/*

    Copyright (C) 2016 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    View controller that displays a single selected media item.

*/

import UIKit

import AVFoundation

/// View controller that combines both a `PlaybackViewController` and a `PlaybackDetailsViewController`.

class MediaViewController: UIViewController {

    // MARK: Properties

    @IBOutlet var stackView: UIStackView!

    private var playbackViewController: PlaybackViewController!

    private var playbackDetailsViewController: PlaybackDetailsViewController!

    private let player = AVPlayer()

    var mediaURL: URL? {

        didSet {

            // Create a new item for our AVPlayer

            updatePlayerItem()

        }

    }

    // MARK: UIViewController

    override func viewDidLoad() {

        super.viewDidLoad()

        // Make sure our AVPlayer has an AVPlayerItem if we already got a URL

        updatePlayerItem()

        // Setup sub-view controllers.

        // 1) A PlaybackViewController for the video and playback controls.

        playbackViewController = storyboard?.instantiateViewController(withIdentifier: "Playback") as! PlaybackViewController

        playbackViewController.player = player

        // 2) A PlaybackDetailsViewController for property values.

        playbackDetailsViewController = storyboard?.instantiateViewController(withIdentifier: "PlaybackDetails") as! PlaybackDetailsViewController

        playbackDetailsViewController.player = player

        // Add both new views to our stackView.

        stackView.addArrangedSubview(playbackViewController.view)

        stackView.addArrangedSubview(playbackDetailsViewController.view)

    }

    // MARK: Convenience

    private func updatePlayerItem() {

        if let mediaURL = mediaURL {

            player.replaceCurrentItem(with: AVPlayerItem(url: mediaURL))

        }

        else {

            player.replaceCurrentItem(with: nil)

        }

    }

}