SwiftLint/Source/swiftlint/Commands/AutoCorrectCommand.swift

import Commandant
import Result
import SwiftLintFramework

struct AutoCorrectCommand: CommandProtocol {
    let verb = "autocorrect"
    let function = "Automatically correct warnings and errors"

    func run(_ options: AutoCorrectOptions) -> Result<(), CommandantError<()>> {
        let configuration = Configuration(options: options)
        let cache = options.ignoreCache ? nil : LinterCache(configuration: configuration)
        let indentWidth: Int
        var useTabs: Bool

        switch configuration.indentation {
        case .tabs:
            indentWidth = 4
            useTabs = true
        case .spaces(let count):
            indentWidth = count
            useTabs = false
        }

        if options.useTabs {
            queuedPrintError("'use-tabs' is deprecated and will be completely removed" +
                " in a future release. 'indentation' can now be defined in a configuration file.")
            useTabs = options.useTabs
        }

        return configuration.visitLintableFiles(path: options.path, action: "Correcting",
                                                quiet: options.quiet,
                                                useScriptInputFiles: options.useScriptInputFiles,
                                                forceExclude: options.forceExclude,
                                                cache: cache, parallel: true) { linter in
            let corrections = linter.correct()
            if !corrections.isEmpty && !options.quiet {
                let correctionLogs = corrections.map({ $0.consoleDescription })
                queuedPrint(correctionLogs.joined(separator: "\n"))
            }
            if options.format {
                let formattedContents = try? linter.file.format(trimmingTrailingWhitespace: true,
                                                                useTabs: useTabs,
                                                                indentWidth: indentWidth)
                _ = try? formattedContents?
                    .write(toFile: linter.file.path!, atomically: true, encoding: .utf8)
            }
        }.flatMap { files in
            if !options.quiet {
                let pluralSuffix = { (collection: [Any]) -> String in
                    return collection.count != 1 ? "s" : ""
                }
                queuedPrintError("Done correcting \(files.count) file\(pluralSuffix(files))!")
            }
            return .success(())
        }
    }
}

struct AutoCorrectOptions: OptionsProtocol {
    let path: String
    let configurationFile: String
    let useScriptInputFiles: Bool
    let quiet: Bool
    let forceExclude: Bool
    let format: Bool
    let cachePath: String
    let ignoreCache: Bool
    let useTabs: Bool

    // swiftlint:disable line_length
    static func create(_ path: String) -> (_ configurationFile: String) -> (_ useScriptInputFiles: Bool) -> (_ quiet: Bool) -> (_ forceExclude: Bool) -> (_ format: Bool) -> (_ cachePath: String) -> (_ ignoreCache: Bool) -> (_ useTabs: Bool) -> AutoCorrectOptions {
        return { configurationFile in { useScriptInputFiles in { quiet in { forceExclude in { format in { cachePath in { ignoreCache in { useTabs in
            self.init(path: path, configurationFile: configurationFile, useScriptInputFiles: useScriptInputFiles, quiet: quiet, forceExclude: forceExclude, format: format, cachePath: cachePath, ignoreCache: ignoreCache, useTabs: useTabs)
        }}}}}}}}
    }

    static func evaluate(_ mode: CommandMode) -> Result<AutoCorrectOptions, CommandantError<CommandantError<()>>> {
        // swiftlint:enable line_length
        return create
            <*> mode <| pathOption(action: "correct")
            <*> mode <| configOption
            <*> mode <| useScriptInputFilesOption
            <*> mode <| quietOption(action: "correcting")
            <*> mode <| Option(key: "force-exclude",
                               defaultValue: false,
                               usage: "exclude files in config `excluded` even if their paths are explicitly specified")
            <*> mode <| Option(key: "format",
                               defaultValue: false,
                               usage: "should reformat the Swift files")
            <*> mode <| Option(key: "cache-path", defaultValue: "",
                               usage: "the directory of the cache used when correcting")
            <*> mode <| Option(key: "no-cache", defaultValue: false,
                               usage: "ignore cache when correcting")
            <*> mode <| Option(key: "use-tabs",
                               defaultValue: false,
                               usage: "should use tabs over spaces when reformatting. Deprecated.")
    }
}