/*
    * 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.echo;
  
  import java.util.concurrent.atomic.AtomicLong;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  
  import org.jboss.netty.buffer.ChannelBuffer;
  import org.jboss.netty.buffer.ChannelBuffers;
  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;
  
  /**
   * Handler implementation for the echo client.  It initiates the ping-pong
   * traffic between the echo client and server by sending the first message to
   * the server.
   *
   * @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 EchoClientHandler extends SimpleChannelUpstreamHandler {
  
      private static final Logger logger = Logger.getLogger(
              EchoClientHandler.class.getName());
  
      private final ChannelBuffer firstMessage;
      private final AtomicLong transferredBytes = new AtomicLong();
  
      /**
       * Creates a client-side handler.
       */
      public EchoClientHandler(int firstMessageSize) {
          if (firstMessageSize <= 0) {
              throw new IllegalArgumentException(
                      "firstMessageSize: " + firstMessageSize);
          }
          firstMessage = ChannelBuffers.buffer(firstMessageSize);
          for (int i = 0; i < firstMessage.capacity(); i ++) {
              firstMessage.writeByte((byte) i);
          }
      }
  
      public long getTransferredBytes() {
          return transferredBytes.get();
      }
  
      @Override
      public void channelConnected(
              ChannelHandlerContext ctx, ChannelStateEvent e) {
          // Send the first message.  Server will not send anything here
          // because the firstMessage's capacity is 0.
          e.getChannel().write(firstMessage);
      }
  
      @Override
      public void messageReceived(
              ChannelHandlerContext ctx, MessageEvent e) {
          // Send back the received message to the remote peer.
          transferredBytes.addAndGet(((ChannelBuffer) e.getMessage()).readableBytes());
          e.getChannel().write(e.getMessage());
      }
  
      @Override
      public void exceptionCaught(
              ChannelHandlerContext ctx, ExceptionEvent e) {
          // Close the connection when an exception is raised.
          logger.log(
                  Level.WARNING,
                  "Unexpected exception from downstream.",
                  e.getCause());
          e.getChannel().close();
      }
  }