/*

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

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    A `GKComponent` and associated delegate that manage and respond to a `GKRuleSystem` for an entity.

*/

import GameplayKit

protocol RulesComponentDelegate: class {

    // Called whenever the rules component finishes evaluating its rules.

    func rulesComponent(rulesComponent: RulesComponent, didFinishEvaluatingRuleSystem ruleSystem: GKRuleSystem)

}

class RulesComponent: GKComponent {

    // MARK: Properties

    weak var delegate: RulesComponentDelegate?

    var ruleSystem: GKRuleSystem

    /// The amount of time that has passed since the `TaskBot` last evaluated its rules.

    private var timeSinceRulesUpdate: TimeInterval = 0.0

    // MARK: Initializers

    override init() {

        ruleSystem = GKRuleSystem()

        super.init()

    }

    init(rules: [GKRule]) {

        ruleSystem = GKRuleSystem()

        ruleSystem.add(rules)

        super.init()

    }

    required init?(coder aDecoder: NSCoder) {

        fatalError("init(coder:) has not been implemented")

    }

    // MARK: GKComponent Life Cycle

    override func update(deltaTime seconds: TimeInterval) {

        timeSinceRulesUpdate += seconds

        if timeSinceRulesUpdate < GameplayConfiguration.TaskBot.rulesUpdateWaitDuration { return }

        timeSinceRulesUpdate = 0.0

        if let taskBot = entity as? TaskBot,

            let level = taskBot.component(ofType: RenderComponent.self)?.node.scene as? LevelScene,

            let entitySnapshot = level.entitySnapshotForEntity(entity: taskBot),

            !taskBot.isGood {

            ruleSystem.reset()

            ruleSystem.state["snapshot"] = entitySnapshot

            ruleSystem.evaluate()

            delegate?.rulesComponent(rulesComponent: self, didFinishEvaluatingRuleSystem: ruleSystem)

        }

    }

}