/**
 * Copyright 2013 Facebook, Inc.
 *
 * 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.
 *
 * @providesModule EventListener
 */

/**
 * Upstream version of event listener. Does not take into account specific
 * nature of platform.
 */
var EventListener = {
  /**
   * Listens to bubbled events on a DOM node.
   *
   * @param {Element} el DOM element to register listener on.
   * @param {string} handlerBaseName 'click'/'mouseover'
   * @param {Function!} cb Callback function
   */
  listen: function(el, handlerBaseName, cb) {
    if (el.addEventListener) {
      el.addEventListener(handlerBaseName, cb, false);
    } else if (el.attachEvent) {
      el.attachEvent('on' + handlerBaseName, cb);
    }
  },

  /**
   * Listens to captured events on a DOM node.
   *
   * @see `EventListener.listen` for params.
   * @throws Exception if addEventListener is not supported.
   */
  capture: function(el, handlerBaseName, cb) {
    if (!el.addEventListener) {
      if (__DEV__) {
        console.error(
          'You are attempting to use addEventListener ' +
          'in a browser that does not support it.' +
          'This likely means that you will not receive events that ' +
          'your application relies on (such as scroll).');
      }
      return;
    } else {
      el.addEventListener(handlerBaseName, cb, true);
    }
  }
};

module.exports = EventListener;
