/*
    * 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.logging.log4j.core.net.server;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.nio.charset.Charset;
  import java.util.concurrent.atomic.AtomicReference;
  import javax.jms.JMSException;
  import javax.jms.Message;
  import javax.jms.MessageConsumer;
  import javax.jms.MessageListener;
  import javax.jms.ObjectMessage;
  
  import org.apache.logging.log4j.LoggingException;
  import org.apache.logging.log4j.core.LifeCycle;
  import org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.core.LogEventListener;
  import org.apache.logging.log4j.core.appender.mom.JmsManager;
  import org.apache.logging.log4j.core.net.JndiManager;
  
  /**
   * LogEventListener server that receives LogEvents over a JMS {@link javax.jms.Destination}.
   *
   * @since 2.1
   */
  public class JmsServer extends LogEventListener implements MessageListener, LifeCycle {
  
      private final AtomicReference<State> state = new AtomicReference<>(State.INITIALIZED);
      private final JmsManager jmsManager;
      private MessageConsumer messageConsumer;
  
      public JmsServer(final String connectionFactoryBindingName,
                       final String destinationBindingName,
                       final String username,
                       final String password) {
          final String managerName = JmsServer.class.getName() + '@' + JmsServer.class.hashCode();
          final JndiManager jndiManager = JndiManager.getDefaultManager(managerName);
          jmsManager = JmsManager.getJmsManager(managerName, jndiManager, connectionFactoryBindingName,
              destinationBindingName, username, password);
      }
  
      @Override
      public State getState() {
          return state.get();
      }
  
      @Override
      public void onMessage(final Message message) {
          try {
              if (message instanceof ObjectMessage) {
                  final Object body = ((ObjectMessage) message).getObject();
                  if (body instanceof LogEvent) {
                      log((LogEvent) body);
                  } else {
                      LOGGER.warn("Expected ObjectMessage to contain LogEvent. Got type {} instead.", body.getClass());
                  }
              } else {
                  LOGGER.warn("Received message of type {} and JMSType {} which cannot be handled.", message.getClass(),
                      message.getJMSType());
              }
          } catch (final JMSException e) {
              LOGGER.catching(e);
          }
      }
  
      @Override
      public void initialize() {
      }
  
      @Override
      public void start() {
          if (state.compareAndSet(State.INITIALIZED, State.STARTING)) {
              try {
                  messageConsumer = jmsManager.createMessageConsumer();
                  messageConsumer.setMessageListener(this);
              } catch (final JMSException e) {
                  throw new LoggingException(e);
              }
          }
      }
  
      @Override
     public void stop() {
         try {
             messageConsumer.close();
         } catch (final JMSException ignored) {
         }
         jmsManager.release();
     }
 
     @Override
     public boolean isStarted() {
         return state.get() == State.STARTED;
     }
 
     @Override
     public boolean isStopped() {
         return state.get() == State.STOPPED;
     }
 
     /**
      * Starts and runs this server until the user types "exit" into standard input.
      *
      * @throws IOException
      * @since 2.6
      */
     public void run() throws IOException {
         this.start();
         System.out.println("Type \"exit\" to quit.");
         final BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in, Charset.defaultCharset()));
         while (true) {
             final String line = stdin.readLine();
             if (line == null || line.equalsIgnoreCase("exit")) {
                 System.out.println("Exiting. Kill the application if it does not exit due to daemon threads.");
                 this.stop();
                 return;
             }
         }
     }
 
 }