/**
 * jQuery UI Carousel 1.0.0
 * 
 * (based on jCarouselLite 1.0.1)
 *
 * Copyright (c) 2008 Chris Leishman (chrisleishman.com)
 * Dual licensed under the MIT (MIT-LICENSE.txt)
 * and GPL (GPL-LICENSE.txt) licenses.
 */
(function($) {
    
$.widget('ui.carousel', {
    _init: function() {
        var self = this, o = this.options, div = this.element;
        
        this.running = false;
        this.curr = o.start;
        
        o.animCss = o.vertical? 'top':'left';
        o.sizeCss = o.vertical? 'height':'width';
        
        var ul = $("ul", div), tLi = $("li", ul), tl = tLi.size(), v = o.visible;

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

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

        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"});

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

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

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

        if (o.auto) {
            setInterval(function() {
                self.next();
            }, o.auto+o.speed);
        }
    },
    
    prev: function() {
        return this._go(this.curr - this.options.scroll);
    },

    next: function() {
        return this._go(this.curr + this.options.scroll);
    },

    visible: function(from) {
        if (from == undefined) from = this.curr;
        return this.element.find('li').slice(from).slice(0, this.options.visible);
    },

    at: function() {
        return this.curr;
    },

    view: function(item) {
        var o = this.options, curr = this.curr;
        if (o.circular)
            item = item + o.visible;
        if (item >= curr && item < curr + o.visible)
            return;
        var s = o.scroll;
        return this._go((item < curr)? (curr - (Math.floor((curr-item)/s)*s + s)) : (curr + (Math.floor((item-curr)/s)*s)));
    },
    
    reset: function() {
        var o = this.options;
        if (this.curr == o.start) return;
        this.curr = o.start;
        ul.css(o.animCss, -(this.curr * o.liSize));
    },
    
    _go: function(to) {
        var self = this, o = this.options, e = this.element;
        var v = o.visible, ul = this.element.find('ul');
        
        if (!self.running) {
            var prev = self.curr;
            var next;

            if (o.circular) {            // If circular we are in first or last, then goto the other end
                if (to == self.curr) return;
                if (to <= o.start-v-1) {           // If first, then goto last
                    ul.css(o.animCss, -((o.itemLength-(v*2))*o.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.
                    next = to==o.start-v-1 ? o.itemLength-(v*2)-1 : o.itemLength-(v*2)-o.scroll;
                } else if (to >= o.itemLength - v + 1) { // If last, then goto first
                    ul.css(o.animCss, -((v)*o.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.
                    next = to==o.itemLength-v+1 ? v+1 : v+o.scroll;
                } else {
                    next = to;
                }
            } else {
                if (to > o.itemLength-v)
                    to = o.itemLength-v;
                if (to < 0)
                    to = 0;
                // If non-circular and to points to first or last, we just return.
                if (to == self.curr) return;
                else next = to;
            }

            o.beforeStart.call(e, self.visible(self.curr), self.visible(next));
            self.running = true;
            self.curr = next;

            ul.animate(
                o.animCss == "left" ? { left: -(self.curr*o.liSize) } : { top: -(self.curr*o.liSize) } , o.speed, o.easing,
                function() {
                    self.running = false;
                    o.afterEnd.call(e, self.visible(self.curr), self.visible(prev));
                }
            );
        }
        return false;
    },

    _css: function(el, prop) {
        return parseInt($.css(el[0], prop)) || 0;
    },
    _width: function(el) {
        return  el[0].offsetWidth + this._css(el, 'marginLeft') + this._css(el, 'marginRight');
    },
    _height: function(el) {
        return el[0].offsetHeight + this._css(el, 'marginTop') + this._css(el, 'marginBottom');
    }
});


$.extend($.ui.carousel, {
    defaults: {
        auto: null,
        speed: 200,
        easing: null,
        vertical: false,
        circular: true,
        visible: 3,
        start: 0,
        scroll: 1,
        beforeStart: function(visibleBefore, visibleAfter) { },
        afterEnd: function(visibleAfter, visibleBefore) { }
    }
});


})(jQuery);