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.applib.services.session;
  
  import java.util.Date;
  import java.util.UUID;
  
  /**
   * Defines an API to track the status of the current sessions
   * (&quot;users logged on&quot;) on the system.
   *
   * <p>
   *     Multiple implementations can be registered; all will be called.
   * </p>
   *
   * @since 1.x {@index}
   */
  public interface SessionSubscriber {
  
      enum Type {
          LOGIN,
          LOGOUT
      }
  
      enum CausedBy {
          USER,
          SESSION_EXPIRATION,
          RESTART
      }
  
      /**
       * Callback to log the session.
       *
       * @param type
       * @param username
       * @param date
       * @param causedBy
       * @param sessionGuid - guaranteed to be unique
       * @param httpSessionId - generally expected to be unique, provided to correlate with other logs
       */
      void log(
              Type type,
              String username,
              Date date,
              CausedBy causedBy,
              UUID sessionGuid,
              String httpSessionId);
  
  }
  