/**
 * 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($) {

	function Carousel() {

		return {
			next: function() {				
			}
		}
	}

$.fn.jCarouselLite = function(options) {
    options = $.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

    }, options || {});

    this.each(function() {

				$(this).data = new Carousel();

        var running = false, animCss=options.vertical?"top":"left", sizeCss=options.vertical?"height":"width";
        var div  = $(this), ul = $("ul", div), tLi = $("li", ul), tl = tLi.size();
				var self = this;

				$(self).data('visible', options.visible);
				
        if (options.circular) {
            ul.prepend(tLi.slice(tl- $(self).data('visible') -1+1).clone())
              .append(tLi.slice(0, $(self).data('visible') ).clone());
            options.start +=  $(self).data('visible') ;
        }

        var li = $("li", ul), itemLength = li.size();
				var current = options.start;

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

        li.css({overflow: "hidden", 'float': options.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  = options.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 *  $(self).data('visible') ;                           // size of entire div(total length for just the visible items)

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

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

				var $scroll_timer = false;

				if (options.btnPrev) {

					$(options.btnPrev)
						.click(function() {
							return go(current-options.scroll);
						})
						.hover(function() {
							go(current-options.scroll);

							$scroll_timer = setInterval(function() {
								go(current-options.scroll);
							}, 700);
						}, function() {
							clearInterval($scroll_timer);
						});
				}

				if (options.btnNext) {

					$(options.btnNext)
						.click(function() {
							return go(current+options.scroll);
						})
						.hover(function() {
							go(current+options.scroll);
							
							$scroll_timer = setInterval(function() {
								go(current+options.scroll);
							}, 700);
						}, function() {
							clearInterval($scroll_timer);
						});
				}

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

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

				if(options.auto)
						setInterval(function() {
								go(current+options.scroll);
						}, options.auto+options.speed);

				function vis() {
            return li.slice(current).slice(0, $(self).data('visible') );
        };

        function go(to) {
					if (!running) {

							if (options.beforeStart) {
								options.beforeStart.call(this, vis());
							}

							if(options.circular) {            // If circular we are in first or last, then goto the other end
									if(to<=options.start- $(self).data('visible') -1) {           // If first, then goto last
											ul.css(animCss, -((itemLength-( $(self).data('visible') *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.
											current = to==options.start- $(self).data('visible') -1 ? itemLength-( $(self).data('visible') *2)-1 : itemLength-( $(self).data('visible') *2)-options.scroll;
									} else if(to>=itemLength- $(self).data('visible') +1) { // If last, then goto first
											ul.css(animCss, -( ( $(self).data('visible') ) * 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.
											current = to==itemLength- $(self).data('visible') +1 ?  $(self).data('visible') +1 :  $(self).data('visible') +options.scroll;
									} else current = to;
							} else {                    // If non-circular and to points to first or last, we just return.
								if (to < 0 || to > itemLength -  $(self).data('visible') ) return;
								else current = to;
							}                           // If neither overrides it, the curr will still be "to" and we can proceed.

							running = true;

							ul.animate(
									animCss == "left" ? {left: -(current*liSize)} : {top: -(current*liSize)} , options.speed, options.easing,
									function() {
											if(options.afterEnd)
													options.afterEnd.call(this, vis());
											running = false;
									}
							);
							// Disable buttons when the carousel reaches the last/first, and enable when not
							if(!options.circular) {
									$(options.btnPrev + "," + options.btnNext).removeClass("disabled");
									$( (current-options.scroll<0 && options.btnPrev)
											||
										 (current+options.scroll > itemLength- $(self).data('visible')  && options.btnNext)
											||
										 []
									 ).addClass("disabled");
							}

					}

					return false;
				};
    });

		return this;
};

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);