/*
    * 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.http.helloworld;
  
  import org.jboss.netty.buffer.ChannelBuffers;
  import org.jboss.netty.channel.Channel;
  import org.jboss.netty.channel.ChannelFuture;
  import org.jboss.netty.channel.ChannelFutureListener;
  import org.jboss.netty.channel.ChannelHandlerContext;
  import org.jboss.netty.channel.Channels;
  import org.jboss.netty.channel.ExceptionEvent;
  import org.jboss.netty.channel.MessageEvent;
  import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
  import org.jboss.netty.handler.codec.http.DefaultHttpResponse;
  import org.jboss.netty.handler.codec.http.HttpRequest;
  import org.jboss.netty.handler.codec.http.HttpResponse;
  
  import static org.jboss.netty.handler.codec.http.HttpHeaders.Names.*;
  import static org.jboss.netty.handler.codec.http.HttpHeaders.*;
  import static org.jboss.netty.handler.codec.http.HttpResponseStatus.*;
  import static org.jboss.netty.handler.codec.http.HttpVersion.*;
  
  public class HttpHelloWorldServerHandler extends SimpleChannelUpstreamHandler {
  
      private static final byte[] CONTENT = { 'H', 'e', 'l', 'l', 'o', ' ', 'W', 'o', 'r', 'l', 'd' };
  
      @Override
      public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
          Object msg = e.getMessage();
          Channel ch = e.getChannel();
          if (msg instanceof HttpRequest) {
              HttpRequest req = (HttpRequest) msg;
  
              if (is100ContinueExpected(req)) {
                  Channels.write(ctx, Channels.future(ch), new DefaultHttpResponse(HTTP_1_1, CONTINUE));
              }
  
              boolean keepAlive = isKeepAlive(req);
              HttpResponse response = new DefaultHttpResponse(HTTP_1_1, OK);
              response.setContent(ChannelBuffers.wrappedBuffer(CONTENT));
              response.headers().set(CONTENT_TYPE, "text/plain");
              response.headers().set(CONTENT_LENGTH, response.getContent().readableBytes());
  
              if (!keepAlive) {
                  ChannelFuture f = Channels.future(ch);
                  f.addListener(ChannelFutureListener.CLOSE);
                  Channels.write(ctx, f, response);
              } else {
                  response.headers().set(CONNECTION, Values.KEEP_ALIVE);
                  Channels.write(ctx, Channels.future(ch), response);
              }
          }
      }
  
      @Override
      public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
          e.getCause().printStackTrace();
          e.getChannel().close();
      }
  }