/*

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

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    Defines the view controller for the default scene.

*/

import AVFoundation

import AVKit

class StartViewController: UIViewController {

    // MARK: Properties

    @IBOutlet weak var startButton: UIButton!

    let player = AVPlayer()

    var sourceURL: NSURL? {

        // Update `playerViewController` with new source movie.

        didSet {

            let playerItem: AVPlayerItem?

            if let sourceURL = sourceURL {

                playerItem = AVPlayerItem(URL: sourceURL)

                startButton.enabled = true

            }

            else {

                playerItem = nil

                startButton.enabled = false

            }

            player.replaceCurrentItemWithPlayerItem(playerItem)

        }

    }

    let defaultSourceURL = NSBundle.mainBundle().URLForResource("ElephantSeals", withExtension: "mov")!

    let outputURL = NSURL(fileURLWithPath: NSTemporaryDirectory() + "out.mov")

    static let embedSegueName = "playerViewController"

    // MARK: View Controller

    override func viewDidLoad() {

        super.viewDidLoad()

        // Default to disabled, until we establish a source.

        startButton.enabled = false

        // Establish a source.

        sourceURL = defaultSourceURL

    }

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {

        if segue.identifier == StartViewController.embedSegueName {

            // This segue fires before `viewDidLoad()` is invoked.

            let playerViewController = segue.destinationViewController as! AVPlayerViewController

            playerViewController.player = player

        }

        else {

            // Stop playback when transitioning to next scene.

            player.pause()

            let nextViewController = segue.destinationViewController as! ProgressViewController

            /*

                We cannot get here if there is no source, because `startButton`

                will be disabled.

            */

            nextViewController.sourceURL = sourceURL

            nextViewController.outputURL = outputURL

        }

    }

}