/*
    * Copyright 2013 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 io.netty.example.http.helloworld;
  
  import io.netty.buffer.Unpooled;
  import io.netty.channel.ChannelFutureListener;
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.channel.ChannelInboundHandlerAdapter;
  import io.netty.handler.codec.http.DefaultFullHttpResponse;
  import io.netty.handler.codec.http.FullHttpResponse;
  import io.netty.handler.codec.http.HttpHeaders;
  import io.netty.handler.codec.http.HttpRequest;
  
  import static io.netty.handler.codec.http.HttpHeaders.Names.*;
  import static io.netty.handler.codec.http.HttpHeaders.Values;
  import static io.netty.handler.codec.http.HttpResponseStatus.*;
  import static io.netty.handler.codec.http.HttpVersion.*;
  
  public class HttpHelloWorldServerHandler extends ChannelInboundHandlerAdapter {
      private static final byte[] CONTENT = { 'H', 'e', 'l', 'l', 'o', ' ', 'W', 'o', 'r', 'l', 'd' };
  
      @Override
      public void channelReadComplete(ChannelHandlerContext ctx) {
          ctx.flush();
      }
  
      @Override
      public void channelRead(ChannelHandlerContext ctx, Object msg) {
          if (msg instanceof HttpRequest) {
              HttpRequest req = (HttpRequest) msg;
  
              if (HttpHeaders.is100ContinueExpected(req)) {
                  ctx.write(new DefaultFullHttpResponse(HTTP_1_1, CONTINUE));
              }
              boolean keepAlive = HttpHeaders.isKeepAlive(req);
              FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, OK, Unpooled.wrappedBuffer(CONTENT));
              response.headers().set(CONTENT_TYPE, "text/plain");
              response.headers().set(CONTENT_LENGTH, response.content().readableBytes());
  
              if (!keepAlive) {
                  ctx.write(response).addListener(ChannelFutureListener.CLOSE);
              } else {
                  response.headers().set(CONNECTION, Values.KEEP_ALIVE);
                  ctx.write(response);
              }
          }
      }
  
      @Override
      public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
          cause.printStackTrace();
          ctx.close();
      }
  }