/*
    * 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.log4j.net;
  
  import java.net.ServerSocket;
  import java.net.Socket;
  import java.util.List;
  import java.util.Vector;
  
  import org.apache.log4j.plugins.Pauseable;
  import org.apache.log4j.plugins.Plugin;
  import org.apache.log4j.plugins.Receiver;
  import org.apache.log4j.spi.LoggerRepository;
  import org.apache.log4j.spi.LoggingEvent;
  
  
  /**
    XMLSocketReceiver receives a remote logging event via XML on a configured
    socket and "posts" it to a LoggerRepository as if the event were
    generated locally. This class is designed to receive events from
    the XMLSocketAppender class (or classes that send compatible events).
    <p>
    This receiver supports log files created using log4j's XMLLayout, as well as java.util.logging
    XMLFormatter (via the org.apache.log4j.spi.Decoder interface).
    <p>
    By default, log4j's XMLLayout is supported (no need to specify a decoder in that case).
    <p>
    To configure this receiver to support java.util.logging's XMLFormatter, specify a 'decoder' param
    of org.apache.log4j.xml.UtilLoggingXMLDecoder.
    <p>
    Once the event has been "posted", it will be handled by the
    appenders currently configured in the LoggerRespository.
  
    @author Mark Womack
    @author Scott Deboy &lt;sdeboy@apache.org&gt;
  
  */
  public class XMLSocketReceiver extends Receiver implements Runnable, PortBased, Pauseable {
    private boolean paused;
    //default to log4j xml decoder
    protected String decoder = "org.apache.log4j.xml.XMLDecoder";
    private ServerSocket serverSocket;
    private List socketList = new Vector();
    private Thread rThread;
    public static final int DEFAULT_PORT = 4448;
    protected int port = DEFAULT_PORT;
    private boolean advertiseViaMulticastDNS;
    private ZeroConfSupport zeroConf;
  
    /**
     * The MulticastDNS zone advertised by an XMLSocketReceiver
     */
    public static final String ZONE = "_log4j_xml_tcpaccept_receiver.local.";
  
    /*
     * Log4j doesn't provide an XMLSocketAppender, but the MulticastDNS zone that should be advertised by one is:
     * _log4j_xml_tcpconnect_appender.local.
     */
  
    public XMLSocketReceiver() {
    }
  
    public XMLSocketReceiver(int _port) {
      port = _port;
    }
  
    public XMLSocketReceiver(int _port, LoggerRepository _repository) {
      port = _port;
      repository = _repository;
    }
  
    /**
      Get the port to receive logging events on. */
    public int getPort() {
      return port;
    }
  
    /**
      Set the port to receive logging events on. */
    public void setPort(int _port) {
      port = _port;
    }
  
    public String getDecoder() {
     return decoder;
   }
 
   /**
    *Specify the class name implementing org.apache.log4j.spi.Decoder that can process the file.
    */
   public void setDecoder(String _decoder) {
     decoder = _decoder;
   }
 
   public boolean isPaused() {
     return paused;
   }
 
   public void setPaused(boolean b) {
     paused = b;
   }
 
   /**
    * Returns true if the receiver is the same class and they are
    * configured for the same properties, and super class also considers
    * them to be equivalent. This is used by PluginRegistry when determining
    * if the a similarly configured receiver is being started.
    * 
    * @param testPlugin The plugin to test equivalency against.
    * @return boolean True if the testPlugin is equivalent to this plugin.
    */
   public boolean isEquivalent(Plugin testPlugin) {
     if ((testPlugin != null) && testPlugin instanceof XMLSocketReceiver) {
       XMLSocketReceiver sReceiver = (XMLSocketReceiver) testPlugin;
 
       return (port == sReceiver.getPort() && super.isEquivalent(testPlugin));
     }
 
     return false;
   }
 
   public int hashCode() {
   	
   	int result = 37 * (repository != null? repository.hashCode():0);
   	result = result * 37 + port;
   	return (result * 37 + (getName() != null? getName().hashCode():0));
   }
 
   /**
     Sets the flag to indicate if receiver is active or not.
    @param b new value
    */
   protected synchronized void setActive(final boolean b) {
     active = b;
   }
 
   /**
     Starts the SocketReceiver with the current options. */
   public void activateOptions() {
     if (!isActive()) {
       rThread = new Thread(this);
       rThread.setDaemon(true);
       rThread.start();
 
       if (advertiseViaMulticastDNS) {
         zeroConf = new ZeroConfSupport(ZONE, port, getName());
         zeroConf.advertise();
       }
 
       active = true;
     }
   }
 
   public void setAdvertiseViaMulticastDNS(boolean advertiseViaMulticastDNS) {
     this.advertiseViaMulticastDNS = advertiseViaMulticastDNS;
   }
 
   public boolean isAdvertiseViaMulticastDNS() {
     return advertiseViaMulticastDNS;
   }
 
   /**
     Called when the receiver should be stopped. Closes the
     server socket and all of the open sockets. */
   public synchronized void shutdown() {
     // mark this as no longer running
     active = false;
 
     if (rThread != null) {
       rThread.interrupt();
       rThread = null;
     }
     doShutdown();
   }
 
     /**
      * Does the actual shutting down by closing the server socket
      * and any connected sockets that have been created.
      */
     private synchronized void doShutdown() {
       active = false;
 
       getLogger().debug("{} doShutdown called", getName());
 
       // close the server socket
       closeServerSocket();
 
       // close all of the accepted sockets
       closeAllAcceptedSockets();
 
       if (advertiseViaMulticastDNS) {
           zeroConf.unadvertise();
       }
     }
 
     /**
       * Closes the server socket, if created.
       */
      private void closeServerSocket() {
        getLogger().debug("{} closing server socket", getName());
 
        try {
          if (serverSocket != null) {
            serverSocket.close();
          }
        } catch (Exception e) {
          // ignore for now
        }
 
        serverSocket = null;
      }
 
     /**
       * Closes all the connected sockets in the List.
       */
      private synchronized void closeAllAcceptedSockets() {
        for (int x = 0; x < socketList.size(); x++) {
          try {
            ((Socket) socketList.get(x)).close();
          } catch (Exception e) {
            // ignore for now
          }
        }
 
        // clear member variables
        socketList.clear();
      }
 
   /**
     Loop, accepting new socket connections. */
   public void run() {
       /**
         * Ensure we start fresh.
         */
     getLogger().debug("performing socket cleanup prior to entering loop for {}",  name);
     closeServerSocket();
     closeAllAcceptedSockets();
     getLogger().debug("socket cleanup complete for {}", name);       
     active = true;
 
     // start the server socket
     try {
       serverSocket = new ServerSocket(port);
     } catch (Exception e) {
       getLogger().error(
         "error starting SocketReceiver (" + this.getName()
         + "), receiver did not start", e);
       active = false;
       doShutdown();
 
       return;
     }
 
     Socket socket = null;
 
     try {
       getLogger().debug("in run-about to enter while isactiveloop");
 
       active = true;
 
       while (!rThread.isInterrupted()) {
         // if we have a socket, start watching it
         if (socket != null) {
           getLogger().debug("socket not null - creating and starting socketnode");
           socketList.add(socket);
 
           XMLSocketNode node = new XMLSocketNode(decoder, socket, this);
           node.setLoggerRepository(this.repository);
           new Thread(node).start();
           socket = null;
         }
 
         getLogger().debug("waiting to accept socket");
 
         // wait for a socket to open, then loop to start it
         socket = serverSocket.accept();
         getLogger().debug("accepted socket");
       }
 
       // socket not watched because we a no longer running
       // so close it now.
       if (socket != null) {
         socket.close();
       }
     } catch (Exception e) {
       getLogger().warn(
         "socket server disconnected, stopping");
     }
   }
 
   /* (non-Javadoc)
    * @see org.apache.log4j.plugins.Receiver#doPost(org.apache.log4j.spi.LoggingEvent)
    */
   public void doPost(LoggingEvent event) {
     if(!isPaused()){
       super.doPost(event);
     }
   }
 
 
 }