTask(with: request, completionHandler: { (cacheURL, response, error) in
-            guard let cacheURL = cacheURL, let httpResponse = response as? HTTPURLResponse , httpResponse.statusCode < 300 else {
-                let code = FileProviderHTTPErrorCode(rawValue: (response as? HTTPURLResponse)?.statusCode ?? -1)
-                let errorData : Data? = nil //Data(contentsOf:cacheURL) // TODO: Figure out how to get error response data for the error description
-                let serverError : FileProviderOneDriveError? = code != nil ? FileProviderOneDriveError(code: code!, path: path, errorDescription: String(data: errorData ?? Data(), encoding: .utf8)) : nil
-                completionHandler?(serverError ?? error)
-                return
-            }
-            do {
-                try FileManager.default.moveItem(at: cacheURL, to: destURL)
-                completionHandler?(nil)
-            } catch let e {
-                completionHandler?(e)
-            }
-        })
-        task.taskDescription = opType.json
-        task.resume()
-        return RemoteOperationHandle(operationType: opType, tasks: [task])
-    }
-}
-
-extension OneDriveFileProvider: FileProviderReadWrite {
-    public func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
-        if length == 0 || offset < 0 {
-            dispatch_queue.async {
-                completionHandler(Data(), nil)
-            }
-            return nil
-        }
-        
-        let opType = FileOperationType.fetch(path: path)
-        let url =  URL(string: escaped(path: path) + ":/content", relativeTo: driveURL)!
-        var request = URLRequest(url: url)
-        request.httpMethod = "GET"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        if length > 0 {
-            request.setValue("bytes=\(offset)-\(offset + length - 1)", forHTTPHeaderField: "Range")
-        } else if offset > 0 && length < 0 {
-            request.setValue("bytes=\(offset)-", forHTTPHeaderField: "Range")
-        }
-        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
-            var serverError: FileProviderOneDriveError?
-            if let httpResponse = response as? HTTPURLResponse , httpResponse.statusCode >= 300, let code = FileProviderHTTPErrorCode(rawValue: httpResponse.statusCode) {
-                serverError = FileProviderOneDriveError(code: code, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8))
-            }
-            let filedata = serverError ?? error == nil ? data : nil
-            completionHandler(filedata, serverError ?? error)
-        })
-        task.taskDescription = opType.json
-        task.resume()
-        return RemoteOperationHandle(operationType: opType, tasks: [task])
-    }
-    
-    public func writeContents(path: String, contents data: Data, atomically: Bool, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.modify(path: path)
-        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
-            return nil
-        }
-        // FIXME: remove 150MB restriction
-        return upload_simple(path, data: data, overwrite: overwrite, operation: opType, completionHandler: completionHandler)
-    }
-    
-    public func searchFiles(path: String, recursive: Bool, query: String, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) {
-        var foundFiles = [OneDriveFileObject]()
-        search(path, query: query, foundItem: { (file) in
-            foundFiles.append(file)
-            foundItemHandler?(file)
-            }, completionHandler: { (error) in
-                completionHandler(foundFiles, error)
-        })
-    }
-    
-    fileprivate func registerNotifcation(path: String, eventHandler: (() -> Void)) {
-        /* There is two ways to monitor folders changing in OneDrive. Either using webooks
-         * which means you have to implement a server to translate it to push notifications
-         * or using apiv2 list_folder/longpoll method. The second one is implemeted here.
-         * Tough webhooks are much more efficient, longpoll is much simpler to implement!
-         * You can implemnt your own webhook service and replace this method accordingly.
-         */
-        NotImplemented()
-    }
-    fileprivate func unregisterNotifcation(path: String) {
-        NotImplemented()
-    }
-    
-    /**
-     Genrates a public url to a file to be shared with other users and can be downloaded without authentication.
-     
-     - Parameters:
-       - to: path of file, including file/directory name.
-       - completionHandler: a block with result of directory entries or error.
-         `link`: a url returned by OneDrive to share.
-         `attribute`: `nil` for OneDrive.
-         `expiration`: `nil` for OneDrive, as it doesn't expires.
-         `error`: Error returned by OneDrive.
-     */
-    open func publicLink(to path: String, completionHandler: @escaping ((_ link: URL?, _ attribute: OneDriveFileObject?, _ expiration: Date?, _ error: Error?) -> Void)) {
-        let url =  URL(string: escaped(path: path) + ":/action.createLink", relativeTo: driveURL)!
-        var request = URLRequest(url: url)
-        request.httpMethod = "POST"
-        let requestDictionary: [String: AnyObject] = ["type": "view" as NSString]
-        request.httpBody = dictionaryToJSON(requestDictionary)?.data(using: .utf8)
-        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
-            var serverError: FileProviderOneDriveError?
-            var link: URL?
-            if let response = response as? HTTPURLResponse {
-                let code = FileProviderHTTPErrorCode(rawValue: response.statusCode)
-                serverError = code != nil ? FileProviderOneDriveError(code: code!, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8)) : nil
-                if let data = data, let jsonStr = String(data: data, encoding: .utf8), let json = jsonToDictionary(jsonStr) {
-                    if let linkDic = json["link"] as? NSDictionary, let linkStr = linkDic["webUrl"] as? String {
-                        link = URL(string: linkStr)
-                    }
-                }
-            }
-            
-            completionHandler(link, nil, nil, serverError ?? error)
-        })
-        task.resume()
-    }
-}
-
-
-extension OneDriveFileProvider: ExtendedFileProvider {
-    public func thumbnailOfFileSupported(path: String) -> Bool {
-        return true
-    }
-    
-    public func propertiesOfFileSupported(path: String) -> Bool {
-        let fileExt = (path as NSString).pathExtension.lowercased()
-        switch fileExt {
-        case "jpg", "jpeg", "bmp", "gif", "png", "tif", "tiff":
-            return true
-        case "mp3", "aac", "m4a", "wma":
-            return true
-        case "mp4", "mpg", "3gp", "mov", "avi", "wmv":
-            return true
-        default:
-            return false
-        }
-    }
-    
-    public func thumbnailOfFile(path: String, dimension: CGSize?, completionHandler: @escaping ((_ image: ImageClass?, _ error: Error?) -> Void)) {
-        let url: URL
-        if let dimension = dimension {
-            url = URL(string: escaped(path: path) + ":/thumbnails/0/=c\(dimension.width)x\(dimension.height)/content", relativeTo: driveURL)!
-        } else {
-            url = URL(string: escaped(path: path) + ":/thumbnails/0/small/content", relativeTo: driveURL)!
-        }
-        
-        var request = URLRequest(url: url)
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        let task = self.session.dataTask(with: request, completionHandler: { (data, response, error) in
-            var image: ImageClass? = nil
-            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
-                let responseError = FileProviderOneDriveError(code: rCode, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8))
-                completionHandler(nil, responseError)
-                return
-            }
-            if let data = data {
-                image = ImageClass(data: data)
-            }
-            completionHandler(image, error)
-        })
-        task.resume()
-    }
-    
-    public func propertiesOfFile(path: String, completionHandler: @escaping ((_ propertiesDictionary: [String : Any], _ keys: [String], _ error: Error?) -> Void)) {
-        let url = URL(string: escaped(path: path), relativeTo: driveURL)!
-        var request = URLRequest(url: url)
-        request.httpMethod = "GET"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
-            var serverError: FileProviderOneDriveError?
-            var dic = [String: Any]()
-            var keys = [String]()
-            if let response = response as? HTTPURLResponse {
-                let code = FileProviderHTTPErrorCode(rawValue: response.statusCode)
-                serverError = code != nil ? FileProviderOneDriveError(code: code!, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8)) : nil
-                if let data = data, let jsonStr = String(data: data, encoding: .utf8), let json = jsonToDictionary(jsonStr) {
-                    (dic, keys) = self.mapMediaInfo(json)
-                }
-            }
-            completionHandler(dic, keys, serverError ?? error)
-        })
-        task.resume()
-    }
-}
-
-extension OneDriveFileProvider: FileProvider {
-    open func copy(with zone: NSZone? = nil) -> Any {
-        let copy = OneDriveFileProvider(credential: self.credential, serverURL: self.baseURL, drive: self.drive, cache: self.cache)
-        copy.currentPath = self.currentPath
-        copy.delegate = self.delegate
-        copy.fileOperationDelegate = self.fileOperationDelegate
-        copy.useCache = self.useCache
-        copy.validatingCache = self.validatingCache
-        return copy
-    }
-}
@@ -0,0 +1,333 @@
+
+//
+//  OneDriveFileProvider.swift
+//  FileProvider
+//
+//  Created by Amir Abbas Mousavian.
+//  Copyright © 2017 Mousavian. Distributed under MIT license.
+//
+
+import Foundation
+import CoreGraphics
+
+/**
+ Allows accessing to OneDrive stored files, either hosted on Microsoft servers or business coprporate one.
+ This provider doesn't cache or save files internally, however you can set `useCache` and `cache` properties
+ to use Foundation `NSURLCache` system.
+ 
+ - Note: Uploading files and data are limited to 100MB, for now.
+ */
+open class OneDriveFileProvider: HTTPFileProvider, FileProviderSharing {
+    override open class var type: String { return "OneDrive" }
+    /// Drive name for user, default is `root`. Changing its value will effect on new operations.
+    open var drive: String
+    
+    /**
+     Initializer for Onedrive provider with given client ID and Token.
+     These parameters must be retrieved via [Authentication for the OneDrive API](https://dev.onedrive.com/auth/readme.htm).
+     
+     There are libraries like [p2/OAuth2](https://github.com/p2/OAuth2) or [OAuthSwift](https://github.com/OAuthSwift/OAuthSwift) which can facilate the procedure to retrieve token.
+     The latter is easier to use and prefered. Also you can use [auth0/Lock](https://github.com/auth0/Lock.iOS-OSX) which provides graphical user interface.
+     
+     - Parameters:
+       - credential: a `URLCredential` object with Client ID set as `user` and Token set as `password`.
+       - serverURL: server url, Set it if you are trying to connect OneDrive Business server, otherwise leave it
+         `nil` to connect to OneDrive Personal uses.
+       - drive: drive name for user on server, default value is `root`.
+       - cache: A URLCache to cache downloaded files and contents.
+     */
+    public init(credential: URLCredential?, serverURL: URL? = nil, drive: String = "root", cache: URLCache? = nil) {
+        let baseURL = serverURL?.absoluteURL ?? URL(string: "https://api.onedrive.com/")!
+        let refinedBaseURL = baseURL.absoluteString.hasSuffix("/") ? baseURL : baseURL.appendingPathComponent("")
+        self.drive = drive
+        super.init(baseURL: refinedBaseURL, credential: credential, cache: cache)
+    }
+    
+    public required convenience init?(coder aDecoder: NSCoder) {
+        self.init(credential: aDecoder.decodeObject(forKey: "credential") as? URLCredential,
+                  serverURL: aDecoder.decodeObject(forKey: "baseURL") as? URL,
+                  drive: aDecoder.decodeObject(forKey: "drive") as? String ?? "root")
+        self.currentPath   = aDecoder.decodeObject(forKey: "currentPath") as? String ?? ""
+        self.useCache = aDecoder.decodeBool(forKey: "useCache")
+        self.validatingCache = aDecoder.decodeBool(forKey: "validatingCache")
+    }
+    
+    open override func encode(with aCoder: NSCoder) {
+        super.encode(with: aCoder)
+        aCoder.encode(self.drive, forKey: "drive")
+    }
+    
+    open override func copy(with zone: NSZone? = nil) -> Any {
+        let copy = OneDriveFileProvider(credential: self.credential, serverURL: self.baseURL, drive: self.drive, cache: self.cache)
+        copy.currentPath = self.currentPath
+        copy.delegate = self.delegate
+        copy.fileOperationDelegate = self.fileOperationDelegate
+        copy.useCache = self.useCache
+        copy.validatingCache = self.validatingCache
+        return copy
+    }
+    
+    open override func contentsOfDirectory(path: String, completionHandler: @escaping ((_ contents: [FileObject], _ error: Error?) -> Void)) {
+        list(path) { (contents, cursor, error) in
+            completionHandler(contents, error)
+        }
+    }
+    
+    open override func attributesOfItem(path: String, completionHandler: @escaping ((_ attributes: FileObject?, _ error: Error?) -> Void)) {
+        var request = URLRequest(url: url(of: path))
+        request.httpMethod = "GET"
+        request.set(httpAuthentication: credential, with: .oAuth2)
+        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
+            var serverError: FileProviderOneDriveError?
+            var fileObject: OneDriveFileObject?
+            if let response = response as? HTTPURLResponse {
+                let code = FileProviderHTTPErrorCode(rawValue: response.statusCode)
+                serverError = code != nil ? FileProviderOneDriveError(code: code!, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8)) : nil
+                if let json = data?.deserializeJSON(), let file = OneDriveFileObject(baseURL: self.baseURL, drive: self.drive, json: json) {
+                    fileObject = file
+                }
+            }
+            completionHandler(fileObject, serverError ?? error)
+        }) 
+        task.resume()
+    }
+    
+    open override func storageProperties(completionHandler: @escaping ((_ total: Int64, _ used: Int64) -> Void)) {
+        var request = URLRequest(url: url(of: ""))
+        request.httpMethod = "GET"
+        request.set(httpAuthentication: credential, with: .oAuth2)
+        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
+            var totalSize: Int64 = -1
+            var usedSize: Int64 = 0
+            if let json = data?.deserializeJSON() {
+                totalSize = (json["total"] as? NSNumber)?.int64Value ?? -1
+                usedSize = (json["used"] as? NSNumber)?.int64Value ?? 0
+            }
+            completionHandler(totalSize, usedSize)
+        }) 
+        task.resume()
+    }
+    
+    open override func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) -> Progress? {
+        var foundFiles = [OneDriveFileObject]()
+        var queryStr: String?
+        queryStr = query.findValue(forKey: "name") as? String ?? query.findAllValues(forKey: nil).flatMap { $0.value as? String }.first
+        guard let finalQueryStr = queryStr else { return nil }
+        let progress = Progress(parent: nil, userInfo: nil)
+        progress.setUserInfoObject(url(of: path), forKey: .fileURLKey)
+        search(path, query: finalQueryStr, recursive: recursive, progress: progress, foundItem: { (file) in
+            if query.evaluate(with: file.mapPredicate()) {
+                foundFiles.append(file)
+                foundItemHandler?(file)
+            }
+        }, completionHandler: { (error) in
+            completionHandler(foundFiles, error)
+        })
+        return progress
+    }
+    
+    open func url(of path: String, modifier: String? = nil) -> URL {
+        var rpath: String = path
+        
+        let driveURL = baseURL!.appendingPathComponent("drive/\(drive):/")
+        
+        if rpath.hasPrefix("/") {
+            _=rpath.characters.removeFirst()
+        }
+        if rpath.isEmpty {
+            if let modifier = modifier {
+                return driveURL.appendingPathComponent(modifier)
+            }
+            return driveURL
+        }
+        
+        rpath = rpath.trimmingCharacters(in: pathTrimSet)
+        if let modifier = modifier {
+            rpath = rpath + ":/" + modifier
+        }
+        
+        return  driveURL.appendingPathComponent(rpath)
+    }
+    
+    open override func isReachable(completionHandler: @escaping (Bool) -> Void) {
+        var request = URLRequest(url: url(of: ""))
+        request.httpMethod = "HEAD"
+        request.set(httpAuthentication: credential, with: .oAuth2)
+        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
+            let status = (response as? HTTPURLResponse)?.statusCode ?? 400
+            completionHandler(status == 200)
+        })
+        task.resume()
+    }
+    
+    override func request(for operation: FileOperationType, overwrite: Bool = false, attributes: [URLResourceKey : Any] = [:]) -> URLRequest {
+        let method: String
+        let url: URL
+        switch operation {
+        case .fetch(path: let path):
+            method = "GET"
+            url = self.url(of: path, modifier: "content")
+        case .modify(path: let path):
+            method = "PUT"
+            let queryStr = overwrite ? "" : "?@name.conflictBehavior=fail"
+            url = self.url(of: path, modifier: "content\(queryStr)")
+        case .create(path: let path):
+            method = "CREATE"
+            url = self.url(of: path)
+        case .copy(let source, let dest) where !source.hasPrefix("file://") && !dest.hasPrefix("file://"):
+            method = "POST"
+            url = self.url(of: source)
+        case .copy(let source, let dest) where source.hasPrefix("file://"):
+            method = "PUT"
+            let queryStr = overwrite ? "" : "?@name.conflictBehavior=fail"
+            url = self.url(of: dest, modifier: "content\(queryStr)")
+        case .copy(let source, let dest) where dest.hasPrefix("file://"):
+            method = "GET"
+            url = self.url(of: source, modifier: "content")
+        case .move(source: let source, destination: _):
+            method = "PATCH"
+            url = self.url(of: source)
+        case .remove(path: let path):
+            method = "DELETE"
+            url = self.url(of: path)
+        default: // link
+            fatalError("Unimplemented operation \(operation.description) in \(#file)")
+        }
+        var request = URLRequest(url: url)
+        request.httpMethod = method
+        request.set(httpAuthentication: credential, with: .oAuth2)
+        
+        switch operation {
+        case .copy(let source, let dest) where !source.hasPrefix("file://") && !dest.hasPrefix("file://"),
+             .move(source: let source, destination: let dest):
+            request.set(httpContentType: .json)
+            let cdest = (correctPath(dest) as NSString?)!
+            var requestDictionary = [String: AnyObject]()
+            requestDictionary["parentReference"] = ("/drive/\(drive):" + cdest.deletingLastPathComponent) as NSString
+            requestDictionary["name"] = cdest.lastPathComponent as NSString
+            request.httpBody = Data(jsonDictionary: requestDictionary)
+        default:
+            break
+        }
+        
+        return request
+    }
+    
+    override func serverError(with code: FileProviderHTTPErrorCode, path: String?, data: Data?) -> FileProviderHTTPError {
+        return FileProviderOneDriveError(code: code, path: path ?? "", errorDescription:  data.flatMap({ String(data: $0, encoding: .utf8) }))
+    }
+    
+    override func upload_simple(_ targetPath: String, request: URLRequest, data: Data?, localFile: URL?, operation: FileOperationType, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let size = data?.count ?? Int((try? localFile?.resourceValues(forKeys: [.fileSizeKey]))??.fileSize ?? -1)
+        if size > 100 * 1024 * 1024 {
+            let error = FileProviderOneDriveError(code: .payloadTooLarge, path: targetPath, errorDescription: nil)
+            completionHandler?(error)
+            self.delegateNotify(operation, error: error)
+            return nil
+        }
+        
+        return super.upload_simple(targetPath, request: request, data: data, localFile: localFile, operation: operation, completionHandler: completionHandler)
+    }
+
+    fileprivate func registerNotifcation(path: String, eventHandler: (() -> Void)) {
+        /* There is two ways to monitor folders changing in OneDrive. Either using webooks
+         * which means you have to implement a server to translate it to push notifications
+         * or using apiv2 list_folder/longpoll method. The second one is implemeted here.
+         * Tough webhooks are much more efficient, longpoll is much simpler to implement!
+         * You can implemnt your own webhook service and replace this method accordingly.
+         */
+        NotImplemented()
+    }
+    fileprivate func unregisterNotifcation(path: String) {
+        NotImplemented()
+    }
+    
+    open func publicLink(to path: String, completionHandler: @escaping ((_ link: URL?, _ attribute: FileObject?, _ expiration: Date?, _ error: Error?) -> Void)) {
+        var request = URLRequest(url: self.url(of: path, modifier: "action.createLink"))
+        request.httpMethod = "POST"
+        let requestDictionary: [String: AnyObject] = ["type": "view" as NSString]
+        request.httpBody = Data(jsonDictionary: requestDictionary)
+        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
+            var serverError: FileProviderOneDriveError?
+            var link: URL?
+            if let response = response as? HTTPURLResponse {
+                let code = FileProviderHTTPErrorCode(rawValue: response.statusCode)
+                serverError = code != nil ? FileProviderOneDriveError(code: code!, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8)) : nil
+                if let json = data?.deserializeJSON() {
+                    if let linkDic = json["link"] as? NSDictionary, let linkStr = linkDic["webUrl"] as? String {
+                        link = URL(string: linkStr)
+                    }
+                }
+            }
+            
+            completionHandler(link, nil, nil, serverError ?? error)
+        })
+        task.resume()
+    }
+}
+
+
+extension OneDriveFileProvider: ExtendedFileProvider {
+    open func thumbnailOfFileSupported(path: String) -> Bool {
+        return true
+    }
+    
+    open func propertiesOfFileSupported(path: String) -> Bool {
+        let fileExt = (path as NSString).pathExtension.lowercased()
+        switch fileExt {
+        case "jpg", "jpeg", "bmp", "gif", "png", "tif", "tiff":
+            return true
+        case "mp3", "aac", "m4a", "wma":
+            return true
+        case "mp4", "mpg", "3gp", "mov", "avi", "wmv":
+            return true
+        default:
+            return false
+        }
+    }
+    
+    open func thumbnailOfFile(path: String, dimension: CGSize?, completionHandler: @escaping ((_ image: ImageClass?, _ error: Error?) -> Void)) {
+        let url: URL
+        if let dimension = dimension {
+            url = self.url(of: path, modifier: "thumbnails/0/=c\(dimension.width)x\(dimension.height)/content")
+        } else {
+            url =  self.url(of: path, modifier: "thumbnails/0/small/content")
+        }
+        
+        var request = URLRequest(url: url)
+        request.set(httpAuthentication: credential, with: .oAuth2)
+        let task = self.session.dataTask(with: request, completionHandler: { (data, response, error) in
+            var image: ImageClass? = nil
+            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
+                let responseError = FileProviderOneDriveError(code: rCode, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8))
+                completionHandler(nil, responseError)
+                return
+            }
+            if let data = data {
+                image = ImageClass(data: data)
+            }
+            completionHandler(image, error)
+        })
+        task.resume()
+    }
+    
+    open func propertiesOfFile(path: String, completionHandler: @escaping ((_ propertiesDictionary: [String : Any], _ keys: [String], _ error: Error?) -> Void)) {
+        var request = URLRequest(url: url(of: path))
+        request.httpMethod = "GET"
+        request.set(httpAuthentication: credential, with: .oAuth2)
+        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
+            var serverError: FileProviderOneDriveError?
+            var dic = [String: Any]()
+            var keys = [String]()
+            if let response = response as? HTTPURLResponse {
+                let code = FileProviderHTTPErrorCode(rawValue: response.statusCode)
+                serverError = code != nil ? FileProviderOneDriveError(code: code!, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8)) : nil
+                if let json = data?.deserializeJSON() {
+                    (dic, keys) = self.mapMediaInfo(json)
+                }
+            }
+            completionHandler(dic, keys, serverError ?? error)
+        })
+        task.resume()
+    }
+}
@@ -8,40 +8,48 @@

 import Foundation

+/// Error returned by OneDrive server when trying to access or do operations on a file or folder.
 public struct FileProviderOneDriveError: FileProviderHTTPError {
    public let code: FileProviderHTTPErrorCode
    public let path: String
    public let errorDescription: String?
 }

+/// Containts path, url and attributes of a OneDrive file or resource.
 public final class OneDriveFileObject: FileObject {
    internal init(baseURL: URL?, name: String, path: String) {
-        var rpath = path
-        if path.hasPrefix("/") {
-            rpath.remove(at: rpath.startIndex)
+        var rpath = (URL(string:path)?.appendingPathComponent(name).absoluteString)!
+        if rpath.hasPrefix("/") {
+            _=rpath.characters.removeFirst()
        }
-        let url = URL(string: rpath, relativeTo: baseURL) ?? URL(string: path)!
-        super.init(url: url, name: name, path: path)
+        let url = URL(string: rpath, relativeTo: baseURL) ?? URL(string: rpath)!
+        
+        super.init(url: url, name: name, path: rpath.removingPercentEncoding ?? path)
    }
    
    internal convenience init? (baseURL: URL?, drive: String, jsonStr: String) {
-        guard let json = jsonToDictionary(jsonStr) else { return nil }
+        guard let json = jsonStr.deserializeJSON() else { return nil }
        self.init(baseURL: baseURL, drive: drive, json: json)
    }
    
    internal convenience init? (baseURL: URL?, drive: String, json: [String: AnyObject]) {
        guard let name = json["name"] as? String else { return nil }
        guard let path = (json["parentReference"] as? NSDictionary)?["path"] as? String else { return nil }
-        let lPath = path.replacingOccurrences(of: "/drive/\(drive):", with: "/", options: .anchored, range: nil)
+        var lPath = path.replacingOccurrences(of: "/drive/\(drive):", with: "/", options: .anchored, range: nil)
+        lPath = lPath.replacingOccurrences(of: "/:", with: "", options: .anchored)
+        lPath = lPath.replacingOccurrences(of: "//", with: "", options: .anchored)
        self.init(baseURL: baseURL, name: name, path: lPath)
        self.size = (json["size"] as? NSNumber)?.int64Value ?? -1
-        self.modifiedDate = resolve(dateString: json["lastModifiedDateTime"] as? String ?? "")
-        self.creationDate = resolve(dateString: json["createdDateTime"] as? String ?? "")
-        self.type = (json["folder"] as? String) != nil ? .directory : .regular
+        self.modifiedDate = Date(rfcString: json["lastModifiedDateTime"] as? String ?? "")
+        self.creationDate = Date(rfcString: json["createdDateTime"] as? String ?? "")
+        self.type = json["folder"] != nil ? .directory : .regular
        self.id = json["id"] as? String
        self.entryTag = json["eTag"] as? String
    }
    
+    /// The document identifier is a value assigned by the OneDrive to a file.
+    /// This value is used to identify the document regardless of where it is moved on a volume.
+    /// The identifier persists across system restarts.
    open internal(set) var id: String? {
        get {
            return allValues[.documentIdentifierKey] as? String
@@ -51,52 +59,48 @@ public final class OneDriveFileObject: FileObject {
        }
    }
    
+    /// MIME type of file contents returned by OneDrive server.
    open internal(set) var contentType: String {
        get {
-            return allValues[.mimeType] as? String ?? ""
+            return allValues[.mimeTypeKey] as? String ?? ""
        }
        set {
-            allValues[.mimeType] = newValue
+            allValues[.mimeTypeKey] = newValue
        }
    }
    
+    /// HTTP E-Tag, can be used to mark changed files.
    open internal(set) var entryTag: String? {
        get {
-            return allValues[.entryTag] as? String
+            return allValues[.entryTagKey] as? String
        }
        set {
-            allValues[.entryTag] = newValue
+            allValues[.entryTagKey] = newValue
        }
    }
 }

 // codebeat:disable[ARITY]
 internal extension OneDriveFileProvider {
-    func list(_ path: String, cursor: String? = nil, prevContents: [OneDriveFileObject] = [], completionHandler: @escaping ((_ contents: [FileObject], _ cursor: String?, _ error: Error?) -> Void)) {
-        let url: URL
-        if let cursor = cursor {
-            url = URL(string: cursor)!
-        } else {
-            url = URL(string: escaped(path: path), relativeTo: driveURL)!
-        }
+    func list(_ path: String, cursor: URL? = nil, prevContents: [OneDriveFileObject] = [], completionHandler: @escaping ((_ contents: [FileObject], _ cursor: String?, _ error: Error?) -> Void)) {
+        let url = cursor ?? self.url(of: path, modifier: "children")
        var request = URLRequest(url: url)
        request.httpMethod = "GET"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
+        request.set(httpAuthentication: credential, with: .oAuth2)
        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
            var responseError: FileProviderOneDriveError?
            var files = prevContents
            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
                responseError = FileProviderOneDriveError(code: rCode, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8))
            }
-            if let data = data, let jsonStr = String(data: data, encoding: .utf8) {
-                let json = jsonToDictionary(jsonStr)
-                if let entries = json?["value"] as? [AnyObject] , entries.count > 0 {
+            if let json = data?.deserializeJSON() {
+                if let entries = json["value"] as? [AnyObject] , entries.count > 0 {
                    for entry in entries {
                        if let entry = entry as? [String: AnyObject], let file = OneDriveFileObject(baseURL: self.baseURL, drive: self.drive, json: entry) {
                            files.append(file)
                        }
                    }
-                    let ncursor = json?["@odata.nextLink"] as? String
+                    let ncursor: URL? = (json["@odata.nextLink"] as? String).flatMap { URL(string: $0) }
                    let hasmore = ncursor != nil
                    if hasmore {
                        self.list(path, cursor: ncursor, prevContents: files, completionHandler: completionHandler)
@@ -110,90 +114,34 @@ internal extension OneDriveFileProvider {
        task.resume()
    }
    
-    func upload_simple(_ targetPath: String, data: Data, modifiedDate: Date = Date(), overwrite: Bool, operation: FileOperationType, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        if data.count > 100 * 1024 * 1024 {
-            let error = FileProviderOneDriveError(code: .payloadTooLarge, path: targetPath, errorDescription: nil)
-            completionHandler?(error)
-            self.delegateNotify(.create(path: targetPath), error: error)
-            return nil
+    func search(_ startPath: String = "", query: String, recursive: Bool, next: URL? = nil, progress: Progress, foundItem: @escaping ((_ file: OneDriveFileObject) -> Void), completionHandler: @escaping ((_ error: Error?) -> Void)) {
+        if progress.isCancelled {
+            return
        }
-        let queryStr = overwrite ? "" : "?@name.conflictBehavior=fail"
-        let url = URL(string: escaped(path: targetPath) + ":/content" + queryStr, relativeTo: driveURL)!
-        var request = URLRequest(url: url)
-        request.httpMethod = "PUT"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        request.setValue("application/octet-stream", forHTTPHeaderField: "Content-Type")
-        request.httpBody = data
-        let task = session.uploadTask(with: request, from: data, completionHandler: { (data, response, error) in
-            var responseError: FileProviderOneDriveError?
-            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
-                responseError = FileProviderOneDriveError(code: rCode, path: targetPath, errorDescription: String(data: data ?? Data(), encoding: .utf8))
-            }
-            completionHandler?(responseError ?? error)
-            self.delegateNotify(.create(path: targetPath), error: responseError ?? error)
-        })
-        task.taskDescription = operation.json
-        task.resume()
-        return RemoteOperationHandle(operationType: operation, tasks: [task])
-    }
-    
-    func upload_simple(_ targetPath: String, localFile: URL, modifiedDate: Date = Date(), overwrite: Bool, operation: FileOperationType, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let size = (try? localFile.resourceValues(forKeys: [.fileSizeKey]))?.fileSize ?? -1
-        if size > 100 * 1024 * 1024 {
-            let error = FileProviderOneDriveError(code: .payloadTooLarge, path: targetPath, errorDescription: nil)
-            completionHandler?(error)
-            self.delegateNotify(.create(path: targetPath), error: error)
-            return nil
-        }
-        let queryStr = overwrite ? "" : "?@name.conflictBehavior=fail"
-        let url = URL(string: escaped(path: targetPath) + ":/content" + queryStr, relativeTo: driveURL)!
-        var request = URLRequest(url: url)
-        request.httpMethod = "PUT"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
-        request.setValue("application/octet-stream", forHTTPHeaderField: "Content-Type")
-        let task = session.uploadTask(with: request, fromFile: localFile, completionHandler: { (data, response, error) in
-            var responseError: FileProviderOneDriveError?
-            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
-                responseError = FileProviderOneDriveError(code: rCode, path: targetPath, errorDescription: String(data: data ?? Data(), encoding: .utf8))
-            }
-            completionHandler?(responseError ?? error)
-            self.delegateNotify(.create(path: targetPath), error: responseError ?? error)
-        })
-        task.taskDescription = operation.json
-        task.resume()
-        return RemoteOperationHandle(operationType: operation, tasks: [task])
-    }
-    
-    func search(_ startPath: String = "", query: String, next: String? = nil, foundItem:@escaping ((_ file: OneDriveFileObject) -> Void), completionHandler: @escaping ((_ error: Error?) -> Void)) {
+        
        let url: URL
-        if let next = next {
-            url = URL(string: next)!
-        } else if self.escaped(path: startPath) == "" {
-            url = URL(string: "/drive/\(drive)/view.search?q=\(query)", relativeTo: baseURL)!
-        } else {
-            url = URL(string: "\(escaped(path: startPath))/view.search?q=\(query)", relativeTo: driveURL)!
-        }
+        let q = query.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)!
+        let expanded = recursive ? "&expand=children" : ""
+        url = next ?? self.url(of: startPath, modifier: "view.search?q=\(q)\(expanded)")
        var request = URLRequest(url: url)
        request.httpMethod = "GET"
-        request.setValue("Bearer \(credential?.password ?? "")", forHTTPHeaderField: "Authorization")
+        request.set(httpAuthentication: credential, with: .oAuth2)
        
        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
            var responseError: FileProviderOneDriveError?
            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
                responseError = FileProviderOneDriveError(code: rCode, path: startPath, errorDescription: String(data: data ?? Data(), encoding: .utf8))
            }
-            if let data = data, let jsonStr = String(data: data, encoding: .utf8) {
-                let json = jsonToDictionary(jsonStr)
-                if let entries = json?["value"] as? [AnyObject] , entries.count > 0 {
+            if let json = data?.deserializeJSON() {
+                if let entries = json["value"] as? [AnyObject] , entries.count > 0 {
                    for entry in entries {
                        if let entry = entry as? [String: AnyObject], let file = OneDriveFileObject(baseURL: self.baseURL, drive: self.drive, json: entry) {
                            foundItem(file)
                        }
                    }
-                    let next = json?["@odata.nextLink"] as? String
-                    let hasmore = next != nil
-                    if hasmore, let next = next {
-                        self.search(startPath, query: query, next: next, foundItem: foundItem, completionHandler: completionHandler)
+                    let next: URL? = (json["@odata.nextLink"] as? String).flatMap { URL(string: $0) }
+                    if !progress.isCancelled, let next = next {
+                        self.search(startPath, query: query, recursive: recursive, next: next, progress: progress, foundItem: foundItem, completionHandler: completionHandler)
                    } else {
                        completionHandler(responseError ?? error)
                    }
@@ -201,7 +149,11 @@ internal extension OneDriveFileProvider {
                }
            }
            completionHandler(responseError ?? error)
-        }) 
+        })
+        progress.cancellationHandler = { [weak task] in
+            task?.cancel()
+        }
+        progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
        task.resume()
    }
 }
@@ -244,14 +196,14 @@ internal extension OneDriveFileProvider {
        if let location = json["location"] as? [String: Any], let latitude = location["latitude"] as? Double, let longitude = location["longitude"] as? Double {
            OneDriveFileProvider.decimalFormatter.numberStyle = .decimal
            OneDriveFileProvider.decimalFormatter.maximumFractionDigits = 5
-            let latStr = OneDriveFileProvider.decimalFormatter.string(from: NSNumber(value: latitude))
-            let longStr = OneDriveFileProvider.decimalFormatter.string(from: NSNumber(value: longitude))
+            let latStr = OneDriveFileProvider.decimalFormatter.string(from: NSNumber(value: latitude))!
+            let longStr = OneDriveFileProvider.decimalFormatter.string(from: NSNumber(value: longitude))!
            add(key: "Location", value: "\(latStr), \(longStr)")
        }
        if let parent = json["image"] as? [String: Any] ?? json["video"] as? [String: Any], let duration = parent["duration"] as? UInt64 {
-            add(key: "Duration", value: OneDriveFileProvider.formatshort(interval: TimeInterval(duration) / 1000))
+            add(key: "Duration", value: (TimeInterval(duration) / 1000).formatshort)
        }
-        if let timeTakenStr = json["takenDateTime"] as? String, let timeTaken = resolve(dateString: timeTakenStr) {
+        if let timeTakenStr = json["takenDateTime"] as? String, let timeTaken = Date(rfcString: timeTakenStr) {
            OneDriveFileProvider.dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
            add(key: "Date taken", value:  OneDriveFileProvider.dateFormatter.string(from: timeTaken))
        }
@@ -279,14 +231,4 @@ internal extension OneDriveFileProvider {
        
        return (dic, keys)
    }
-    
-    func delegateNotify(_ operation: FileOperationType, error: Error?) {
-        DispatchQueue.main.async(execute: {
-            if error == nil {
-                self.delegate?.fileproviderSucceed(self, operation: operation)
-            } else {
-                self.delegate?.fileproviderFailed(self, operation: operation)
-            }
-        })
-    }
 }
@@ -8,211 +8,338 @@

 import Foundation

-open class RemoteOperationHandle: OperationHandle {
-    
-    internal var tasks: [Weak<URLSessionTask>]
-    
-    open private(set) var operationType: FileOperationType
-    
-    init(operationType: FileOperationType, tasks: [URLSessionTask]) {
-        self.operationType = operationType
-        self.tasks = tasks.map { Weak<URLSessionTask>($0) }
-    }
-    
-    internal func add(task: URLSessionTask) {
-        tasks.append(Weak<URLSessionTask>(task))
-    }
-    
-    private func reape() {
-        self.tasks = tasks.filter { $0.value != nil }
-    }
-    
-    open var bytesSoFar: Int64 {
-        return tasks.reduce(0) {
-            if let task = $1.value as? URLSessionUploadTask {
-                return $0 + task.countOfBytesSent
-            } else {
-                return $0 + ($1.value?.countOfBytesReceived ?? 0)
-            }
-        }
-    }
-    
-    open var totalBytes: Int64 {
-        return tasks.reduce(0) {
-            if let task = $1.value as? URLSessionUploadTask {
-                return $0 + task.countOfBytesExpectedToSend
-            } else {
-                return $0 + ($1.value?.countOfBytesExpectedToSend ?? 0)
-            }
-        }
-    }
-    
-    open func cancel() -> Bool {
-        var canceled = false
-        for taskbox in tasks {
-            taskbox.value?.cancel()
-            canceled = true
-        }
-        return canceled
-    }
-    
-    open var inProgress: Bool {
-        return tasks.reduce(false) { $0 || $1.value?.state ?? .canceling == .running }
-    }
-}
-
+/// A protocol defines properties for errors returned by HTTP/S based providers.
+/// Including Dropbox, OneDrive and WebDAV.
 public protocol FileProviderHTTPError: Error, CustomStringConvertible {
+    /// HTTP status codes as an enum.
+    typealias Code = FileProviderHTTPErrorCode
+    /// HTTP status code returned for error by server.
    var code: FileProviderHTTPErrorCode { get }
+    /// Path of file/folder casued that error
    var path: String { get }
+    /// Contents returned by server as error description
    var errorDescription: String? { get }
-    
-    var description: String { get }
 }

 extension FileProviderHTTPError {
    public var description: String {
        return code.description
    }
+    
+    public var localizedDescription: String {
+        return description
+    }
 }

-class SessionDelegate: NSObject, URLSessionDataDelegate, URLSessionDownloadDelegate {
+internal var completionHandlersForTasks = [String: [Int: SimpleCompletionHandler]]()
+internal var downloadCompletionHandlersForTasks = [String: [Int: (URL) -> Void]]()
+internal var dataCompletionHandlersForTasks = [String: [Int: (Data) -> Void]]()
+
+internal func initEmptySessionHandler(_ uuid: String) {
+    completionHandlersForTasks[uuid] = [:]
+    downloadCompletionHandlersForTasks[uuid] = [:]
+    dataCompletionHandlersForTasks[uuid] = [:]
+}
+
+internal func removeSessionHandler(for uuid: String) {
+    _ = completionHandlersForTasks.removeValue(forKey: uuid)
+    _ = downloadCompletionHandlersForTasks.removeValue(forKey: uuid)
+    _ = dataCompletionHandlersForTasks.removeValue(forKey: uuid)
+}
+
+/// All objects set to `FileProviderRemote.session` must be an instance of this class
+final public class SessionDelegate: NSObject, URLSessionDataDelegate, URLSessionDownloadDelegate, URLSessionStreamDelegate {
    
-    weak var fileProvider: FileProvider?
+    weak var fileProvider: (FileProviderBasicRemote & FileProviderOperations)?
    var credential: URLCredential?
    
-    var finishDownloadHandler: ((_ session: Foundation.URLSession, _ downloadTask: URLSessionDownloadTask, _ didFinishDownloadingToURL: URL) -> Void)?
-    var didSendDataHandler: ((_ session: Foundation.URLSession, _ task: URLSessionTask, _ bytesSent: Int64, _ totalBytesSent: Int64, _ totalBytesExpectedToSend: Int64) -> Void)?
-    var didReceivedData: ((_ session: Foundation.URLSession, _ downloadTask: URLSessionDownloadTask, _ bytesWritten: Int64, _ totalBytesWritten: Int64, _ totalBytesExpectedToWrite: Int64) -> Void)?
+    /// Forwardng URLSessionDownloadTaskDelegate call
+    public var finishDownloadHandler: ((_ session: URLSession, _ downloadTask: URLSessionDownloadTask, _ didFinishDownloadingToURL: URL) -> Void)?
+    /// Forwardng URLSessionTaskDelegate call
+    public var didSendDataHandler: ((_ session: URLSession, _ task: URLSessionTask, _ bytesSent: Int64, _ totalBytesSent: Int64, _ totalBytesExpectedToSend: Int64) -> Void)?
+    /// Forwardng URLSessionDownloadTaskDelegate call
+    public var didReceivedData: ((_ session: URLSession, _ downloadTask: URLSessionDownloadTask, _ bytesWritten: Int64, _ totalBytesWritten: Int64, _ totalBytesExpectedToWrite: Int64) -> Void)?
+    /// Forwardng URLSessionStreamTaskDelegate call
+    public var didBecomeStream :((_ session: URLSession, _ taskId: Int, _ didBecome: InputStream, _ outputStream: OutputStream) -> Void)?
    
-    init(fileProvider: FileProvider, credential: URLCredential?) {
+    public init(fileProvider: FileProviderBasicRemote & FileProviderOperations) {
        self.fileProvider = fileProvider
-        self.credential = credential
+        self.credential = fileProvider.credential
+    }
+    
+    open override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
+        if let progress = context?.load(as: Progress.self), let newVal = change?[.newKey] as? Int64 {
+            switch keyPath ?? "" {
+            case #keyPath(URLSessionTask.countOfBytesReceived):
+                progress.completedUnitCount = newVal
+                if let startTime = progress.userInfo[ProgressUserInfoKey.startingTimeKey] as? Date, let task = object as? URLSessionTask {
+                    let elapsed = Date().timeIntervalSince(startTime)
+                    let throughput = Double(newVal) / elapsed
+                    progress.setUserInfoObject(NSNumber(value: throughput), forKey: .throughputKey)
+                    if task.countOfBytesExpectedToReceive > 0 {
+                        let remain = task.countOfBytesExpectedToReceive - task.countOfBytesReceived
+                        let estimatedTimeRemaining = Double(remain) / elapsed
+                        progress.setUserInfoObject(NSNumber(value: estimatedTimeRemaining), forKey: .estimatedTimeRemainingKey)
+                    }
+                }
+            case #keyPath(URLSessionTask.countOfBytesSent):
+                progress.completedUnitCount = newVal
+                if let startTime = progress.userInfo[ProgressUserInfoKey.startingTimeKey] as? Date, let task = object as? URLSessionTask {
+                    let elapsed = Date().timeIntervalSince(startTime)
+                    let throughput = Double(newVal) / elapsed
+                    progress.setUserInfoObject(NSNumber(value: throughput), forKey: .throughputKey)
+                    if task.countOfBytesExpectedToSend > 0 {
+                        let remain = task.countOfBytesExpectedToSend - task.countOfBytesSent
+                        let estimatedTimeRemaining = Double(remain) / elapsed
+                        progress.setUserInfoObject(NSNumber(value: estimatedTimeRemaining), forKey: .estimatedTimeRemainingKey)
+                    }
+                }
+            case #keyPath(URLSessionTask.countOfBytesExpectedToReceive), #keyPath(URLSessionTask.countOfBytesExpectedToSend):
+                progress.totalUnitCount = newVal
+            default:
+                super.observeValue(forKeyPath: keyPath, of: object, change: change, context: context)
+            }
+        }
    }
    
    // codebeat:disable[ARITY]
-    func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {
-        self.finishDownloadHandler?(session, downloadTask, location)
-        return
+    public func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
+        if task is URLSessionDownloadTask {
+            task.removeObserver(self, forKeyPath: #keyPath(URLSessionTask.countOfBytesReceived))
+            task.removeObserver(self, forKeyPath: #keyPath(URLSessionTask.countOfBytesExpectedToReceive))
+        }
+        if task is URLSessionUploadTask {
+            task.removeObserver(self, forKeyPath: #keyPath(URLSessionTask.countOfBytesSent))
+            //task.removeObserver(self, forKeyPath: #keyPath(URLSessionTask.countOfBytesExpectedToSend))
+        }
+        if !(error == nil && task is URLSessionDownloadTask) {
+            let completionHandler = completionHandlersForTasks[session.sessionDescription!]?[task.taskIdentifier] ?? nil
+            completionHandler?(error)
+            _ = completionHandlersForTasks[session.sessionDescription!]?.removeValue(forKey: task.taskIdentifier)
+        }
+        
+        guard let json = task.taskDescription?.deserializeJSON(),
+            let op = FileOperationType(json: json), let fileProvider = fileProvider else {
+                return
+        }
+        
+        if !(task is URLSessionDownloadTask), case FileOperationType.fetch = op {
+            return
+        }
+        if #available(iOS 9.0, macOS 10.11, *) {
+            if task is URLSessionStreamTask {
+                return
+            }
+        }
+        
+        DispatchQueue.main.async {
+            if let error = error {
+                fileProvider.delegate?.fileproviderFailed(fileProvider, operation: op, error: error)
+            } else {
+                fileProvider.delegate?.fileproviderSucceed(fileProvider, operation: op)
+            }
+        }
    }
    
-    func urlSession(_ session: URLSession, task: URLSessionTask, didSendBodyData bytesSent: Int64, totalBytesSent: Int64, totalBytesExpectedToSend: Int64) {
+    public func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) {
+        let completionHandler = dataCompletionHandlersForTasks[session.sessionDescription!]?[dataTask.taskIdentifier] ?? nil
+        completionHandler?(data)
+        _ = dataCompletionHandlersForTasks[session.sessionDescription!]?.removeValue(forKey: dataTask.taskIdentifier)
+    }
+    
+    public func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {
+        self.finishDownloadHandler?(session, downloadTask, location)
+        
+        let dcompletionHandler = downloadCompletionHandlersForTasks[session.sessionDescription!]?[downloadTask.taskIdentifier]
+        dcompletionHandler?(location)
+        _ = downloadCompletionHandlersForTasks[session.sessionDescription!]?.removeValue(forKey: downloadTask.taskIdentifier)
+        _ = completionHandlersForTasks[session.sessionDescription!]?.removeValue(forKey: downloadTask.taskIdentifier)
+    }
+    
+    public func urlSession(_ session: URLSession, task: URLSessionTask, didSendBodyData bytesSent: Int64, totalBytesSent: Int64, totalBytesExpectedToSend: Int64) {
        self.didSendDataHandler?(session, task, bytesSent, totalBytesSent, totalBytesExpectedToSend)
        
-        guard let desc = task.taskDescription, let json = jsonToDictionary(desc) else {
+        guard let json = task.taskDescription?.deserializeJSON(),
+              let op = FileOperationType(json: json), let fileProvider = fileProvider else {
            return
        }
-        guard let type = json["type"] as? String, let source = json["source"] as? String else {
-            return
-        }
-        let dest = json["dest"] as? String
-        let op : FileOperationType
-        switch type {
-        case "Create":
-            op = .create(path: source)
-        case "Copy":
-            guard let dest = dest else { return }
-            op = .copy(source: source, destination: dest)
-        case "Move":
-            guard let dest = dest else { return }
-            op = .move(source: source, destination: dest)
-        case "Modify":
-            op = .modify(path: source)
-        case "Remove":
-            op = .remove(path: source)
-        case "Link":
-            guard let dest = dest else { return }
-            op = .link(link: source, target: dest)
+        
+        switch op {
+        case .create(path: let path):
+            if path.hasSuffix("/") { return }
+            break
+        case .modify:
+            break
+        case .copy(source: let source, destination: _) where source.hasPrefix("file://"):
+            break
        default:
            return
        }
        
-        let progress = Float(totalBytesSent) / Float(totalBytesExpectedToSend)
-        
-        fileProvider?.delegate?.fileproviderProgress(fileProvider!, operation: op, progress: progress)
+        fileProvider.delegateNotify(op, progress: Double(totalBytesSent) / Double(totalBytesExpectedToSend))
    }
    
-    func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didWriteData bytesWritten: Int64, totalBytesWritten: Int64, totalBytesExpectedToWrite: Int64) {
+    public func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didWriteData bytesWritten: Int64, totalBytesWritten: Int64, totalBytesExpectedToWrite: Int64) {
        self.didReceivedData?(session, downloadTask, bytesWritten, totalBytesWritten, totalBytesExpectedToWrite)
        
-        guard let desc = downloadTask.taskDescription, let json = jsonToDictionary(desc), let source = json["source"] as? String, let dest = json["dest"] as? String else {
+        if totalBytesExpectedToWrite == NSURLSessionTransferSizeUnknown { return }
+        
+        guard let json = downloadTask.taskDescription?.deserializeJSON(),
+              let op = FileOperationType(json: json), let fileProvider = fileProvider else {
            return
        }
        
-        fileProvider?.delegate?.fileproviderProgress(fileProvider!, operation: .copy(source: source, destination: dest), progress: Float(totalBytesWritten) / Float(totalBytesExpectedToWrite))
+        fileProvider.delegateNotify(op, progress: Double(totalBytesWritten) / Double(totalBytesExpectedToWrite))
    }
    
-    func urlSession(_ session: URLSession, task: URLSessionTask, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
-        let deposition: Foundation.URLSession.AuthChallengeDisposition = credential != nil ? .useCredential : .performDefaultHandling
-        completionHandler(deposition, credential)
+    public func urlSession(_ session: URLSession, task: URLSessionTask, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
+        authenticate(didReceive: challenge, completionHandler: completionHandler)
    }
    
-    func urlSession(_ session: URLSession, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
-        let deposition: Foundation.URLSession.AuthChallengeDisposition = credential != nil ? .useCredential : .performDefaultHandling
-        completionHandler(deposition, credential)
+    public func urlSession(_ session: URLSession, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
+        authenticate(didReceive: challenge, completionHandler: completionHandler)
+    }
+    
+    func authenticate(didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
+        switch (challenge.previousFailureCount, credential != nil) {
+        case (0...1, true):
+            completionHandler(.useCredential, credential)
+        case (0, false):
+            completionHandler(.useCredential, challenge.proposedCredential)
+        default:
+            completionHandler(.performDefaultHandling, nil)
+        }
+    }
+    
+    @available(iOS 9.0, macOS 10.11, *)
+    public func urlSession(_ session: URLSession, streamTask: URLSessionStreamTask, didBecome inputStream: InputStream, outputStream: OutputStream) {
+        self.didBecomeStream?(session, streamTask.taskIdentifier, inputStream, outputStream)
    }
 }

-public enum FileProviderHTTPErrorCode: Int {
+/// HTTP status codes as an enum.
+public enum FileProviderHTTPErrorCode: Int, CustomStringConvertible {
+    /// `Continue` informational status with HTTP code 100
    case `continue` = 100
+    /// `Switching Protocols` informational status with HTTP code 101
    case switchingProtocols = 101
+    /// `Processing` informational status with HTTP code 102
    case processing = 102
+    /// `OK` success status with HTTP code 200
    case ok = 200
+    /// `Created` success status with HTTP code 201
    case created = 201
+    /// `Accepted` success status with HTTP code 202
    case accepted = 202
+    /// `Non Authoritative Information` success status with HTTP code 203
    case nonAuthoritativeInformation = 203
+    /// `No Content` success status with HTTP code 204
    case noContent = 204
+    /// `ResetcContent` success status with HTTP code 205
    case resetContent = 205
+    /// `Partial Content` success status with HTTP code 206
    case partialContent = 206
+    /// `Multi Status` success status with HTTP code 207
    case multiStatus = 207
+    /// `Already Reported` success status with HTTP code 208
    case alreadyReported = 208
+    /// `IM Used` success status with HTTP code 226
    case imUsed = 226
+    /// `Multiple Choices` redirection status with HTTP code 300
    case multipleChoices = 300
+    /// `Moved Permanently` redirection status with HTTP code 301
    case movedPermanently = 301
+    /// `Found` redirection status with HTTP code 302
    case found = 302
+    /// `See Other` redirection status with HTTP code 303
    case seeOther = 303
+    /// `Not Modified` redirection status with HTTP code 304
    case notModified = 304
+    /// `Use Proxy` redirection status with HTTP code 305
    case useProxy = 305
+    /// `Switch Proxy` redirection status with HTTP code 306
    case switchProxy = 306
+    /// `Temporary Redirect` redirection status with HTTP code 307
    case temporaryRedirect = 307
+    /// `Permanent Redirect` redirection status with HTTP code 308
    case permanentRedirect = 308
+    /// `Bad Request` client error status with HTTP code 400
    case badRequest = 400
+    /// `Unauthorized` client error status with HTTP code 401
    case unauthorized = 401
+    /// `Payment Required` client error status with HTTP code 402
    case paymentRequired = 402
+    /// `Forbidden` client error status with HTTP code 403
    case forbidden = 403
+    /// `Not Found` client error status with HTTP code 404
    case notFound = 404
+    /// `Method Not Allowed` client error status with HTTP code 405
    case methodNotAllowed = 405
+    /// `Not Acceptable` client error status with HTTP code 406
    case notAcceptable = 406
+    /// `Proxy Authentication Required` client error status with HTTP code 407
    case proxyAuthenticationRequired = 407
+    /// `Request Timeout` client error status with HTTP code 408
    case requestTimeout = 408
+    /// `Conflict` client error status with HTTP code 409
    case conflict = 409
+    /// `Gone` client error status with HTTP code 410
    case gone = 410
+    /// `Length Required` client error status with HTTP code 411
    case lengthRequired = 411
+    /// `Precondition Failed` client error status with HTTP code 412
    case preconditionFailed = 412
+    /// `Payload Too Large` client error status with HTTP code 413
    case payloadTooLarge = 413
+    /// `URI Too Long` client error status with HTTP code 414
    case uriTooLong = 414
+    /// `Unsupported Media Type` status with HTTP code 415
    case unsupportedMediaType = 415
+    /// `Range Not Satisfiable` client error status with HTTP code 416
    case rangeNotSatisfiable = 416
+    /// `Expectation Failed` client error status with HTTP code 417
    case expectationFailed = 417
+    /// `Misdirected Request` client error status with HTTP code 421
    case misdirectedRequest = 421
+    /// `Unprocessable Entity` client error status with HTTP code 422
    case unprocessableEntity = 422
+    /// `Locked` client error status with HTTP code 423
    case locked = 423
+    /// `Failed Dependency` client error status with HTTP code 424
    case failedDependency = 424
+    /// `Unordered Collection` client error status with HTTP code 425
    case unorderedCollection = 425
+    /// `Upgrade Required` client error status with HTTP code 426
    case upgradeRequired = 426
+    /// `Precondition Required` client error status with HTTP code 428
    case preconditionRequired = 428
+    /// `Too Many Requests` client error status with HTTP code 429
    case tooManyRequests = 429
+    /// `Request Header Fields Too Large` client error status with HTTP code 431
    case requestHeaderFieldsTooLarge = 431
+    /// `Unavailable For Legal Reasons` client error status with HTTP code 451
    case unavailableForLegalReasons = 451
+    /// `Internal Server Error` server error status with HTTP code 500
    case internalServerError = 500
+    /// `Bad Gateway` server error status with HTTP code 502
    case badGateway = 502
+    /// `Service Unavailable` server error status with HTTP code 503
    case serviceUnavailable = 503
+    /// `Gateway Timeout` server error status with HTTP code 504
    case gatewayTimeout = 504
+    /// `HTTP Version Not Supported` server error status with HTTP code 505
    case httpVersionNotSupported = 505
-    case variantlsoNegotiates = 506
+    /// `Variant Also Negotiates` server error status with HTTP code 506
+    case variantAlsoNegotiates = 506
+    /// `Insufficient Storage` server error status with HTTP code 507
    case insufficientStorage = 507
+    /// `Loop Detected` server error status with HTTP code 508
    case loopDetected = 508
+    /// `Bandwidth Limit Exceeded` server error status with HTTP code 509
    case bandwidthLimitExceeded = 509
+    /// `Not Extended` server error status with HTTP code 510
    case notExtended = 510
+    /// `Network Authentication Required` server error status with HTTP code 511
    case networkAuthenticationRequired = 511
    
    fileprivate static let status1xx: [Int: String] = [100: "Continue", 101: "Switching Protocols", 102: "Processing"]
@@ -233,6 +360,7 @@ public enum FileProviderHTTPErrorCode: Int {
        }
    }
    
+    /// Description of status based on first digit which indicated fail or success.
    public var typeDescription: String {
        switch self.rawValue {
        case 100...199: return "Informational"
@@ -240,7 +368,7 @@ public enum FileProviderHTTPErrorCode: Int {
        case 300...399: return "Redirection"
        case 400...499: return "Client Error"
        case 500...599: return "Server Error"
-        default: return "Server Error"
+        default: return "Unknown Error"
        }
    }
 }
@@ -11,11 +11,11 @@ import Foundation
 // This client implementation is for little-endian platform, namely x86, x64 & arm
 // For big-endian platforms like PowerPC, there must be a huge overhaul

-protocol SMBProtocolClientDelegate: class {
-    func receivedResponse(client: SMB2ProtocolClient, response: SMBResponse, for: SMBRequest)
+protocol FileProviderSMBTaskDelegate: class {
+    func receivedResponse(client: FileProviderSMBTask, response: SMBResponse, for: SMBRequest)
 }

-class SMB2ProtocolClient: FPSStreamTask {
+class FileProviderSMBTask: FileProviderStreamTask {
    var timeout: TimeInterval = 30
    
    private(set) var lastMessageID: UInt64 = 0
@@ -31,14 +31,14 @@ class SMB2ProtocolClient: FPSStreamTask {
    private(set) var requestStack = [Int: SMBRequest]()
    private(set) var responseStack = [Int: SMBResponse]()
    
-    weak var delegate: SMBProtocolClientDelegate?
+    weak var delegate: FileProviderSMBTaskDelegate?
    
    func sendNegotiate(completionHandler: SimpleCompletionHandler) -> UInt64 {
        let mId = messageId()
        let smbHeader = SMB2.Header(command: .NEGOTIATE, creditRequestResponse: UInt16(126), messageId: mId, treeId: UInt32(0), sessionId: UInt64(0))
        let msg = SMB2.NegotiateRequest()
        let data = createSMB2Message(header: smbHeader, message: msg)
-        self.writeData(data, timeout: 0, completionHandler: { (e) in
+        self.write(data, timeout: timeout, completionHandler: { (e) in
            completionHandler?(e)
        })
        return mId
@@ -50,9 +50,9 @@ class SMB2ProtocolClient: FPSStreamTask {
        let smbHeader = SMB2.Header(command: SMB2.Command.SESSION_SETUP, creditRequestResponse: credit, messageId: mId, treeId: UInt32(0), sessionId: sessionId)
        let msg = SMB2.SessionSetupRequest(singing: [])
        let data = createSMB2Message(header: smbHeader, message: msg)
-        self.writeData(data, timeout: 0, completionHandler: { (e) in
+        self.write(data, timeout: timeout, completionHandler: { (e) in
            if self.sessionId == 0 {
-                self.readData(OfMinLength: 64, maxLength: 65536, timeout: self.timeout, completionHandler: { (data, eof, e2) in
+                self.readData(ofMinLength: 64, maxLength: 65536, timeout: self.timeout, completionHandler: { (data, eof, e2) in
                    // TODO: set session id
                    completionHandler?(e2 ?? e)
                })
@@ -68,15 +68,12 @@ class SMB2ProtocolClient: FPSStreamTask {
        }
        let mId = messageId()
        let smbHeader = SMB2.Header(command: .TREE_CONNECT, creditRequestResponse: 123, messageId: mId, treeId: 0, sessionId: sessionId)
-        var share = ""
        let cmp = url.pathComponents
-        if cmp.count > 0 {
-            share = cmp[0]
-        }
+        let share = cmp.first ?? ""
        let tcHeader = SMB2.TreeConnectRequest.Header(flags: [])
        let msg = SMB2.TreeConnectRequest(header: tcHeader, host: host, share: share)
        let data = createSMB2Message(header: smbHeader, message: msg!)
-        self.writeData(data, timeout: 0, completionHandler: { (e) in
+        self.write(data, timeout: timeout, completionHandler: { (e) in
            completionHandler?(e)
            
        })
@@ -88,7 +85,7 @@ class SMB2ProtocolClient: FPSStreamTask {
        let smbHeader = SMB2.Header(command: .TREE_DISCONNECT, creditRequestResponse: 111, messageId: mId, treeId: treeId, sessionId: sessionId)
        let msg = SMB2.TreeDisconnect()
        let data = createSMB2Message(header: smbHeader, message: msg)
-        self.writeData(data, timeout: 0, completionHandler: { (e) in
+        self.write(data, timeout: timeout, completionHandler: { (e) in
            completionHandler?(e)
        })
        return mId
@@ -99,7 +96,7 @@ class SMB2ProtocolClient: FPSStreamTask {
        let smbHeader = SMB2.Header(command: .LOGOFF, creditRequestResponse: 0, messageId: mId, treeId: 0, sessionId: sessionId)
        let msg = SMB2.LogOff()
        let data = createSMB2Message(header: smbHeader, message: msg)
-        self.writeData(data, timeout: 0, completionHandler: { (e) in
+        self.write(data, timeout: timeout, completionHandler: { (e) in
            completionHandler?(e)
        })
        return mId
@@ -111,7 +108,7 @@ class SMB2ProtocolClient: FPSStreamTask {
 }

 // MARK: create and analyse messages
-extension SMB2ProtocolClient {
+extension FileProviderSMBTask {
    func determineSMBVersion(_ data: Data) -> Float {
        let smbverChar: Int8 = Int8(bitPattern: data.first ?? 0)
        let version = 0 - smbverChar
@@ -10,28 +10,52 @@ import Foundation

 class SMBFileProvider: FileProvider, FileProviderMonitor {
    open class var type: String { return "SMB" }
-    open var isPathRelative: Bool = true
    open var baseURL: URL?
    open var currentPath: String = ""
    open var dispatch_queue: DispatchQueue
    open var operation_queue: OperationQueue
    open weak var delegate: FileProviderDelegate?
-    open let credential: URLCredential?
+    open var credential: URLCredential?
    
    public typealias FileObjectClass = FileObject
    
-    public init? (baseURL: URL, credential: URLCredential, afterInitialized: SimpleCompletionHandler) {
+    public init? (baseURL: URL, credential: URLCredential?) {
        guard baseURL.uw_scheme.lowercased() == "smb" else {
            return nil
        }
        self.baseURL = baseURL.appendingPathComponent("")
-        dispatch_queue = DispatchQueue(label: "FileProvider.\(type(of: self).type)", attributes: .concurrent)
+        
+        #if swift(>=3.1)
+        let queueLabel = "FileProvider.\(Swift.type(of: self).type)"
+        #else
+        let queueLabel = "FileProvider.\(type(of: self).type)"
+        #endif
+        dispatch_queue = DispatchQueue(label: queueLabel, attributes: .concurrent)
        operation_queue = OperationQueue()
-        operation_queue.name = "FileProvider.\(type(of: self).type).Operation"
+        operation_queue.name = "\(queueLabel).Operation"
        
        self.credential = credential
    }
-        
+    
+    public required convenience init?(coder aDecoder: NSCoder) {
+        guard let baseURL = aDecoder.decodeObject(forKey: "baseURL") as? URL else {
+            return nil
+        }
+        self.init(baseURL: baseURL,
+                  credential: aDecoder.decodeObject(forKey: "credential") as? URLCredential)
+        self.currentPath   = aDecoder.decodeObject(forKey: "currentPath") as? String ?? ""
+    }
+    
+    open func encode(with aCoder: NSCoder) {
+        aCoder.encode(self.baseURL, forKey: "baseURL")
+        aCoder.encode(self.credential, forKey: "credential")
+        aCoder.encode(self.currentPath, forKey: "currentPath")
+    }
+    
+    public static var supportsSecureCoding: Bool {
+        return true
+    }
+    
    open func contentsOfDirectory(path: String, completionHandler: @escaping ((_ contents: [FileObjectClass], _ error: Error?) -> Void)) {
        NotImplemented()
    }
@@ -44,62 +68,62 @@ class SMBFileProvider: FileProvider, FileProviderMonitor {
        NotImplemented()
    }
    
+    func isReachable(completionHandler: @escaping (Bool) -> Void) {
+        NotImplemented()
+    }
+    
    open weak var fileOperationDelegate: FileOperationDelegate?
    
-    open func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> Progress? {
        NotImplemented()
        return nil
    }
    
-    open func create(file fileName: String, at atPath: String, contents data: Data?, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func moveItem(path: String, to toPath: String, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> Progress? {
        NotImplemented()
        return nil
    }
    
-    open func moveItem(path: String, to toPath: String, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func copyItem(path: String, to toPath: String, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> Progress? {
        NotImplemented()
        return nil
    }
    
-    open func copyItem(path: String, to toPath: String, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func removeItem(path: String, completionHandler: SimpleCompletionHandler) -> Progress? {
        NotImplemented()
        return nil
    }
    
-    open func removeItem(path: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func copyItem(localFile: URL, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> Progress? {
        NotImplemented()
        return nil
    }
    
-    open func copyItem(localFile: URL, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func copyItem(path: String, toLocalURL: URL, completionHandler: SimpleCompletionHandler) -> Progress? {
        NotImplemented()
        return nil
    }
    
-    open func copyItem(path: String, toLocalURL: URL, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func contents(path: String, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> Progress? {
        NotImplemented()
        return nil
    }
    
-    open func contents(path: String, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
+    open func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> Progress? {
        NotImplemented()
        return nil
    }
    
-    open func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
+    open func writeContents(path: String, contents data: Data?, atomically: Bool, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> Progress? {
        NotImplemented()
        return nil
    }
    
-    open func writeContents(path: String, contents data: Data, atomically: Bool, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler:((FileObjectClass) -> Void)?, completionHandler: @escaping ((_ files: [FileObjectClass], _ error: Error?) -> Void)) -> Progress? {
        NotImplemented()
        return nil
    }
    
-    open func searchFiles(path: String, recursive: Bool, query: String, foundItemHandler:((FileObjectClass) -> Void)?, completionHandler: @escaping ((_ files: [FileObjectClass], _ error: Error?) -> Void)) {
-        NotImplemented()
-    }
-    
    open func registerNotifcation(path: String, eventHandler: @escaping (() -> Void)) {
        NotImplemented()
    }
@@ -113,7 +137,7 @@ class SMBFileProvider: FileProvider, FileProviderMonitor {
    }
    
    open func copy(with zone: NSZone? = nil) -> Any {
-        let copy = SMBFileProvider(baseURL: self.baseURL!, credential: self.credential!, afterInitialized: { _ in })!
+        let copy = SMBFileProvider(baseURL: self.baseURL!, credential: self.credential!)!
        copy.currentPath = self.currentPath
        copy.delegate = self.delegate
        copy.fileOperationDelegate = self.fileOperationDelegate
@@ -122,7 +146,7 @@ class SMBFileProvider: FileProvider, FileProviderMonitor {
 }

 // MARK: basic CIFS interactivity
-public enum SMBFileProviderError: Int, Error, CustomStringConvertible {
+enum SMBFileProviderError: Int, Error, CustomStringConvertible {
    case badHeader
    case incompatibleHeader
    case incorrectParamsLength
@@ -66,32 +66,3 @@ struct SMBTime {
        return Date(timeIntervalSince1970: Double(self.time) / 10000000 - 11644473600)
    }
 }
-
-extension Data {
-    init<T>(value: T) {
-        var value = value
-        self = Data(buffer: UnsafeBufferPointer(start: &value, count: 1))
-    }
-    
-    func scanValue<T>() -> T? {
-        guard MemoryLayout<T>.size <= self.count else { return nil }
-        return self.withUnsafeBytes { $0.pointee }
-    }
-    
-    func scanValue<T>(start: Int) -> T? {
-        let length = MemoryLayout<T>.size
-        guard self.count >= start + length else { return nil }
-        return self.subdata(in: start..<start+length).withUnsafeBytes { $0.pointee }
-    }
-    
-    func scanString(start: Int = 0, length: Int, encoding: String.Encoding) -> String? {
-        guard self.count >= start + length else { return nil }
-        return String(data: self.subdata(in: start..<start+length), encoding: encoding)
-    }
-    
-    static func mapMemory<T, U>(from: T) -> U? {
-        guard MemoryLayout<T>.size >= MemoryLayout<U>.size else { return nil }
-        let data = Data(value: from)
-        return data.scanValue()
-    }
-}
@@ -106,6 +106,7 @@ extension SMB2 {
            let flags: WriteRequest.Flags
        }
        
+        // codebeat:disable[ARITY]
        init(fileId: FileId, offset: UInt64, remainingBytes: UInt32 = 0, data: Data, channel: Channel = .NONE, channelInfo: ChannelInfo? = nil, flags: WriteRequest.Flags = []) {
            var channelInfoOffset: UInt16 = 0
            var channelInfoLength: UInt16 = 0
@@ -118,6 +119,7 @@ extension SMB2 {
            self.channelInfo = channelInfo
            self.fileData = data
        }
+        // codebeat:enable[ARITY]
        
        func data() -> Data {
            var result = Data(value: self.header)
@@ -243,7 +243,7 @@ extension SMB2 {
                    if data.count < offset + 48 {
                        return nil
                    }
-                    let datestring = data.scanString(start: offset, length: 48, encoding: .utf16)
+                    let datestring = data.scanString(start: offset, length: 48, using: .utf16)
                    if let datestring = datestring, let date = dateFormatter.date(from: datestring) {
                        snapshots.append(SMBTime(date: date))
                    }
@@ -92,7 +92,7 @@ extension SMB2 {
                }
                
                let fileNameLen = Int(data.scanValue(start: offset + 8) as UInt32? ?? 0)
-                let fileName = data.scanString(start: offset + 12, length: fileNameLen, encoding: .utf16) ?? ""
+                let fileName = data.scanString(start: offset + 12, length: fileNameLen, using: .utf16) ?? ""
                result.append((action: action, fileName: fileName))
                
                offset += Int(nextOffset)
@@ -85,7 +85,7 @@ extension SMB2 {
                    return []
                }
                let headersize = MemoryLayout.size(ofValue: header)
-                let fileName = buffer.scanString(start: headersize, length: Int(header.fileNameLength), encoding: .utf16) ?? ""
+                let fileName = buffer.scanString(start: headersize, length: Int(header.fileNameLength), using: .utf16) ?? ""
                result.append((header: header, fileName: fileName))
                if header.nextEntryOffset == 0 {
                    break
@@ -216,12 +216,12 @@ extension SMB2 {
        var asAllInformation: (header: FileAllInformationHeader, name: String) {
            let header: FileAllInformationHeader = buffer.scanValue()!
            let headersize = MemoryLayout<FileAllInformationHeader>.size
-            let name = buffer.scanString(start: headersize, length: Int(header.nameLength), encoding: .utf16) ?? ""
+            let name = buffer.scanString(start: headersize, length: Int(header.nameLength), using: .utf16) ?? ""
            return (header, name)
        }
        
        var asAlternateNameInformation: String {
-            return buffer.scanString(start: 0, length: buffer.count, encoding: .utf16) ?? ""
+            return buffer.scanString(start: 0, length: buffer.count, using: .utf16) ?? ""
        }
        
        var asAttributeTagInformation: FileAttributeTagInformation {
@@ -280,14 +280,14 @@ extension SMB2 {
        var asStreamInformation: (header: FileStreamInformationHeader, name: String) {
            let header: FileStreamInformationHeader = buffer.scanValue()!
            let headersize = MemoryLayout<FileStreamInformationHeader>.size
-            let name = buffer.scanString(start: headersize, length: Int(header.streamNameLength), encoding: .utf16) ?? ""
+            let name = buffer.scanString(start: headersize, length: Int(header.streamNameLength), using: .utf16) ?? ""
            return (header, name)
        }
        
        var asFsVolumeInformation: (header: FileFsVolumeInformationHeader, name: String) {
            let header: FileFsVolumeInformationHeader = buffer.scanValue()!
            let headersize = MemoryLayout<FileFsVolumeInformationHeader>.size
-            let name = buffer.scanString(start: headersize, length: Int(header.labelLength), encoding: .utf16) ?? ""
+            let name = buffer.scanString(start: headersize, length: Int(header.labelLength), using: .utf16) ?? ""
            return (header, name)
        }
        
@@ -302,7 +302,7 @@ extension SMB2 {
        var asFsAttributeInformation: (header: FileFsAttributeInformationHeader, name: String) {
            let header: FileFsAttributeInformationHeader = buffer.scanValue()!
            let headersize = MemoryLayout<FileFsAttributeInformationHeader>.size
-            let name = buffer.scanString(start: headersize, length: Int(header.nameLength), encoding: .utf16) ?? ""
+            let name = buffer.scanString(start: headersize, length: Int(header.nameLength), using: .utf16) ?? ""
            return (header, name)
        }
        
@@ -7,43 +7,22 @@
 //

 import Foundation
+import CoreGraphics

-/// Because this class uses NSURLSession, it's necessary to disable App Transport Security
-/// in case of using this class with unencrypted HTTP connection.
-
-open class WebDAVFileProvider: FileProviderBasicRemote {
-    open class var type: String { return "WebDAV" }
-    open let isPathRelative: Bool
-    open let baseURL: URL?
-    open var currentPath: String
-    
-    open var dispatch_queue: DispatchQueue
-    open var operation_queue: OperationQueue {
-        willSet {
-            assert(_session == nil, "It's not effective to change dispatch_queue property after session is initialized.")
-        }
-    }
-    
-    public weak var delegate: FileProviderDelegate?
-    open let credential: URLCredential?
-    open private(set) var cache: URLCache?
-    public var useCache: Bool
-    public var validatingCache: Bool
-    
-    fileprivate var _session: URLSession?
-    fileprivate var sessionDelegate: SessionDelegate?
-    public var session: URLSession {
-        if _session == nil {
-            self.sessionDelegate = SessionDelegate(fileProvider: self, credential: credential)
-            let queue = OperationQueue()
-            //queue.underlyingQueue = dispatch_queue
-            let config = URLSessionConfiguration.default
-            config.urlCache = cache
-            config.requestCachePolicy = .returnCacheDataElseLoad
-            _session = URLSession(configuration: config, delegate: sessionDelegate as URLSessionDownloadDelegate?, delegateQueue: queue)
-        }
-        return _session!
-    }
+/**
+ Allows accessing to WebDAV server files. This provider doesn't cache or save files internally, however you can
+ set `useCache` and `cache` properties to use Foundation `NSURLCache` system.
+ 
+ WebDAV system supported by many cloud services including [Box.com](https://www.box.com/home) 
+ and [Yandex disk](https://disk.yandex.com) and [ownCloud](https://owncloud.org).
+ 
+ - Important: Because this class uses `URLSession`, it's necessary to disable App Transport Security
+     in case of using this class with unencrypted HTTP connection.
+     [Read this to know how](http://iosdevtips.co/post/121756573323/ios-9-xcode-7-http-connect-server-error).
+*/
+open class WebDAVFileProvider: HTTPFileProvider, FileProviderSharing {
+    override open class var type: String { return "WebDAV" }
+    public var credentialType: URLRequest.AuthenticationType = .digest
    
    /**
     Initializes WebDAV provider.
@@ -51,42 +30,63 @@ open class WebDAVFileProvider: FileProviderBasicRemote {
     - Parameters:
       - baseURL: Location of WebDAV server.
       - credential: An `URLCredential` object with `user` and `password`.
-       - cache: A URLCache to cache downloaded files and contents. If set to nil, URLCache.shared object will be used.
+       - cache: A URLCache to cache downloaded files and contents.
    */
    public init? (baseURL: URL, credential: URLCredential?, cache: URLCache? = nil) {
        if  !["http", "https"].contains(baseURL.uw_scheme.lowercased()) {
            return nil
        }
-        self.baseURL = baseURL.appendingPathComponent("")
-        self.isPathRelative = true
-        self.currentPath = ""
-        self.useCache = false
-        self.validatingCache = true
-        self.cache = cache
-        self.credential = credential
-        dispatch_queue = DispatchQueue(label: "FileProvider.\(type(of: self).type)", attributes: .concurrent)
-        operation_queue = OperationQueue()
-        operation_queue.name = "FileProvider.\(type(of: self).type).Operation"
+        let refinedBaseURL = (baseURL.absoluteString.hasSuffix("/") ? baseURL : baseURL.appendingPathComponent("")).absoluteURL
+        super.init(baseURL: refinedBaseURL, credential: credential, cache: cache)
    }
    
-    deinit {
-        if fileProviderCancelTasksOnInvalidating {
-            _session?.invalidateAndCancel()
-        } else {
-            _session?.finishTasksAndInvalidate()
+    public required convenience init?(coder aDecoder: NSCoder) {
+        guard let baseURL = aDecoder.decodeObject(forKey: "baseURL") as? URL else {
+            return nil
        }
+        self.init(baseURL: baseURL,
+                  credential: aDecoder.decodeObject(forKey: "credential") as? URLCredential)
+        self.currentPath   = aDecoder.decodeObject(forKey: "currentPath") as? String ?? ""
+        self.useCache        = aDecoder.decodeBool(forKey: "useCache")
+        self.validatingCache = aDecoder.decodeBool(forKey: "validatingCache")
    }
    
-    open func contentsOfDirectory(path: String, completionHandler: @escaping ((_ contents: [FileObject], _ error: Error?) -> Void)) {
-        let opType = FileOperationType.fetch(path: path)
+    override open func copy(with zone: NSZone? = nil) -> Any {
+        let copy = WebDAVFileProvider(baseURL: self.baseURL!, credential: self.credential, cache: self.cache)!
+        copy.currentPath = self.currentPath
+        copy.delegate = self.delegate
+        copy.fileOperationDelegate = self.fileOperationDelegate
+        copy.useCache = self.useCache
+        copy.validatingCache = self.validatingCache
+        return copy
+    }
+    
+    override open func contentsOfDirectory(path: String, completionHandler: @escaping (([FileObject], Error?) -> Void)) {
+        self.contentsOfDirectory(path: path, including: [], completionHandler: completionHandler)
+    }
+    
+    /**
+     Returns an Array of `FileObject`s identifying the the directory entries via asynchronous completion handler.
+     
+     If the directory contains no entries or an error is occured, this method will return the empty array.
+     
+     - Parameter path: path to target directory. If empty, root will be iterated.
+     - Parameter including: An array which determines which file properties should be considered to fetch.
+     - Parameter completionHandler: a closure with result of directory entries or error.
+         - `contents`: An array of `FileObject` identifying the the directory entries.
+         - `error`: Error returned by system.
+     */
+    open func contentsOfDirectory(path: String, including: [URLResourceKey], completionHandler: @escaping ((_ contents: [FileObject], _ error: Error?) -> Void)) {
+        let operation = FileOperationType.fetch(path: path)
        let url = self.url(of: path).appendingPathComponent("")
        var request = URLRequest(url: url)
        request.httpMethod = "PROPFIND"
        request.setValue("1", forHTTPHeaderField: "Depth")
-        request.setValue("text/xml; charset=\"utf-8\"", forHTTPHeaderField: "Content-Type")
-        request.httpBody = "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<D:propfind xmlns:D=\"DAV:\">\n<D:allprop/></D:propfind>".data(using: .utf8)
+        request.set(httpAuthentication: credential, with: credentialType)
+        request.set(httpContentType: .xml, charset: .utf8)
+        request.httpBody = "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<D:propfind xmlns:D=\"DAV:\">\n\(WebDavFileObject.propString(including))\n</D:propfind>".data(using: .utf8)
        request.setValue(String(request.httpBody!.count), forHTTPHeaderField: "Content-Length")
-        runDataTask(with: request, operationHandle: RemoteOperationHandle(operationType: opType, tasks: []), completionHandler: { (data, response, error) in
+        runDataTask(with: request, operation: operation, completionHandler: { (data, response, error) in
            var responseError: FileProviderWebDavError?
            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
                responseError = FileProviderWebDavError(code: rCode, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8), url: url)
@@ -105,13 +105,29 @@ open class WebDAVFileProvider: FileProviderBasicRemote {
        })
    }
    
-    open func attributesOfItem(path: String, completionHandler: @escaping ((_ attributes: FileObject?, _ error: Error?) -> Void)) {
+    override open func attributesOfItem(path: String, completionHandler: @escaping ((_ attributes: FileObject?, _ error: Error?) -> Void)) {
+        self.attributesOfItem(path: path, including: [], completionHandler: completionHandler)
+    }
+    
+    /**
+     Returns a `FileObject` containing the attributes of the item (file, directory, symlink, etc.) at the path in question via asynchronous completion handler.
+     
+     If the directory contains no entries or an error is occured, this method will return the empty `FileObject`.
+     
+     - Parameter path: path to target directory. If empty, attributes of root will be returned.
+     - Parameter including: An array which determines which file properties should be considered to fetch.
+     - Parameter completionHandler: a closure with result of directory entries or error.
+         - `attributes`: A `FileObject` containing the attributes of the item.
+         - `error`: Error returned by system.
+     */
+    open func attributesOfItem(path: String, including: [URLResourceKey], completionHandler: @escaping ((_ attributes: FileObject?, _ error: Error?) -> Void)) {
        let url = self.url(of: path)
        var request = URLRequest(url: url)
        request.httpMethod = "PROPFIND"
-        request.setValue("1", forHTTPHeaderField: "Depth")
-        request.setValue("text/xml; charset=\"utf-8\"", forHTTPHeaderField: "Content-Type")
-        request.httpBody = "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<D:propfind xmlns:D=\"DAV:\">\n<D:allprop/></D:propfind>".data(using: .utf8)
+        request.setValue("0", forHTTPHeaderField: "Depth")
+        request.set(httpAuthentication: credential, with: credentialType)
+        request.set(httpContentType: .xml, charset: .utf8)
+        request.httpBody = "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<D:propfind xmlns:D=\"DAV:\">\n\(WebDavFileObject.propString(including))\n</D:propfind>".data(using: .utf8)
        request.setValue(String(request.httpBody!.count), forHTTPHeaderField: "Content-Length")
        runDataTask(with: request, completionHandler: { (data, response, error) in
            var responseError: FileProviderWebDavError?
@@ -129,7 +145,7 @@ open class WebDAVFileProvider: FileProviderBasicRemote {
        })
    }
    
-    open func storageProperties(completionHandler: @escaping ((_ total: Int64, _ used: Int64) -> Void)) {
+    override open func storageProperties(completionHandler: @escaping ((_ total: Int64, _ used: Int64) -> Void)) {
        // Not all WebDAV clients implements RFC2518 which allows geting storage quota.
        // In this case you won't get error. totalSize is NSURLSessionTransferSizeUnknown
        // and used space is zero.
@@ -139,7 +155,8 @@ open class WebDAVFileProvider: FileProviderBasicRemote {
        var request = URLRequest(url: baseURL)
        request.httpMethod = "PROPFIND"
        request.setValue("0", forHTTPHeaderField: "Depth")
-        request.setValue("text/xml; charset=\"utf-8\"", forHTTPHeaderField: "Content-Type")
+        request.set(httpAuthentication: credential, with: credentialType)
+        request.set(httpContentType: .xml, charset: .utf8)
        request.httpBody = "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<D:propfind xmlns:D=\"DAV:\">\n<D:prop><D:quota-available-bytes/><D:quota-used-bytes/></D:prop>\n</D:propfind>".data(using: .utf8)
        request.setValue(String(request.httpBody!.count), forHTTPHeaderField: "Content-Length")
        runDataTask(with: request, completionHandler: { (data, response, error) in
@@ -156,252 +173,18 @@ open class WebDAVFileProvider: FileProviderBasicRemote {
        })
    }
    
-    open weak var fileOperationDelegate: FileOperationDelegate?
-}
-
-extension WebDAVFileProvider: FileProviderOperations {
-    @discardableResult
-    public func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.create(path: (atPath as NSString).appendingPathComponent(folderName) + "/")
-        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
-            return nil
-        }
-        let url = self.url(of: atPath).appendingPathComponent(folderName, isDirectory: true)
-        var request = URLRequest(url: url)
-        request.httpMethod = "MKCOL"
-        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
-            var responseError: FileProviderWebDavError?
-            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
-                responseError = FileProviderWebDavError(code: rCode, path: url.relativePath, errorDescription: String(data: data ?? Data(), encoding: .utf8), url: url)
-            }
-            completionHandler?(responseError ?? error)
-            self.delegateNotify(opType, error: responseError ?? error)
-        })
-        task.taskDescription = opType.json
-        task.resume()
-        return RemoteOperationHandle(operationType: opType, tasks: [task])
-    }
-    
-    @discardableResult
-    public func create(file fileName: String, at path: String, contents data: Data?, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.create(path: (path as NSString).appendingPathComponent(fileName))
-        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
-            return nil
-        }
-        let url = self.url(of: path).appendingPathComponent(fileName)
-        var request = URLRequest(url: url)
-        request.httpMethod = "PUT"
-        let task = session.uploadTask(with: request, from: data, completionHandler: { (data, response, error) in
-            var responseError: FileProviderWebDavError?
-            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
-                responseError = FileProviderWebDavError(code: rCode, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8), url: url)
-            }
-            completionHandler?(responseError ?? error)
-            self.delegateNotify(opType, error: responseError ?? error)
-        })
-        task.taskDescription = opType.json
-        task.resume()
-        return RemoteOperationHandle(operationType: opType, tasks: [task])
-    }
-    
-    @discardableResult
-    public func moveItem(path: String, to toPath: String, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.move(source: path, destination: toPath)
-        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
-            return nil
-        }
-        return self.doOperation(operation: opType, overwrite: overwrite, completionHandler: completionHandler)
-    }
-    
-    @discardableResult
-    public func copyItem(path: String, to toPath: String, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.copy(source: path, destination: toPath)
-        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
-            return nil
-        }
-        return self.doOperation(operation: opType, overwrite: overwrite, completionHandler: completionHandler)
-    }
-    
-    @discardableResult
-    public func removeItem(path: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.remove(path: path)
-        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
-            return nil
-        }
-        return self.doOperation(operation: opType, completionHandler: completionHandler)
-    }
-    
-    func doOperation(operation opType: FileOperationType, overwrite: Bool? = nil, completionHandler: SimpleCompletionHandler) -> OperationHandle?  {
-        let source = opType.source!
-        let sourceURL = self.url(of: source)
-        var request = URLRequest(url: sourceURL)
-        if let dest = opType.destination {
-            request.setValue(url(of:dest).absoluteString, forHTTPHeaderField: "Destination")
-        }
-        switch opType {
-        case .copy:
-            request.httpMethod = "COPY"
-        case .move:
-            request.httpMethod = "MOVE"
-        case .remove:
-            request.httpMethod = "DELETE"
-        default:
-            return nil
-        }
-        
-        if let overwrite = overwrite, !overwrite {
-            request.setValue("F", forHTTPHeaderField: "Overwrite")
-        }
-        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
-            var responseError: FileProviderWebDavError?
-            if let response = response as? HTTPURLResponse, let code = FileProviderHTTPErrorCode(rawValue: response.statusCode) {
-                if response.statusCode >= 300  {
-                    responseError = FileProviderWebDavError(code: code, path: source, errorDescription: String(data: data ?? Data(), encoding: .utf8), url: sourceURL)
-                }
-                if code == .multiStatus, let data = data {
-                    let xresponses = DavResponse.parse(xmlResponse: data, baseURL: self.baseURL)
-                    for xresponse in xresponses where (xresponse.status ?? 0) >= 300 {
-                        let error = FileProviderWebDavError(code: code, path: source, errorDescription: String(data: data, encoding: .utf8), url: sourceURL)
-                        completionHandler?(error)
-                    }
-                }
-            }
-            if (response as? HTTPURLResponse)?.statusCode ?? 0 != FileProviderHTTPErrorCode.multiStatus.rawValue {
-                completionHandler?(responseError ?? error)
-            }
-            
-            self.delegateNotify(opType, error: responseError ?? error)
-        })
-        task.taskDescription = opType.json
-        task.resume()
-        return RemoteOperationHandle(operationType: opType, tasks: [task])
-    }
-    
-    @discardableResult
-    public func copyItem(localFile: URL, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        // TODO: Make use of overwrite parameter
-        let opType = FileOperationType.copy(source: localFile.absoluteString, destination: toPath)
-        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
-            return nil
-        }
-        let url = self.url(of:toPath)
-        var request = URLRequest(url: url)
-        request.httpMethod = "PUT"
-        let task = session.uploadTask(with: request, fromFile: localFile, completionHandler: { (data, response, error) in
-            var responseError: FileProviderWebDavError?
-            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
-                responseError = FileProviderWebDavError(code: rCode, path: toPath, errorDescription: String(data: data ?? Data(), encoding: .utf8), url: url)
-            }
-            completionHandler?(responseError ?? error)
-            self.delegateNotify(opType, error: responseError ?? error)
-        }) 
-        task.taskDescription = opType.json
-        task.resume()
-        return RemoteOperationHandle(operationType: opType, tasks: [task])
-    }
-    
-    @discardableResult
-    public func copyItem(path: String, toLocalURL: URL, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.copy(source: path, destination: toLocalURL.absoluteString)
-        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
-            return nil
-        }
-        let url = self.url(of:path)
-        let request = URLRequest(url: url)
-        let task = session.downloadTask(with: request, completionHandler: { (sourceFileURL, response, error) in
-            var responseError: FileProviderWebDavError?
-            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
-                responseError = FileProviderWebDavError(code: rCode, path: path, errorDescription: nil, url: url)
-            }
-            if let sourceFileURL = sourceFileURL {
-                do {
-                    try FileManager.default.copyItem(at: sourceFileURL, to: toLocalURL)
-                } catch let e {
-                    completionHandler?(e)
-                    return
-                }
-            }
-            completionHandler?(responseError ?? error)
-            self.delegateNotify(opType, error: responseError ?? error)
-        }) 
-        task.taskDescription = opType.json
-        task.resume()
-        return RemoteOperationHandle(operationType: opType, tasks: [task])
-    }
-}
-
-extension WebDAVFileProvider: FileProviderReadWrite {
-    @discardableResult
-    public func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
-        if length == 0 || offset < 0 {
-            dispatch_queue.async {
-                completionHandler(Data(), nil)
-            }
-            return nil
-        }
-        
-        let opType = FileOperationType.fetch(path: path)
-        let url = self.url(of: path)
-        var request = URLRequest(url: url)
-        request.httpMethod = "GET"
-        if length > 0 {
-            request.setValue("bytes=\(offset)-\(offset + length - 1)", forHTTPHeaderField: "Range")
-        } else if offset > 0 && length < 0 {
-            request.setValue("bytes=\(offset)-", forHTTPHeaderField: "Range")
-        }
-        let handle = RemoteOperationHandle(operationType: opType, tasks: [])
-        runDataTask(with: request, operationHandle: handle, completionHandler: { (data, response, error) in
-            var responseError: FileProviderWebDavError?
-            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
-                responseError = FileProviderWebDavError(code: rCode, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8), url: url)
-            }
-            completionHandler(data, responseError ?? error)
-        })
-        return handle
-    }
-    
-    @discardableResult
-    public func writeContents(path: String, contents data: Data, atomically: Bool, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
-        let opType = FileOperationType.modify(path: path)
-        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
-            return nil
-        }
-        // FIXME: lock destination before writing process
-        let url = atomically ? self.url(of: path).appendingPathExtension("tmp") : self.url(of: path)
-        var request = URLRequest(url: url)
-        request.httpMethod = "PUT"
-        if !overwrite {
-            request.setValue("F", forHTTPHeaderField: "Overwrite")
-        }
-        let task = session.uploadTask(with: request, from: data, completionHandler: { (data, response, error) in
-            var responseError: FileProviderWebDavError?
-            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
-                responseError = FileProviderWebDavError(code: rCode, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8), url: self.url(of: path))
-            }
-            defer {
-                self.delegateNotify(opType, error: responseError ?? error)
-            }
-            if let error = error {
-                completionHandler?(error)
-                return
-            }
-            if atomically {
-                self.moveItem(path: (path as NSString).appendingPathExtension("tmp")!, to: path, completionHandler: completionHandler)
-            }
-        }) 
-        task.taskDescription = opType.json
-        task.resume()
-        return RemoteOperationHandle(operationType: opType, tasks: [task])
-    }
-    
-    public func searchFiles(path: String, recursive: Bool, query: String, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) {
+    override open func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) -> Progress? {
        let url = self.url(of: path)
        var request = URLRequest(url: url)
        request.httpMethod = "PROPFIND"
-        //request.setValue("1", forHTTPHeaderField: "Depth")
-        request.setValue("text/xml; charset=\"utf-8\"", forHTTPHeaderField: "Content-Type")
+        // Depth infinity is disabled on some servers. Implement workaround?!
+        request.setValue(recursive ? "infinity" : "1", forHTTPHeaderField: "Depth")
+        request.set(httpAuthentication: credential, with: credentialType)
+        request.set(httpContentType: .xml, charset: .utf8)
        request.httpBody = "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<D:propfind xmlns:D=\"DAV:\">\n<D:allprop/></D:propfind>".data(using: .utf8)
-        runDataTask(with: request, completionHandler: { (data, response, error) in
+        let progress = Progress(parent: nil, userInfo: nil)
+        progress.setUserInfoObject(url, forKey: .fileURLKey)
+        let task = session.dataTask(with: request) { (data, response, error) in
            // FIXME: paginating results
            var responseError: FileProviderWebDavError?
            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
@@ -411,21 +194,140 @@ extension WebDAVFileProvider: FileProviderReadWrite {
                let xresponse = DavResponse.parse(xmlResponse: data, baseURL: self.baseURL)
                var fileObjects = [WebDavFileObject]()
                for attr in xresponse {
-                    let path = attr.href.path
-                    if !((path as NSString).lastPathComponent.contains(query)) {
+                    let fileObject = WebDavFileObject(attr)
+                    if !query.evaluate(with: fileObject.mapPredicate()) {
                        continue
                    }
-                    let fileObject = WebDavFileObject(attr)
+                    
                    fileObjects.append(fileObject)
+                    progress.completedUnitCount = Int64(fileObjects.count)
                    foundItemHandler?(fileObject)
                }
                completionHandler(fileObjects, responseError ?? error)
                return
            }
            completionHandler([], responseError ?? error)
+        }
+        progress.cancellationHandler = { [weak task] in
+            task?.cancel()
+        }
+        progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
+        task.resume()
+        return progress
+    }
+    
+    override open func isReachable(completionHandler: @escaping (Bool) -> Void) {
+        var request = URLRequest(url: baseURL!)
+        request.httpMethod = "PROPFIND"
+        request.setValue("0", forHTTPHeaderField: "Depth")
+        request.set(httpAuthentication: credential, with: credentialType)
+        request.set(httpContentType: .xml, charset: .utf8)
+        request.httpBody = "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<D:propfind xmlns:D=\"DAV:\">\n<D:prop><D:quota-available-bytes/><D:quota-used-bytes/></D:prop>\n</D:propfind>".data(using: .utf8)
+        request.setValue(String(request.httpBody!.count), forHTTPHeaderField: "Content-Length")
+        runDataTask(with: request, completionHandler: { (data, response, error) in
+            let status = (response as? HTTPURLResponse)?.statusCode ?? 400
+            completionHandler(status < 300)
        })
    }
    
+    open func publicLink(to path: String, completionHandler: @escaping ((URL?, FileObject?, Date?, Error?) -> Void)) {
+        guard self.baseURL?.host?.contains("dav.yandex.") ?? false else {
+            dispatch_queue.async {
+                completionHandler(nil, nil, nil, self.throwError(path, code: URLError.resourceUnavailable))
+            }
+            return
+        }
+        
+        let url = self.url(of: path)
+        var request = URLRequest(url: url)
+        request.httpMethod = "PROPPATCH"
+        request.set(httpAuthentication: credential, with: credentialType)
+        request.set(httpContentType: .xml, charset: .utf8)
+        let body = "<propertyupdate xmlns=\"DAV:\">\n<set><prop>\n<public_url xmlns=\"urn:yandex:disk:meta\">true</public_url>\n</prop></set>\n</propertyupdate>"
+        request.httpBody = body.data(using: .utf8)
+        request.setValue(String(request.httpBody!.count), forHTTPHeaderField: "Content-Length")
+        runDataTask(with: request, completionHandler: { (data, response, error) in
+            var responseError: FileProviderWebDavError?
+            if let code = (response as? HTTPURLResponse)?.statusCode, code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
+                responseError = FileProviderWebDavError(code: rCode, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8), url: url)
+            }
+            if let data = data {
+                let xresponse = DavResponse.parse(xmlResponse: data, baseURL: self.baseURL)
+                if let urlStr = xresponse.first?.prop["public_url"], let url = URL(string: urlStr) {
+                    completionHandler(url, nil, nil, nil)
+                    return
+                }
+            }
+            completionHandler(nil, nil, nil, responseError ?? error)
+        })
+    }
+    
+    override func request(for operation: FileOperationType, overwrite: Bool = true, attributes: [URLResourceKey: Any] = [:]) -> URLRequest {
+        let method: String
+        let url: URL
+        let sourceURL = self.url(of: operation.source)
+        
+        switch operation {
+        case .fetch:
+            method = "GET"
+            url = sourceURL
+        case .create:
+            if sourceURL.absoluteString.hasSuffix("/") {
+                method = "MKCOL"
+                url = sourceURL
+            } else {
+                fallthrough
+            }
+        case .modify:
+            method = "PUT"
+            url = sourceURL
+            break
+        case .copy(let source, let dest):
+            if source.hasPrefix("file://") {
+                method = "PUT"
+                url = self.url(of: dest)
+            } else if dest.hasPrefix("file://") {
+                method = "GET"
+                url = sourceURL
+            } else {
+                method = "COPY"
+                url = sourceURL
+            }
+        case .move:
+            method = "MOVE"
+            url = sourceURL
+        case .remove:
+            method = "DELETE"
+            url = sourceURL
+        default:
+            fatalError("Unimplemented operation \(operation.description) in \(#file)")
+        }
+        
+        var request = URLRequest(url: url)
+        request.httpMethod = method
+        request.set(httpAuthentication: credential, with: credentialType)
+        request.setValue(overwrite ? "T" : "F", forHTTPHeaderField: "Overwrite")
+        if let dest = operation.destination, !dest.hasPrefix("file://") {
+            request.setValue(self.url(of:dest).absoluteString, forHTTPHeaderField: "Destination")
+        }
+        
+        return request
+    }
+    
+    override func serverError(with code: FileProviderHTTPErrorCode, path: String?, data: Data?) -> FileProviderHTTPError {
+        return FileProviderWebDavError(code: code, path: path ?? "", errorDescription:  data.flatMap({ String(data: $0, encoding: .utf8) }), url: self.url(of: path ?? ""))
+    }
+    
+    override func multiStatusHandler(source: String, data: Data, completionHandler: SimpleCompletionHandler) {
+        let xresponses = DavResponse.parse(xmlResponse: data, baseURL: self.baseURL)
+        for xresponse in xresponses where (xresponse.status ?? 0) >= 300 {
+            let code = xresponse.status.flatMap { FileProviderHTTPErrorCode(rawValue: $0) } ?? .internalServerError
+            let error = FileProviderWebDavError(code: code, path: source, errorDescription: String(data: data, encoding: .utf8), url: self.url(of: source))
+            completionHandler?(error)
+        }
+    }
+    
+    /*
    fileprivate func registerNotifcation(path: String, eventHandler: (() -> Void)) {
        /* There is no unified api for monitoring WebDAV server content change/update
         * Microsoft Exchange uses SUBSCRIBE method, Apple uses push notification system.
@@ -437,36 +339,58 @@ extension WebDAVFileProvider: FileProviderReadWrite {
    }
    fileprivate func unregisterNotifcation(path: String) {
        NotImplemented()
-    }
+    }*/
    // TODO: implements methods for lock mechanism
 }

-extension WebDAVFileProvider: FileProvider {
-    open func copy(with zone: NSZone? = nil) -> Any {
-        let copy = WebDAVFileProvider(baseURL: self.baseURL!, credential: self.credential, cache: self.cache)!
-        copy.currentPath = self.currentPath
-        copy.delegate = self.delegate
-        copy.fileOperationDelegate = self.fileOperationDelegate
-        copy.useCache = self.useCache
-        copy.validatingCache = self.validatingCache
-        return copy
+extension WebDAVFileProvider: ExtendedFileProvider {
+    open func thumbnailOfFileSupported(path: String) -> Bool {
+        guard self.baseURL?.host?.contains("dav.yandex.") ?? false else {
+            return false
+        }
+        let supportedExt: [String] = ["jpg", "jpeg", "png", "gif"]
+        return supportedExt.contains((path as NSString).pathExtension)
+    }
+    
+    open func thumbnailOfFile(path: String, dimension: CGSize?, completionHandler: @escaping ((ImageClass?, Error?) -> Void)) {
+        guard self.baseURL?.host?.contains("dav.yandex.") ?? false else {
+            dispatch_queue.async {
+                completionHandler(nil, self.throwError(path, code: URLError.resourceUnavailable))
+            }
+            return
+        }
+        
+        let dimension = dimension ?? CGSize(width: 64, height: 64)
+        let url = URL(string: self.url(of: path).absoluteString + "?preview&size=\(dimension.width)x\(dimension.height)")!
+        var request = URLRequest(url: url)
+        request.httpMethod = "GET"
+        request.set(httpAuthentication: credential, with: credentialType)
+        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
+            var responseError: FileProviderWebDavError?
+            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
+                responseError = FileProviderWebDavError(code: rCode, path: url.relativePath, errorDescription: String(data: data ?? Data(), encoding: .utf8), url: url)
+                completionHandler(nil, responseError ?? error)
+                return
+            }
+            
+            completionHandler(data.flatMap({ ImageClass(data: $0) }), nil)
+        })
+        task.resume()
+    }
+    
+    open func propertiesOfFileSupported(path: String) -> Bool {
+        return false
+    }
+    
+    open func propertiesOfFile(path: String, completionHandler: @escaping (([String : Any], [String], Error?) -> Void)) {
+        dispatch_queue.async {
+            completionHandler([:], [], self.throwError(path, code: URLError.resourceUnavailable))
+        }
    }
 }

 // MARK: WEBDAV XML response implementation

-internal extension WebDAVFileProvider {
-    fileprivate func delegateNotify(_ operation: FileOperationType, error: Error?) {
-        DispatchQueue.main.async(execute: {
-            if error == nil {
-                self.delegate?.fileproviderSucceed(self, operation: operation)
-            } else {
-                self.delegate?.fileproviderFailed(self, operation: operation)
-            }
-        })
-    }
-}
-
 struct DavResponse {
    let href: URL
    let hrefString: String
@@ -475,12 +399,9 @@ struct DavResponse {
    
    init? (_ node: AEXMLElement, baseURL: URL?) {
        
-        func removeSlash(_ str: String) -> String {
-            if str.hasPrefix("/") {
-                return str.substring(from: str.index(after: str.startIndex))
-            } else {
-                return str
-            }
+        func standardizePath(_ str: String) -> String {
+            let trimmedStr = str.hasPrefix("/") ? str.substring(from: str.index(after: str.startIndex)) : str
+            return trimmedStr.addingPercentEncoding(withAllowedCharacters: .filePathAllowed) ?? str
        }
        
        // find node names with namespace
@@ -502,9 +423,14 @@ struct DavResponse {
        guard let hrefString = node[hreftag].value else { return nil }
        
        // trying to figure out relative path out of href
-        let hrefAbsolute = URL(string: hrefString, relativeTo: baseURL)?.absoluteString ?? hrefString
-        let relativePath = hrefAbsolute.replacingOccurrences(of: baseURL?.absoluteString ?? "", with: "", options: .anchored, range: nil)
-        let hrefURL = URL(string: removeSlash(relativePath), relativeTo: baseURL) ?? baseURL
+        let hrefAbsolute = URL(string: hrefString, relativeTo: baseURL)?.absoluteURL
+        let relativePath: String
+        if hrefAbsolute?.host?.replacingOccurrences(of: "www.", with: "", options: .anchored) == baseURL?.host?.replacingOccurrences(of: "www.", with: "", options: .anchored) {
+            relativePath = hrefAbsolute?.path.replacingOccurrences(of: baseURL?.absoluteURL.path ?? "", with: "", options: .anchored, range: nil) ?? hrefString
+        } else {
+            relativePath = hrefAbsolute?.absoluteString.replacingOccurrences(of: baseURL?.absoluteString ?? "", with: "", options: .anchored, range: nil) ?? hrefString
+        }
+        let hrefURL = URL(string: standardizePath(relativePath), relativeTo: baseURL) ?? baseURL
        
        guard let href = hrefURL?.standardized else { return nil }
        
@@ -542,69 +468,101 @@ struct DavResponse {
    }
    
    static func parse(xmlResponse: Data, baseURL: URL?) -> [DavResponse] {
+        guard let xml = try? AEXMLDocument(xml: xmlResponse) else { return [] }
        var result = [DavResponse]()
-        do {
-            let xml = try AEXMLDocument(xml: xmlResponse)
-            var rootnode = xml.root
-            var responsetag = "response"
-            for node in rootnode.all ?? [] where node.name.lowercased().hasSuffix("multistatus") {
-                rootnode = node
+        var rootnode = xml.root
+        var responsetag = "response"
+        for node in rootnode.all ?? [] where node.name.lowercased().hasSuffix("multistatus") {
+            rootnode = node
+        }
+        for node in rootnode.children where node.name.lowercased().hasSuffix("response") {
+            responsetag = node.name
+            break
+        }
+        for responseNode in rootnode[responsetag].all ?? [] {
+            if let davResponse = DavResponse(responseNode, baseURL: baseURL) {
+                result.append(davResponse)
            }
-            for node in rootnode.children where node.name.lowercased().hasSuffix("response") {
-                responsetag = node.name
-                break
-            }
-            for responseNode in rootnode[responsetag].all ?? [] {
-                if let davResponse = DavResponse(responseNode, baseURL: baseURL) {
-                    result.append(davResponse)
-                }
-            }
-        } catch _ {
        }
        return result
    }
 }

+/// Containts path, url and attributes of a WebDAV file or resource.
 public final class WebDavFileObject: FileObject {
    internal init(_ davResponse: DavResponse) {
        let href = davResponse.href
-        let name = davResponse.prop["displayname"] ?? (davResponse.hrefString.removingPercentEncoding! as NSString).lastPathComponent
+        let name = davResponse.prop["displayname"] ?? davResponse.href.lastPathComponent
        let relativePath = href.relativePath
        let path = relativePath.hasPrefix("/") ? relativePath : ("/" + relativePath)
        super.init(url: href, name: name, path: path)
        self.size = Int64(davResponse.prop["getcontentlength"] ?? "-1") ?? NSURLSessionTransferSizeUnknown
-        self.creationDate = resolve(dateString: davResponse.prop["creationdate"] ?? "")
-        self.modifiedDate = resolve(dateString: davResponse.prop["getlastmodified"] ?? "")
+        self.creationDate = Date(rfcString: davResponse.prop["creationdate"] ?? "")
+        self.modifiedDate = Date(rfcString: davResponse.prop["getlastmodified"] ?? "")
        self.contentType = davResponse.prop["getcontenttype"] ?? "octet/stream"
        self.isHidden = (Int(davResponse.prop["ishidden"] ?? "0") ?? 0) > 0
        self.type = self.contentType == "httpd/unix-directory" ? .directory : .regular
        self.entryTag = davResponse.prop["getetag"]
    }
    
-    /// MIME type of the file
+    /// MIME type of the file.
    open internal(set) var contentType: String {
        get {
-            return allValues[.mimeType] as? String ?? ""
+            return allValues[.mimeTypeKey] as? String ?? ""
        }
        set {
-            allValues[.mimeType] = newValue
+            allValues[.mimeTypeKey] = newValue
        }
    }
    
-    /// HTTP E-Tag, can be used to mark changed files
+    /// HTTP E-Tag, can be used to mark changed files.
    open internal(set) var entryTag: String? {
        get {
-            return allValues[.entryTag] as? String
+            return allValues[.entryTagKey] as? String
        }
        set {
-            allValues[.entryTag] = newValue
+            allValues[.entryTagKey] = newValue
        }
    }
+    
+    internal class func resourceKeyToDAVProp(_ key: URLResourceKey) -> String? {
+        switch key {
+        case URLResourceKey.fileSizeKey:
+            return "getcontentlength"
+        case URLResourceKey.creationDateKey:
+            return "creationdate"
+        case URLResourceKey.contentModificationDateKey:
+            return "getlastmodified"
+        case URLResourceKey.fileResourceTypeKey, URLResourceKey.mimeTypeKey:
+            return "getcontenttype"
+        case URLResourceKey.isHiddenKey:
+            return "ishidden"
+        case URLResourceKey.entryTagKey:
+            return "getetag"
+        default:
+            return nil
+        }
+    }
+    
+    internal class func propString(_ keys: [URLResourceKey]) -> String {
+        var propKeys = ""
+        for item in keys {
+            if let prop = WebDavFileObject.resourceKeyToDAVProp(item) {
+                propKeys += "<D:prop><D:\(prop)/></D:prop>"
+            }
+        }
+        if propKeys.isEmpty {
+            propKeys = "<D:allprop/>"
+        }
+        return propKeys
+    }
 }

+/// Error returned by WebDAV server when trying to access or do operations on a file or folder.
 public struct FileProviderWebDavError: FileProviderHTTPError {
    public let code: FileProviderHTTPErrorCode
    public let path: String
    public let errorDescription: String?
+    /// URL of resource caused error.
    public let url: URL
 }
Author	SHA1	Message	Date
Amir Abbas	c7201a8be7	Fixed currentPath docs, delegateNotify method default error arg	2017-08-29 01:40:15 +04:30
Amir Abbas	d2a03369fd	Fixed FTP crash on rucursive remove	2017-08-28 00:06:02 +04:30
Amir Abbas	d08098008a	Removed FoundationErrorEnum, Refactoed delegate progress routine	2017-08-27 13:48:29 +04:30
Amir Abbas	3c5303214e	Fixed Array extension error in HashMAC	2017-08-24 15:08:22 +04:30
Amir Abbas	ad8f333d16	Fixed swift 3 compile error on Array extenson	2017-08-24 08:36:11 +04:30
Amir Abbas	5e8f653c52	Fixed compile bug in Swift 3.0 for Array.Iterator.Element	2017-08-23 23:21:17 +04:30
Amir Abbas	e4cd7ddf22	Fixed Quality<T> percision	2017-08-23 22:18:18 +04:30
Amir Abbas	1efb0e3fe5	Fixed Quality<T>	2017-08-23 22:15:45 +04:30
Amir Abbas	1292856646	Added convenience methods for URLRequest headers	2017-08-23 22:04:47 +04:30
Amir Abbas	e39f9c29ec	Merge commit '3d44de0b407c3cd604189cc161dc1fc039409763'	2017-08-23 10:54:59 +04:30
Amir Abbas	f43199c22a	fixed colon in url string problem across provider	2017-08-23 10:52:45 +04:30
Amir Abbas Mousavian	3d44de0b40	Added missed filePathAllowed const to CharacterSet	2017-08-23 01:22:19 +04:30
Amir Abbas	21b5214481	Deprecate currentPath property, returning error in provider delegate - Using checkResourceIsReachable to check file exists - fixed bug: downloading/uploading files with colon in name	2017-08-23 01:19:56 +04:30
Amir Abbas	f0b4925db2	Consistancy to delegate call in all contents(of:) methods - renamed opType instances to operation - moved to v2 in Dropbox - removed redundant CloudFileProvider methods	2017-08-20 22:41:53 +04:30
Amir Abbas	0da957d25f	Making protocol method implementations overridable	2017-08-19 19:47:54 +04:30
Amir Abbas	0de558c160	Recursive search fixed in FTP, OneDrive, WebDAV	2017-08-19 06:49:15 +04:30
Amir Abbas	cad68da076	Refactored Dropbox, WebDAV & OneDrive to HTTPFileProvider - FileOperationType.source is not optional anymore - critical bugfix: KVO exception crash on task completion	2017-08-19 05:51:25 +04:30
Amir Abbas Mousavian	39da09edd4	Merge pull request #60 from evilutioner/master Fixed file downloading progress	2017-08-15 18:53:21 +04:30
Amir Abbas	5129aee1b5	Added fileURL to Progress	2017-08-15 18:41:48 +04:30
Oleg Marchik	478f0819b5	Fixed file downloading progress	2017-08-15 16:57:50 +03:00
Amir Abbas	b2a7800f7c	Fixed typo	2017-08-15 15:08:06 +04:30
Amir Abbas	96c102d156	Updated readme and podspec to ver 0.19.0	2017-08-15 14:57:36 +04:30
Amir Abbas	8aedd8e72a	Replaced OperationHandle with (NS)Progress	2017-08-15 13:42:41 +04:30
Amir Abbas	5b55debe8a	Fix warning in OneDrive provider	2017-08-12 17:50:00 +04:30
Amir Abbas Mousavian	0fa062a946	Merge pull request #59 from evilutioner/master OneDrive: list folder issue fixed, removed escape symbols in path	2017-08-11 20:43:28 +04:30
Oleg Marchik	879f86c1f9	Merge branch 'master' into master	2017-08-11 18:07:25 +03:00
Oleg Marchik	80d5f02bbd	OneDrive: list folder issue fixed, removed escape symbols in path	2017-08-11 18:04:18 +03:00
Amir Abbas Mousavian	b8a7721b2f	Merge pull request #58 from evilutioner/master Dropbox bug fixing: added unicode symbols support in http header path	2017-08-10 22:29:08 +04:30
Oleg Marchik	44b4784cd3	Important dropbox bug fixing: added unicode symbols support in path	2017-08-10 11:36:15 +03:00
Amir Abbas	7d9e2247f2	Fixed Compile error, removed redundant comments	2017-08-04 00:30:46 +04:30
Amir Abbas Mousavian	0ace562442	Merge pull request #57 from evilutioner/master Fixed outdated OneDrive API	2017-08-04 00:27:36 +04:30
evilutioner	63d831ef90	Merge branch 'master' into master	2017-08-01 16:08:51 +03:00
Oleg Marchik	d6b91348a3	Fixed outdated OneDrive API	2017-08-01 12:55:39 +03:00
Amir Abbas	fd9d4c1ab4	Probable fix for # 55 (OneDrive url issue)	2017-07-31 20:10:40 +04:30
Amir Abbas	41e266c2a9	Fix #54(FTP login), Refactored ExtendedLocalFileProvider	2017-07-17 05:36:30 +04:30
Amir Abbas	6127f4a7d9	Fixed Readme errors	2017-07-14 19:28:41 +04:30
Amir Abbas	faca943beb	Updated Readme fot FTP and SMB description	2017-07-14 16:49:55 +04:30
Amir Abbas	9345436fa2	Enhanced PDF Meta-info, Better FTPS handling	2017-07-14 16:49:24 +04:30
Amir Abbas	6228d88d41	Adjusting readme badges	2017-07-05 21:35:15 +04:30
Amir Abbas	5b395915a9	Updated Readme for Pods and SPM file	2017-07-02 18:26:34 +04:30
Amir Abbas	e4f12a502b	Fixed repo name and Readme	2017-07-01 16:57:23 +04:30
Amir Abbas	8faad0ec65	Fixed project name in schemes	2017-07-01 14:14:45 +04:30
Amir Abbas	bd5569d213	Updated scheme names	2017-07-01 14:09:39 +04:30
Amir Abbas	14ed279879	Renamed framework for compatibility with iOS 11	2017-07-01 13:50:22 +04:30
Amir Abbas	fd293f7bdb	[Amend] Fixed swift 3.0 compile error for type(of:)	2017-07-01 11:08:49 +04:30
Amir Abbas	3d9625e243	Fixed swift 3.0 compile error for type(of:)	2017-07-01 11:03:22 +04:30
Amir Abbas	0d017ebfc4	Fix #52 (Swift 4.0 source compatibility)	2017-07-01 10:47:48 +04:30
Amir Abbas	fd36df67f3	FTP passive property encoding - removed redundant protocol conforming	2017-07-01 09:43:45 +04:30
Amir Abbas	5be8c4ef5e	podspec and version update	2017-06-27 14:02:00 +04:30
Amir Abbas	0374fd7688	Making ftp active data task creation async	2017-06-24 12:09:16 +04:30
Amir Abbas	5ddfa43555	Fix #49 (Workaround colon in url path bug in NSURL relative url)	2017-06-24 12:04:50 +04:30
Amir Abbas	21850bb548	Probable fix for #51	2017-06-24 11:44:12 +04:30
Amir Abbas	b166e111e0	FTP Active mode, FTPS bugfix, possible fix for #47	2017-05-25 17:33:56 +04:30
Amir Abbas	1dd7561215	Caching ftp server support for RFC3659, Possible fix for #47	2017-05-23 19:10:04 +04:30
Amir Abbas	f94719deb0	Fixes #39 (FTP listing), Error domain determination	2017-05-05 13:02:07 +04:30
Amir Abbas	b13df0a977	Fixes #38 (Creating folder on WebDAV)	2017-05-05 10:06:17 +04:30
Amir Abbas	24af7aa4c2	Fixed LocalFileProvider init baseURL issue	2017-04-20 01:27:59 +04:30
Amir Abbas	06039ad993	CloudFileProvider operation handle improvements	2017-04-20 01:06:36 +04:30
Amir Abbas Mousavian	d8fec3e346	Merge pull request #37 from hansvdam/master Making `inProgress` of LocalFileProvider working	2017-04-18 14:22:08 +04:30
Hans van Dam	5c93bc8731	making 'inProgress' of LocalFileProvider work more consistently	2017-04-18 11:03:35 +02:00
Hans van Dam	61ba245189	making 'inProgress' of LocalFileProvider work	2017-04-17 18:16:04 +02:00
Amir Abbas	02e6cd37dd	WebDAV OAuth 1,2 support	2017-04-16 19:19:17 +04:30
Amir Abbas	55608fb8d0	New FileProviderSharing protocol for publicLinks - fixed DropboxFileProvider.propertiesOfFile() bug - minor URLRequest refactors - Added documentation and scope declaration	2017-04-16 19:07:45 +04:30
Amir Abbas	3e3582f6fa	Changed DropboxFileProvider.type constant to “Dropbox”	2017-04-15 21:31:47 +04:30
Amir Abbas	dd7a9d20b6	Fixed macOS build error	2017-04-14 23:26:40 +04:30
Amir Abbas	d4a9b4a34f	Fixed Dropbox thumbnail issue	2017-04-14 22:07:35 +04:30
Amir Abbas	34c663e62c	FileObject.url is unwraped. fixed url initializing from path	2017-04-14 18:57:50 +04:30
Amir Abbas	1415dda987	Fixed #36 (FTP Uploading bug)	2017-04-14 18:55:07 +04:30
Amir Abbas	cd465c1288	Fixes #35 (Dropbox handlers), Fixed FTP response reading length	2017-04-14 11:15:09 +04:30
Amir Abbas	a605b0cd85	Added FTP Recursive listing, Implemented ftp search - Implemented FTP full directory remove - Fixed FTP STOR bug - Implemented relativePath(of:) for FTP - Initial implementation of FTP active mode	2017-04-11 22:21:13 +04:30
Amir Abbas	bf7043de29	Fixed `relativePath(of:)` bug, made it overridable - Fixed StreamTask.taskDescription bug	2017-04-11 19:43:34 +04:30
Amir Abbas	ff5e13931f	Fixed WebDAVProvider.contents bug, refactored FTP Error	2017-04-09 14:09:03 +04:30
Amir Abbas	75af738d2e	Made SessionDelegate init public, fixed pod issue	2017-04-05 02:05:28 +04:30
Amir Abbas	f54a1253e4	Throwing error when trying to upload a directory	2017-04-05 00:24:24 +04:30
Amir Abbas	1394a92662	Add Documentation	2017-04-03 21:03:48 +04:30
Amir Abbas	dab171c755	Setting sessionDelgate credential to updated one.	2017-04-03 18:59:50 +04:30
Amir Abbas	ea5de2e2aa	Added progress for content(path:) method - Fixed issue with colliding handlers between sessions. - Sessions can be set. - SessionDelegate class is now public.	2017-04-03 18:50:13 +04:30
Amir Abbas	2253cca086	Fixed deprecated URLResourceKey items	2017-04-03 12:52:27 +04:30
Amir Abbas	e15a900ade	Renamed URLResourceKey additions to have `Key` prefix	2017-04-03 12:49:35 +04:30
Amir Abbas	5c2c56c44c	Fixed: Calling completion handler for upload task - Added including (file object properties) argument to WebDAV provider (resolves #31)	2017-04-03 12:41:11 +04:30
Amir Abbas Mousavian	ff4bbdf0de	Updated readme and podspec for FTP, minor fixes.	2017-04-01 14:56:20 +04:30
Amir Abbas Mousavian	163a218ac2	Fixed operation progress (in delegate) for all remote providers - Now also compatible with background session - added delegate notify (success, progress, failure) to FTP - added `FTPFileProvider.useAppleImplementation`, allows developer choose to use apple download task instead of custom implementation - enabling to download non-text files in FTP - implementation of `url(of:) in FTP - various fixes in error reporting - disabled closing streams in ftpQuit() due to crash	2017-04-01 01:33:56 +04:30
Amir Abbas Mousavian	81401ee36f	Added Documentation, refactors of related Date methods	2017-03-31 10:15:39 +04:30
Amir Abbas Mousavian	759ba3c7bf	Added AEXML license file	2017-03-31 00:49:08 +04:30
Amir Abbas Mousavian	f5c8f6308b	FileProviderStreamTask (URLSessionStreakTask replica) is now public - closing streams after ftpQuit() executed. - added ability to add FTP Active Mode.	2017-03-30 23:49:28 +04:30
Amir Abbas Mousavian	4dbb0adb18	FTP better error handling	2017-03-30 13:16:03 +04:30
Amir Abbas Mousavian	bf62d585fd	implemented FTP copy fallback, FTPS manual auth	2017-03-30 10:41:14 +04:30
Amir Abbas Mousavian	f21f658874	Deprecated create(file:) method, replaced by writeContents() - RemoteOperationHandle now retains task - FTP provider returns correct operation handle task	2017-03-29 23:03:04 +04:30
Amir Abbas	e6eba3d198	Fixed macOS and tvOS build	2017-03-29 10:13:47 +04:30
Amir Abbas	6959a14dc1	Fixed compiler error, closing streams in FTP provider	2017-03-29 09:29:22 +04:30
Amir Abbas	29a9e0fb82	Initial implementation of FTP - ftp copy and search is not implemented	2017-03-29 04:17:03 +04:30
Amir Abbas Mousavian	c7b4e1f124	Ensure baseURL is absolute, fixed warnings for Swift 3.1	2017-03-28 19:25:41 +04:30
Amir Abbas Mousavian	99a433a0fc	Credential is open to set anytime	2017-03-26 15:54:55 +04:30
Amir Abbas Mousavian	4023fbc62e	Fixed: WebDAV file listing omit files contains space in name	2017-03-26 02:03:43 +04:30
Amir Abbas Mousavian	1045901d7c	Added NSCoding support - Better relative path handling in WebDAV - obsolete deprecated methods	2017-03-25 19:19:49 +04:30
Amir Abbas	528d5eebc3	Fixed relativePath(of:) crash	2017-03-18 15:58:44 +03:30
Amir Abbas	079f8f4b77	Refactored methods to extensions	2017-03-17 15:52:58 +03:30
Amir Abbas	e12f386a9d	Refactored DispatchTime, better ExposureTime calculation	2017-03-11 03:02:02 +03:30
Amir Abbas	38e217bc19	Better LocalFileObject initialization with empty path	2017-03-09 17:34:00 +03:30
Amir Abbas	0b41abd4ef	Optimized PDF thumbnail/meta handling - Fixed ISO speed and GPS Area image meta - Fixed Dropbox `name ! BEGINSWiTH %` search query	2017-03-01 13:28:44 +03:30
Amir Abbas	aa781adeb2	Fixed searchFiles() from string, fixing “BEGINSWITH” typo	2017-02-24 16:53:59 +03:30
Amir Abbas	d61e51ba1c	Fixes #29 (WebDAV authentication), minor lints/optimiziations	2017-02-24 16:24:34 +03:30
Amir Abbas	cdff7db32e	Fixed OneDriveProvider bugs - fixed and enhanced searching files in Dropbox	2017-02-21 00:48:59 +03:30
Amir Abbas	9533a0e3c9	Removed redundant `isPathRelative` property. Now is always true. - Note: Check documentation to workaround - Improvement: Disabling `LocalFileProviderMonitor` while handler is running	2017-02-20 00:14:55 +03:30
Amir Abbas	194673b3b6	Added NSPredicate to searchFiles method - public functions became open, now is overridable - fixed urlCache documentation	2017-02-19 13:34:55 +03:30
Amir Abbas	194c8a41aa	Fixed readme	2017-02-18 09:08:55 +03:30
Amir Abbas Mousavian	c290377433	Updated Readme, travis.yml	2017-02-16 20:56:24 +03:30
Amir Abbas Mousavian	330a22c45d	Completed Documentation, fixed a small bug.	2017-02-16 13:00:50 +03:30
Amir Abbas	e899804e28	Added isReachable method to test connectivity - Fixed Cloud provider bug when moving/deleting evicted file	2017-02-14 22:58:07 +03:30
Amir Abbas	489a9a16d0	Updated documentation, fixed Cloud provider paths bugs	2017-02-14 12:24:06 +03:30
Amir Abbas	93359d5173	Made FileProviders equatable	2017-02-13 16:45:34 +03:30
Amir Abbas	12ff3a410d	Fixed critical bug in LocalFileObject when decoding path	2017-02-13 16:31:29 +03:30
Amir Abbas	a7de09362b	Equatable FileObject, async completion handler in cloud provider	2017-02-13 12:06:09 +03:30
Amir Abbas	b1fe37cf2a	Updated Readme, fixed several bugs - non-locking snapshot of file while uploading to iCloud - fixed: `CloudFIleProvider.doOperation()` couldn’t handle local urls - fixed: FileProvider.type didn’t work correctly	2017-02-12 22:45:30 +03:30
Amir Abbas	bd59eacee2	Fixed bugs in providers and LocalFileObject initializing	2017-02-12 03:07:40 +03:30