/**
 * Copyright 2014-2015, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
 * @providesModule ReactComponentEnvironment
 */

'use strict';

var invariant = require('invariant');

var injected = false;

var ReactComponentEnvironment = {

  /**
   * Optionally injectable environment dependent cleanup hook. (server vs.
   * browser etc). Example: A browser system caches DOM nodes based on component
   * ID and must remove that cache entry when this instance is unmounted.
   */
  unmountIDFromEnvironment: null,

  /**
   * Optionally injectable hook for swapping out mount images in the middle of
   * the tree.
   */
  replaceNodeWithMarkupByID: null,

  /**
   * Optionally injectable hook for processing a queue of child updates. Will
   * later move into MultiChildComponents.
   */
  processChildrenUpdates: null,

  injection: {
    injectEnvironment: function(environment) {
      invariant(
        !injected,
        'ReactCompositeComponent: injectEnvironment() can only be called once.'
      );
      ReactComponentEnvironment.unmountIDFromEnvironment =
        environment.unmountIDFromEnvironment;
      ReactComponentEnvironment.replaceNodeWithMarkupByID =
        environment.replaceNodeWithMarkupByID;
      ReactComponentEnvironment.processChildrenUpdates =
        environment.processChildrenUpdates;
      injected = true;
    }
  }

};

module.exports = ReactComponentEnvironment;
