import {ResizableScene} from "../Login/ResizableScene";
import GameObject = Phaser.GameObjects.GameObject;
import Events = Phaser.Scenes.Events;
import AnimationEvents = Phaser.Animations.Events;

/**
 * A scene that can track its dirty/pristine state.
 */
export abstract class DirtyScene extends ResizableScene {
    private isAlreadyTracking: boolean = false;
    protected dirty:boolean = true;
    private objectListChanged:boolean = true;

    /**
     * Track all objects added to the scene and adds a callback each time an animation is added.
     * Whenever an object is added, removed, or when an animation is played, the dirty state is set to true.
     *
     * Note: this does not work with animations from sprites inside containers.
     */
    protected trackDirtyAnims(): void {
        if (this.isAlreadyTracking) {
            return;
        }
        this.isAlreadyTracking = true;
        const trackAnimationFunction = this.trackAnimation.bind(this);
        this.events.on(Events.ADDED_TO_SCENE, (gameObject: GameObject) => {
            this.objectListChanged = true;
            gameObject.on(AnimationEvents.ANIMATION_UPDATE, trackAnimationFunction);
        });

        this.events.on(Events.REMOVED_FROM_SCENE, (gameObject: GameObject) => {
            this.objectListChanged = true;
            gameObject.removeListener(AnimationEvents.ANIMATION_UPDATE, trackAnimationFunction);
        });

        this.events.on(Events.RENDER, () => {
            this.objectListChanged = false;
        });
    }

    private trackAnimation(): void {
        this.objectListChanged = true;
    }

    public isDirty(): boolean {
        return this.dirty || this.objectListChanged;
    }

    public onResize(ev: UIEvent): void {
        this.objectListChanged = true;
    }
}