/**
 * Copyright (c) Istituto Nazionale di Fisica Nucleare (INFN). 2006-2016
 *
 * 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 org.glite.security.voms.admin.operations.groups;

import java.util.Iterator;
import java.util.List;

import org.glite.security.voms.admin.event.EventManager;
import org.glite.security.voms.admin.event.user.membership.UserRemovedFromGroupEvent;
import org.glite.security.voms.admin.operations.BaseVomsOperation;
import org.glite.security.voms.admin.operations.VOMSContext;
import org.glite.security.voms.admin.operations.VOMSPermission;
import org.glite.security.voms.admin.operations.users.FindUserOperation;
import org.glite.security.voms.admin.persistence.dao.VOMSUserDAO;
import org.glite.security.voms.admin.persistence.error.NoSuchGroupException;
import org.glite.security.voms.admin.persistence.error.NoSuchUserException;
import org.glite.security.voms.admin.persistence.model.VOMSGroup;
import org.glite.security.voms.admin.persistence.model.VOMSUser;

public class RemoveMemberOperation extends BaseVomsOperation {

  VOMSUser user;

  VOMSGroup group;

  private RemoveMemberOperation(VOMSUser u, VOMSGroup g) {

    user = u;
    group = g;

  }

  protected Object doExecute() {

    // Remove from children group first, if there are some

    List childrenGroups = (List) ListChildrenGroupsOperation.instance(group)
      .execute();

    Iterator i = childrenGroups.iterator();

    while (i.hasNext()) {
      VOMSGroup childGroup = (VOMSGroup) i.next();
      if (user.isMember(childGroup))
        instance(user, childGroup).execute();
    }

    VOMSUserDAO.instance().removeFromGroup(user, group);

    EventManager.instance().dispatch(new UserRemovedFromGroupEvent(user, group));

    return null;
  }

  public static RemoveMemberOperation instance(VOMSUser u, VOMSGroup g) {

    return new RemoveMemberOperation(u, g);
  }

  public static RemoveMemberOperation instance(String groupName,
    String username, String caDn) {

    VOMSUser u = (VOMSUser) FindUserOperation.instance(username, caDn)
      .execute();
    VOMSGroup g = (VOMSGroup) FindGroupOperation.instance(groupName).execute();

    if (u == null)
      throw new NoSuchUserException("User '" + username + "," + caDn
        + "' not found in this vo.");

    if (g == null)
      throw new NoSuchGroupException("Group '" + groupName
        + "' does not exist in this vo.");

    return new RemoveMemberOperation(u, g);

  }

  protected void setupPermissions() {

    addRequiredPermission(VOMSContext.instance(group.getParent()),
      VOMSPermission.getContainerReadPermission());
    addRequiredPermission(VOMSContext.instance(group), VOMSPermission
      .getMembershipRWPermissions().setContainerReadPermission());
  }

}