/*

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

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    A class to manage the display of an overlay set of nodes on top of an existing scene.

*/

import SpriteKit

class SceneOverlay {

    // MARK: Properties

    let backgroundNode: SKSpriteNode

    let contentNode: SKSpriteNode

    let nativeContentSize: CGSize

    // MARK: Intialization

    init(overlaySceneFileName fileName: String, zPosition: CGFloat) {

        // Load the scene and get the overlay node from it.

        let overlayScene = SKScene(fileNamed: fileName)!

        let contentTemplateNode = overlayScene.childNode(withName: "Overlay") as! SKSpriteNode

        // Create a background node with the same color as the template.

        backgroundNode = SKSpriteNode(color: contentTemplateNode.color, size: contentTemplateNode.size)

        backgroundNode.zPosition = zPosition

        // Copy the template node into the background node.

        contentNode = contentTemplateNode.copy() as! SKSpriteNode

        contentNode.position = .zero

        backgroundNode.addChild(contentNode)

        // Set the content node to a clear color to allow the background node to be seen through it.

        contentNode.color = .clear

        // Store the current size of the content to allow it to be scaled correctly.

        nativeContentSize = contentNode.size

    }

    func updateScale() {

        guard let viewSize = backgroundNode.scene?.view?.frame.size else {

            return

        }

        // Resize the background node.

        backgroundNode.size = viewSize

        // Scale the content so that the height always fits.

        let scale = viewSize.height / nativeContentSize.height

        contentNode.setScale(scale)

    }

}