/*

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

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    An `SKScene` used to represent and manage the home and end scenes of the game.

*/

import SpriteKit

class HomeEndScene: BaseScene {

    // MARK: Properties

    /// Returns the background node from the scene.

    override var backgroundNode: SKSpriteNode? {

        return childNode(withName: "backgroundNode") as? SKSpriteNode

    }

    /// The screen recorder button for the scene (if it has one).

    var screenRecorderButton: ButtonNode? {

        return backgroundNode?.childNode(withName: ButtonIdentifier.screenRecorderToggle.rawValue) as? ButtonNode

    }

    /// The "NEW GAME" button which allows the player to proceed to the first level.

    var proceedButton: ButtonNode? {

        return backgroundNode?.childNode(withName: ButtonIdentifier.proceedToNextScene.rawValue) as? ButtonNode

    }

    /// An array of objects for `SceneLoader` notifications.

    private var sceneLoaderNotificationObservers = [Any]()

    // MARK: Deinitialization

    deinit {

        // Deregister for scene loader notifications.

        for observer in sceneLoaderNotificationObservers {

            NotificationCenter.default.removeObserver(observer)

        }

    }

    // MARK: Scene Life Cycle

    override func didMove(to view: SKView) {

        super.didMove(to: view)

        #if os(iOS)

        screenRecorderButton?.isSelected = screenRecordingToggleEnabled

        #else

        screenRecorderButton?.isHidden = true

        #endif

        // Enable focus based navigation. 

        focusChangesEnabled = true

        registerForNotifications()

        centerCameraOnPoint(point: backgroundNode!.position)

        // Begin loading the first level as soon as the view appears.

        sceneManager.prepareScene(identifier: .level(1))

        let levelLoader = sceneManager.sceneLoader(forSceneIdentifier: .level(1))

        // If the first level is not ready, hide the buttons until we are notified.

        if !(levelLoader.stateMachine.currentState is SceneLoaderResourcesReadyState) {

            proceedButton?.alpha = 0.0

            proceedButton?.isUserInteractionEnabled = false

            screenRecorderButton?.alpha = 0.0

            screenRecorderButton?.isUserInteractionEnabled = false

        }

    }

    func registerForNotifications() {

        // Only register for notifications if we haven't done so already.

        guard sceneLoaderNotificationObservers.isEmpty else { return }

        // Create a closure to pass as a notification handler for when loading completes or fails.

        let handleSceneLoaderNotification: (Notification) -> () = { [unowned self] notification in

            let sceneLoader = notification.object as! SceneLoader

            // Show the proceed button if the `sceneLoader` pertains to a `LevelScene`.

            if sceneLoader.sceneMetadata.sceneType is LevelScene.Type {

                // Allow the proceed and screen to be tapped or clicked.

                self.proceedButton?.isUserInteractionEnabled = true

                self.screenRecorderButton?.isUserInteractionEnabled = true

                // Fade in the proceed and screen recorder buttons.

                self.screenRecorderButton?.run(SKAction.fadeIn(withDuration: 1.0))

                // Clear the initial `proceedButton` focus.

                self.proceedButton?.isFocused = false

                self.proceedButton?.run(SKAction.fadeIn(withDuration: 1.0)) {

                    // Indicate that the `proceedButton` is focused.

                    self.resetFocus()

                }

            }

        }

        // Register for scene loader notifications.

        let completeNotification = NotificationCenter.default.addObserver(forName: NSNotification.Name.SceneLoaderDidCompleteNotification, object: nil, queue: OperationQueue.main, using: handleSceneLoaderNotification)

        let failNotification = NotificationCenter.default.addObserver(forName: NSNotification.Name.SceneLoaderDidFailNotification, object: nil, queue: OperationQueue.main, using: handleSceneLoaderNotification)

        // Keep track of the notifications we are registered to so we can remove them in `deinit`.

        sceneLoaderNotificationObservers += [completeNotification, failNotification]

    }

}