/*
    * 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.example.telnet;
  
  import java.net.InetAddress;
  import java.util.Date;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  
  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;
  
  /**
   * Handles a server-side channel.
   *
   * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
   * @author <a href="http://gleamynode.net/">Trustin Lee</a>
   *
   * @version $Rev: 2121 $, $Date: 2010-02-02 09:38:07 +0900 (Tue, 02 Feb 2010) $
   */
  public class TelnetServerHandler extends SimpleChannelUpstreamHandler {
  
      private static final Logger logger = Logger.getLogger(
              TelnetServerHandler.class.getName());
  
      @Override
      public void handleUpstream(
              ChannelHandlerContext ctx, ChannelEvent e) throws Exception {
          if (e instanceof ChannelStateEvent) {
              logger.info(e.toString());
          }
          super.handleUpstream(ctx, e);
      }
  
      @Override
      public void channelConnected(
              ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
          // Send greeting for a new connection.
          e.getChannel().write(
                  "Welcome to " + InetAddress.getLocalHost().getHostName() + "!\r\n");
          e.getChannel().write("It is " + new Date() + " now.\r\n");
      }
  
      @Override
      public void messageReceived(
              ChannelHandlerContext ctx, MessageEvent e) {
  
          // Cast to a String first.
          // We know it is a String because we put some codec in TelnetPipelineFactory.
          String request = (String) e.getMessage();
  
          // Generate and write a response.
          String response;
          boolean close = false;
          if (request.length() == 0) {
              response = "Please type something.\r\n";
          } else if (request.toLowerCase().equals("bye")) {
              response = "Have a good day!\r\n";
              close = true;
          } else {
              response = "Did you say '" + request + "'?\r\n";
          }
  
          // We do not need to write a ChannelBuffer here.
          // We know the encoder inserted at TelnetPipelineFactory will do the conversion.
          ChannelFuture future = e.getChannel().write(response);
  
          // Close the connection after sending 'Have a good day!'
          // if the client has sent 'bye'.
          if (close) {
              future.addListener(ChannelFutureListener.CLOSE);
          }
      }
  
      @Override
      public void exceptionCaught(
              ChannelHandlerContext ctx, ExceptionEvent e) {
          logger.log(
                  Level.WARNING,
                  "Unexpected exception from downstream.",
                 e.getCause());
         e.getChannel().close();
     }
 }