import UIKit
import Flutter
import AVFoundation
import MediaPlayer

import flutter_downloader

@available(iOS 11, *)
@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
    var player: AVPlayer?
    var volume: Float = 1
    var muted: Bool = false
    var lastTrack: String = ""
    var channel: FlutterMethodChannel!
    override func application(
        _ application: UIApplication,
        didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
    ) -> Bool {
        GeneratedPluginRegistrant.register(with: self)
        FlutterDownloaderPlugin.setPluginRegistrantCallback(registerPlugins)
        let controller : FlutterViewController = window?.rootViewController as! FlutterViewController
        channel = FlutterMethodChannel(name: "lighthouse_audio_stream", binaryMessenger: controller.binaryMessenger)

        NotificationCenter.default.addObserver(
            self,
            selector: #selector(playerItemDidReachEnd),
            name: NSNotification.Name.AVPlayerItemDidPlayToEndTime,
            object: nil
        )

        channel.setMethodCallHandler({
                (call: FlutterMethodCall, result: @escaping FlutterResult) -> Void in
                switch(call.method) {
                case "play":
                    if let args = call.arguments as? Dictionary<String, String> {
                        let url = args["url"] ?? ""
                        let title = args["title"] ?? ""
                        let description = args["description"] ?? ""
                        let image = args["image"] ?? ""
                        if (url.isEmpty) {
                            result(FlutterError.init(code: "no url passed", message: "nill", details: "Nill"))
                        } else {
                            do {
                               let isSameTrack = self.lastTrack == url;
                               if !isSameTrack {
                                   self.lastTrack = url;
                               }
                               try self.play(url: url, isSameTrack: isSameTrack, title: title, description: description, image: image)
                               UIApplication.shared.beginReceivingRemoteControlEvents()
                               result(0)
                           } catch {
                               result(0)
                           }
                        }
                    } else {
                        result(FlutterError.init(code: "no url passed", message: "nill", details: "Nill"))
                    }
                    result(0)
                    return
                case "disk":
                    if let args = call.arguments as? Dictionary<String, Any>,
                        let path = args["path"] as? String {
                        result(self.diskUsage(path: path))
                    } else {
                        result(FlutterError.init(code: "no url passed", message: "nill", details: "Nill"))
                    }
                    result(0)
                    return
                case "seek":
                    if let args = call.arguments as? Dictionary<String, Any>,
                        let pos = args["pos"] as? Double {
                        self.seek(pos: pos / 1000)
                        result(nil)
                    } else {
                        result(FlutterError.init(code: "no position passed", message: "nill", details: "Nill"))
                    }
                    result(0)
                    return
                case "pause":
                    self.pause()
                    result(nil)
                    return
                case "stop":
                    self.stop()
                    result(nil)
                    return
                case "mute":
                    self.mute()
                    result(nil)
                    return
                case "forward":
                    self.seekTo(forward: true)
                    return
                case "rewind":
                    self.seekTo(forward: false)
                    return
                case "currentPos":
                    let position = self.currentPos();
                    result(position)
                    return
                case "rate":
                    self.rate()
                    result(nil)
                    return
                default:
                    result(FlutterMethodNotImplemented)
                }
            })
        return super.application(application, didFinishLaunchingWithOptions: launchOptions)
    }

    @objc func playerItemDidReachEnd(notification: NSNotification) {
        channel.invokeMethod("stop", arguments: 0)
    }


    override func remoteControlReceived(with event: UIEvent?) {
        guard let event = event else {

            return
        }
        guard event.type == UIEvent.EventType.remoteControl else {
            return
        }
        switch event.subtype {
        case UIEventSubtype.remoteControlPlay:
            player?.play()
            channel.invokeMethod("playing", arguments: 0)
        case UIEventSubtype.remoteControlPause:
            player?.pause()
            channel.invokeMethod("pause", arguments: nil)
        case UIEventSubtype.remoteControlTogglePlayPause:
            print("received toggle\n")
        case UIEventSubtype.remoteControlNextTrack:
            channel.invokeMethod("next", arguments: nil)
        case UIEventSubtype.remoteControlPreviousTrack:
            channel.invokeMethod("prev", arguments: nil)
        default:
            print("received \(event.subtype) which we did not process\n")
        }
    }



    private func play(url: String, isSameTrack: Bool, title: String, description: String, image: String) throws {
        let location: URL? = url.hasPrefix("http") ? URL(string: url) : NSURL.fileURL(withPath: url);
        if let audioUrl = location {

            if (player == nil || !isSameTrack) {
                player = AVPlayer(url: audioUrl)
                player?.automaticallyWaitsToMinimizeStalling = false;
                setupNowPlayingInfo(title: title, artist: description, image: image)
            }
            player?.play()
        } else {
            throw PlayerErrors.InvalidUrl
        }
    }

    private func seekTo(forward: Bool)  {
        if player != nil {
            let currentPos = CMTimeGetSeconds(player?.currentTime() ?? CMTime(seconds: 0.0, preferredTimescale: 1))
            let goto = forward ? (currentPos + 10.0) : (currentPos - 10.0)
            player?.seek(to: CMTime(seconds: goto, preferredTimescale: 1))
        }
    }

    private func seek(pos: Double)  {
        if player != nil {
            player?.seek(to: CMTime(seconds: pos, preferredTimescale: 1))
        }
    }

    private func pause() {
        if player != nil {
            player?.pause()
        }
    }

    private func stop() {
        if player != nil {
            player?.pause()
            player = nil
        }
    }

    private func rate() {
        if let url = URL(string: "itms-apps://apple.com/app/com.thelighthouseapp.app") {
            UIApplication.shared.open(url)
        }
    }

    private func currentPos() -> [String: Double] {
        if player != nil {
            var duration = CMTimeGetSeconds(player?.currentItem?.duration ?? CMTime(seconds: 1.0, preferredTimescale: 1))
            if (duration.isNaN || duration < 1) {
                duration = 1
            }
            let currentTime = CMTimeGetSeconds(player?.currentTime() ?? CMTime(seconds: 0.0, preferredTimescale: 1));
            MPNowPlayingInfoCenter.default().nowPlayingInfo?[MPNowPlayingInfoPropertyElapsedPlaybackTime] = (currentTime / duration) * 100
            return ["duration": duration * 1000.0, "currentPos": currentTime * 1000.0]
        }
        return ["duration": 1.0, "currentPos": 0.0]
    }

    private func mute() {
        if player != nil {
            if muted {
                player?.volume = volume
                muted = false
            } else {
                volume = player?.volume ?? 1.0
                player?.volume = 0.0
                muted = true
            }
        }
    }

    @available(iOS 11, *)
    private func diskUsage(path: String) -> [String: Int] {
        let dirURL = URL(fileURLWithPath: path)
        do {
            let values = try dirURL.resourceValues(forKeys: [.volumeAvailableCapacityKey, .fileSizeKey, .isDirectoryKey])
            if (values.isDirectory ?? false) {
                let diskSize = values.volumeAvailableCapacity ?? 0
                var usedSpace = 0
                (FileManager.default.enumerator(at: dirURL, includingPropertiesForKeys: nil)?.allObjects as? [URL])?.lazy.forEach {
                    usedSpace += (try? $0.resourceValues(forKeys: [.totalFileAllocatedSizeKey]))?.totalFileAllocatedSize ?? 0
                }
                return ["totalSpace": diskSize, "usedSpace": usedSpace]
            } else {
                return ["totalSpace": 1, "usedSpace": 0]
            }
        } catch {
            return ["totalSpace": 1, "usedSpace": 0]
        }
    }

    func setupNowPlayingInfo(title: String, artist: String, image: String) {
            var nowPlayingInfo = [String: Any]()
            nowPlayingInfo[MPMediaItemPropertyTitle] = title
            nowPlayingInfo[MPMediaItemPropertyArtist] = artist
            MPNowPlayingInfoCenter.default().nowPlayingInfo = nowPlayingInfo
    }

        fileprivate func setupAudioSession() {
            do {
                try AVAudioSession.sharedInstance().setCategory(AVAudioSession.Category.playback, mode: .default)
                try AVAudioSession.sharedInstance().setActive(true)
            } catch let sessionErr {
                print("Failed to activate session:", sessionErr)
            }
        }

        deinit {
            NotificationCenter.default.removeObserver(self)
        }

}

enum PlayerErrors: Error {
    case InvalidUrl

    func val() -> String {
        switch self {
        case .InvalidUrl:
            return "Cannot play file from this url"
        }
    }
}

private func registerPlugins(registry: FlutterPluginRegistry) {
    if (!registry.hasPlugin("FlutterDownloaderPlugin")) {
        FlutterDownloaderPlugin.register(with: registry.registrar(forPlugin: "FlutterDownloaderPlugin"))
    }
}