content: /*
   *  Licensed to the Apache Software Foundation (ASF) under one
   *  or more contributor license agreements.  See the NOTICE file
   *  distributed with this work for additional information
   *  regarding copyright ownership.  The ASF licenses this file
   *  to you 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 org.apache.causeway.core.security.authentication;
  
  import org.apache.causeway.applib.services.iactnlayer.InteractionContext;
  
  /**
   * Represents an authentication mechanism capable of authenticating certain
   * types of {@link AuthenticationRequest} and returning an {@link InteractionContext}
   * if the credentials are valid.
   *
   * <p>
   *     There can be multiple {@link Authenticator}s registered.  If so, all
   *     Authenticators that can authenticate any given {@link AuthenticationRequest}
   *     must
   * </p>
   *
   * @apiNote This is a framework internal class and so does not constitute a formal API.
   *
   * @since 1.x but refactored in v2 {@index}
   */
  public interface Authenticator {
  
      /**
       * Whether the provided {@link AuthenticationRequest} is recognized by this
       * {@link Authenticator}.
       */
      boolean canAuthenticate(Class<? extends AuthenticationRequest> authenticationRequestClass);
  
      /**
       * Authenticates the provided {@link AuthenticationRequest request},
       * returning a non-null {@link InteractionContext} if valid.
       *
       * @param code
       *            - a hint; is guaranteed by the framework to be unique, but the authenticator decides whether to use it or not.
       */
      InteractionContext authenticate(AuthenticationRequest request, String code);
  
      /**
       * Invalidates this {@link InteractionContext}, meaning that the user will need
       * to log in again to use the application.
       */
      void logout();
  }
  