var Blender = new Class(
{
    /**
	 * The Blender class constructor. <br />
	 * @constructor Blender
	 * @param {string|img element} img The id of or actual image element to be faded
	 * @param {array(string)} list  An array of paths (relative or absolute) of the images
	 * @param {object} [options] An object of options.
	 */
	initialize: function(img, list, options) {
		this.img = $(img);
		this.list = list;

		/**
		 * The default options object.
		 * @class
		 * @param {string} [id] The id used as queue scope. (default: img.id)
		 * @param {float} [fadeDuration] The time in seconds of the fade in/out. (default: 2.5)
		 * @param {float} [displayDuration] The time in seconds that the image is not faded out after being faded in. (default: 2.5)
		 * @param {bool} [autoSize] Set true if the image should be sized to it's container. Maintains aspect ratio. (default: false)
		 * @param {bool} [autoStart] If false the Blender will not start until Blender#start is called. (default: true)
		 * @param {bool} [noWrap] If false the Blender will not wrap the image in a div and use the image's parent container. (default: false)
		 * @param {object} [attributes] An associative array of attributes given to the image. (default: {})
		 * @param {string} [dir] The directory that all images reside in. Used as a prefix for the image src. (default: null)
		 * @param {function} [beforeBlend] A function that is called before the images are blended. 2 parameters are passed: 1. the image being faded out; 2. the image being faded in (default: null)
		 * @param {int} [startIndex] The index of the first new image to be shown. (default: 0)
		 */
		this.options = $extend({
			id: this.img.id,
			fadeDuration: 2.5,
			displayDuration: 2.5,
			autoSize: false,
			autoStart: true,
			noWrap: false,
			attributes: {},
			dir: "",
			beforeBlend: null,
			startIndex: 0
		}, options || {});

		this.index = this.options.startIndex;
		if(this.options.noWrap) {
			this.container = this.img.getParent();
		} else {
			this.container = new Element("div").setStyles({ position: "relative", width: this.img.width + "px", height: this.img.height + "px" });
			this.img.getParent().replaceChild(this.container, this.img);
			this.container.appendChild(this.img);
		}
		this.loadedObserver = this.loaded.bind(this);
		this.nextObserver = this.next.bind(this);

		this.stopped = true;
		if(this.options.autoStart) {
			setTimeout(this.start.bind(this), this.options.displayDuration * 1000);
		}
	},
	/**
	 * Starts the fading if the autoStart option was set to false or after a call to stop.
	 */
	start: function() {
		if(!this.stopped) {
			return;
		}
		this.stopped = false;
		this.next();
	},
	/**
	 * Stops the fading and sets the opacity of the current image to 100%.
	 */
	stop: function() {
		this.stopped = true;
		try { clearTimeout(this.timeout); } catch(ex) { }
//		try { Effect.Queues.get(this.options.id).each(function(effect) { effect.cancel() }) } catch(ex) { }
        
        if(this.oldImg.fx){this.oldImg.fx.stop();}
		if(this.img.fx){this.img.fx.stop();}
		
		if(this.oldImg) {
			this.container.removeChild(this.oldImg);
			this.oldImg = null;
		}
		Element.setOpacity(this.img, 1);
	},
	/**
	 * Loads the next image in list
	 * @private
	 */
	next: function() {
		if(this.oldImg) {
			this.container.removeChild(this.oldImg);
		}
		this.oldImg = this.img;
		if(this.stopped || this.list.length == 0) {
			return;
		}
		++this.index;
		if(this.index >= this.list.length) {
			this.index = 0;
		}
		this.img = new Element("img", this.options.attributes);
		this.img.addEvent("load", this.loadedObserver);
		this.img.src = this.options.dir + this.list[this.index];
	},	
	/**
	 * Event listener for image loaded
	 * @private
	 */
	loaded: function() {
		this.img.removeEvent("load", this.loadedObserver);
		if(this.options.autoSize) {
			this.resize(this.img);
		}
		this.img.setOpacity(0);
		
		this.container.appendChild(this.img);
		//alert("padding-top:" + this.co ntainer.getStyle("padding-top") + " - left:" + this.container.getStyle("padding-left"));
		this.img.setStyles({ position: "absolute", top: this.container.getStyle("padding-top"), left: this.container.getStyle("padding-left") });
		if(typeof this.options.beforeBlend == "function") {
			this.options.beforeBlend(this.oldImg, this.img);
		}
		
		if(this.oldImg.fx){this.oldImg.fx.stop();}
		if(this.img.fx){this.img.fx.stop();}
		
		this.oldImg.fx = this.oldImg.effect('opacity', {duration: this.options.fadeDuration * 1000}).start(0);
		this.img.fx = this.img.effect('opacity', {duration: this.options.fadeDuration * 1000}).start(1);
		
//		new Effect.Opacity(this.oldImg, { duration: this.options.fadeDuration, from: 1.0, to: 0.0, queue: { scope: this.options.id } });
//		new Effect.Opacity(this.img, { duration: this.options.fadeDuration, from: 0.0, to: 1.0, queue: { scope: this.options.id } });
		this.timeout = setTimeout(this.nextObserver, (this.options.fadeDuration + this.options.displayDuration) * 1000);
	},
	/**
	 * Resize the image to the container while maintaining aspect ratio
	 * @private
	 */
	resize: function(img) {
		var dim = this.container.getDimensions();
		dim.width -= parseInt(this.container.getStyle("padding-left")) +
			parseInt(this.container.getStyle("padding-right")) +
			parseInt(this.container.getStyle("border-left-width")) +
			parseInt(this.container.getStyle("border-right-width"));
		dim.height -= parseInt(this.container.getStyle("padding-top")) +
			parseInt(this.container.getStyle("padding-bottom")) +
			parseInt(this.container.getStyle("border-top-width")) +
			parseInt(this.container.getStyle("border-bottom-width"));

		var dw = dim.width / img.width;
		var dh = dim.height / img.height;
		var w1 = img.width * dh;
		var h1 = img.height * dw;

		if(dw > dh) {
			img.width = w1;
			img.height = dim.height;
		} else {
			img.width = dim.width;
			img.height = h1;
		}
	}
});