/*
    * 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:
    *
    *   https://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.echo;
  
  import io.netty.bootstrap.ServerBootstrap;
  import io.netty.channel.ChannelFuture;
  import io.netty.channel.ChannelInitializer;
  import io.netty.channel.ChannelOption;
  import io.netty.channel.ChannelPipeline;
  import io.netty.channel.EventLoopGroup;
  import io.netty.channel.nio.NioEventLoopGroup;
  import io.netty.channel.socket.SocketChannel;
  import io.netty.channel.socket.nio.NioServerSocketChannel;
  import io.netty.handler.logging.LogLevel;
  import io.netty.handler.logging.LoggingHandler;
  import io.netty.handler.ssl.SslContext;
  import io.netty.handler.ssl.SslContextBuilder;
  import io.netty.handler.ssl.util.SelfSignedCertificate;
  
  /**
   * Echoes back any received data from a client.
   */
  public final class EchoServer {
  
      static final boolean SSL = System.getProperty("ssl") != null;
      static final int PORT = Integer.parseInt(System.getProperty("port", "8007"));
  
      public static void main(String[] args) throws Exception {
          // Configure SSL.
          final SslContext sslCtx;
          if (SSL) {
              SelfSignedCertificate ssc = new SelfSignedCertificate();
              sslCtx = SslContextBuilder.forServer(ssc.certificate(), ssc.privateKey()).build();
          } else {
              sslCtx = null;
          }
  
          // Configure the server.
          EventLoopGroup bossGroup = new NioEventLoopGroup(1);
          EventLoopGroup workerGroup = new NioEventLoopGroup();
          final EchoServerHandler serverHandler = new EchoServerHandler();
          try {
              ServerBootstrap b = new ServerBootstrap();
              b.group(bossGroup, workerGroup)
               .channel(NioServerSocketChannel.class)
               .option(ChannelOption.SO_BACKLOG, 100)
               .handler(new LoggingHandler(LogLevel.INFO))
               .childHandler(new ChannelInitializer<SocketChannel>() {
                   @Override
                   public void initChannel(SocketChannel ch) throws Exception {
                       ChannelPipeline p = ch.pipeline();
                       if (sslCtx != null) {
                           p.addLast(sslCtx.newHandler(ch.alloc()));
                       }
                       //p.addLast(new LoggingHandler(LogLevel.INFO));
                       p.addLast(serverHandler);
                   }
               });
  
              // Start the server.
              ChannelFuture f = b.bind(PORT).sync();
  
              // Wait until the server socket is closed.
              f.channel().closeFuture().sync();
          } finally {
              // Shut down all event loops to terminate all threads.
              bossGroup.shutdownGracefully();
              workerGroup.shutdownGracefully();
          }
      }
  }