/**
 * Sticky Plugin v1.0.2 for jQuery
 * =======================================
 *
 * Author: Anthony Garand
 *
 * Improvements by German M. Bravo (Kronuz) and Ruud Kamphuis (ruudk)
 * Improvements by Leonardo C. Daronco (daronco)
 * Created: 2/14/2011
 * Date: 16/04/2015
 * Website: http://labs.anthonygarand.com/sticky
 *
 * Description: Makes an element on the page stick on the screen as you scroll
 * It will only set the 'top' and 'position' of your element, you
 * might need to adjust the width in some cases.
 */ 

(function($) {
  var slice = Array.prototype.slice; // save ref to original slice()
  var splice = Array.prototype.splice; // save ref to original slice()

var defaults = {
    topSpacing: 0,
    bottomSpacing: 0,
    className: 'is-sticky',
    wrapperClassName: 'sticky-wrapper',
    center: false,
    getWidthFrom: '',
    widthFromWrapper: true, // works only when .getWidthFrom is empty
    responsiveWidth: false
  },
  $window = $(window),
  $document = $(document),
  sticked = [],
  windowHeight = $window.height(),
  scroller = function() {
    var scrollTop = $window.scrollTop(),
      documentHeight = $document.height(),
      dwh = documentHeight - windowHeight,
      extra = (scrollTop > dwh) ? dwh - scrollTop : 0;

    for (var i = 0; i < sticked.length; i++) {
      var s = sticked[i],
        elementTop = s.stickyWrapper.offset().top,
        etse = elementTop - s.topSpacing - extra;

      if (scrollTop <= etse) {
        if (s.currentTop !== null) {
          s.stickyElement
            .css({
              'width': '',
              'position': '',
              'top': ''
            });
          s.stickyElement.parent().removeClass(s.className);
          s.stickyElement.trigger('sticky-end', [s]);
          s.currentTop = null;
        }
      }
      else {
        var newTop = documentHeight - s.stickyElement.outerHeight()
          - s.topSpacing - s.bottomSpacing - scrollTop - extra;
        if (newTop < 0) {
          newTop = newTop + s.topSpacing;
        } else {
          newTop = s.topSpacing;
        }
        if (s.currentTop != newTop) {
          var newWidth;
          if ( s.getWidthFrom ) {
              newWidth = $(s.getWidthFrom).width() || null;
          }
          else if(s.widthFromWrapper) {
              newWidth = s.stickyWrapper.width();
          }
          if ( newWidth == null ) {
              newWidth = s.stickyElement.width();
          }
          s.stickyElement
            .css('width', newWidth)
            .css('position', 'fixed')
            .css('top', newTop);

          s.stickyElement.parent().addClass(s.className);

          if (s.currentTop === null) {
            s.stickyElement.trigger('sticky-start', [s]);
          } else {
            // sticky is started but it have to be repositioned
            s.stickyElement.trigger('sticky-update', [s]);
          }

          if (s.currentTop === s.topSpacing && s.currentTop > newTop || s.currentTop === null && newTop < s.topSpacing) {
            // just reached bottom || just started to stick but bottom is already reached
            s.stickyElement.trigger('sticky-bottom-reached', [s]);
          } else if(s.currentTop !== null && newTop === s.topSpacing && s.currentTop < newTop) {
            // sticky is started && sticked at topSpacing && overflowing from top just finished
            s.stickyElement.trigger('sticky-bottom-unreached', [s]);
          }

          s.currentTop = newTop;
        }
      }
    }
  },
  resizer = function() {
    windowHeight = $window.height();

    for (var i = 0; i < sticked.length; i++) {
      var s = sticked[i];
      var newWidth = null;
      if ( s.getWidthFrom ) {
          if ( s.responsiveWidth === true ) {
              newWidth = $(s.getWidthFrom).width();
          }
      }
      else if(s.widthFromWrapper) {
          newWidth = s.stickyWrapper.width();
      }
      if ( newWidth != null ) {
          s.stickyElement.css('width', newWidth);
      }
    }
  },
  methods = {
    init: function(options) {
      var o = $.extend({}, defaults, options);
      return this.each(function() {
        var stickyElement = $(this);

        var stickyId = stickyElement.attr('id');
        var stickyHeight = stickyElement.outerHeight();
        var wrapperId = stickyId ? stickyId + '-' + defaults.wrapperClassName : defaults.wrapperClassName
        var wrapper = $('<div></div>')
          .attr('id', wrapperId)
          .addClass(o.wrapperClassName);

        stickyElement.wrapAll(wrapper);

        var stickyWrapper = stickyElement.parent();

        if (o.center) {
          stickyWrapper.css({width:stickyElement.outerWidth(),marginLeft:"auto",marginRight:"auto"});
        }

        if (stickyElement.css("float") == "right") {
          stickyElement.css({"float":"none"}).parent().css({"float":"right"});
        }

        stickyWrapper.css('height', stickyHeight);

        o.stickyElement = stickyElement;
        o.stickyWrapper = stickyWrapper;
        o.currentTop    = null;

        sticked.push(o);
      });
    },
    update: scroller,
    unstick: function(options) {
      return this.each(function() {
        var that = this;
        var unstickyElement = $(that);

        var removeIdx = -1;
        var i = sticked.length;
        while ( i-- > 0 )
        {
          if (sticked[i].stickyElement.get(0) === that)
          {
              splice.call(sticked,i,1);
              removeIdx = i;
          }
        }
        if(removeIdx != -1)
        {
          unstickyElement.unwrap();
          unstickyElement
            .css({
              'width': '',
              'position': '',
              'top': '',
              'float': ''
            })
          ;
        }
      });
    }
  };

// should be more efficient than using $window.scroll(scroller) and $window.resize(resizer):
if (window.addEventListener) {
  window.addEventListener('scroll', scroller, false);
  window.addEventListener('resize', resizer, false);
} else if (window.attachEvent) {
  window.attachEvent('onscroll', scroller);
  window.attachEvent('onresize', resizer);
}

$.fn.sticky = function(method) {
  if (methods[method]) {
    return methods[method].apply(this, slice.call(arguments, 1));
  } else if (typeof method === 'object' || !method ) {
    return methods.init.apply( this, arguments );
  } else {
    $.error('Method ' + method + ' does not exist on jQuery.sticky');
  }
};

$.fn.unstick = function(method) {
  if (methods[method]) {
    return methods[method].apply(this, slice.call(arguments, 1));
  } else if (typeof method === 'object' || !method ) {
    return methods.unstick.apply( this, arguments );
  } else {
    $.error('Method ' + method + ' does not exist on jQuery.sticky');
  }

};
$(function() {
  setTimeout(scroller, 0);
});
})(jQuery);
