/**
 * Copyright (c) 2013 Marc J. Schmidt

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 */
/**
 * Copyright Marc J. Schmidt. See the LICENSE file at the top-level
 * directory of this distribution and at
 * https://github.com/marcj/css-element-queries/blob/master/LICENSE.
 */
;
(function() {

  /**
   * Class for dimension change detection.
   *
   * @param {Element|Element[]|Elements|jQuery} element
   * @param {Function} callback
   *
   * @constructor
   */
  this.ResizeSensor = function(element, callback) {
    /**
     *
     * @constructor
     */
    function EventQueue() {
      this.q = [];
      this.add = function(ev) {
        this.q.push(ev);
      };

      var i, j;
      this.call = function() {
        for (i = 0, j = this.q.length; i < j; i++) {
          this.q[i].call();
        }
      };
    }

    /**
     * @param {HTMLElement} element
     * @param {String}      prop
     * @returns {String|Number}
     */
    function getComputedStyle(element, prop) {
      if (element.currentStyle) {
        return element.currentStyle[prop];
      } else if (window.getComputedStyle) {
        return window.getComputedStyle(element, null).getPropertyValue(prop);
      } else {
        return element.style[prop];
      }
    }

    /**
     *
     * @param {HTMLElement} element
     * @param {Function}    resized
     */
    function attachResizeEvent(element, resized) {
      if (!element.resizedAttached) {
        element.resizedAttached = new EventQueue();
        element.resizedAttached.add(resized);
      } else if (element.resizedAttached) {
        element.resizedAttached.add(resized);
        return;
      }

      element.resizeSensor = document.createElement('div');
      element.resizeSensor.className = 'resize-sensor';
      var style = 'position: absolute; left: 0; top: 0; right: 0; bottom: 0; overflow: scroll; z-index: -1; visibility: hidden;';
      var styleChild = 'position: absolute; left: 0; top: 0;';

      element.resizeSensor.style.cssText = style;
      element.resizeSensor.innerHTML =
        '<div class="resize-sensor-expand" style="' + style + '">' +
        '<div style="' + styleChild + '"></div>' +
        '</div>' +
        '<div class="resize-sensor-shrink" style="' + style + '">' +
        '<div style="' + styleChild + ' width: 200%; height: 200%"></div>' +
        '</div>';
      element.appendChild(element.resizeSensor);

      if (!{fixed: 1, absolute: 1}[getComputedStyle(element, 'position')]) {
        element.style.position = 'relative';
      }

      var expand = element.resizeSensor.childNodes[0];
      var expandChild = expand.childNodes[0];
      var shrink = element.resizeSensor.childNodes[1];
      var shrinkChild = shrink.childNodes[0];

      var lastWidth, lastHeight;

      var reset = function() {
        expandChild.style.width = expand.offsetWidth + 10 + 'px';
        expandChild.style.height = expand.offsetHeight + 10 + 'px';
        expand.scrollLeft = expand.scrollWidth;
        expand.scrollTop = expand.scrollHeight;
        shrink.scrollLeft = shrink.scrollWidth;
        shrink.scrollTop = shrink.scrollHeight;
        lastWidth = element.offsetWidth;
        lastHeight = element.offsetHeight;
      };

      reset();

      var changed = function() {
        if (element.resizedAttached) {
          element.resizedAttached.call();
        }
      };

      var addEvent = function(el, name, cb) {
        if (el.attachEvent) {
          el.attachEvent('on' + name, cb);
        } else {
          el.addEventListener(name, cb);
        }
      };

      var onScroll = function() {
        if (element.offsetWidth != lastWidth || element.offsetHeight != lastHeight) {
          changed();
        }
        reset();
      }

      addEvent(expand, 'scroll', onScroll);
      addEvent(shrink, 'scroll', onScroll);
    }

    var elementType = Object.prototype.toString.call(element);
    var isCollectionTyped = ('[object Array]' === elementType
      || ('[object NodeList]' === elementType)
      || ('[object HTMLCollection]' === elementType)
      || ('undefined' !== typeof jQuery && element instanceof jQuery) //jquery
      || ('undefined' !== typeof Elements && element instanceof Elements) //mootools
    );

    if (isCollectionTyped) {
      var i = 0, j = element.length;
      for (; i < j; i++) {
        attachResizeEvent(element[i], callback);
      }
    } else {
      attachResizeEvent(element, callback);
    }

    this.detach = function() {
      if (isCollectionTyped) {
        var i = 0, j = element.length;
        for (; i < j; i++) {
          ResizeSensor.detach(element[i]);
        }
      } else {
        ResizeSensor.detach(element);
      }
    };
  };

  this.ResizeSensor.detach = function(element) {
    if (element.resizeSensor) {
      element.removeChild(element.resizeSensor);
      delete element.resizeSensor;
      delete element.resizedAttached;
    }
  };

})();