/**
    * Copyright 2005-2006 the original author or authors.
    *
    * Licensed under the Gnu General Pubic 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.opensource.org/licenses/gpl-license.php
    *
   * 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 General Public License for more details.
   */
  package org.figure8.join.core.messaging;
  
  import org.figure8.join.core.setup.ActiveMQConfigurator;
  import org.figure8.join.util.LogUtil;
  
  import org.apache.commons.logging.Log;
  import org.activemq.broker.BrokerContainer;
  import org.activemq.broker.BrokerConnector;
  import org.activemq.broker.impl.BrokerContainerImpl;
  import org.activemq.spring.BrokerFactoryBean;
  import org.activemq.spring.SpringBrokerContainerFactory;
  import org.activemq.transport.TransportServerChannel;
  import org.activemq.transport.tcp.TcpTransportServerChannel;
  
  import java.net.URI;
  import java.util.List;
  /**
   * This factory is an extension of the Spring <code>BrokerFactory</code>
   * provided by ActiveMQ. This configurable broker factory only creates broker
   * if we are on the asynchronous side of the application. It also replaces
   * the URL of the TCP transport layer provided into the configuration file by
   * the one configured by application administrator (during the setup process,
   * through the <code>ActiveMQConfigurator</code> helper object).
   *
   * @see org.figure8.join.core.setup.ApplicationConfig
   * @see org.figure8.join.core.setup.ActiveMQConfigurator
   *
   * @author <a href="mailto:laurent.broudoux@free.fr">Laurent Broudoux</a>
   * @version $Revision: 1.3 $
   */
  public class ConfigurableBrokerFactoryBean extends BrokerFactoryBean{
  
     // Static -------------------------------------------------------------------
  
     /** Get a commons logger. */
     private static Log log = LogUtil.getLog(ConfigurableBrokerFactoryBean.class);
  
  
     // Attributes ---------------------------------------------------------------
  
     /** The wrapped ActiveMQ broker container. */
     protected BrokerContainer broker = null;
     /** Helper object for configuring ActiveMQ connection factory. */
     private ActiveMQConfigurator configurator = null;
  
  
     // Public -------------------------------------------------------------------
  
     /** @param configurator Helper for configuring connection factory */
     public void setActiveMQConfigurator(ActiveMQConfigurator configurator){
        this.configurator = configurator;
     }
  
  
     // Protected ----------------------------------------------------------------
  
     /**
      * Update the url of the TCP trasnport server channel of the
      * previously created borker. This later is replaced with the one
      * coming from {@link ActiveMQConfigurator}.
      */
     protected void updateBrokerTransportChannelUrl() throws Exception{
        if (broker != null){
           log.info("Updating the url of Tcp transport channel");
           // Browse the available transport connectors.
           List connectors = broker.getTransportConnectors();
           for (int i=0; i < connectors.size(); i++){
              BrokerConnector connector = (BrokerConnector)connectors.get(i);
              // Find the Tcp server channel.
              TransportServerChannel channel = connector.getServerChannel();
              if (channel instanceof TcpTransportServerChannel){
                 // Get its URL from configurator.
                 String serverUrl = configurator.getActiveMQProperty("brokerURL");
                 URI serverUri = new URI(serverUrl);
                 // Build a new Tcp channel with our URI because existing one cannot be changed.
                 TcpTransportServerChannel tcpChannel = ((TcpTransportServerChannel)channel);
                 TcpTransportServerChannel ourChannel = new TcpTransportServerChannel(tcpChannel.getWireFormat(), serverUri);
                 tcpChannel.stop();
                 // Replace the existing connector by our channel.
                 broker.removeConnector(connector);
                 broker.addConnector(ourChannel);
                 log.info("TcpTransport url is: " + ourChannel.getUrl());
                 break;
              }
           }
       }
    }
 
 
    // Override of BrokerFactoryBean --------------------------------------------
 
    /**
     * We must ovveride this method cause broker container is private
     * into ActiveMQ <code>BrokerFactoryBean</code>.
     * @throws Exception this does not happen (return null if no object)
     * @return The created ActiveMQ broker.
     */
    public Object getObject() throws Exception{
       return broker;
    }
 
    /**
     * Override of broker creation method from ActiveMQ BrokerFactory. This
     * implementation only creates and starts the broker if we are on the
     * asynchronous side of the application. More over, the transport url
     * of the broker is replaced by the one from {@link ActiveMQConfigurator}.
     * @throws Exception IllegalArgumentException if broker factory is not well configured
     */
    public void afterPropertiesSet() throws Exception{
       // Check if we are on asynchronous side of application.
       if (configurator.getApplicationConfig().isAsynchronousSide()){
          log.info("On the asynchronous side of application. Creating broker...");
          if (getConfig() == null)
             throw new IllegalArgumentException("config property must be set");
          // Create broker.
          broker = SpringBrokerContainerFactory.newInstance(getConfig());
          // Update broker transport uri before starting.
          try {updateBrokerTransportChannelUrl();}
          catch (Exception e){
             log.error("Exception while updating the url of the TcpTransport layer");
             log.error("Here's the detailed message: " + e.getMessage());
             throw e;
          }
          broker.start();
       }
       else{
          // Initialize a dummy broker to not get Spring crash on startup...
          broker = new BrokerContainerImpl("dummyBroker");
       }
    }
 
    /**
     * Stop the wrapped broker before destroy. We must ovveride this method
     * cause broker container is private into ActiveMQ <code>BrokerFactoryBean</code>.
     * @throws Exception if something wrong occurs during broker stop
     */
    public void destroy() throws Exception{
       if (broker != null)
          broker.stop();
    }
 }