(function ($, window) {

var offsets = {
  top: 0,
  right: 0,
  bottom: 0,
  left: 0
};

/**
 * Provides displacement of page box
 */

Drupal.settings.displace = {};
Drupal.settings.displace.elements = [];


Drupal.displace = Drupal.displace || {};

/**
 * Attaches the Displace behavior to each element with '.displace' class.
 */
Drupal.behaviors.Displace = {
  attach: function (context, settings) {

    $('.displace').once('displace', function() {
      var $el = $(this);

      var settings = {};
      if ($el.hasClass('displace-top')) settings.top = true;
      if ($el.hasClass('displace-right')) settings.right = true;
      if ($el.hasClass('displace-bottom')) settings.bottom = true;
      if ($el.hasClass('displace-left')) settings.left = true;

      Drupal.settings.displace.elements.push(new Drupal.displace(this, settings));
    });
  }
}

/**
 * Displacement object.
 */
Drupal.displace = function (element, settings) {
  var defaults = {
    top: false,
    right: false,
    bottom: false,
    left: false
  };

  $.extend(this, defaults, settings);

  this.element = element;
}

/**
 * Get all displacement offsets or for one edge only
 */
Drupal.displace.getOffsets = function (refresh, edge) {
  var edge = edge || false;
  if (refresh) {
    var edges = edge ? [edge] : ['top', 'right', 'bottom', 'left'];

    for (e in edges) {
      offsets[edges[e]] = 0;

      for (i in Drupal.settings.displace.elements) {
        var displaceObject = Drupal.settings.displace.elements[i];

        if (displaceObject[edges[e]]) {
          offsets[edges[e]] += displaceObject.getDisplace(edges[e]);
        } 
      }
    }
  }

  return edge ? offsets[edge] : offsets;
}

/**
 * Returns a displacement for given edge
 */
Drupal.displace.prototype.getDisplace = function (edge) {
  var offset = 0;

  switch (edge) {
    case 'left':
    case 'right':
      offset = $(this.element).outerWidth();
      break;
    case 'top':
    case 'bottom':
      offset = $(this.element).outerHeight();
  }

  return offset;
}

})(jQuery, this);