/*
    * Copyright 2012 The Netty Project
    *
    * The Netty Project 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.example.securechat;
  
  import org.jboss.netty.channel.Channel;
  import org.jboss.netty.channel.ChannelEvent;
  import org.jboss.netty.channel.ChannelFuture;
  import org.jboss.netty.channel.ChannelFutureListener;
  import org.jboss.netty.channel.ChannelHandlerContext;
  import org.jboss.netty.channel.ChannelStateEvent;
  import org.jboss.netty.channel.ExceptionEvent;
  import org.jboss.netty.channel.MessageEvent;
  import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
  import org.jboss.netty.channel.group.ChannelGroup;
  import org.jboss.netty.channel.group.DefaultChannelGroup;
  import org.jboss.netty.handler.ssl.SslHandler;
  
  import java.net.InetAddress;
  
  /**
   * Handles a server-side channel.
   */
  public class SecureChatServerHandler extends SimpleChannelUpstreamHandler {
  
      static final ChannelGroup channels = new DefaultChannelGroup();
  
      @Override
      public void handleUpstream(ChannelHandlerContext ctx, ChannelEvent e) throws Exception {
          if (e instanceof ChannelStateEvent) {
              System.err.println(e);
          }
          super.handleUpstream(ctx, e);
      }
  
      @Override
      public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) {
          // Get the SslHandler in the current pipeline.
          // We added it in SecureChatPipelineFactory.
          final SslHandler sslHandler = ctx.getPipeline().get(SslHandler.class);
  
          // Get notified when SSL handshake is done.
          ChannelFuture handshakeFuture = sslHandler.handshake();
          handshakeFuture.addListener(new Greeter(sslHandler));
      }
  
      @Override
      public void channelDisconnected(ChannelHandlerContext ctx, ChannelStateEvent e) {
          // Unregister the channel from the global channel list
          // so the channel does not receive messages anymore.
          channels.remove(e.getChannel());
      }
  
      @Override
      public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
  
          // Convert to a String first.
          String request = (String) e.getMessage();
  
          // Send the received message to all channels but the current one.
          for (Channel c: channels) {
              if (c != e.getChannel()) {
                  c.write("[" + e.getChannel().getRemoteAddress() + "] " +
                          request + '\n');
              } else {
                  c.write("[you] " + request + '\n');
              }
          }
  
          // Close the connection if the client has sent 'bye'.
          if ("bye".equals(request.toLowerCase())) {
              e.getChannel().close();
          }
      }
  
      @Override
      public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
          e.getCause().printStackTrace();
          e.getChannel().close();
      }
  
      private static final class Greeter implements ChannelFutureListener {
  
          private final SslHandler sslHandler;
  
          Greeter(SslHandler sslHandler) {
              this.sslHandler = sslHandler;
         }
 
         public void operationComplete(ChannelFuture future) throws Exception {
             if (future.isSuccess()) {
                 // Once session is secured, send a greeting.
                 future.getChannel().write(
                         "Welcome to " + InetAddress.getLocalHost().getHostName() + " secure chat service!\n");
                 future.getChannel().write(
                         "Your session is protected by " + sslHandler.getEngine().getSession().getCipherSuite() +
                         " cipher suite.\n");
 
                 // Register the channel to the global channel list
                 // so the channel received the messages from others.
                 channels.add(future.getChannel());
             } else {
                 future.getChannel().close();
             }
         }
     }
 }