/**
* 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
*/

/**
* Creates a carousel-style navigation widget for images/any-content from a simple HTML markup.
*
* The HTML markup that is used to build the carousel can be as simple as...
*
*  <div class="carousel">
*      <ul>
*          <li><img src="image/1.jpg" alt="1"></li>
*          <li><img src="image/2.jpg" alt="2"></li>
*          <li><img src="image/3.jpg" alt="3"></li>
*      </ul>
*  </div>
*
* As you can see, this snippet is nothing but a simple div containing an unordered list of images.
* You don't need any special "class" attribute, or a special "css" file for this plugin.
* I am using a class attribute just for the sake of explanation here.
*
* To navigate the elements of the carousel, you need some kind of navigation buttons.
* For example, you will need a "previous" button to go backward, and a "next" button to go forward.
* This need not be part of the carousel "div" itself. It can be any element in your page.
* Lets assume that the following elements in your document can be used as next, and prev buttons...
*
* <button class="prev">&lt;&lt;</button>
* <button class="next">&gt;&gt;</button>
*
* Now, all you need to do is call the carousel component on the div element that represents it, and pass in the
* navigation buttons as options.
*
* $(".carousel").jCarouselLite({
*      btnNext: ".next",
*      btnPrev: ".prev"
* });
*
* That's it, you would have now converted your raw div, into a magnificient carousel.
*
* There are quite a few other options that you can use to customize it though.
* Each will be explained with an example below.
*
* @param an options object - You can specify all the options shown below as an options object param.
*
* @option btnPrev, btnNext : string - no defaults
* @example
* $(".carousel").jCarouselLite({
*      btnNext: ".next",
*      btnPrev: ".prev"
* });
* @desc Creates a basic carousel. Clicking "btnPrev" navigates backwards and "btnNext" navigates forward.
*
* @option btnGo - array - no defaults
* @example
* $(".carousel").jCarouselLite({
*      btnNext: ".next",
*      btnPrev: ".prev",
*      btnGo: [".0", ".1", ".2"]
* });
* @desc If you don't want next and previous buttons for navigation, instead you prefer custom navigation based on
* the item number within the carousel, you can use this option. Just supply an array of selectors for each element
* in the carousel. The index of the array represents the index of the element. What i mean is, if the
* first element in the array is ".0", it means that when the element represented by ".0" is clicked, the carousel
* will slide to the first element and so on and so forth. This feature is very powerful. For example, i made a tabbed
* interface out of it by making my navigation elements styled like tabs in css. As the carousel is capable of holding
* any content, not just images, you can have a very simple tabbed navigation in minutes without using any other plugin.
* The best part is that, the tab will "slide" based on the provided effect. :-)
*
* @option mouseWheel : boolean - default is false
* @example
* $(".carousel").jCarouselLite({
*      mouseWheel: true
* });
* @desc The carousel can also be navigated using the mouse wheel interface of a scroll mouse instead of using buttons.
* To get this feature working, you have to do 2 things. First, you have to include the mouse-wheel plugin from brandon.
* Second, you will have to set the option "mouseWheel" to true. That's it, now you will be able to navigate your carousel
* using the mouse wheel. Using buttons and mouseWheel or not mutually exclusive. You can still have buttons for navigation
* as well. They complement each other. To use both together, just supply the options required for both as shown below.
* @example
* $(".carousel").jCarouselLite({
*      btnNext: ".next",
*      btnPrev: ".prev",
*      mouseWheel: true
* });
*
* @option auto : number - default is null, meaning autoscroll is disabled by default
* @example
* $(".carousel").jCarouselLite({
*      auto: 800,
*      speed: 500
* });
* @desc You can make your carousel auto-navigate itself by specfying a millisecond value in this option.
* The value you specify is the amount of time between 2 slides. The default is null, and that disables auto scrolling.
* Specify this value and magically your carousel will start auto scrolling.
*
* @option speed : number - 200 is default
* @example
* $(".carousel").jCarouselLite({
*      btnNext: ".next",
*      btnPrev: ".prev",
*      speed: 800
* });
* @desc Specifying a speed will slow-down or speed-up the sliding speed of your carousel. Try it out with
* different speeds like 800, 600, 1500 etc. Providing 0, will remove the slide effect.
*
* @option easing : string - no easing effects by default.
* @example
* $(".carousel").jCarouselLite({
*      btnNext: ".next",
*      btnPrev: ".prev",
*      easing: "bounceout"
* });
* @desc You can specify any easing effect. Note: You need easing plugin for that. Once specified,
* the carousel will slide based on the provided easing effect.
*
* @option vertical : boolean - default is false
* @example
* $(".carousel").jCarouselLite({
*      btnNext: ".next",
*      btnPrev: ".prev",
*      vertical: true
* });
* @desc Determines the direction of the carousel. true, means the carousel will display vertically. The next and
* prev buttons will slide the items vertically as well. The default is false, which means that the carousel will
* display horizontally. The next and prev items will slide the items from left-right in this case.
*
* @option circular : boolean - default is true
* @example
* $(".carousel").jCarouselLite({
*      btnNext: ".next",
*      btnPrev: ".prev",
*      circular: false
* });
* @desc Setting it to true enables circular navigation. This means, if you click "next" after you reach the last
* element, you will automatically slide to the first element and vice versa. If you set circular to false, then
* if you click on the "next" button after you reach the last element, you will stay in the last element itself
* and similarly for "previous" button and first element.
*
* @option visible : number - default is 3
* @example
* $(".carousel").jCarouselLite({
*      btnNext: ".next",
*      btnPrev: ".prev",
*      visible: 4
* });
* @desc This specifies the number of items visible at all times within the carousel. The default is 3.
* You are even free to experiment with real numbers. Eg: "3.5" will have 3 items fully visible and the
* last item half visible. This gives you the effect of showing the user that there are more images to the right.
*
* @option start : number - default is 0
* @example
* $(".carousel").jCarouselLite({
*      btnNext: ".next",
*      btnPrev: ".prev",
*      start: 2
* });
* @desc You can specify from which item the carousel should start. Remember, the first item in the carousel
* has a start of 0, and so on.
*
* @option scrool : number - default is 1
* @example
* $(".carousel").jCarouselLite({
*      btnNext: ".next",
*      btnPrev: ".prev",
*      scroll: 2
* });
* @desc The number of items that should scroll/slide when you click the next/prev navigation buttons. By
* default, only one item is scrolled, but you may set it to any number. Eg: setting it to "2" will scroll
* 2 items when you click the next or previous buttons.
*
* @option beforeStart, afterEnd : function - callbacks
* @example
* $(".carousel").jCarouselLite({
*      btnNext: ".next",
*      btnPrev: ".prev",
*      beforeStart: function(a) {
*          alert("Before animation starts:" + a);
*      },
*      afterEnd: function(a) {
*          alert("After animation ends:" + a);
*      }
* });
* @desc If you wanted to do some logic in your page before the slide starts and after the slide ends, you can
* register these 2 callbacks. The functions will be passed an argument that represents an array of elements that
* are visible at the time of callback.
*
*
* @cat Plugins/Image Gallery
* @author Ganeshji Marwaha/ganeshread@gmail.com
*/

(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,
            visible: 3,
            start: 0,
            scroll: 1,

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

        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 = $("ul", div), tLi = $("li", ul), tl = tLi.size(), v = o.visible, container = $(this).parent();

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

            var liHeight = maxHeight(li);
            var innerDivs = $("li div", ul);
            if (innerDivs != null) {
                innerDivs.css("line-height", liHeight);
            }
            li.css({ overflow: "hidden", "float": o.vertical ? "none" : "left", height: liHeight });
            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[0]);    // Full li size(incl margin)-Used for animation
            var btnWidth = css($(o.btnNext), "width") + css($(o.btnNext), "margin-left") + css($(o.btnNext), "margin-right");
            var divSize = css(container, "width") - (2 * btnWidth); // size of entire div(total length for just the visible items)
            div.css(sizeCss, divSize + "px");                       // Width of the DIV. length of visible images

            var listItemWidth = totalWidth(li);
            // If the combined width of the list items is less than the available width of the container then we don't
            // really need the jcarousel functionality so hide buttons and return.
            if (listItemWidth < css(container, "width")) {
                div.css(sizeCss, listItemWidth + "px");
                return false;
            }
            $(o.btnNext).css("display", "block");
            $(o.btnPrev).css("display", "block");

            v = Math.floor(divSize / liSize);
            o.scroll = (v > 1) ? v - 1 : 1;

            // size of full ul(total length, not just for the visible items)
            var ulSize = 0;
            for (var i = 0; i < li.length; i++) {
                var img = jQuery("a img", li[i])[0];
                ulSize += img.offsetWidth + css($(img), "paddingLeft") + +css($(img), "paddingRight") + css($(img), "borderLeftWidth") + css($(img), "borderRightWidth");
            }
            ul.css(sizeCss, ulSize + "px").css(animCss, -(curr * liSize));

            // set start position
            var leftOffset = calculateLeftOffset(li, curr);
            ul.css("left", -leftOffset);

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

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

            if (o.btnGo)
                $.each(o.btnGo, function(i, val) {
                    $(val).click(function() {
                        return go(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(btn) {
                if (!running) {

                    if (o.beforeStart)
                        o.beforeStart.call(this, vis());

                    if ($(btn).is('.disabled'))
                        return;

                    running = true;

                    var scrollPosition = 0;
                    if (btn == o.btnNext) {
                        scrollPosition = scrollRight();
                    } else {
                        scrollPosition = scrollLeft();
                    }

                    ul.animate(
                        animCss == "left" ? { left: -(scrollPosition)} : { 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
                    $(o.btnPrev + "," + o.btnNext).removeClass("disabled");
                    $((scrollPosition <= 0 && o.btnPrev) || (scrollPosition + divSize >= listItemWidth && o.btnNext) || []).addClass("disabled");
                }
                return false;
            };

            function scrollRight() {
                var leftOffset = calculateLeftOffset(li, curr);
                var scrollAmount = 0;
                while ((scrollAmount + width(li[curr])) < divSize) {
                    scrollAmount += width(li[curr++]);
                }
                curr -= 1; // minus one because we do an extra increment before the last test in the loop above
                if ((listItemWidth - (leftOffset + scrollAmount)) < divSize) {
                    leftOffset = listItemWidth - divSize;
                } else {
                    leftOffset += scrollAmount;
                }

                return leftOffset;
            };

            function scrollLeft() {
                var leftOffset = calculateLeftOffset(li, curr);
                var scrollAmount = 0;
                while (curr > 0 && (scrollAmount + width(li[--curr])) < divSize) {
                    scrollAmount += width(li[curr]);
                }
                curr += 1; // increment one because we do an extra decrement before the last test in the loop above
                if ((leftOffset - scrollAmount) <= 0) {
                    leftOffset = 0;
                    curr = 0;
                } else {
                    leftOffset -= scrollAmount;
                }

                return leftOffset;
            };

            $(this).one("removeEvents", function() {
                if (o.btnPrev)
                    $(o.btnPrev).unbind('click');

                if (o.btnNext)
                    $(o.btnNext).unbind('click');
            });
        });
    };

    function css(el, prop) {
        return parseInt($.css(el[0], prop)) || 0;
    };
    function width(el) {
        // the .children[0] hack below is necessary as IE 7 and lower aren't calculating the width of the li
        // elements correctly.
        return el.children[0].offsetWidth + css($(el), 'marginLeft') + css($(el), 'marginRight');
    };
    function height(el) {
        return el[0].offsetHeight + css(el, 'marginTop') + css(el, 'marginBottom');
    };
    function calculateLeftOffset(listItems, index) {
        var leftOffset = 0;
        for (var i = 0; i < index; i++) {
            leftOffset += width(listItems[i])
        }

        return leftOffset;
    };
    function totalWidth(el) {
        var size = 0;
        for (var i = 0; i < el.length; i++) {
            size += width(el[i]);
        }

        return size;
    };
    function maxHeight(el) {
        var maxHeight = 0;
        for (var i = 0; i < el.length; i++) {
            if (css($(el[i]), "height") > maxHeight)
                maxHeight = css($(el[i]), "height");
        }

        return maxHeight;
    };
    
    $.fn.removejCarouselLite = function() {
        return this.trigger("removeEvents");
    };

})(jQuery);