import AVKit
import UIKit

protocol VideoViewDelegate {
    func didEndVideo()
    func didEndVideo(of instance: VideoView)
    func isVideoReady()
}

class VideoView: UIView {
    
    var playerLayer: AVPlayerLayer?
    var player: AVPlayer?
    var isLoop: Bool = false
    
    var delegate: VideoViewDelegate!
    
    var observer: NSKeyValueObservation?
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        backgroundColor = .black
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }
    
    func ply(for url: URL) {
        player = AVPlayer(url: url)
        playerLayer = AVPlayerLayer(player: player)
        playerLayer?.frame = bounds
        playerLayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill
        
        if let playerLayer = self.playerLayer {
            layer.addSublayer(playerLayer)
        }
        
        NotificationCenter.default.addObserver(self, selector: #selector(reachTheEndOfTheVideo), name: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: self.player?.currentItem)
    }
    
    func prepare(url: URL) {
        player?.replaceCurrentItem(with: AVPlayerItem(url: url))
        NotificationCenter.default.addObserver(self, selector: #selector(reachTheEndOfTheVideo), name: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: self.player?.currentItem)
    }
    
    func destroyMe() {
        stop()
        NotificationCenter.default.removeObserver(self)
        observer?.invalidate()
    }
    
    func play() {
        if player?.timeControlStatus != AVPlayer.TimeControlStatus.playing {
            player?.play()
        }
    }
    
    func pause() {
        player?.pause()
    }
    
    func stop() {
        player?.pause()
        player?.seek(to: CMTime.zero)
    }
    
    @objc
    func reachTheEndOfTheVideo(_ notification: Notification) {
        if isLoop {
            player?.pause()
            player?.seek(to: CMTime.zero)
            player?.play()
        } else {
            player?.pause()
            player?.seek(to: CMTime.zero)
            
            UIView.animate(withDuration: 0.4) { [weak self] in
                self!.transform = .identity
            }
            if delegate != nil { delegate.didEndVideo() }
            if delegate != nil { delegate.didEndVideo(of: self) }
        }
    }
}