RarFileProvider.swift

//
//  ZipFileProvider
//  ExtDownloader
//
//  Created by Amir Abbas on 1/30/1396 AP.
//  Copyright © 1396 AP Mousavian. All rights reserved.
//

import Foundation
import FilesProvider
import UnrarKit

// TODO: Progress
class RarFileProvider: FileProvider {
    open class var type: String { return "RarCompressed" }
    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 var credential: URLCredential? {
        didSet {
            archive.password = credential?.password
        }
    }
    
    fileprivate var archive: URKArchive
    
    /// Initializes provider for the specified zip file in local URL.
    ///
    /// - Parameter baseURL: Local URL location for base directory.
    public init?(baseURL: URL) {
        guard baseURL.isFileURL || baseURL.scheme == "compressed" else {
            fatalError("Cannot initialize a Local provider from remote URL.")
        }
        guard let archive = try? URKArchive(path: baseURL.path) else {
            return nil
        }
        self.archive = archive
        let base = (baseURL.path.hasSuffix("/") ? baseURL : baseURL.appendingPathComponent("")).absoluteURL
        var components = URLComponents(url: base, resolvingAgainstBaseURL: true)
        components?.scheme = "compressed"
        self.baseURL = components?.url ?? base
        self.currentPath = ""
        self.credential = nil
        
        dispatch_queue = DispatchQueue(label: "FileProvider.\(Swift.type(of: self).type)", attributes: .concurrent)
        operation_queue = OperationQueue()
        operation_queue.name = "FileProvider.\(Swift.type(of: self).type).Operation"
    }
    
    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 ?? ""
    }
    
    open func encode(with aCoder: NSCoder) {
        aCoder.encode(self.baseURL, forKey: "baseURL")
        aCoder.encode(self.currentPath, forKey: "currentPath")
    }
    
    public static var supportsSecureCoding: Bool {
        return true
    }
    
    public func copy(with zone: NSZone? = nil) -> Any {
        let copy = RarFileProvider(baseURL: self.baseURL!)!
        copy.currentPath = self.currentPath
        copy.delegate = self.delegate
        copy.fileOperationDelegate = self.fileOperationDelegate
        return copy
    }
    
    open func contentsOfDirectory(path: String, completionHandler: @escaping (_ contents: [FileObject], _ error: Error?) -> Void) {
        dispatch_queue.async {
            do {
                let barePath = path.trimmingCharacters(in: CharacterSet(charactersIn: "/ "))
                let list = try self.archive.listFileInfo()
                let contents = list.filter({ $0.filename.deletingLastPathComponent == barePath }).map { RarFileObject(baseURL: self.baseURL!, info: $0) }
                completionHandler(contents, nil)
            } catch {
                completionHandler([], error)
            }
        }
    }
    
    open func attributesOfItem(path: String, completionHandler: @escaping (_ attributes: FileObject?, _ error: Error?) -> Void) {
        let barePath = path.trimmingCharacters(in: CharacterSet(charactersIn: "/ "))
        let parentPath = path.deletingLastPathComponent.trimmingCharacters(in: CharacterSet(charactersIn: "/ "))
        self.contentsOfDirectory(path: parentPath) { (contents, error) in
            let file = contents.first(where: { $0.path == barePath })
            completionHandler(file, error)
        }
    }
    
    open func storageProperties(completionHandler: (@escaping (_ volume: VolumeObject?) -> Void)) {
        dispatch_queue.async {
            do {
                let list = try self.archive.listFileInfo()
                let used: Int64 = list.reduce(0) { $0 + $1.uncompressedSize }
                var allValues: [URLResourceKey: Any] = [.volumeAvailableCapacityKey: -used]
                allValues[.volumeURLKey] = self.archive.fileURL
                allValues[.volumeNameKey] = self.archive.fileURL?.lastPathComponent
                allValues[.volumeIsReadOnlyKey] = true
                let volume = VolumeObject(allValues: allValues)
                completionHandler(volume)
            } catch {
                completionHandler(nil)
            }
        }
    }
    
    open func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping (_ files: [FileObject], _ error: Error?) -> Void) -> Progress? {
        dispatch_queue.async {
            do {
                let list = try self.archive.listFileInfo()
                let contents = list.map({ RarFileObject(baseURL: self.baseURL!, info: $0) }).filter { query.evaluate(with: $0.mapPredicate()) }
                completionHandler(contents, nil)
            } catch {
                completionHandler([], error)
            }
        }
        return nil
    }
    
    open func isReachable(completionHandler: @escaping (Bool) -> Void) {
        dispatch_queue.async {
            completionHandler(self.archive.filename != nil && self.archive.validatePassword())
        }
    }
    
    open func isPasswordProtected() -> Bool {
        return self.archive.isPasswordProtected() && !self.archive.validatePassword()
    }
    
    open weak var fileOperationDelegate : FileOperationDelegate?
    
    @discardableResult
    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 moveItem(path: String, to toPath: String, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> Progress? {
        let operation = FileOperationType.move(source: path, destination: toPath)
        
        if !overwrite && FileManager.default.fileExists(atPath: self.url(of: toPath).path) {
            let errorpath = self.baseURL!.lastPathComponent.appendingPathComponent(toPath)
            let error = CocoaError(.fileWriteFileExists, userInfo: [NSFilePathErrorKey: errorpath])
            completionHandler?(error)
            return nil
        }
        
        return self.doOperation(operation, overwrite: overwrite, completionHandler: completionHandler)
    }
    
    @discardableResult
    open func copyItem(path: String, to toPath: String, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> Progress? {
        let operation = FileOperationType.copy(source: path, destination: toPath)
        
        if !overwrite && FileManager.default.fileExists(atPath: self.url(of: toPath).path) {
            self.dispatch_queue.async {
                let errorpath = self.baseURL!.lastPathComponent.appendingPathComponent(toPath)
                let error = CocoaError(.fileWriteFileExists, userInfo: [NSFilePathErrorKey: errorpath])
                completionHandler?(error)
            }
            return nil
        }
        
        return self.doOperation(operation, overwrite: overwrite, completionHandler: completionHandler)
    }
    
    @discardableResult
    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) -> Progress? {
        let operation = FileOperationType.copy(source: localFile.absoluteString, destination: toPath)
        return self.doOperation(operation, overwrite: overwrite, completionHandler: completionHandler)
    }
    
    @discardableResult
    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)
    }
    
    @discardableResult
    fileprivate func doOperation(_ operation: FileOperationType, data: Data? = nil, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> Progress? {
        
        func askPassword(file: URKFileInfo) {
            if file.isEncryptedWithPassword {
                let group = DispatchGroup()
                let msg = "Please enter password to access \(self.type)"
                let okBtn = Utility.UI.AlertButton(title: NSLocalizedString("OK", comment: "button"), buttonType: Utility.UI.ButtonType.default, buttonHandler: { fields in
                    let credential = URLCredential(user: "anonymous", password: fields[0], persistence: .forSession)
                    self.credential = credential
                    group.leave()
                })
                let cancel = Utility.UI.AlertButton(title: NSLocalizedString("Cancel", comment: "button"), buttonType: .cancel, buttonHandler: { _ in
                    group.leave()
                })
                let passBox = Utility.UI.AlertTextField(placeHolder: "password", defaultValue: "", textInputTraits: TextInputTraits())
                group.enter()
                DispatchQueue.main.async {
                    Utility.UI.askAlert(msg, withTitle: NSLocalizedString("\(self.type) Credential", comment: "Remote credential"), viewController: UIApplication.shared.mn_topViewController()!, buttons: [okBtn, cancel], textFields: [passBox])
                }
                group.wait()
            }
        }
        
        let pathTrim = CharacterSet(charactersIn: "/")
        operation_queue.addOperation {
            do {
                switch operation {
                case .create(path: let path), .modify(path: let path), .remove(path: let path):
                    let errorpath = self.baseURL!.lastPathComponent.appendingPathComponent(path)
                    let error = CocoaError(.fileWriteVolumeReadOnly, userInfo: [NSFilePathErrorKey: errorpath])
                    throw error
                case .copy(source: let source, destination: let dest):
                    if dest.hasPrefix("file://"), let destURL = URL(string: dest) {
                        let files = try self.archive.listFileInfo().filter { $0.filename.hasPrefix(source.trimmingCharacters(in: pathTrim)) }
                        for (i, file) in files.enumerated() {
                            askPassword(file: file)
                            
                            let finalRelPath = file.filename.replacingOccurrences(of: source.trimmingCharacters(in: pathTrim), with: "", options: .anchored).trimmingCharacters(in: pathTrim)
                            let finalDestURL = destURL.appendingPathComponent(finalRelPath)
                            if file.isDirectory {
                                try FileManager.default.createDirectory(atPath: finalDestURL.path, withIntermediateDirectories: true, attributes: [.modificationDate: file.timestamp])
                            } else {
                                let data = try self.archive.extractData(fromFile: file.filename, progress: { progress in
                                    self.delegateNotify(operation, progress: (Double(i) + Double(progress)) / Double(files.count))
                                })
                                try data.write(to: finalDestURL)
                                try? FileManager.default.setAttributes([FileAttributeKey.modificationDate:file.timestamp], ofItemAtPath: finalDestURL.path)
                            }
                        }
                    } else {
                        let errorpath = self.baseURL!.lastPathComponent.appendingPathComponent(dest)
                        let error = CocoaError(.fileWriteVolumeReadOnly, userInfo: [NSFilePathErrorKey: errorpath])
                        throw error
                    }
                case .move(source: _, destination: let dest):
                    let errorpath = self.baseURL!.lastPathComponent.appendingPathComponent(dest)
                    let error = CocoaError(.fileWriteVolumeReadOnly, userInfo: [NSFilePathErrorKey: errorpath])
                    throw error
                default:
                    return
                }
                completionHandler?(nil)
                self.delegateNotify(operation)
            } catch {
                completionHandler?(error)
                self.delegateNotify(operation, error: error)
            }
        }
        return nil
    }
    
    @discardableResult
    open func contents(path: String, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> Progress? {
        let operation = FileOperationType.fetch(path: path)
        let barePath = path.trimmingCharacters(in: CharacterSet(charactersIn: "/ "))
        dispatch_queue.async {
            do {
                let data = try self.archive.extractData(fromFile: barePath, progress: { (progress) in
                    self.delegateNotify(operation, progress: Double(progress))
                })
                completionHandler(data, nil)
                self.delegateNotify(operation)
            } catch {
                completionHandler(nil, error)
                self.delegateNotify(operation, error: error)
            }
        }
        return nil
    }
    
    @discardableResult
    open func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> Progress? {
        return self.contents(path: path) { (data, error) in
            let range: Range<Int> = Int(offset)..<(Int(offset) + length)
            completionHandler(data?.subdata(in: range), error)
        }
    }
    
    @discardableResult
    open func writeContents(path: String, contents data: Data?, atomically: Bool, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> Progress? {
        let operation: FileOperationType = .modify(path: path)
        return self.doOperation(operation, data: data ?? Data(), overwrite: overwrite, completionHandler: completionHandler)
    }
    
    fileprivate func delegateNotify(_ operation: FileOperationType, error: Error? = nil) {
        DispatchQueue.main.async(execute: {
            if let error = error {
                self.delegate?.fileproviderFailed(self, operation: operation, error: error)
            } else {
                self.delegate?.fileproviderSucceed(self, operation: operation)
            }
        })
    }
    
    fileprivate func delegateNotify(_ operation: FileOperationType, progress: Double) {
        DispatchQueue.main.async(execute: {
            self.delegate?.fileproviderProgress(self, operation: operation, progress: Float(progress))
        })
    }
}

class RarFileObject: FileObject {
    init(baseURL: URL, info: URKFileInfo) {
        var allValues = [URLResourceKey: Any]()
        allValues = [URLResourceKey: Any]()
        var path = info.filename.trimmingCharacters(in: CharacterSet(charactersIn: "/"))
        if info.isDirectory {
            path.append("/")
        }
        allValues[.fileURLKey] = URL(string: path, relativeTo: baseURL)
        allValues[.nameKey] =  info.filename.lastPathComponent
        allValues[.pathKey] = path
        allValues[.fileSizeKey] = Int64(info.uncompressedSize)
        allValues[.fileResourceTypeKey] = info.isDirectory ? URLFileResourceType.directory : URLFileResourceType.regular
        allValues[.documentIdentifierKey] = info.crc
        allValues[.fileAllocatedSizeKey] = Int64(info.compressedSize)
        allValues[.isEncryptedKey] = info.isEncryptedWithPassword
        super.init(allValues: allValues)
    }
    
    var compressedSize: Int64? {
        get {
            return allValues[.fileAllocatedSizeKey] as? Int64
        }
    }
    
    var isEncrypted: Bool {
        get {
            return allValues[.isEncryptedKey] as? Bool ?? false
        }
    }
    
    var crc: UInt? {
        get {
            return allValues[.documentIdentifierKey] as? UInt
        }
    }
}