// Copyright 2017 The Nomulus Authors. All Rights Reserved.
//
// 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.

package google.registry.request.auth;

/**
 * Authentication level.
 *
 * <p>Used by {@link Auth} to specify what authentication is required, and by {@link AuthResult})
 * to specify what authentication was found. These are a series of levels, from least to most
 * authentication required. The lowest level of requirement, NONE, can be satisfied by any level
 * of authentication, while the highest level, USER, can only be satisfied by the authentication of
 * a specific user. The level returned may be higher than what was required, if more authentication
 * turns out to be possible. For instance, if an authenticated user is found, USER will be returned
 * even if no authentication was required.
 */
public enum AuthLevel {

  /** No authentication was required/found. */
  NONE,

  /**
   * Authentication required, but user not required.
   *
   * <p>In Auth: Authentication is required, but app-internal authentication (which isn't associated
   * with a specific user) is permitted.
   *
   * <p>In AuthResult: App-internal authentication was successful.
   */
  APP,

  /**
   * Authentication required, user required.
   *
   * <p>In Auth: Authentication is required, and app-internal authentication is forbidden, meaning
   * that a valid authentication result will contain specific user information.
   *
   * <p>In AuthResult: A valid user was authenticated.
   */
  USER
}