/**
* 
* @module Kiwi
* 
*/

module Kiwi {

	/**
	* A Camera is used to render a particular section of the game world on the stage. Each Camera has a coordinates which are held in the transform property, and a width/height. Note: This class should never be directly instantiated but instead should be made through a CameraManager's 'create' method.
	*
	* @class Camera
	* @namespace Kiwi
	* @constructor
	* @param game {Kiwi.Game} The game that this camera belongs to.
	* @param id {Number} A unique ID for this camera 
	* @param name {String} The name this camera goes by
	* @param x {Number} The x coordinate of the camera
	* @param y {Number} The y coordinate of the camera
	* @param width {Number} The width of the camera
	* @param height {Number} The cameras height
	* @return {Kiwi.Camera}
	* 
	*/
	export class Camera {

		constructor(game: Kiwi.Game, id: number, name: string,x:number,y:number,width:number,height:number) {

			this._game = game;
			this.id = id;
			this.name = name;
			
			//size could autoresize to fit stage
			this.width = width;
			this.height = height;
			this.transform = new Kiwi.Geom.Transform(x, y);
			this.transform.rotPointX = x + width / 2;
			this.transform.rotPointY = y + height / 2;

			this._game.stage.onResize.add(this._updatedStageSize, this);

			this._scratchMatrix = new Kiwi.Geom.Matrix();
		}

		/**
		* The width of this camara.
		* @property width
		* @type Number
		* @public
		*/
		public width: number;

		/**
		* The height of this camera.
		* @property height
		* @type Number
		* @public
		*/
		public height: number;

		/**
		* The type of object this is.
		* @method objType
		* @return {String} "Camera"
		* @public
		*/
		public objType() {
			return "Camera";
		}

		/**
		* If true then the camera will be resized to fit the stage when the stage is resized
		* @property fitToStage
		* @type boolean
		* @default true
		* @public
		*/
		public fitToStage: boolean = true;

		/** 
		* The Transform controls the location of the camera within the game world. Also controls the cameras scale and rotation.
		* @property transform
		* @type Kiwi.Geom.Transform
		* @public
		*/
		public transform: Kiwi.Geom.Transform;

		/**
		* Updates the width/height of this camera. Is used when the stage resizes.
		* @method _updatedStageSize
		* @param width {Number} The new width of the camera.
		* @param height {Number} The new height of the camera.
		* @private
		*/
		private _updatedStageSize(width: number, height: number) {

			this.width = width;
			this.height = height;

		}

		/**
		* The game this Group belongs to
		* @property game
		* @type Kiwi.Game
		* @private
		*/
		private _game: Kiwi.Game;

		/**
		* A unique identifier for this Layer within the game used internally by the framework. See the name property for a friendly version.
		* @property id
		* @type number
		* @public
		*/
		public id: number;

		/**
		* A name for this Camera. This is not checked for uniqueness within the Game, but is very useful for debugging.
		* @property name
		* @type string
		* @public
		*/
		public name: string;

		/**
		* Controls whether this Camera is rendered
		* @property _visible
		* @type boolean
		* @private
		*/
		private _visible: boolean;

		/**
		* Controls whether this Camera is rendered.
		* @property visible
		* @type boolean
		* @public
		*/
		public get visible(): boolean {
			return this._visible;
		}
		public set visible(val: boolean) {
			this._visible = val;
		}

		/**
		* A flag that indicates whether this camera needs to be rendered again at the next update loop, or if nothing has changed so it doesn't.
		* @property _dirty
		* @type boolean
		* @private
		* @deprecated As of 1.1.0, no use has been found for this property.
		*/
		private _dirty: boolean;

		/**
		* A value used by components to control if the camera needs re-rendering.
		* @property dirty
		* @type boolean
		* @public
		* @deprecated As of 1.1.0, no use has been found for this property.
		*/
		public get dirty(): boolean {
			return this._dirty;
		}
		public set dirty(val: boolean) {
			this._dirty = val;
		}

		/**
		* Scratch matrix used in geometry calculations
		*
		* @property _scratchMatrix
		* @type Kiwi.Geom.Matrix
		* @private
		* @since 1.3.1
		*/
		private _scratchMatrix: Kiwi.Geom.Matrix;

		/**
		* Convert from screen coordinates to world coordinates.
		* Apply this camera's inverted matrix to an object with x and y
		* properties representing a point and return the transformed point.
		* Useful for calculating coordinates with the mouse.
		* @method transformPoint
		* @param point {Kiwi.Geom.Point} 
		* @return {Kiwi.Geom.Point} Transformed clone of the original Point.
		* @public
		*/
		public transformPoint(point: Kiwi.Geom.Point): Kiwi.Geom.Point {
			var m,
				np = point.clone();

			this._scratchMatrix.copyFrom( this.transform.getConcatenatedMatrix() );

			m = this._scratchMatrix;
			m.append( 1,0,0,1, -this.transform.rotPointX, -this.transform.rotPointY );
			m.invert();

			return m.transformPoint(np);
		}

		/**
		* Convert from world coordinates to screen coordinates.
		* Useful for assessing visibility.
		* Similar to "transformPoint", but in reverse.
		* @method transformPointToScreen
		* @param point {Kiwi.Geom.Point}
		* @return {Kiwi.Geom.Point} Transformed clone of the original Point.
		* @public
		* @since 1.2.0
		*/
		public transformPointToScreen( point: Kiwi.Geom.Point ): Kiwi.Geom.Point {
			var m,
				np = point.clone();

			this._scratchMatrix.copyFrom( this.transform.getConcatenatedMatrix() );

			m = this._scratchMatrix;
			m.append( 1,0,0,1, -this.transform.rotPointX, -this.transform.rotPointY );

			return m.transformPoint(np);
		}

		/**
		* The update loop that is executed every frame.
		* @method update
		* @public
		*/
		public update() {

		}

		/**
		* The render loop that is executed whilst the game is playing.
		* @method render
		* @public
		*/
		public render() {

			this._game.renderer.render(this);

		}

	}

}