/**
 * @license
 * Copyright 2019 Google LLC
 *
 * 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.
 */

import { FirebaseNamespace } from './public-types';
import { createSubscribe, deepExtend, ErrorFactory } from '@firebase/util';
import { FirebaseAppImpl } from './firebaseApp';
import { createFirebaseNamespaceCore } from './firebaseNamespaceCore';

/**
 * Return a firebase namespace object.
 *
 * In production, this will be called exactly once and the result
 * assigned to the 'firebase' global.  It may be called multiple times
 * in unit tests.
 */
export function createFirebaseNamespace(): FirebaseNamespace {
  const namespace = createFirebaseNamespaceCore(FirebaseAppImpl);
  namespace.INTERNAL = {
    ...namespace.INTERNAL,
    createFirebaseNamespace,
    extendNamespace,
    createSubscribe,
    ErrorFactory,
    deepExtend
  };

  /**
   * Patch the top-level firebase namespace with additional properties.
   *
   * firebase.INTERNAL.extendNamespace()
   */
  function extendNamespace(props: { [prop: string]: unknown }): void {
    deepExtend(namespace, props);
  }

  return namespace;
}

export const firebase = createFirebaseNamespace();