/*
    * 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.io.IOException;
  import java.net.ServerSocket;
  import java.net.Socket;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Enumeration;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  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;
  
  
  /**
    SocketReceiver receives a remote logging event on a configured
    socket and "posts" it to a LoggerRepository as if the event was
    generated locally. This class is designed to receive events from
    the SocketAppender class (or classes that send compatible events).
  
    <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 (sdeboy@apache.org)
    @author Paul Smith (psmith@apache.org)
  */
  public class SocketReceiver extends Receiver implements Runnable, PortBased,
    Pauseable {
      /**
       * socket map.
       */
    private Map socketMap = new HashMap();
      /**
       * Paused.
       */
    private boolean paused;
      /**
       * Thread.
       */
    private Thread rThread;
      /**
       * Port.
       */
    protected int port;
      /**
       * Server socket.
       */
    private ServerSocket serverSocket;
      /**
       * Socket list.
       */
    private Vector socketList = new Vector();
  
    /**
     * The MulticastDNS zone advertised by a SocketReceiver
     */
    public static final String ZONE = "_log4j_obj_tcpaccept_receiver.local.";
  
      /**
       * Listener.
       */
    private SocketNodeEventListener listener = null;
      /**
       * Listeners.
       */
    private List listenerList = Collections.synchronizedList(new ArrayList());
    private boolean advertiseViaMulticastDNS;
    private ZeroConfSupport zeroConf;
  
      /**
       * Create new instance.
       */
    public SocketReceiver() {
          super();
   }
 
     /**
      * Create new instance.
      * @param p port
      */
   public SocketReceiver(final int p) {
     super();
     port = p;
   }
 
     /**
      * Create new instance.
      * @param p port
      * @param repo logger repository
      */
   public SocketReceiver(final int p, final LoggerRepository repo) {
     super();
     this.port = p;
     repository = repo;
   }
 
     /** {@inheritDoc} */
   public int getPort() {
     return port;
   }
 
   /** {@inheritDoc} */
   public void setPort(final int p) {
     port = p;
   }
 
   /**
    * 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(final Plugin testPlugin) {
     if ((testPlugin != null) && testPlugin instanceof SocketReceiver) {
       SocketReceiver sReceiver = (SocketReceiver) testPlugin;
 
       return (port == sReceiver.getPort() && super.isEquivalent(testPlugin));
     }
 
     return false;
   }
 
   /**
     Starts the SocketReceiver with the current options. */
   public void activateOptions() {
     if (!isActive()) {
       //      shutdown();
       rThread = new Thread(this);
       rThread.setDaemon(true);
       rThread.start();
       if (advertiseViaMulticastDNS) {
         zeroConf = new ZeroConfSupport(ZONE, port, getName());
         zeroConf.advertise();
       }
 
       active = true;
     }
   }
 
   /**
    * Called when the receiver should be stopped. Closes the
    * server socket and all of the open sockets.
    */
   public synchronized void shutdown() {
     getLogger().debug(getName() + " received shutdown request");
 
     // mark this as no longer running
     active = false;
 
     if (rThread != null) {
       rThread.interrupt();
       rThread = null;
     }
     if (advertiseViaMulticastDNS) {
         zeroConf.unadvertise();
     }
 
     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(getName() + " doShutdown called");
 
     // close the server socket
     closeServerSocket();
 
     // close all of the accepted sockets
     closeAllAcceptedSockets();
   }
 
   /**
    * 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
     socketMap.clear();
     socketList.clear();
   }
 
   /**
     Sets the flag to indicate if receiver is active or not.
    @param b new value
    */
   protected synchronized void setActive(final boolean b) {
     active = b;
   }
 
   public void setAdvertiseViaMulticastDNS(boolean advertiseViaMulticastDNS) {
       this.advertiseViaMulticastDNS = advertiseViaMulticastDNS;
   }
 
   public boolean isAdvertiseViaMulticastDNS() {
       return advertiseViaMulticastDNS;
   }
 
   /**
     Loop, accepting new socket connections. */
   public void run() {
     /**
      * Ensure we start fresh.
      */
     closeServerSocket();
     closeAllAcceptedSockets();
 
     // 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;
 
       return;
     }
 
     Socket socket = null;
 
     try {
       getLogger().debug("in run-about to enter while not interrupted loop");
 
       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);
 
           SocketNode13 node = new SocketNode13(socket, this);
           synchronized (listenerList) {
             for (Iterator iter = listenerList.iterator();
                  iter.hasNext();) {
                 SocketNodeEventListener l =
                         (SocketNodeEventListener) iter.next();
                 node.addSocketNodeEventListener(l);
             }
           }
           socketMap.put(socket, node);
           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");
       }
     } catch (Exception e) {
       getLogger().warn(
         "exception while watching socket server in SocketReceiver ("
         + this.getName() + "), stopping");
     }
 
     getLogger().debug("{} has exited the not interrupted loop", getName());
 
     // socket not watched because we a no longer running
     // so close it now.
     if (socket != null) {
       try {
         socket.close();
       } catch (IOException e1) {
         getLogger().warn("socket exception caught - socket closed");
       }
     }
 
     getLogger().debug("{} is exiting main run loop", getName());
   }
 
   /**
    * Returns a Vector of SocketDetail representing the IP/Domain name
    * of the currently connected sockets that this receiver has
    * been responsible for creating.
    * @return Vector of SocketDetails
    */
   public Vector getConnectedSocketDetails() {
     Vector details = new Vector(socketList.size());
 
     for (Enumeration enumeration = socketList.elements();
          enumeration.hasMoreElements();
             ) {
       Socket socket = (Socket) enumeration.nextElement();
       details.add(
         new SocketDetail(socket, (SocketNode13) socketMap.get(socket)));
     }
 
     return details;
   }
 
   /**
    * Returns the currently configured SocketNodeEventListener that
    * will be automatically set for each SocketNode created.
    * @return SocketNodeEventListener currently configured
    *
    * @deprecated This receiver now supports multiple listeners
    */
   public SocketNodeEventListener getListener() {
     return listener;
   }
 
   /**
    * Adds the listener to the list of listeners to be notified of the
    * respective event.
    * @param l the listener to add to the list
    */
   public void addSocketNodeEventListener(
           final SocketNodeEventListener l) {
     listenerList.add(l);
   }
 
   /**
    * Removes the registered Listener from this instances list of
    * listeners.  If the listener has not been registered, then invoking
    * this method has no effect.
    *
    * @param l the SocketNodeEventListener to remove
    */
   public void removeSocketNodeEventListener(
           final SocketNodeEventListener l) {
     listenerList.remove(l);
   }
 
   /**
    * Sets the SocketNodeEventListener that will be used for each
    * created SocketNode.
    * @param l the listener to set on each creation of a SocketNode
    * @deprecated This receiver now supports multiple listeners and
    * so this method simply removes the listener (if there already)
    * and readds it to the list.
    *
    * The passed listener will also be returned via the getListener()
    * method still, but this is also deprecated
    */
   public void setListener(final SocketNodeEventListener l) {
     removeSocketNodeEventListener(l);
     addSocketNodeEventListener(l);
     this.listener = l;
   }
 
     /** {@inheritDoc} */
   public boolean isPaused() {
     return paused;
   }
 
     /** {@inheritDoc} */
   public void setPaused(final boolean b) {
     paused = b;
   }
 
     /**
      * Socket detail.
      */
   private static final class SocketDetail implements AddressBased, PortBased,
     Pauseable {
       /**
        * Address.
        */
     private String address;
       /**
        * Port.
        */
     private int port;
       /**
        * Socket node.
        */
     private SocketNode13 socketNode;
 
       /**
        * Create new instance.
        * @param socket socket
        * @param node socket node
        */
     private SocketDetail(final Socket socket,
                          final SocketNode13 node) {
       super();
       this.address = socket.getInetAddress().getHostName();
       this.port = socket.getPort();
       this.socketNode = node;
     }
 
       /** {@inheritDoc} */
     public String getAddress() {
       return address;
     }
 
       /** {@inheritDoc} */
     public int getPort() {
       return port;
     }
 
       /** {@inheritDoc} */
     public String getName() {
       return "Socket";
     }
 
       /** {@inheritDoc} */
     public boolean isActive() {
       return true;
     }
 
       /** {@inheritDoc} */
     public boolean isPaused() {
       return socketNode.isPaused();
     }
 
       /** {@inheritDoc} */
     public void setPaused(final boolean b) {
       socketNode.setPaused(b);
     }
   }
     /** {@inheritDoc} */
   public void doPost(final LoggingEvent event) {
     if (!isPaused()) {
       super.doPost(event);
     }
   }
 
 }