/**
 * @license
 * Copyright 2015 Google Inc. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

(function() {
  'use strict';

  /**
   * Class constructor for Button MDL component.
   * Implements MDL component design pattern defined at:
   * https://github.com/jasonmayes/mdl-component-design-pattern
   *
   * @param {HTMLElement} element The element that will be upgraded.
   */
  var MaterialButton = function MaterialButton(element) {
    this.element_ = element;

    // Initialize instance.
    this.init();
  };
  window['MaterialButton'] = MaterialButton;

  /**
   * Store constants in one place so they can be updated easily.
   *
   * @enum {string | number}
   * @private
   */
  MaterialButton.prototype.Constant_ = {
    // None for now.
  };

  /**
   * Store strings for class names defined by this component that are used in
   * JavaScript. This allows us to simply change it in one place should we
   * decide to modify at a later date.
   *
   * @enum {string}
   * @private
   */
  MaterialButton.prototype.CssClasses_ = {
    RIPPLE_EFFECT: 'mdl-js-ripple-effect',
    RIPPLE_CONTAINER: 'mdl-button__ripple-container',
    RIPPLE: 'mdl-ripple'
  };

  /**
   * Handle blur of element.
   *
   * @param {Event} event The event that fired.
   * @private
   */
  MaterialButton.prototype.blurHandler_ = function(event) {
    if (event) {
      this.element_.blur();
    }
  };

  // Public methods.

  /**
   * Disable button.
   *
   * @public
   */
  MaterialButton.prototype.disable = function() {
    this.element_.disabled = true;
  };
  MaterialButton.prototype['disable'] = MaterialButton.prototype.disable;

  /**
   * Enable button.
   *
   * @public
   */
  MaterialButton.prototype.enable = function() {
    this.element_.disabled = false;
  };
  MaterialButton.prototype['enable'] = MaterialButton.prototype.enable;

  /**
   * Initialize element.
   */
  MaterialButton.prototype.init = function() {
    if (this.element_) {
      if (this.element_.classList.contains(this.CssClasses_.RIPPLE_EFFECT)) {
        var rippleContainer = document.createElement('span');
        rippleContainer.classList.add(this.CssClasses_.RIPPLE_CONTAINER);
        this.rippleElement_ = document.createElement('span');
        this.rippleElement_.classList.add(this.CssClasses_.RIPPLE);
        rippleContainer.appendChild(this.rippleElement_);
        this.boundRippleBlurHandler = this.blurHandler_.bind(this);
        this.rippleElement_.addEventListener('mouseup', this.boundRippleBlurHandler);
        this.element_.appendChild(rippleContainer);
      }
      this.boundButtonBlurHandler = this.blurHandler_.bind(this);
      this.element_.addEventListener('mouseup', this.boundButtonBlurHandler);
      this.element_.addEventListener('mouseleave', this.boundButtonBlurHandler);
    }
  };

  /**
   * Downgrade the element.
   *
   * @private
   */
  MaterialButton.prototype.mdlDowngrade_ = function() {
    if (this.rippleElement_) {
      this.rippleElement_.removeEventListener('mouseup', this.boundRippleBlurHandler);
    }
    this.element_.removeEventListener('mouseup', this.boundButtonBlurHandler);
    this.element_.removeEventListener('mouseleave', this.boundButtonBlurHandler);
  };

  /**
   * Public alias for the downgrade method.
   *
   * @public
   */
  MaterialButton.prototype.mdlDowngrade =
      MaterialButton.prototype.mdlDowngrade_;

  MaterialButton.prototype['mdlDowngrade'] =
      MaterialButton.prototype.mdlDowngrade;

  // The component registers itself. It can assume componentHandler is available
  // in the global scope.
  componentHandler.register({
    constructor: MaterialButton,
    classAsString: 'MaterialButton',
    cssClass: 'mdl-js-button',
    widget: true
  });
})();