/*

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

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    The state `GroundBot`s are in immediately prior to starting their ramming attack.

*/

import SpriteKit

import GameplayKit

class GroundBotPreAttackState: GKState {

    // MARK: Properties

    unowned var entity: GroundBot

    /// The amount of time the `GroundBot` has been in its "pre-attack" state.

    var elapsedTime: TimeInterval = 0.0

    /// The `AnimationComponent` associated with the `entity`.

    var animationComponent: AnimationComponent {

        guard let animationComponent = entity.component(ofType: AnimationComponent.self) else { fatalError("A GroundBotPreAttackState's entity must have an AnimationComponent.") }

        return animationComponent

    }

    // MARK: Initializers

    required init(entity: GroundBot) {

        self.entity = entity

    }

    // MARK: GPState Life Cycle

    override func didEnter(from previousState: GKState?) {

        super.didEnter(from: previousState)

        // Reset the tracking of how long the `GroundBot` has been in a "pre-attack" state.

        elapsedTime = 0.0

        // Request the "attack" animation for this state's `GroundBot`.

        animationComponent.requestedAnimationState = .attack

    }

    override func update(deltaTime seconds: TimeInterval) {

        super.update(deltaTime: seconds)

        elapsedTime += seconds

        /*

            If the `GroundBot` has been in its "pre-attack" state for long enough,

            move to the attack state.

        */

        if elapsedTime >= GameplayConfiguration.TaskBot.preAttackStateDuration {

            stateMachine?.enter(GroundBotAttackState.self)

        }

    }

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

        switch stateClass {

            case is TaskBotAgentControlledState.Type, is GroundBotAttackState.Type, is TaskBotZappedState.Type:

                return true

            default:

                return false

        }

    }

}