define(["exports", "module"], function (exports, module) {
  /**
   * Copyright 2013-2014, Facebook, Inc.
   * All rights reserved.
   *
   * This file contains a modified version of:
   * https://github.com/facebook/react/blob/v0.12.0/src/addons/transitions/ReactTransitionEvents.js
   *
   * This source code is licensed under the BSD-style license found here:
   * https://github.com/facebook/react/blob/v0.12.0/LICENSE
   * An additional grant of patent rights can be found here:
   * https://github.com/facebook/react/blob/v0.12.0/PATENTS
   */

  "use strict";

  var canUseDOM = !!(typeof window !== "undefined" && window.document && window.document.createElement);

  /**
   * EVENT_NAME_MAP is used to determine which event fired when a
   * transition/animation ends, based on the style property used to
   * define that event.
   */
  var EVENT_NAME_MAP = {
    transitionend: {
      transition: "transitionend",
      WebkitTransition: "webkitTransitionEnd",
      MozTransition: "mozTransitionEnd",
      OTransition: "oTransitionEnd",
      msTransition: "MSTransitionEnd"
    },

    animationend: {
      animation: "animationend",
      WebkitAnimation: "webkitAnimationEnd",
      MozAnimation: "mozAnimationEnd",
      OAnimation: "oAnimationEnd",
      msAnimation: "MSAnimationEnd"
    }
  };

  var endEvents = [];

  function detectEvents() {
    var testEl = document.createElement("div");
    var style = testEl.style;

    // On some platforms, in particular some releases of Android 4.x,
    // the un-prefixed "animation" and "transition" properties are defined on the
    // style object but the events that fire will still be prefixed, so we need
    // to check if the un-prefixed events are useable, and if not remove them
    // from the map
    if (!("AnimationEvent" in window)) {
      delete EVENT_NAME_MAP.animationend.animation;
    }

    if (!("TransitionEvent" in window)) {
      delete EVENT_NAME_MAP.transitionend.transition;
    }

    for (var baseEventName in EVENT_NAME_MAP) {
      var baseEvents = EVENT_NAME_MAP[baseEventName];
      for (var styleName in baseEvents) {
        if (styleName in style) {
          endEvents.push(baseEvents[styleName]);
          break;
        }
      }
    }
  }

  if (canUseDOM) {
    detectEvents();
  }

  // We use the raw {add|remove}EventListener() call because EventListener
  // does not know how to remove event listeners and we really should
  // clean up. Also, these events are not triggered in older browsers
  // so we should be A-OK here.

  function addEventListener(node, eventName, eventListener) {
    node.addEventListener(eventName, eventListener, false);
  }

  function removeEventListener(node, eventName, eventListener) {
    node.removeEventListener(eventName, eventListener, false);
  }

  var ReactTransitionEvents = {
    addEndEventListener: function addEndEventListener(node, eventListener) {
      if (endEvents.length === 0) {
        // If CSS transitions are not supported, trigger an "end animation"
        // event immediately.
        window.setTimeout(eventListener, 0);
        return;
      }
      endEvents.forEach(function (endEvent) {
        addEventListener(node, endEvent, eventListener);
      });
    },

    removeEndEventListener: function removeEndEventListener(node, eventListener) {
      if (endEvents.length === 0) {
        return;
      }
      endEvents.forEach(function (endEvent) {
        removeEventListener(node, endEvent, eventListener);
      });
    }
  };

  module.exports = ReactTransitionEvents;
});