/*

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

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    A `GKComponent` that tracks the "charge" (or "health") of a `PlayerBot` or `TaskBot`. For a `PlayerBot`, "charge" indicates how much power the `PlayerBot` has left before it must recharge (during which time the `PlayerBot` is inactive). For a `TaskBot`, "charge" indicates whether the `TaskBot` is "good" or "bad".

*/

import SpriteKit

import GameplayKit

protocol ChargeComponentDelegate: class {

    // Called whenever a `ChargeComponent` loses charge through a call to `loseCharge`

    func chargeComponentDidLoseCharge(chargeComponent: ChargeComponent)

}

class ChargeComponent: GKComponent {

    // MARK: Properties

    var charge: Double

    let maximumCharge: Double

    var percentageCharge: Double {

        if maximumCharge == 0 {

            return 0.0

        }

        return charge / maximumCharge

    }

    var hasCharge: Bool {

        return (charge > 0.0)

    }

    var isFullyCharged: Bool {

        return charge == maximumCharge

    }

    /**

        A `ChargeBar` used to show the current charge level. The `ChargeBar`'s node

        is added to the scene when the component's entity is added to a `LevelScene`

        via `addEntity(_:)`.

    */

    let chargeBar: ChargeBar?

    weak var delegate: ChargeComponentDelegate?

    // MARK: Initializers

    init(charge: Double, maximumCharge: Double, displaysChargeBar: Bool = false) {

        self.charge = charge

        self.maximumCharge = maximumCharge

        // Create a `ChargeBar` if this `ChargeComponent` should display one.

        if displaysChargeBar {

            chargeBar = ChargeBar()

        }

        else {

            chargeBar = nil

        }

        super.init()

        chargeBar?.level = percentageCharge

    }

    required init?(coder aDecoder: NSCoder) {

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

    }

    // MARK: Component actions

    func loseCharge(chargeToLose: Double) {

        var newCharge = charge - chargeToLose

        // Clamp the new value to the valid range.

        newCharge = min(maximumCharge, newCharge)

        newCharge = max(0.0, newCharge)

        // Check if the new charge is less than the current charge.

        if newCharge < charge {

            charge = newCharge

            chargeBar?.level = percentageCharge

            delegate?.chargeComponentDidLoseCharge(chargeComponent: self)

        }

    }

    func addCharge(chargeToAdd: Double) {

        var newCharge = charge + chargeToAdd

        // Clamp the new value to the valid range.

        newCharge = min(maximumCharge, newCharge)

        newCharge = max(0.0, newCharge)

        // Check if the new charge is greater than the current charge.

        if newCharge > charge {

            charge = newCharge

            chargeBar?.level = percentageCharge

        }

    }

}