// Sticky Plugin v1.0.4 for jQuery
// =============
// Author: Anthony Garand
// Improvements by German M. Bravo (Kronuz) and Ruud Kamphuis (ruudk)
// Improvements by Leonardo C. Daronco (daronco)
// Created: 02/14/2011
// Date: 07/20/2015
// Website: http://stickyjs.com/
// 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 (factory) {
  if (typeof define === 'function' && define.amd) {
      // AMD. Register as an anonymous module.
      define(['jquery'], factory);
  } else if (typeof module === 'object' && module.exports) {
      // Node/CommonJS
      module.exports = factory(require('jquery'));
  } else {
      // Browser globals
      factory(jQuery);
  }
}(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,
    zIndex: 'inherit'
  },
  $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, l = sticked.length; i < l; i++) {
      var s = sticked[i],
        elementTop = s.stickyWrapper.offset().top,
        etse = elementTop - s.topSpacing - extra;

      //update height in case of dynamic content
      s.stickyWrapper.css('height', s.stickyElement.outerHeight());

      if (scrollTop <= etse) {
        if (s.currentTop !== null) {
          s.stickyElement
            .css({
              'width': '',
              'position': '',
              'top': '',
              'z-index': ''
            });
          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) {
              padding =  s.stickyElement.innerWidth() - s.stickyElement.width();
              newWidth = $(s.getWidthFrom).width() - padding || 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)
            .css('z-index', s.zIndex);

          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;
        }

        // Check if sticky has reached end of container and stop sticking
        var stickyWrapperContainer = s.stickyWrapper.parent();
        var unstick = (s.stickyElement.offset().top + s.stickyElement.outerHeight() >= stickyWrapperContainer.offset().top + stickyWrapperContainer.outerHeight()) && (s.stickyElement.offset().top <= s.topSpacing);

        if( unstick ) {
          s.stickyElement
            .css('position', 'absolute')
            .css('top', '')
            .css('bottom', 0)
            .css('z-index', '');
        } else {
          s.stickyElement
            .css('position', 'fixed')
            .css('top', newTop)
            .css('bottom', '')
            .css('z-index', s.zIndex);
        }
      }
    }
  },
  resizer = function() {
    windowHeight = $window.height();

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

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

        stickyElement.wrapAll(function() {
          if ($(this).parent("#" + wrapperId).length == 0) {
                  return 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"});
        }

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

        sticked.push(o);

        methods.setWrapperHeight(this);
        methods.setupChangeListeners(this);
      });
    },

    setWrapperHeight: function(stickyElement) {
      var element = $(stickyElement);
      var stickyWrapper = element.parent();
      if (stickyWrapper) {
        stickyWrapper.css('height', element.outerHeight());
      }
    },

    setupChangeListeners: function(stickyElement) {
      if (window.MutationObserver) {
        var mutationObserver = new window.MutationObserver(function(mutations) {
          if (mutations[0].addedNodes.length || mutations[0].removedNodes.length) {
            methods.setWrapperHeight(stickyElement);
          }
        });
        mutationObserver.observe(stickyElement, {subtree: true, childList: true});
      } else {
        if (window.addEventListener) {
          stickyElement.addEventListener('DOMNodeInserted', function() {
            methods.setWrapperHeight(stickyElement);
          }, false);
          stickyElement.addEventListener('DOMNodeRemoved', function() {
            methods.setWrapperHeight(stickyElement);
          }, false);
        } else if (window.attachEvent) {
          stickyElement.attachEvent('onDOMNodeInserted', function() {
            methods.setWrapperHeight(stickyElement);
          });
          stickyElement.attachEvent('onDOMNodeRemoved', function() {
            methods.setWrapperHeight(stickyElement);
          });
        }
      }
    },
    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': '',
              'z-index': ''
            })
          ;
        }
      });
    }
  };

// 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);
});
}));
