import { ISceneComponent, SceneComponentConstants } from "sceneComponent";
import { PostProcessRenderPipelineManager } from "PostProcess";
import { Scene } from "scene";

declare module "scene" {
    export interface Scene {
        /** @hidden (Backing field) */
        _postProcessRenderPipelineManager: PostProcessRenderPipelineManager;

        /**
         * Gets the postprocess render pipeline manager
         * @see http://doc.babylonjs.com/how_to/how_to_use_postprocessrenderpipeline
         * @see http://doc.babylonjs.com/how_to/using_default_rendering_pipeline
         */
        readonly postProcessRenderPipelineManager: PostProcessRenderPipelineManager;
    }
}

    Object.defineProperty(Scene.prototype, "postProcessRenderPipelineManager", {
        get: function(this: Scene) {
            if (!this._postProcessRenderPipelineManager) {
                // Register the G Buffer component to the scene.
                let component = this._getComponent(SceneComponentConstants.NAME_POSTPROCESSRENDERPIPELINEMANAGER) as PostProcessRenderPipelineManagerSceneComponent;
                if (!component) {
                    component = new PostProcessRenderPipelineManagerSceneComponent(this);
                    this._addComponent(component);
                }
                this._postProcessRenderPipelineManager = new PostProcessRenderPipelineManager();
            }

            return this._postProcessRenderPipelineManager;
        },
        enumerable: true,
        configurable: true
    });

    /**
     * Defines the Render Pipeline scene component responsible to rendering pipelines
     */
    export class PostProcessRenderPipelineManagerSceneComponent implements ISceneComponent {
        /**
         * The component name helpfull to identify the component in the list of scene components.
         */
        public readonly name = SceneComponentConstants.NAME_POSTPROCESSRENDERPIPELINEMANAGER;

        /**
         * The scene the component belongs to.
         */
        public scene: Scene;

        /**
         * Creates a new instance of the component for the given scene
         * @param scene Defines the scene to register the component in
         */
        constructor(scene: Scene) {
            this.scene = scene;
        }

        /**
         * Registers the component in a given scene
         */
        public register(): void {
            this.scene._gatherRenderTargetsStage.registerStep(SceneComponentConstants.STEP_GATHERRENDERTARGETS_POSTPROCESSRENDERPIPELINEMANAGER, this, this._gatherRenderTargets);
        }

        /**
         * Rebuilds the elements related to this component in case of
         * context lost for instance.
         */
        public rebuild(): void {
            if (this.scene._postProcessRenderPipelineManager) {
                this.scene._postProcessRenderPipelineManager._rebuild();
            }
        }

        /**
         * Disposes the component and the associated ressources
         */
        public dispose(): void {
            if (this.scene._postProcessRenderPipelineManager) {
                this.scene._postProcessRenderPipelineManager.dispose();
            }
        }

        private _gatherRenderTargets(): void {
            if (this.scene._postProcessRenderPipelineManager) {
                this.scene._postProcessRenderPipelineManager.update();
            }
        }
    }