/**
 * 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($) {

$.jCarouselLite = {
  version: '1.3.1'
};

$.fn.jCarouselLite = function(options) {
  var o = $.extend({}, $.fn.jCarouselLite.defaults, options);

  return this.each(function() {

    var running = false,
        animCss=o.vertical?"top":"left",
        aniProps = {},
        sizeCss=o.vertical?"height":"width",
        self = this,
        div = $(this),
        ul = div.find('ul').eq(0),
        tLi = ul.children('li'),
        tl = tLi.length,
        v = o.visible,
        start = Math.min(o.start, tl-1);

    if (o.circular) {
        ul.prepend(tLi.slice(tl-v-1+1).clone(true))
          .append(tLi.slice(0,v).clone(true));
        start += v;
    }
    var li = ul.children('li'),
        itemLength = li.length,
        curr = start;
    div.css("visibility", "visible");

    li.css({overflow: o.vertical ? "hidden" : 'visible', 'float': o.vertical ? "none" : "left"});
    ul.css({margin: "0", padding: "0", position: "relative", listStyleType: "none", zIndex: 1});
    div.css({overflow: "hidden", position: "relative", zIndex: 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({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

    // CHANGED: bind click handlers to prev and next buttons, if set (Karl Swedberg)
    $.each([ 'btnPrev', 'btnNext' ], function(index, btn) {
      if ( o[btn] ) {
        o['$' + btn] = $.isFunction( o[btn] ) ? o[btn].call( div[0] ) : $( o[btn] );

        o['$' + btn].bind('click.jc', function() {
          var step = index == 0 ? curr-o.scroll : curr+o.scroll;
          return go( step );
        });
      }
    });

    if (!o.circular) {
      if (o.btnPrev && start == 0) {
        o.$btnPrev.addClass(o.btnDisabledClass);
      }
      if ( o.btnNext && start + o.visible >= itemLength ) {
        o.$btnNext.addClass(o.btnDisabledClass);
      }
    }
    if (o.btnGo) {
      $.each(o.btnGo, function(i, val) {
        $(val).bind('click.jc', function() {
          return go(o.circular ? o.visible+i : i);
        });
      });
    }

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

    if (o.auto) {
      // CHANGED: Added pause on hover (Karl Swedberg)
      var advanceCounter = 0,
          autoStop = iterations(tl,o);

      var advancer = function() {
        self.setAutoAdvance = setTimeout(function() {

          if (!autoStop || autoStop > advanceCounter) {
            go(curr+o.scroll);
            advanceCounter++;
            advancer();
          }
        }, o.timeout+o.speed);
      };

      advancer();

      div
      .bind('pauseCarousel.jc', function(event) {
        clearTimeout(self.setAutoAdvance);
        div.data('pausedjc', true);
      })
      .bind('resumeCarousel.jc', function(event) {
        advancer();
        div.removeData('pausedjc');
      });

      if (o.pause) {
        div.bind('mouseenter.jc', function() {
          div.trigger('pauseCarousel');
        }).bind('mouseleave.jc', function() {
          div.trigger('resumeCarousel');
        });
      }
    }

    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<=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==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;
          }

        // If non-circular and to points beyond first or last, we change to first or last.
        } else {
          // Disable buttons when the carousel reaches the last/first, and enable when not
          o.$btnPrev.toggleClass(o.btnDisabledClass, o.btnPrev && to <= 0);
          o.$btnNext.toggleClass(o.btnDisabledClass, o.btnNext && to > itemLength-v);

          if (to<0) {
            curr = 0;
          } else if (to>itemLength-v) {
            curr = itemLength-v;
          } else {
            curr = to;
          }
        }

        running = true;
        aniProps[animCss] = -(curr*liSize);

        ul.animate(aniProps, o.speed, o.easing, function() {
          if (o.afterEnd) {
            o.afterEnd.call(this, vis());
          }
          running = false;
        });

      }
      return false;
    } // end if !running

    div.bind('endCarousel.jc', function() {
      if (self.setAutoAdvance) {
        clearTimeout(self.setAutoAdvance);
      }
      if (o.btnPrev) {
        o[$btnPrev].addClass(o.btnDisabledClass).unbind('.jc');
      }
      if (o.btnNext) {
        o[$btnNext].addClass(o.btnDisabledClass).unbind('.jc');
      }
      if (o.btnGo) {
        $.each(o.btnGo, function(i, val) {
          $(val).unbind('.jc');
        });
      }
      if (self.setAutoAdvance) {
        self.setAutoAdvance = null;
      }
      div.removeData('pausejc');
      div.unbind('.jc');
    });
  });
};
$.fn.jCarouselLite.defaults = {
  btnPrev: null,
  btnNext: null,
  btnDisabledClass: 'disabled',
  btnGo: null,
  mouseWheel: false,

  speed: 200,
  easing: null,
  auto: false, // true to enable auto scrolling
  autoStop: false, // number of times before autoscrolling will stop. (if circular is false, won't iterate more than number of items)
  timeout: 4000, // milliseconds between scrolls
  pause: true, // pause scrolling on hover

  vertical: false,
  circular: true, // continue scrolling when reach the last item
  visible: 3,
  start: 0, // index of item to show initially in the first posiition
  scroll: 1, // number of items to scroll at a time

  beforeStart: null,
  afterEnd: null
};

function css(el, prop) {
  return parseInt($.css(el[0], prop), 10) || 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');
}
function iterations(itemLength, options) {
  return options.autoStop && (options.circular ? options.autoStop : Math.min(itemLength, options.autoStop));
}
})(jQuery);