/**
 * System takes care of updating all the entities (based on their component data)
 * @param graphics
 * @param apiSystem GameLib.API.System
 * @constructor
 */
GameLib.System = function(
    graphics,
    apiSystem
) {

    this.graphics = graphics;
    this.graphics.isNotThreeThrow();

    if (GameLib.Utils.UndefinedOrNull(apiSystem)) {
        apiSystem = {};
    }

	if (apiSystem instanceof GameLib.System) {
		return apiSystem;
	}

    GameLib.API.System.call(
		this,
		apiSystem.id,
		apiSystem.name,
		apiSystem.systemType,
		apiSystem.entityManager,
		apiSystem.parentEntity
	);

    if (this.entityManager instanceof GameLib.API.EntityManager) {
        this.entityManager = new GameLib.EntityManager(
            this.graphics,
            this.entityManager
        );
    }

    this.saveCallback = null;
    this.loadCallback = null;

};

GameLib.System.prototype = Object.create(GameLib.API.System.prototype);
GameLib.System.prototype.constructor = GameLib.System;

GameLib.System.SYSTEM_TYPE_NONE			= 0x0;
GameLib.System.SYSTEM_TYPE_RENDER       = 0x1;
GameLib.System.SYSTEM_TYPE_ANIMATION    = 0x2;
GameLib.System.SYSTEM_TYPE_INPUT        = 0x4;
GameLib.System.SYSTEM_TYPE_STORAGE		= 0x8;
GameLib.System.SYSTEM_TYPE_GUI			= 0x10;
GameLib.System.SYSTEM_TYPE_ALL          = 0xFFFF;

/**
 * @callback
 * @override
 */
GameLib.System.prototype.start = function() {

	if (this.systemType === GameLib.System.SYSTEM_TYPE_INPUT) {

		/**
		 * Hookup all editor input capabilities
		 */
		var entities = this.entityManager.query([GameLib.D3.Input.Editor]);

		entities.map(function(entity){

			var component = entity.getFirstComponent(GameLib.D3.Input.Editor);

			component.mouseDown		= component.onMouseDown(entity, this.entityManager).bind(component);
			component.mouseMove		= component.onMouseMove(entity).bind(component);
			component.keyDown		= component.onKeyDown(entity, this.entityManager).bind(component);
			component.keyUp			= component.onKeyUp(entity, this.entityManager).bind(component);

			component.domElement.instance.addEventListener('mousedown', component.mouseDown, false);
			component.domElement.instance.addEventListener('mousemove', component.mouseMove, false);
			component.domElement.instance.addEventListener('keydown',   component.keyDown, false);
			component.domElement.instance.addEventListener('keyup',     component.keyUp, false);

            component.controls = new THREE.EditorControls(
				component.camera.instance,
				component.domElement.instance
			);

            /**
             * After our mouse 'up' editor controls would have updated our camera
             * instance, so we need to update our game-lib camera to reflect these
             * changes - we override
             */
            component.mouseUp = function(center) {
                return function() {
                    var camera = entity.getFirstComponent(GameLib.D3.Camera);
                    camera.position.x = camera.instance.position.x;
                    camera.position.y = camera.instance.position.y;
                    camera.position.z = camera.instance.position.z;

                    camera.quaternion.x = camera.instance.quaternion.x;
                    camera.quaternion.y = camera.instance.quaternion.y;
                    camera.quaternion.z = camera.instance.quaternion.z;
                    camera.quaternion.w = camera.instance.quaternion.w;

                    camera.lookAt.x = center.x;
                    camera.lookAt.y = center.y;
                    camera.lookAt.z = center.z;

                    camera.lookAt.instance.copy(center);
                };
            }(component.controls.center).bind(component);

            /**
             * Same applies to our mouse 'scroll' event
             */
            component.mouseWheel = function() {
                return function() {
                    var camera = entity.getFirstComponent(GameLib.D3.Camera);
                    camera.position.x = camera.instance.position.x;
                    camera.position.y = camera.instance.position.y;
                    camera.position.z = camera.instance.position.z;
                };
            }.bind(component);

            component.domElement.instance.addEventListener('mousewheel', component.mouseWheel, false);
            component.domElement.instance.addEventListener('mouseup',    component.mouseUp, false);

		}.bind(this))
	}

	if (this.systemType === GameLib.System.SYSTEM_TYPE_RENDER) {

		this.renderEntities = this.entityManager.query(
			[
				GameLib.D3.Viewport,
				GameLib.D3.Scene,
				GameLib.D3.Renderer,
				GameLib.D3.Camera
			]
		);

		this.renderEntities.map(
			function(entity) {
				var stats = entity.getFirstComponent(GameLib.D3.Stats);
				stats.resize();
				stats.domElement.instance.parentElement.appendChild(stats.instance.dom);
			}
		)
	}

	if (this.systemType === GameLib.System.SYSTEM_TYPE_GUI) {

		var guis = this.entityManager.queryComponents(GameLib.GUI);

		guis.map(function(gui){
			gui.domElement.instance.parentElement.appendChild(gui.instance.domElement);
		})

	}
	
	if (this.systemType === GameLib.System.SYSTEM_TYPE_ANIMATION) {
		// this.pathFollowingObjects 	= this.entityManager.query([GameLib.D3.PathFollowing]);
		// this.followObjects 			= this.entityManager.query([GameLib.D3.Follow]);
		// this.meshObjects 			= this.entityManager.query([GameLib.D3.Mesh]);
		// this.lookAtObjects 			= this.entityManager.query([GameLib.D3.LookAt]);
		// this.cameraObjects 			= this.entityManager.query([GameLib.D3.Camera]);
		// this.lightObjects 			= this.entityManager.query([GameLib.D3.Light]);
	}

    if (this.systemType === GameLib.System.SYSTEM_TYPE_STORAGE) {

	    this.subscribe(
            GameLib.Event.SAVE,
            this.save
        );

        this.subscribe(
            GameLib.Event.LOAD,
            this.load
        )
    }


    this.update();

};

/**
 * @callback
 * @override
 */
GameLib.System.prototype.update = function(deltaTime) {

	if (this.systemType === GameLib.System.SYSTEM_TYPE_INPUT) {
		// this.driveInputObjects.forEach(
		// 	function(object) {
		// 		object.update(deltaTime);
		// 	}
		// );
	}

	if (this.systemType === GameLib.System.SYSTEM_TYPE_ANIMATION) {

		this.pathFollowingObjects.forEach(
			function(object) {
				object.update(deltaTime);
			}
		);

		this.followObjects.forEach(
			function(object) {
				object.update(deltaTime);
			}
		);

		this.lookAtObjects.forEach(
			function(object) {
				object.update(deltaTime);
			}
		);

		this.meshObjects.forEach(
			function(object) {
				object.updateInstance();
			}
		);

		this.cameraObjects.forEach(
			function(object) {
				object.updateInstance();
			}
		);

		this.lightObjects.forEach(
			function(object) {
				object.updateInstance();
			}
		);
	}

    if (this.systemType === GameLib.System.SYSTEM_TYPE_RENDER) {

		this.renderEntities.map(

			function(renderEntity) {

				var stats		= renderEntity.getFirstComponent(GameLib.D3.Stats);
				stats.instance.begin();

				var renderer	= renderEntity.getFirstComponent(GameLib.D3.Renderer);
				var camera		= renderEntity.getFirstComponent(GameLib.D3.Camera);
				var viewports 	= renderEntity.getComponents(GameLib.D3.Viewport);
				var scenes 		= renderEntity.getComponents(GameLib.D3.Scene);

				if (viewports.length > 1) {
					renderer.instance.autoClear = false;
				}

				if (scenes.length > 1) {
					renderer.instance.autoClear = false;
				}

				renderer.instance.clear();

				viewports.map(
				    function(viewport){

						renderer.instance.setViewport(
							viewport.x * renderer.width,
							viewport.y * renderer.height,
							viewport.width * renderer.width,
							viewport.height * renderer.height
						);

						function renderScene(scene) {
                            if (scene.activeCamera) {
                                renderer.instance.render(
                                    scene.instance,
                                    scene.activeCamera.instance
                                );
                            } else {
                                renderer.instance.render(
                                    scene.instance,
                                    camera.instance
                                );
                            }
                        }

						if (viewport.scenes && viewport.scenes.length > 0) {
						    viewport.scenes.map(renderScene);
                        } else {
                            scenes.map(renderScene);
                        }
					}
				);


				stats.instance.end();
			}
		);
    }

};

/**
 * @callback
 * @override
 */
GameLib.System.prototype.stop = function() {

	if (this.systemType === GameLib.System.SYSTEM_TYPE_INPUT) {

		/**
		 * Now remove all editor input capabilities
		 */
		var entities = this.entityManager.query([GameLib.D3.Input.Editor]);

		entities.map(function(entity){
			var component = entity.getFirstComponent(GameLib.D3.Input.Editor);
			component.domElement.instance.removeEventListener('mousedown', component.mouseDown, false);
			component.domElement.instance.removeEventListener('mousemove', component.mouseMove, false);
			component.domElement.instance.removeEventListener('keydown', component.keyDown, false);
			component.domElement.instance.removeEventListener('keyup', component.keyUp, false);
			component.controls.dispose();
            component.domElement.instance.removeEventListener('mouseup', component.mouseUp, false);
            component.domElement.instance.removeEventListener('mousewheel', component.mouseWheel, false);
		});

		console.log('stopped all input systems');
	}

	if (this.systemType === GameLib.System.SYSTEM_TYPE_GUI) {
		console.log('stopping GUI system');
		var guis = this.entityManager.queryComponents(GameLib.GUI);

		guis.map(function(gui){
			gui.domElement.instance.parentElement.removeChild(gui.instance.domElement);
		})
	}

	if (this.systemType === GameLib.System.SYSTEM_TYPE_RENDER) {

		this.renderEntities.map(
			function(entity) {
				var stats = entity.getFirstComponent(GameLib.D3.Stats);
				stats.domElement.instance.parentElement.removeChild(stats.instance.dom);
			}
		);

		this.renderEntities	= [];
	}

	if (this.systemType === GameLib.System.SYSTEM_TYPE_ANIMATION) {
		// this.pathFollowingObjects 	= [];
		// this.followObjects 			= [];
		// this.meshObjects 			= [];
		// this.lookAtObjects 			= [];
		// this.cameraObjects 			= [];
		// this.lightObjects 			= [];
	}

    if (this.systemType === GameLib.System.SYSTEM_TYPE_STORAGE) {

	    this.unsubscribe(
            GameLib.Event.SAVE,
            this.save
        );

        this.unsubscribe(
            GameLib.Event.LOAD,
            this.load
        )
    }

};

/**
 * Converts runtime vector to API Vector
 * @returns {GameLib.API.System}
 */
GameLib.System.prototype.toApiObject = function() {

    return new GameLib.API.System(
        this.id,
        this.name,
        this.systemType,
        GameLib.Utils.IdOrNull(this.entityManager),
        GameLib.Utils.IdOrNull(this.parentEntity)
    );
};