/**
 * @author Mat Groves http://matgroves.com/ @Doormat23
 */

PIXI.blendModes = {};
PIXI.blendModes.NORMAL = 0;
PIXI.blendModes.SCREEN = 1;


/**
 * The SPrite object is the base for all textured objects that are rendered to the screen
 *
 * @class Sprite
 * @extends DisplayObjectContainer
 * @constructor
 * @param texture {Texture} The texture for this sprite
 * @type String
 */
PIXI.Sprite = function(texture)
{
	PIXI.DisplayObjectContainer.call( this );

	/**
	 * The anchor sets the origin point of the texture.
	 * The default is 0,0 this means the textures origin is the top left 
	 * Setting than anchor to 0.5,0.5 means the textures origin is centered
	 * Setting the anchor to 1,1 would mean the textures origin points will be the bottom right
	 *
     * @property anchor
     * @type Point
     */
	this.anchor = new PIXI.Point();

	/**
	 * The texture that the sprite is using
	 *
	 * @property texture
	 * @type Texture
	 */
	this.texture = texture;

	/**
	 * The blend mode of sprite.
	 * currently supports PIXI.blendModes.NORMAL and PIXI.blendModes.SCREEN
	 *
	 * @property blendMode
	 * @type Number
	 */
	this.blendMode = PIXI.blendModes.NORMAL;

	/**
	 * The width of the sprite (this is initially set by the texture)
	 *
	 * @property _width
	 * @type Number
	 * @private
	 */
	this._width = 0;

	/**
	 * The height of the sprite (this is initially set by the texture)
	 *
	 * @property _height
	 * @type Number
	 * @private
	 */
	this._height = 0;

	if(texture.baseTexture.hasLoaded)
	{
		this.updateFrame = true;
	}
	else
	{
		this.onTextureUpdateBind = this.onTextureUpdate.bind(this);
		this.texture.addEventListener( 'update', this.onTextureUpdateBind );
	}

	this.renderable = true;
}

// constructor
PIXI.Sprite.prototype = Object.create( PIXI.DisplayObjectContainer.prototype );
PIXI.Sprite.prototype.constructor = PIXI.Sprite;

/**
 * The width of the sprite, setting this will actually modify the scale to acheive the value set
 *
 * @property width
 * @type Number
 */
Object.defineProperty(PIXI.Sprite.prototype, 'width', {
    get: function() {
        return this.scale.x * this.texture.frame.width;
    },
    set: function(value) {
    	this.scale.x = value / this.texture.frame.width
        this._width = value;
    }
});

/**
 * The height of the sprite, setting this will actually modify the scale to acheive the value set
 *
 * @property height
 * @type Number
 */
Object.defineProperty(PIXI.Sprite.prototype, 'height', {
    get: function() {
        return  this.scale.y * this.texture.frame.height;
    },
    set: function(value) {
    	this.scale.y = value / this.texture.frame.height
        this._height = value;
    }
});

/**
 * Sets the texture of the sprite
 *
 * @method setTexture
 * @param texture {Texture} The PIXI texture that is displayed by the sprite
 */
PIXI.Sprite.prototype.setTexture = function(texture)
{
	// stop current texture;
	if(this.texture.baseTexture != texture.baseTexture)
	{
		this.textureChange = true;	
		this.texture = texture;
		
		if(this.__renderGroup)
		{
			this.__renderGroup.updateTexture(this);
		}
	}
	else
	{
		this.texture = texture;
	}
	
	this.updateFrame = true;
}

/**
 * When the texture is updated, this event will fire to update the scale and frame
 *
 * @method onTextureUpdate
 * @param event
 * @private
 */
PIXI.Sprite.prototype.onTextureUpdate = function(event)
{
	//this.texture.removeEventListener( 'update', this.onTextureUpdateBind );
	
	// so if _width is 0 then width was not set..
	if(this._width)this.scale.x = this._width / this.texture.frame.width;
	if(this._height)this.scale.y = this._height / this.texture.frame.height;
	
	this.updateFrame = true;
}

// some helper functions..

/**
 * 
 * Helper function that creates a sprite that will contain a texture from the TextureCache based on the frameId
 * The frame ids are created when a Texture packer file has been loaded
 *
 * @method fromFrame
 * @static
 * @param frameId {String} The frame Id of the texture in the cache
 * @return {Sprite} A new Sprite using a texture from the texture cache matching the frameId
 */
PIXI.Sprite.fromFrame = function(frameId)
{
	var texture = PIXI.TextureCache[frameId];
	if(!texture)throw new Error("The frameId '"+ frameId +"' does not exist in the texture cache" + this);
	return new PIXI.Sprite(texture);
}

/**
 * 
 * Helper function that creates a sprite that will contain a texture based on an image url
 * If the image is not in the texture cache it will be loaded
 *
 * @method fromImage
 * @static
 * @param imageId {String} The image url of the texture
 * @return {Sprite} A new Sprite using a texture from the texture cache matching the image id
 */
PIXI.Sprite.fromImage = function(imageId)
{
	var texture = PIXI.Texture.fromImage(imageId);
	return new PIXI.Sprite(texture);
}