/*! Copyright © 2011 Piotr Rochala (rocha.la)

* Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php)
* and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
*
* Version: 1.3.8
*
*/

(function($) {

$.fn.extend({
  slimScroll: function(options) {

    var defaults = {

      // width in pixels of the visible scroll area
      width : 'auto',

      // height in pixels of the visible scroll area
      height : '250px',

      // width in pixels of the scrollbar and rail
      size : '7px',

      // scrollbar color, accepts any hex/color value
      color: '#000',

      // scrollbar position - left/right
      position : 'right',

      // distance in pixels between the side edge and the scrollbar
      distance : '1px',

      // default scroll position on load - top / bottom / $('selector')
      start : 'top',

      // sets scrollbar opacity
      opacity : .4,

      // enables always-on mode for the scrollbar
      alwaysVisible : false,

      // check if we should hide the scrollbar when user is hovering over
      disableFadeOut : false,

      // sets visibility of the rail
      railVisible : false,

      // sets rail color
      railColor : '#333',

      // sets rail opacity
      railOpacity : .2,

      // whether  we should use jQuery UI Draggable to enable bar dragging
      railDraggable : true,

      // defautlt CSS class of the slimscroll rail
      railClass : 'slimScrollRail',

      // defautlt CSS class of the slimscroll bar
      barClass : 'slimScrollBar',

      // defautlt CSS class of the slimscroll wrapper
      wrapperClass : 'slimScrollDiv',

      // check if mousewheel should scroll the window if we reach top/bottom
      allowPageScroll : false,

      // scroll amount applied to each mouse wheel step
      wheelStep : 20,

      // scroll amount applied when user is using gestures
      touchScrollStep : 200,

      // sets border radius
      borderRadius: '7px',

      // sets border radius of the rail
      railBorderRadius : '7px'
    };

    var o = $.extend(defaults, options);

    // do it for every element that matches selector
    this.each(function(){

    var isOverPanel, isOverBar, isDragg, queueHide, touchDif,
      barHeight, percentScroll, lastScroll,
      divS = '<div></div>',
      minBarHeight = 30,
      releaseScroll = false;

      // used in event handlers and for better minification
      var me = $(this);

      // ensure we are not binding it again
      if (me.parent().hasClass(o.wrapperClass))
      {
          // start from last bar position
          var offset = me.scrollTop();

          // find bar and rail
          bar = me.siblings('.' + o.barClass);
          rail = me.siblings('.' + o.railClass);

          getBarHeight();

          // check if we should scroll existing instance
          if ($.isPlainObject(options))
          {
            // Pass height: auto to an existing slimscroll object to force a resize after contents have changed
            if ( 'height' in options && options.height == 'auto' ) {
              me.parent().css('height', 'auto');
              me.css('height', 'auto');
              var height = me.parent().parent().height();
              me.parent().css('height', height);
              me.css('height', height);
            } else if ('height' in options) {
              var h = options.height;
              me.parent().css('height', h);
              me.css('height', h);
            }

            if ('scrollTo' in options)
            {
              // jump to a static point
              offset = parseInt(o.scrollTo);
            }
            else if ('scrollBy' in options)
            {
              // jump by value pixels
              offset += parseInt(o.scrollBy);
            }
            else if ('destroy' in options)
            {
              // remove slimscroll elements
              bar.remove();
              rail.remove();
              me.unwrap();
              return;
            }

            // scroll content by the given offset
            scrollContent(offset, false, true);
          }

          return;
      }
      else if ($.isPlainObject(options))
      {
          if ('destroy' in options)
          {
              return;
          }
      }

      // optionally set height to the parent's height
      o.height = (o.height == 'auto') ? me.parent().height() : o.height;

      // wrap content
      var wrapper = $(divS)
        .addClass(o.wrapperClass)
        .css({
          position: 'relative',
          overflow: 'hidden',
          width: o.width,
          height: o.height
        });

      // update style for the div
      me.css({
        overflow: 'hidden',
        width: o.width,
        height: o.height
      });

      // create scrollbar rail
      var rail = $(divS)
        .addClass(o.railClass)
        .css({
          width: o.size,
          height: '100%',
          position: 'absolute',
          top: 0,
          display: (o.alwaysVisible && o.railVisible) ? 'block' : 'none',
          'border-radius': o.railBorderRadius,
          background: o.railColor,
          opacity: o.railOpacity,
          zIndex: 90
        });

      // create scrollbar
      var bar = $(divS)
        .addClass(o.barClass)
        .css({
          background: o.color,
          width: o.size,
          position: 'absolute',
          top: 0,
          opacity: o.opacity,
          display: o.alwaysVisible ? 'block' : 'none',
          'border-radius' : o.borderRadius,
          BorderRadius: o.borderRadius,
          MozBorderRadius: o.borderRadius,
          WebkitBorderRadius: o.borderRadius,
          zIndex: 99
        });

      // set position
      var posCss = (o.position == 'right') ? { right: o.distance } : { left: o.distance };
      rail.css(posCss);
      bar.css(posCss);

      // wrap it
      me.wrap(wrapper);

      // append to parent div
      me.parent().append(bar);
      me.parent().append(rail);

      // make it draggable and no longer dependent on the jqueryUI
      if (o.railDraggable){
        bar.bind("mousedown", function(e) {
          var $doc = $(document);
          isDragg = true;
          t = parseFloat(bar.css('top'));
          pageY = e.pageY;

          $doc.bind("mousemove.slimscroll", function(e){
            currTop = t + e.pageY - pageY;
            bar.css('top', currTop);
            scrollContent(0, bar.position().top, false);// scroll content
          });

          $doc.bind("mouseup.slimscroll", function(e) {
            isDragg = false;hideBar();
            $doc.unbind('.slimscroll');
          });
          return false;
        }).bind("selectstart.slimscroll", function(e){
          e.stopPropagation();
          e.preventDefault();
          return false;
        });
      }

      // on rail over
      rail.hover(function(){
        showBar();
      }, function(){
        hideBar();
      });

      // on bar over
      bar.hover(function(){
        isOverBar = true;
      }, function(){
        isOverBar = false;
      });

      // show on parent mouseover
      me.hover(function(){
        isOverPanel = true;
        showBar();
        hideBar();
      }, function(){
        isOverPanel = false;
        hideBar();
      });

      // support for mobile
      me.bind('touchstart', function(e,b){
        if (e.originalEvent.touches.length)
        {
          // record where touch started
          touchDif = e.originalEvent.touches[0].pageY;
        }
      });

      me.bind('touchmove', function(e){
        // prevent scrolling the page if necessary
        if(!releaseScroll)
        {
                    e.originalEvent.preventDefault();
                    }
        if (e.originalEvent.touches.length)
        {
          // see how far user swiped
          var diff = (touchDif - e.originalEvent.touches[0].pageY) / o.touchScrollStep;
          // scroll content
          scrollContent(diff, true);
          touchDif = e.originalEvent.touches[0].pageY;
        }
      });

      // set up initial height
      getBarHeight();

      // check start position
      if (o.start === 'bottom')
      {
        // scroll content to bottom
        bar.css({ top: me.outerHeight() - bar.outerHeight() });
        scrollContent(0, true);
      }
      else if (o.start !== 'top')
      {
        // assume jQuery selector
        scrollContent($(o.start).position().top, null, true);

        // make sure bar stays hidden
        if (!o.alwaysVisible) { bar.hide(); }
      }

      // attach scroll events
      attachWheel(this);

      function _onWheel(e)
      {
        // use mouse wheel only when mouse is over
        if (!isOverPanel) { return; }

        var e = e || window.event;

        var delta = 0;
        if (e.wheelDelta) { delta = -e.wheelDelta/120; }
        if (e.detail) { delta = e.detail / 3; }

        var target = e.target || e.srcTarget || e.srcElement;
        if ($(target).closest('.' + o.wrapperClass).is(me.parent())) {
          // scroll content
          scrollContent(delta, true);
        }

        // stop window scroll
        if (e.preventDefault && !releaseScroll) { e.preventDefault(); }
        if (!releaseScroll) { e.returnValue = false; }
      }

      function scrollContent(y, isWheel, isJump)
      {
        releaseScroll = false;
        var delta = y;
        var maxTop = me.outerHeight() - bar.outerHeight();

        if (isWheel)
        {
          // move bar with mouse wheel
          delta = parseInt(bar.css('top')) + y * parseInt(o.wheelStep) / 100 * bar.outerHeight();

          // move bar, make sure it doesn't go out
          delta = Math.min(Math.max(delta, 0), maxTop);

          // if scrolling down, make sure a fractional change to the
          // scroll position isn't rounded away when the scrollbar's CSS is set
          // this flooring of delta would happened automatically when
          // bar.css is set below, but we floor here for clarity
          delta = (y > 0) ? Math.ceil(delta) : Math.floor(delta);

          // scroll the scrollbar
          bar.css({ top: delta + 'px' });
        }

        // calculate actual scroll amount
        percentScroll = parseInt(bar.css('top')) / (me.outerHeight() - bar.outerHeight());
        delta = percentScroll * (me[0].scrollHeight - me.outerHeight());

        if (isJump)
        {
          delta = y;
          var offsetTop = delta / me[0].scrollHeight * me.outerHeight();
          offsetTop = Math.min(Math.max(offsetTop, 0), maxTop);
          bar.css({ top: offsetTop + 'px' });
        }

        // scroll content
        me.scrollTop(delta);

        // fire scrolling event
        me.trigger('slimscrolling', ~~delta);

        // ensure bar is visible
        showBar();

        // trigger hide when scroll is stopped
        hideBar();
      }

      function attachWheel(target)
      {
        if (window.addEventListener)
        {
          target.addEventListener('DOMMouseScroll', _onWheel, false );
          target.addEventListener('mousewheel', _onWheel, false );
        }
        else
        {
          document.attachEvent("onmousewheel", _onWheel)
        }
      }

      function getBarHeight()
      {
        // calculate scrollbar height and make sure it is not too small
        barHeight = Math.max((me.outerHeight() / me[0].scrollHeight) * me.outerHeight(), minBarHeight);
        bar.css({ height: barHeight + 'px' });

        // hide scrollbar if content is not long enough
        var display = barHeight == me.outerHeight() ? 'none' : 'block';
        bar.css({ display: display });
      }

      function showBar()
      {
        // recalculate bar height
        getBarHeight();
        clearTimeout(queueHide);

        // when bar reached top or bottom
        if (percentScroll == ~~percentScroll)
        {
          //release wheel
          releaseScroll = o.allowPageScroll;

          // publish approporiate event
          if (lastScroll != percentScroll)
          {
              var msg = (~~percentScroll == 0) ? 'top' : 'bottom';
              me.trigger('slimscroll', msg);
          }
        }
        else
        {
          releaseScroll = false;
        }
        lastScroll = percentScroll;

        // show only when required
        if(barHeight >= me.outerHeight()) {
          //allow window scroll
          releaseScroll = true;
          return;
        }
        bar.stop(true,true).fadeIn('fast');
        if (o.railVisible) { rail.stop(true,true).fadeIn('fast'); }
      }

      function hideBar()
      {
        // only hide when options allow it
        if (!o.alwaysVisible)
        {
          queueHide = setTimeout(function(){
            if (!(o.disableFadeOut && isOverPanel) && !isOverBar && !isDragg)
            {
              bar.fadeOut('slow');
              rail.fadeOut('slow');
            }
          }, 1000);
        }
      }

    });

    // maintain chainability
    return this;
  }
});

$.fn.extend({
  slimscroll: $.fn.slimScroll
});

})(jQuery);