/*

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

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    Defines a header view for the collection view used in `DreamDetailViewController`

                to display a preview of the dream. This view uses an `SKScene` subclass

                called `DreamScene` to display its content, but `DreamScene` instance

                is using a `DreamEffectLayout` under the hood to layout its content.

*/

import UIKit

import SpriteKit

/// A collection view reusable view that displays a full preview for a `Dream`.

class DreamPreviewHeaderReusableView: UICollectionReusableView {

    // MARK: Properties

    static let reuseIdentifier = "\(DreamPreviewHeaderReusableView.self)"

    private let skView: SKView

    var dream: Dream! {

        didSet {

            guard dream != nil else { return }

            // Update scene to reflect the latest properties.

            skView.allowsTransparency = true

            skView.backgroundColor = .clear

            if let scene = skView.scene as? DreamScene {

                scene.size = frame.size

                scene.dream = dream

            }

            else {

                let scene = DreamScene(dream: dream, size: frame.size)

                skView.presentScene(scene)

            }

        }

    }

    // MARK: Initialization

    override init(frame: CGRect) {

        skView = SKView(frame: CGRect(origin: .zero, size: frame.size))

        super.init(frame: frame)

        addSubview(skView)

    }

    required init?(coder aDecoder: NSCoder) {

        fatalError("\(#function) has not been implemented")

    }

}