module BABYLON {
    // Adds the parser to the scene parsers.
    AbstractScene.AddParser(SceneComponentConstants.NAME_SHADOWGENERATOR, (parsedData: any, scene: Scene, container: AssetContainer, rootUrl: string) => {
        // Shadows
        if (parsedData.shadowGenerators !== undefined && parsedData.shadowGenerators !== null) {
            for (var index = 0, cache = parsedData.shadowGenerators.length; index < cache; index++) {
                var parsedShadowGenerator = parsedData.shadowGenerators[index];
                ShadowGenerator.Parse(parsedShadowGenerator, scene);
                // SG would be available on their associated lights
            }
        }
    });

    /**
     * Defines the shadow generator component responsible to manage any shadow generators
     * in a given scene.
     */
    export class ShadowGeneratorSceneComponent implements ISceneSerializableComponent {
        /**
         * The component name helpfull to identify the component in the list of scene components.
         */
        public readonly name = SceneComponentConstants.NAME_SHADOWGENERATOR;

        /**
         * 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_SHADOWGENERATOR, this, this._gatherRenderTargets);
        }

        /**
         * Rebuilds the elements related to this component in case of
         * context lost for instance.
         */
        public rebuild(): void {
            // Nothing To Do Here.
        }

        /**
         * Serializes the component data to the specified json object
         * @param serializationObject The object to serialize to
         */
        public serialize(serializationObject: any): void {
            // Shadows
            serializationObject.shadowGenerators = [];
            var lights = this.scene.lights;
            for (let light of lights) {
                let shadowGenerator = light.getShadowGenerator();
                if (shadowGenerator) {
                    serializationObject.shadowGenerators.push(shadowGenerator.serialize());
                }
            }
        }

        /**
         * Adds all the element from the container to the scene
         * @param container the container holding the elements
         */
        public addFromContainer(container: AbstractScene): void {
            // Nothing To Do Here. (directly attached to a light)
        }

        /**
         * Removes all the elements in the container from the scene
         * @param container contains the elements to remove 
         */
        public removeFromContainer(container: AbstractScene): void{
            // Nothing To Do Here. (directly attached to a light)
        }

        /**
         * Rebuilds the elements related to this component in case of
         * context lost for instance.
         */
        public dispose(): void {
            // Nothing To Do Here.
        }

        private _gatherRenderTargets(renderTargets: SmartArrayNoDuplicate<RenderTargetTexture>): void {
            // Shadows
            var scene = this.scene;
            if (this.scene.shadowsEnabled) {
                for (var lightIndex = 0; lightIndex < scene.lights.length; lightIndex++) {
                    var light = scene.lights[lightIndex];
                    var shadowGenerator = light.getShadowGenerator();

                    if (light.isEnabled() && light.shadowEnabled && shadowGenerator) {
                        var shadowMap = <RenderTargetTexture>(shadowGenerator.getShadowMap());
                        if (scene.textures.indexOf(shadowMap) !== -1) {
                            renderTargets.push(shadowMap);
                        }
                    }
                }
            }
        }
    }
}