/*
    * Copyright 2009 Red Hat, Inc.
    *
    * Red Hat 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.jboss.netty.channel.socket.oio;
  
  import static org.jboss.netty.channel.Channels.*;
  
  import java.io.IOException;
  import java.net.InetAddress;
  import java.net.InetSocketAddress;
  import java.net.MulticastSocket;
  import java.net.NetworkInterface;
  import java.net.SocketAddress;
  import java.net.SocketException;
  
  import org.jboss.netty.channel.AbstractChannel;
  import org.jboss.netty.channel.ChannelException;
  import org.jboss.netty.channel.ChannelFactory;
  import org.jboss.netty.channel.ChannelFuture;
  import org.jboss.netty.channel.ChannelPipeline;
  import org.jboss.netty.channel.ChannelSink;
  import org.jboss.netty.channel.socket.DatagramChannel;
  import org.jboss.netty.channel.socket.DatagramChannelConfig;
  import org.jboss.netty.channel.socket.DefaultDatagramChannelConfig;
  
  /**
   *
   * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
   * @author <a href="http://gleamynode.net/">Trustin Lee</a>
   *
   * @version $Rev: 2080 $, $Date: 2010-01-26 18:04:19 +0900 (Tue, 26 Jan 2010) $
   *
   */
  final class OioDatagramChannel extends AbstractChannel
                                  implements DatagramChannel {
  
      final MulticastSocket socket;
      final Object interestOpsLock = new Object();
      private final DatagramChannelConfig config;
      volatile Thread workerThread;
      private volatile InetSocketAddress localAddress;
      volatile InetSocketAddress remoteAddress;
  
      OioDatagramChannel(
              ChannelFactory factory,
              ChannelPipeline pipeline,
              ChannelSink sink) {
  
          super(null, factory, pipeline, sink);
  
          try {
              socket = new MulticastSocket(null);
          } catch (IOException e) {
              throw new ChannelException("Failed to open a datagram socket.", e);
          }
  
          try {
              socket.setSoTimeout(10);
              socket.setBroadcast(false);
          } catch (SocketException e) {
              throw new ChannelException(
                      "Failed to configure the datagram socket timeout.", e);
          }
          config = new DefaultDatagramChannelConfig(socket);
  
          fireChannelOpen(this);
      }
  
      public DatagramChannelConfig getConfig() {
          return config;
      }
  
      public InetSocketAddress getLocalAddress() {
          InetSocketAddress localAddress = this.localAddress;
          if (localAddress == null) {
              try {
                  this.localAddress = localAddress =
                      (InetSocketAddress) socket.getLocalSocketAddress();
              } catch (Throwable t) {
                  // Sometimes fails on a closed socket in Windows.
                  return null;
              }
          }
          return localAddress;
      }
  
      public InetSocketAddress getRemoteAddress() {
         InetSocketAddress remoteAddress = this.remoteAddress;
         if (remoteAddress == null) {
             try {
                 this.remoteAddress = remoteAddress =
                     (InetSocketAddress) socket.getRemoteSocketAddress();
             } catch (Throwable t) {
                 // Sometimes fails on a closed socket in Windows.
                 return null;
             }
         }
         return remoteAddress;
     }
 
     public boolean isBound() {
         return isOpen() && socket.isBound();
     }
 
     public boolean isConnected() {
         return isOpen() && socket.isConnected();
     }
 
     @Override
     protected boolean setClosed() {
         return super.setClosed();
     }
 
     @Override
     protected void setInterestOpsNow(int interestOps) {
         super.setInterestOpsNow(interestOps);
     }
 
     @Override
     public ChannelFuture write(Object message, SocketAddress remoteAddress) {
         if (remoteAddress == null || remoteAddress.equals(getRemoteAddress())) {
             return super.write(message, null);
         } else {
             return super.write(message, remoteAddress);
         }
     }
 
     public void joinGroup(InetAddress multicastAddress) {
         ensureBound();
         try {
             socket.joinGroup(multicastAddress);
         } catch (IOException e) {
             throw new ChannelException(e);
         }
     }
 
     public void joinGroup(
             InetSocketAddress multicastAddress, NetworkInterface networkInterface) {
         ensureBound();
         try {
             socket.joinGroup(multicastAddress, networkInterface);
         } catch (IOException e) {
             throw new ChannelException(e);
         }
     }
 
     private void ensureBound() {
         if (!isBound()) {
             throw new IllegalStateException(
                     DatagramChannel.class.getName() +
                     " must be bound to join a group.");
         }
     }
 
     public void leaveGroup(InetAddress multicastAddress) {
         try {
             socket.leaveGroup(multicastAddress);
         } catch (IOException e) {
             throw new ChannelException(e);
         }
     }
 
     public void leaveGroup(
             InetSocketAddress multicastAddress, NetworkInterface networkInterface) {
         try {
             socket.leaveGroup(multicastAddress, networkInterface);
         } catch (IOException e) {
             throw new ChannelException(e);
         }
     }
 }