var WebGLManager = require('./WebGLManager'),
    AlphaMaskFilter = require('../filters/spriteMask/SpriteMaskFilter');

/**
 * @class
 * @memberof PIXI
 * @param renderer {PIXI.WebGLRenderer} The renderer this manager works for.
 */
function MaskManager(renderer)
{
    WebGLManager.call(this, renderer);

    //TODO - we don't need both!
    this.scissor = false;
    this.scissorData = null;
    this.scissorRenderTarget = null;

    this.enableScissor = true;

    this.alphaMaskPool = [];
    this.alphaMaskIndex = 0;
}

MaskManager.prototype = Object.create(WebGLManager.prototype);
MaskManager.prototype.constructor = MaskManager;
module.exports = MaskManager;

/**
 * Applies the Mask and adds it to the current filter stack.
 *
 * @param target {PIXI.DisplayObject} Display Object to push the mask to
 * @param maskData {PIXI.Sprite|PIXI.Graphics}
 */
MaskManager.prototype.pushMask = function (target, maskData)
{
    if (maskData.texture)
    {
        this.pushSpriteMask(target, maskData);
    }
    else
    {
        if(this.enableScissor && !this.scissor && !this.renderer.stencilManager.stencilMaskStack.length && maskData.isFastRect())
        {
            var matrix = maskData.worldTransform;

            var rot = Math.atan2(matrix.b, matrix.a);

            // use the nearest degree!
            rot = Math.round(rot * (180/Math.PI));

            if(rot % 90)
            {
                this.pushStencilMask(maskData);
            }
            else
            {
                this.pushScissorMask(target, maskData);
            }
        }
        else
        {
            this.pushStencilMask(maskData);
        }
    }
};

/**
 * Removes the last mask from the mask stack and doesn't return it.
 *
 * @param target {PIXI.DisplayObject} Display Object to pop the mask from
 * @param maskData {Array<*>}
 */
MaskManager.prototype.popMask = function (target, maskData)
{
    if (maskData.texture)
    {
        this.popSpriteMask(target, maskData);
    }
    else
    {
        if(this.enableScissor && !this.renderer.stencilManager.stencilMaskStack.length)
        {
            this.popScissorMask(target, maskData);
        }
        else
        {
            this.popStencilMask(target, maskData);
        }

    }
};

/**
 * Applies the Mask and adds it to the current filter stack.
 *
 * @param target {PIXI.RenderTarget} Display Object to push the sprite mask to
 * @param maskData {PIXI.Sprite} Sprite to be used as the mask
 */
MaskManager.prototype.pushSpriteMask = function (target, maskData)
{
    var alphaMaskFilter = this.alphaMaskPool[this.alphaMaskIndex];

    if (!alphaMaskFilter)
    {
        alphaMaskFilter = this.alphaMaskPool[this.alphaMaskIndex] = [new AlphaMaskFilter(maskData)];
    }

    alphaMaskFilter[0].resolution = this.renderer.resolution;
    alphaMaskFilter[0].maskSprite = maskData;

    //TODO - may cause issues!
    target.filterArea = maskData.getBounds(true);

    this.renderer.filterManager.pushFilter(target, alphaMaskFilter);

    this.alphaMaskIndex++;
};

/**
 * Removes the last filter from the filter stack and doesn't return it.
 *
 */
MaskManager.prototype.popSpriteMask = function ()
{
    this.renderer.filterManager.popFilter();
    this.alphaMaskIndex--;
};


/**
 * Applies the Mask and adds it to the current filter stack.
 *
 * @param maskData {Array<*>}
 */
MaskManager.prototype.pushStencilMask = function (maskData)
{
    this.renderer.currentRenderer.stop();
    this.renderer.stencilManager.pushStencil(maskData);
};

/**
 * Removes the last filter from the filter stack and doesn't return it.
 *
 */
MaskManager.prototype.popStencilMask = function ()
{
    this.renderer.currentRenderer.stop();
    this.renderer.stencilManager.popStencil();
};

/**
 *
 * @param target {PIXI.RenderTarget} Display Object to push the scissor mask to
 * @param maskData
 */
MaskManager.prototype.pushScissorMask = function (target, maskData)
{
    maskData.renderable = true;

    var renderTarget = this.renderer._activeRenderTarget;

    var bounds = maskData.getBounds();

    bounds.fit(renderTarget.size);
    maskData.renderable = false;

    this.renderer.gl.enable(this.renderer.gl.SCISSOR_TEST);

    var resolution = this.renderer.resolution;
    this.renderer.gl.scissor(bounds.x * resolution,
        (renderTarget.root ? renderTarget.size.height - bounds.y - bounds.height : bounds.y) * resolution,
                           bounds.width * resolution,
                           bounds.height * resolution);

    this.scissorRenderTarget = renderTarget;
    this.scissorData = maskData;
    this.scissor = true;
};

/**
 *
 *
 */
MaskManager.prototype.popScissorMask = function ()
{
    this.scissorRenderTarget = null;
    this.scissorData = null;
    this.scissor = false;

    // must be scissor!
    var gl = this.renderer.gl;
    gl.disable(gl.SCISSOR_TEST);
};