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


/**
 * A DisplayObjectContainer represents a collection of display objects.
 * It is the base class of all display objects that act as a container for other objects.
 *
 * @class DisplayObjectContainer
 * @extends DisplayObject
 * @constructor
 */
PIXI.DisplayObjectContainer = function()
{
    PIXI.DisplayObject.call( this );

    /**
     * [read-only] The of children of this container.
     *
     * @property children
     * @type Array<DisplayObject>
     * @readOnly
     */
    this.children = [];
};

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

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

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

/**
 * Adds a child to the container.
 *
 * @method addChild
 * @param child {DisplayObject} The DisplayObject to add to the container
 */
PIXI.DisplayObjectContainer.prototype.addChild = function(child)
{
    if(child.parent)
    {
        //// COULD BE THIS???
        child.parent.removeChild(child);
        //  return;
    }

    child.parent = this;

    this.children.push(child);

    // update the stage refference..

    if(this.stage)this.setStageReference(this.stage)

};

/**
 * Adds a child to the container at a specified index. If the index is out of bounds an error will be thrown
 *
 * @method addChildAt
 * @param child {DisplayObject} The child to add
 * @param index {Number} The index to place the child in
 */
PIXI.DisplayObjectContainer.prototype.addChildAt = function(child, index)
{
    if(index >= 0 && index <= this.children.length)
    {
        if(child.parent)
        {
            child.parent.removeChild(child);
        }

        child.parent = this;

        if(this.stage)this.setStageReference(this.stage)
    }
    else
    {
        throw new Error(child + ' The index '+ index +' supplied is out of bounds ' + this.children.length);
    }
};

/**
 * [NYI] Swaps the depth of 2 displayObjects
 *
 * @method swapChildren
 * @param child {DisplayObject}
 * @param child2 {DisplayObject}
 * @private
 */
PIXI.DisplayObjectContainer.prototype.swapChildren = function(child, child2)
{
    if(child === child2) {
        return;
    }

    var index1 = this.children.indexOf(child);
    var index2 = this.children.indexOf(child2);

    if(index1 < 0 || index2 < 0) {
        throw new Error('swapChildren: Both the supplied DisplayObjects must be a child of the caller.');
    }

    this.children[index1] = child2;
    this.children[index2] = child1;
    
};

/**
 * Returns the Child at the specified index
 *
 * @method getChildAt
 * @param index {Number} The index to get the child from
 */
PIXI.DisplayObjectContainer.prototype.getChildAt = function(index)
{
    if(index >= 0 && index < this.children.length)
    {
        return this.children[index];
    }
    else
    {
        throw new Error('Both the supplied DisplayObjects must be a child of the caller ' + this);
    }
};

/**
 * Removes a child from the container.
 *
 * @method removeChild
 * @param child {DisplayObject} The DisplayObject to remove
 */
PIXI.DisplayObjectContainer.prototype.removeChild = function(child)
{
    var index = this.children.indexOf( child );
    if ( index !== -1 )
    {  
        // update the stage reference..
        if(this.stage)this.removeStageReference();

        child.parent = undefined;
        this.children.splice( index, 1 );
    }
    else
    {
        throw new Error(child + ' The supplied DisplayObject must be a child of the caller ' + this);
    }
};

/*
 * Updates the container's children's transform for rendering
 *
 * @method updateTransform
 * @private
 */
PIXI.DisplayObjectContainer.prototype.updateTransform = function()
{
    this._currentBounds = null;

    if(!this.visible)return;

    PIXI.DisplayObject.prototype.updateTransform.call( this );

    for(var i=0,j=this.children.length; i<j; i++)
    {
        this.children[i].updateTransform();
    }
};

PIXI.DisplayObjectContainer.prototype.getBounds = function()
{    
    if(this.children.length === 0)return PIXI.EmptyRectangle;

    // TODO the bounds have already been calculated this render session so return what we have
   

    var minX = Infinity;
    var minY = Infinity;

    var maxX = -Infinity;
    var maxY = -Infinity;

    var childBounds;
    var childMaxX;
    var childMaxY;

    for(var i=0,j=this.children.length; i<j; i++)
    {
        var child = this.children[i];
        
        if(!child.visible)continue;

        childBounds = this.children[i].getBounds();
     
        minX = minX < childBounds.x ? minX : childBounds.x;
        minY = minY < childBounds.y ? minY : childBounds.y;

        childMaxX = childBounds.width + childBounds.x;
        childMaxY = childBounds.height + childBounds.y;

        maxX = maxX > childMaxX ? maxX : childMaxX;
        maxY = maxY > childMaxY ? maxY : childMaxY;
    }

    var bounds = this._bounds;

    bounds.x = minX;
    bounds.y = minY;
    bounds.width = maxX - minX;
    bounds.height = maxY - minY;

    // TODO: store a refferance so that if this function gets called again in the render cycle we do not have to recacalculate
    //this._currentBounds = bounds;
   
    return bounds;
}

PIXI.DisplayObjectContainer.prototype.setStageReference = function(stage)
{
    this.stage = stage;

    for(var i=0,j=this.children.length; i<j; i++)
    {
        var child = this.children[i];
        if(child.interactive)this.stage.dirty = true;
        child.setStageReference(stage);
    }   
}

PIXI.DisplayObjectContainer.prototype.removeStageReference = function()
{
    for(var i=0,j=this.children.length; i<j; i++)
    {
        var child = this.children[i];
        if(child.interactive)this.stage.dirty = true;
        child.removeStageReference();
        child.stage = null;
    }   
}

PIXI.DisplayObjectContainer.prototype._renderWebGL = function(renderSession)
{
    if(this.visible === false || this.alpha === 0)return;

    if(this._mask || this._filters)
    {
        if(this._mask)
        {
            renderSession.spriteBatch.stop();
            renderSession.maskManager.pushMask(this.mask, renderSession);
            renderSession.spriteBatch.start();
        }

        if(this._filters)
        {    
            renderSession.spriteBatch.flush();
            renderSession.filterManager.pushFilter(this._filterBlock);
        }

        // simple render children!
        for(var i=0,j=this.children.length; i<j; i++)
        {
            var child = this.children[i];
            child._renderWebGL(renderSession);
        }

        renderSession.spriteBatch.stop();

        if(this._filters)renderSession.filterManager.popFilter();
        if(this._mask)renderSession.maskManager.popMask(renderSession);
        
        renderSession.spriteBatch.start();
    }
    else
    {
        // simple render children!
        for(var i=0,j=this.children.length; i<j; i++)
        {
            var child = this.children[i];
            child._renderWebGL(renderSession);
        }
    }
}

PIXI.DisplayObjectContainer.prototype._renderCanvas = function(renderSession)
{
    if(this.visible === false || this.alpha === 0)return;

    if(this._mask)
    {
        renderSession.maskManager.pushMask(this._mask, renderSession.context);
    }

    for(var i=0,j=this.children.length; i<j; i++)
    {
        var child = this.children[i];
        child._renderCanvas(renderSession);
    }

    if(this._mask)
    {
        renderSession.maskManager.popMask(renderSession.context);
    }
}