text: // clang-format off
  
  /*
   * Firebase UI Bindings iOS Library
   *
   * Copyright © 2015 Firebase - All Rights Reserved
   * https://www.firebase.com
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice, this
   * list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binaryform must reproduce the above copyright notice,
   * this list of conditions and the following disclaimer in the documentation
   * and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY FIREBASE AS IS AND ANY EXPRESS OR
   * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
   * EVENT SHALL FIREBASE BE LIABLE FOR ANY DIRECT,
   * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
   * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  // clang-format on
  
  #import <Firebase/Firebase.h>
  
  /**
   * A protocol that defines the contract of authentication state changes from a
   * Firebase database reference.
   */
  @protocol FirebaseAuthDelegate<NSObject>
  
  @required
  /**
   * Method that fires when a user is logged in via any provider. Information about the provider comes
   * through the authProvider.
   * @param provider An instance of FirebaseAuthProvider which contains information about the provider
   * @param authData A class that implements the FirebaseAuthDelegate protocol
   * @return void
   */
  - (void)authProvider:(id)provider onLogin:(FAuthData *)authData;
  
  /**
   * Method that fires when a user is logged out of the current authentication provider.
   * @return void
   */
  - (void)onLogout;
  
  @optional
  /**
   * Method that fires when authentication fails due to an error on the provider side.
   * This could include Firebase authentication (provider incorrectly set up in the Firebase
   * Dashboard)
   * or issues with the provider itself (provider is down, incorrectly provisioned, etc.).
   * @param provider An instance of FirebaseAuthProvider which contains information about the provider
   * @param error
   * @return void
   */
  - (void)authProvider:(id)provider onProviderError:(NSError *)error;
  
  /**
   * Method that fires when authentication fails due to an error on the user side.
   * This could include incorrect email/password, or a user canceling an authentication request
   * with an identity provider.
   * @param provider An instance of FirebaseAuthProvider which contains information about the provider
   * @param error
   * @return void
   */
  - (void)authProvider:(id)provider onUserError:(NSError *)error;
  
  @end
  