(function(global) {

  'use strict';

  var fabric = global.fabric || (global.fabric = { }),
      piBy2   = Math.PI * 2;

  if (fabric.Ellipse) {
    fabric.warn('fabric.Ellipse is already defined.');
    return;
  }

  /**
   * Ellipse class
   * @class fabric.Ellipse
   * @extends fabric.Object
   * @return {fabric.Ellipse} thisArg
   * @see {@link fabric.Ellipse#initialize} for constructor definition
   */
  fabric.Ellipse = fabric.util.createClass(fabric.Object, /** @lends fabric.Ellipse.prototype */ {

    /**
     * Type of an object
     * @type String
     * @default
     */
    type: 'ellipse',

    /**
     * Horizontal radius
     * @type Number
     * @default
     */
    rx:   0,

    /**
     * Vertical radius
     * @type Number
     * @default
     */
    ry:   0,

    cacheProperties: fabric.Object.prototype.cacheProperties.concat('rx', 'ry'),

    /**
     * Constructor
     * @param {Object} [options] Options object
     * @return {fabric.Ellipse} thisArg
     */
    initialize: function(options) {
      this.callSuper('initialize', options);
      this.set('rx', options && options.rx || 0);
      this.set('ry', options && options.ry || 0);
    },

    /**
     * @private
     * @param {String} key
     * @param {*} value
     * @return {fabric.Ellipse} thisArg
     */
    _set: function(key, value) {
      this.callSuper('_set', key, value);
      switch (key) {

        case 'rx':
          this.rx = value;
          this.set('width', value * 2);
          break;

        case 'ry':
          this.ry = value;
          this.set('height', value * 2);
          break;

      }
      return this;
    },

    /**
     * Returns horizontal radius of an object (according to how an object is scaled)
     * @return {Number}
     */
    getRx: function() {
      return this.get('rx') * this.get('scaleX');
    },

    /**
     * Returns Vertical radius of an object (according to how an object is scaled)
     * @return {Number}
     */
    getRy: function() {
      return this.get('ry') * this.get('scaleY');
    },

    /**
     * Returns object representation of an instance
     * @param {Array} [propertiesToInclude] Any properties that you might want to additionally include in the output
     * @return {Object} object representation of an instance
     */
    toObject: function(propertiesToInclude) {
      return this.callSuper('toObject', ['rx', 'ry'].concat(propertiesToInclude));
    },

    /* _TO_SVG_START_ */
    /**
     * Returns svg representation of an instance
     * @return {Array} an array of strings with the specific svg representation
     * of the instance
     */
    _toSVG: function() {
      return [
        '<ellipse ', 'COMMON_PARTS',
        'cx="0" cy="0" ',
        'rx="', this.rx,
        '" ry="', this.ry,
        '" />\n'
      ];
    },
    /* _TO_SVG_END_ */

    /**
     * @private
     * @param {CanvasRenderingContext2D} ctx context to render on
     */
    _render: function(ctx) {
      ctx.beginPath();
      ctx.save();
      ctx.transform(1, 0, 0, this.ry / this.rx, 0, 0);
      ctx.arc(
        0,
        0,
        this.rx,
        0,
        piBy2,
        false);
      ctx.restore();
      this._renderPaintInOrder(ctx);
    },
  });

  /* _FROM_SVG_START_ */
  /**
   * List of attribute names to account for when parsing SVG element (used by {@link fabric.Ellipse.fromElement})
   * @static
   * @memberOf fabric.Ellipse
   * @see http://www.w3.org/TR/SVG/shapes.html#EllipseElement
   */
  fabric.Ellipse.ATTRIBUTE_NAMES = fabric.SHARED_ATTRIBUTES.concat('cx cy rx ry'.split(' '));

  /**
   * Returns {@link fabric.Ellipse} instance from an SVG element
   * @static
   * @memberOf fabric.Ellipse
   * @param {SVGElement} element Element to parse
   * @param {Function} [callback] Options callback invoked after parsing is finished
   * @return {fabric.Ellipse}
   */
  fabric.Ellipse.fromElement = function(element, callback) {

    var parsedAttributes = fabric.parseAttributes(element, fabric.Ellipse.ATTRIBUTE_NAMES);

    parsedAttributes.left = (parsedAttributes.left || 0) - parsedAttributes.rx;
    parsedAttributes.top = (parsedAttributes.top || 0) - parsedAttributes.ry;
    callback(new fabric.Ellipse(parsedAttributes));
  };
  /* _FROM_SVG_END_ */

  /**
   * Returns {@link fabric.Ellipse} instance from an object representation
   * @static
   * @memberOf fabric.Ellipse
   * @param {Object} object Object to create an instance from
   * @param {function} [callback] invoked with new instance as first argument
   * @return {fabric.Ellipse}
   */
  fabric.Ellipse.fromObject = function(object, callback) {
    return fabric.Object._fromObject('Ellipse', object, callback);
  };

})(typeof exports !== 'undefined' ? exports : this);