/**
 * 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($) {                                          // Compliant with jquery.noConflict()
$.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 || {});

	o.btnPrev = $(o.btnPrev);
	o.btnNext = $(o.btnNext);

    return this.each(function() {                           // Returns the element collection. Chainable.

        var running = false, animCss=o.vertical?"top":"left", sizeCss=o.vertical?"height":"width";
        var div = $(this), 
			ul = div.find("ul:first"), 
			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 = ul.children('li'), 
			itemLength = li.size(), 
			curr = o.start;

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

        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"});

        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(o.vertical ? {height: li.height()} : {width: li.width()});
        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.length)
            o.btnPrev.click(function() {
                return go(curr-o.scroll);
            });

        if(o.btnNext.length)
            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(o.circular) {            // If circular we are in first or last, then goto the other end
                    if(to<=o.start-v-1) {           // If first, then goto last
                        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 && to>=itemLength)) return false;
                    else curr = to;
                }                           // If neither overrides it, the curr will still be "to" and we can proceed.

                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)[curr < o.scroll ? 'addClass' : 'removeClass']('disabled');
					$(o.btnNext)[curr >= (itemLength - o.scroll) ? 'addClass' : 'removeClass']('disabled');
                }

            }
            return false;
        };

		$(this).bind('jCarouselLite.go', function(e, to) { go(to); });
    });
};

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);