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.extensions.secman.delegated.springoauth2.dom;
  
  import java.util.Collection;
  import java.util.List;
  
  import jakarta.annotation.Priority;
  import jakarta.inject.Inject;
  
  import org.springframework.context.event.EventListener;
  import org.springframework.core.annotation.Order;
  import org.jspecify.annotations.Nullable;
  import org.springframework.security.authentication.event.InteractiveAuthenticationSuccessEvent;
  import org.springframework.security.oauth2.core.oidc.user.OidcUser;
  import org.springframework.stereotype.Service;
  
  import org.apache.causeway.applib.annotation.PriorityPrecedence;
  import org.apache.causeway.applib.services.factory.FactoryService;
  import org.apache.causeway.applib.services.iactnlayer.InteractionService;
  import org.apache.causeway.core.config.CausewayConfiguration;
  import org.apache.causeway.extensions.secman.applib.role.dom.ApplicationRoleRepository;
  import org.apache.causeway.extensions.secman.applib.user.dom.ApplicationUser;
  import org.apache.causeway.extensions.secman.applib.user.dom.ApplicationUserRepository;
  import org.apache.causeway.extensions.secman.applib.user.dom.ApplicationUserStatus;
  import org.apache.causeway.extensions.secman.applib.user.dom.mixins.ApplicationUser_addRole;
  import org.apache.causeway.extensions.secman.applib.user.dom.mixins.ApplicationUser_updateEmailAddress;
  
  import lombok.RequiredArgsConstructor;
  
  /**
   * This service automatically creates an {@link ApplicationUser} if an end-user successfully logged in via Oauth.
   *
   * <p>
   *     The initial set of rules are as per {@link CausewayConfiguration.Extensions.Secman.DelegatedUsers.AutoCreatePolicy}
   * </p>
   *
   * @since 2.0 {@index}
   */
  @Service
  @RequiredArgsConstructor(onConstructor_ = {@Inject})
  @Priority(PriorityPrecedence.MIDPOINT)
  public class ApplicationUserAutoCreationService {
  
      private final ApplicationUserRepository applicationUserRepository;
      private final ApplicationRoleRepository applicationRoleRepository;
      private final InteractionService interactionService;
      private final CausewayConfiguration causewayConfiguration;
      private final FactoryService factoryService;
  
      @Order(PriorityPrecedence.MIDPOINT)
      @EventListener(InteractiveAuthenticationSuccessEvent.class)
      public void onApplicationEvent(final InteractiveAuthenticationSuccessEvent event) {
  
          var authentication = event.getAuthentication();
          var principal = authentication.getPrincipal();
          if (!(principal instanceof OidcUser)) {
              return;
          }
  
          var oidcUser = (OidcUser) principal;
          var username = oidcUser.getPreferredUsername();
          var email = oidcUser.getEmail();
  
          var secmanConfig = causewayConfiguration.getExtensions().getSecman().getDelegatedUsers();
          switch (secmanConfig.getAutoCreatePolicy()) {
              case DO_NOT_AUTO_CREATE:
                  break;
              case AUTO_CREATE_AS_LOCKED:
                  create(username, email, secmanConfig.getInitialRoleNames(), ApplicationUserStatus.LOCKED);
                  break;
              case AUTO_CREATE_AS_UNLOCKED:
                  create(username, email, secmanConfig.getInitialRoleNames(), ApplicationUserStatus.UNLOCKED);
                  break;
          }
      }
  
      private void create(final String username, final String email, final List<String> initialRoleNames, final ApplicationUserStatus userStatus) {
          interactionService.runAnonymous(() -> {
              var userIfAny = applicationUserRepository.findByUsername(username);
              if (userIfAny.isEmpty()) {
                  var applicationUser = applicationUserRepository.newDelegateUser(username, userStatus);
                  factoryService.mixin(ApplicationUser_updateEmailAddress.class, applicationUser).act(email);
  
                  if (notEmpty(initialRoleNames)) {
                      for (String initialRoleName : initialRoleNames) {
                          addRoleIfExists(applicationUser, initialRoleName);
                      }
                  }
              }
          });
      }
  
      private void addRoleIfExists(final ApplicationUser applicationUser, final String initialRoleName) {
          applicationRoleRepository.findByName(initialRoleName).ifPresent(role -> {
              factoryService.mixin(ApplicationUser_addRole.class, applicationUser).act(role);
          });
      }
  
      private static boolean notEmpty(final List<String> initialRoleNames) {
          return !isEmpty(initialRoleNames);
      }
  
      private static boolean isEmpty(final @Nullable Collection<?> collection) {
          return collection == null || collection.isEmpty();
      }
  
  }
  