partial development in add audio message support

Example/Sources/View Controllers/ChatViewController.swift

@@ -25,6 +25,7 @@ SOFTWARE.
 import UIKit
 import MessageKit
 import MessageInputBar
+import AVFoundation
 
 /// A base class for the example controllers
 class ChatViewController: MessagesViewController, MessagesDataSource {
@@ -32,7 +33,11 @@ class ChatViewController: MessagesViewController, MessagesDataSource {
     override var preferredStatusBarStyle: UIStatusBarStyle {
         return .lightContent
     }
-    
+
+    var audioPlayer: AVAudioPlayer?
+
+    var audioTimer: Timer?
+
     var messageList: [MockMessage] = []
     
     let refreshControl = UIRefreshControl()
@@ -64,6 +69,7 @@ class ChatViewController: MessagesViewController, MessagesDataSource {
     override func viewDidDisappear(_ animated: Bool) {
         super.viewDidDisappear(animated)
         MockSocket.shared.disconnect()
+        self.stopCurrentAudioPlayer()
     }
     
     func loadFirstMessages() {
@@ -204,6 +210,63 @@ extension ChatViewController: MessageCellDelegate {
     func didTapMessageBottomLabel(in cell: MessageCollectionViewCell) {
         print("Bottom label tapped")
     }
+
+    func didTapPlayButton(in cell: AudioMessageCell) {
+        print("Did tap on play button")
+//        guard let indexPath = messagesCollectionView.indexPath(for: cell),
+//              let message = messagesCollectionView.messagesDataSource?.messageForItem(at: indexPath, in: messagesCollectionView) else {
+//                return
+//        }
+//        switch message.kind {
+//        case .audio(let item):
+//            self.stopPreviousAudioIfNeeded(item)
+//            if cell.isPlaying() == true {
+//                audioPlayer?.pause()
+//                self.audioTimer?.invalidate()
+//                cell.pasue()
+//            } else {
+//                if audioPlayer == nil {
+//                    audioPlayer = try? AVAudioPlayer.init(contentsOf: item.url)
+//                    audioPlayer?.delegate = self
+//                }
+//                cell.play()
+//                audioPlayer?.play()
+//                // start timer to update audio pregress
+//                self.audioTimer?.invalidate()
+//                self.audioTimer = Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(ChatViewController.didFireAudioTimer(_:)), userInfo: cell, repeats: true)
+//            }
+//        default: break
+//        }
+    }
+
+    // MARK: - Audio Helpers
+    @objc internal func didFireAudioTimer(_ timer: Timer) {
+        guard let audioCell = timer.userInfo as? AudioMessageCell else {
+            return
+        }
+        let totalDuration = self.audioPlayer?.duration ?? 0.0
+        let currentTime = self.audioPlayer?.currentTime ?? 0.0
+        let percent = (totalDuration != 0) ? (Float(currentTime/totalDuration)) : 0.0
+        audioCell.updateProgress(percent: percent, duration: currentTime)
+    }
+
+    private func stopPreviousAudioIfNeeded(_ currentAudioItem: AudioItem) {
+        // stop a previous audio if current received item url is diffrent than audio player url
+        guard let playingAudioURL = self.audioPlayer?.url else {
+            return  // there is no audio player playing at this moment
+        }
+        if playingAudioURL.absoluteString != currentAudioItem.url.absoluteString {
+            self.stopCurrentAudioPlayer()
+        }
+    }
+
+    fileprivate func stopCurrentAudioPlayer() {
+        guard let player = audioPlayer else {
+            return // there is no audio player to stop
+        }
+        player.stop()  // by calling stop will not audioPlayerDidFinishPlaying(player:flag:) delegate method - it should be called manualy
+        self.audioPlayerDidFinishPlaying(player, successfully: true)
+    }
     
 }
 
@@ -255,3 +318,40 @@ extension ChatViewController: MessageInputBarDelegate {
     }
     
 }
+
+// MARK: - AVAudioPlayerDelegate
+
+extension ChatViewController: AVAudioPlayerDelegate {
+
+    func audioPlayerDidFinishPlaying(_ player: AVAudioPlayer, successfully flag: Bool) {
+        guard let playingURL = player.url, let currentPlayingMessage = self.getMessageWithAudioURL(playingURL) else {
+            return
+        }
+        // update cell that is current playing
+        if let sectionIndex = messageList.index(where: { $0.messageId == currentPlayingMessage.messageId }) {
+            let indexPath = IndexPath.init(row: 0, section: sectionIndex)
+            if let audioCell = messagesCollectionView.cellForItem(at: indexPath) as? AudioMessageCell {
+                audioCell.stop(with: currentPlayingMessage.kind)
+            }
+        }
+        self.audioTimer?.invalidate()
+        self.audioTimer = nil
+        audioPlayer = nil
+    }
+
+    private func getMessageWithAudioURL(_ url: URL) -> MockMessage? {
+        let message = messageList.filter { (message) -> Bool in
+            switch message.kind {
+            case .audio(let audioItem):
+                if audioItem.url.absoluteString == url.absoluteString {
+                    return true
+                }
+            default: break
+            }
+            return false
+        }.first
+
+        return message
+    }
+
+}