/**
 * jCarouselLite - jQuery plugin to navigate images/any content in a carousel style widget.
 * @requires jQuery v1.2 or above
 *
 * http://gmarwaha.com/jquery/jcarousellite/
 *
 * Copyright (c) 2007 Ganeshji Marwaha (gmarwaha.com)
 * Dual licensed under the MIT and GPL licenses:
 * http://www.opensource.org/licenses/mit-license.php
 * http://www.gnu.org/licenses/gpl.html
 *
 * Version: 1.0.1
 * Note: Requires jquery 1.2 or above from version 1.0.1
 */
(function($){
	$.fn.jCarouselLite = function(o)
	{
		o = $.extend({
			btnPrev: null,
			btnNext: null,
			btnGo: null,
			mouseWheel: false,
			auto: null,

			speed: 200,
			easing: null,

			vertical: false,
			circular: true,
			visible: 3,
			start: 0,
			scroll: 1,

			beforeStart: null,
			afterEnd: null
		}, o || {});

		// Returns the element collection. Chainable.
	    return this.each(function()
		{
			var running = false, animCss = o.vertical ? "top" : "left", sizeCss = o.vertical ? "height" : "width";
			var div = $(this), ul = $("ul", div), tLi = $("li", ul), tl = tLi.size(), v = o.visible;

			if(o.circular)
			{
				ul.prepend(tLi.slice(tl-v-1+1).clone())
					.append(tLi.slice(0,v).clone());
				o.start += v;
			}

			var li = $("li", ul), itemLength = li.size(), curr = o.start;

			div.css("visibility", "visible");

			var liSize = o.vertical ? height(li) : width(li);	// Full li size(incl margin)-Used for animation
			var ulSize = liSize * itemLength;					// size of full ul(total length, not just for the visible items)
			var divSize = liSize * v;							// size of entire div(total length for just the visible items)

			li.css({overflow: "hidden", float: o.vertical ? "none" : "left"});
			ul.css({margin: "0", padding: "0", position: "relative", "list-style-type": "none", "z-index": "1"});
			div.css({overflow: "hidden", position: "relative", "z-index": "2", left: "0px"});

			li.css({width: li.width(), height: li.height()});
			ul.css(sizeCss, ulSize+"px").css(animCss, -(curr*liSize));

			div.css(sizeCss, divSize+"px");						// Width of the DIV. length of visible images

			if(o.btnPrev)
				$(o.btnPrev).click(function() {
					return go(curr-o.scroll);
				});

			if(o.btnNext)
				$(o.btnNext).click(function() {
					return go(curr+o.scroll);
				});

			if(o.btnGo)
				$.each(o.btnGo, function(i, val) {
					$(val).click(function() {
						return go(o.circular ? o.visible+i : i);
					});
				});

			if(o.mouseWheel && div.mousewheel)
				div.mousewheel(function(e, d) {
					return d>0 ? go(curr-o.scroll) : go(curr+o.scroll);
				});

			if(o.auto)
				setInterval(function() {
					go(curr+o.scroll);
				}, o.auto+o.speed);

			function vis()
			{
				return li.slice(curr).slice(0,v);
			};

			function go(to)
			{
				if(!running)
				{
					if(o.beforeStart)
	                    o.beforeStart.call(this, vis());

					// If circular we are in first or last, then goto the other end
					if(o.circular)
					{
						// If first, then goto last
						if(to<=o.start-v-1)
						{
							ul.css(animCss, -((itemLength-(v*2))*liSize)+"px");
							// If "scroll" > 1, then the "to" might not be equal to the condition; it can be lesser depending on the number of elements.
							curr = to==o.start-v-1 ? itemLength-(v*2)-1 : itemLength-(v*2)-o.scroll;
						} else if(to>=itemLength-v+1) // If last, then goto first
						{
							ul.css(animCss, -( (v) * liSize ) + "px" );
							// If "scroll" > 1, then the "to" might not be equal to the condition; it can be greater depending on the number of elements.
							curr = to==itemLength-v+1 ? v+1 : v+o.scroll;
						} else curr = to;
					} else {	// If non-circular and to points to first or last, we just return.
						if(to<0 || to>itemLength-v) return;
						else curr = to;
					}

					running = true;

					ul.animate(
						animCss == "left" ? { left: -(curr*liSize) } : { top: -(curr*liSize) }, o.speed, o.easing, function(){
							if(o.afterEnd)
								o.afterEnd.call(this, vis());
							running = false;
						}
					);

					// Disable buttons when the carousel reaches the last/first, and enable when not
					if(!o.circular)
					{
						$(o.btnPrev + "," + o.btnNext).removeClass("disabled");
						$((curr-o.scroll<0 && o.btnPrev) || (curr+o.scroll > itemLength-v && o.btnNext) || []).addClass("disabled");
	                }
				}
				return false;
			};
		});
	};

	function css(el, prop)
	{
		return parseInt($.css(el[0], prop)) || 0;
	};

	function width(el)
	{
		return  el[0].offsetWidth + css(el, 'marginLeft') + css(el, 'marginRight');
	};

	function height(el)
	{
		return el[0].offsetHeight + css(el, 'marginTop') + css(el, 'marginBottom');
	};

})(jQuery);