/*

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

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    A state for use in a dispenser's state machine. This state refills the dispenser with water. It plays a refill animation before exiting.

*/

import SpriteKit

import GameplayKit

class RefillingState: DispenserState {

    // MARK: Properties

    /// A multiplier for the speed of the refilling animation.

    static let timeScale: CGFloat = 5

    /**

        The initial height of the water sprite. Used for calculations in the 

        `playRefillAnimationThenExit(_:)` method.

    */

    static let waterNodeHeight: CGFloat = 280

    // MARK: Initialization

    required init(game: GameScene) {

        super.init(game: game, associatedNodeName: "RefillingState")

    }

    // MARK: GKState overrides

    override func didEnter(from previousState: GKState?) {

        super.didEnter(from: previousState)

        playRefillAnimationThenExit()

    }

    override func isValidNextState(_ stateClass: AnyClass) -> Bool {

        // This state can only transition to the full state. 

        return stateClass is FullState.Type

    }

    // MARK: Other Game Logic

    /**

        Plays the refill animation, then transitions the state machine into the 

        Full state.

    */

    func playRefillAnimationThenExit() {

        // Grab the sprite node for the dispenser's water from the scene.

        let waterNode = game.childNode(withName: "//water") as! SKSpriteNode

        // Calculate the duration of the refilling animation.

        let waterRatio = (RefillingState.waterNodeHeight - waterNode.size.height) / RefillingState.waterNodeHeight

        let refillTime = TimeInterval(RefillingState.timeScale * waterRatio)

        /*

            Create and play the animation, then tell the state machine to enter 

            the full state.

        */

        let refillAction = SKAction(named: "refillDispenser", duration: refillTime)!

        waterNode.run(refillAction, completion: {

            self.stateMachine?.enter(FullState.self)

        }) 

    }

}