var player: AVPlayer?
var playerItem:AVPlayerItem?
fileprivate let seekDuration: Float64 = 10


@IBOutlet weak var labelOverallDuration: UILabel!
@IBOutlet weak var labelCurrentTime: UILabel!
@IBOutlet weak var playbackSlider: UISlider!
@IBOutlet weak var ButtonPlay: UIButton!

//call this mehtod to init audio player 
func initAudioPlayer{
    let url = URL(string: "https://argaamplus.s3.amazonaws.com/eb2fa654-bcf9-41de-829c-4d47c5648352.mp3")
    let playerItem:AVPlayerItem = AVPlayerItem(url: url!)
    player = AVPlayer(playerItem: playerItem)
    
    playbackSlider.minimumValue = 0
    
    //To get overAll duration of the audio
    let duration : CMTime = playerItem.asset.duration
    let seconds : Float64 = CMTimeGetSeconds(duration)
    labelOverallDuration.text = self.stringFromTimeInterval(interval: seconds)
    
    //To get the current duration of the audio
    let currentDuration : CMTime = playerItem.currentTime()
    let currentSeconds : Float64 = CMTimeGetSeconds(currentDuration)
    labelCurrentTime.text = self.stringFromTimeInterval(interval: currentSeconds)
    
    playbackSlider.maximumValue = Float(seconds)
    playbackSlider.isContinuous = true
    
    
    
    player!.addPeriodicTimeObserver(forInterval: CMTimeMakeWithSeconds(1, preferredTimescale: 1), queue: DispatchQueue.main) { (CMTime) -> Void in
        if self.player!.currentItem?.status == .readyToPlay {
            let time : Float64 = CMTimeGetSeconds(self.player!.currentTime());
            self.playbackSlider.value = Float ( time );
            self.labelCurrentTime.text = self.stringFromTimeInterval(interval: time)
        }
        let playbackLikelyToKeepUp = self.player?.currentItem?.isPlaybackLikelyToKeepUp
        if playbackLikelyToKeepUp == false{
            print("IsBuffering")
            self.ButtonPlay.isHidden = true
            //        self.loadingView.isHidden = false
        } else {
            //stop the activity indicator
            print("Buffering completed")
            self.ButtonPlay.isHidden = false
            //        self.loadingView.isHidden = true
        }
    }
   
   //change the progress value
    playbackSlider.addTarget(self, action: #selector(playbackSliderValueChanged(_:)), for: .valueChanged)
    
    //check player has completed playing audio
    NotificationCenter.default.addObserver(self, selector: #selector(self.finishedPlaying(_:)), name: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: playerItem)}


@objc func playbackSliderValueChanged(_ playbackSlider:UISlider) {
    let seconds : Int64 = Int64(playbackSlider.value)
    let targetTime:CMTime = CMTimeMake(value: seconds, timescale: 1)
    player!.seek(to: targetTime)
    if player!.rate == 0 {
        player?.play()
    }
}

@objc func finishedPlaying( _ myNotification:NSNotification) {
    ButtonPlay.setImage(UIImage(named: "play"), for: UIControl.State.normal)
    //reset player when finish   
    playbackSlider.value = 0
    let targetTime:CMTime = CMTimeMake(value: 0, timescale: 1)
    player!.seek(to: targetTime)
}

@IBAction func playButton(_ sender: Any) {
    print("play Button")
    if player?.rate == 0
    {
        player!.play()
        self.ButtonPlay.isHidden = true
        //        self.loadingView.isHidden = false
        ButtonPlay.setImage(UIImage(systemName: "pause"), for: UIControl.State.normal)
    } else {
        player!.pause()
        ButtonPlay.setImage(UIImage(systemName: "play"), for: UIControl.State.normal)
    }
    
}


func stringFromTimeInterval(interval: TimeInterval) -> String {
    let interval = Int(interval)
    let seconds = interval % 60
    let minutes = (interval / 60) % 60
    let hours = (interval / 3600)
    return String(format: "%02d:%02d:%02d", hours, minutes, seconds)
}



@IBAction func seekBackWards(_ sender: Any) {
    if player == nil { return }
    let playerCurrenTime = CMTimeGetSeconds(player!.currentTime())
    var newTime = playerCurrenTime - seekDuration
    if newTime < 0 { newTime = 0 }
    player?.pause()
    let selectedTime: CMTime = CMTimeMake(value: Int64(newTime * 1000 as Float64), timescale: 1000)
    player?.seek(to: selectedTime)
    player?.play()

}


@IBAction func seekForward(_ sender: Any) {
    if player == nil { return }
    if let duration = player!.currentItem?.duration {
       let playerCurrentTime = CMTimeGetSeconds(player!.currentTime())
       let newTime = playerCurrentTime + seekDuration
       if newTime < CMTimeGetSeconds(duration)
       {
          let selectedTime: CMTime = CMTimeMake(value: Int64(newTime * 1000 as 
       Float64), timescale: 1000)
          player!.seek(to: selectedTime)
       }
       player?.pause()
       player?.play()
      }
}