# MembersGroupRemovalFromRoleListener.java

    /*
     * Copyright (C) 2000 - 2025 Silverpeas
     *
     * This program is free software: you can redistribute it and/or modify
     * it under the terms of the GNU Affero General Public License as
     * published by the Free Software Foundation, either version 3 of the
     * License, or (at your option) any later version.
     *
     * As a special exception to the terms and conditions of version 3.0 of
     * the GPL, you may redistribute this Program in connection with Free/Libre
     * Open Source Software ("FLOSS") applications as described in Silverpeas's
     * FLOSS exception.  You should have received a copy of the text describing
     * the FLOSS exception, and it is also available here:
     * "https://www.silverpeas.org/legal/floss_exception.html"
     *
     * This program is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     * GNU Affero General Public License for more details.
     *
     * You should have received a copy of the GNU Affero General Public License
     * along with this program.  If not, see <https://www.gnu.org/licenses/>.
     */

    package org.silverpeas.components.community.model;

    import org.silverpeas.components.community.repository.CommunityOfUsersRepository;
    import org.silverpeas.core.admin.service.AdminException;
    import org.silverpeas.core.admin.service.Administration;
    import org.silverpeas.core.admin.space.SpaceInst;
    import org.silverpeas.core.admin.space.notification.SpaceProfileInstEvent;
    import org.silverpeas.core.admin.user.model.SilverpeasRole;
    import org.silverpeas.core.admin.user.model.User;
    import org.silverpeas.core.annotation.Bean;
    import org.silverpeas.core.notification.system.CDIResourceEventListener;
    import org.silverpeas.kernel.SilverpeasRuntimeException;
    import org.silverpeas.kernel.annotation.Technical;

    import javax.inject.Inject;

    /**
     * A listener of events about the removing of a group of users from a space role profile. The goal
     * is to detect any attempts to remove a group of community members from its community in order to
     * restore it automatically. It is a workaround until such removal becomes impossible in Silverpeas
     * Core. The group of members are put by default in the reader role of a community space and hence
     * the check is done for any update of this role for a community. Thus, any other roles aren't
     * considered even if the group of members has been added/removed in those roles.
     *
     * @author mmoquillon
     */
    @Technical
    @Bean
    public class MembersGroupRemovalFromRoleListener extends CDIResourceEventListener<SpaceProfileInstEvent> {

      @Inject
      private Administration admin;

      @Inject
      private CommunityOfUsersRepository repository;

      @Override
      public void onUpdate(SpaceProfileInstEvent event) {
        var spaceProfileBefore = event.getTransition().getBefore();
        // nothing to do if the role concerned by the update isn't the reader one. Indeed, the group
        // of community members is put in this role by rule and it is from this role the group must
        // not to be removed
        if (!spaceProfileBefore.getName().equals(SilverpeasRole.READER.getName())) {
          return;
        }
        var spaceProfileAfter = event.getTransition().getAfter();
        String spaceId = SpaceInst.SPACE_KEY_PREFIX + spaceProfileBefore.getSpaceFatherId();
        var groupsBefore = spaceProfileBefore.getAllGroups();
        var groupsAfter = spaceProfileAfter.getAllGroups();
        repository.getBySpaceId(spaceId)
            .flatMap(communityOfUsers ->
                communityOfUsers.getCommunitySpace().getMembersGroup()
                    .flatMap(g -> groupsBefore.stream()
                        .filter(id -> id.equals(g.getId()))
                        .filter(id -> !groupsAfter.contains(id))
                        .findFirst())).ifPresent(id -> execute(() -> {
              spaceProfileAfter.addGroup(id);
              admin.updateSpaceProfileInst(spaceProfileAfter, User.getSystemUser().getId());
            }));
      }

      private void execute(AdminOperation operation) {
        try {
          operation.perform();
        } catch (AdminException e) {
          throw new SilverpeasRuntimeException("Unexpected error: " + e.getMessage());
        }
      }

      @FunctionalInterface
      private interface AdminOperation {

        void perform() throws AdminException;
      }
    }