/*
    * junixsocket
    *
    * Copyright 2009-2026 Christian Kohlschütter
    *
    * Licensed 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.newsclub.net.unix.demo.netty;
  
  import java.io.File;
  import java.nio.channels.spi.SelectorProvider;
  import java.util.concurrent.Executor;
  
  import org.newsclub.net.unix.AFSocketAddress;
  import org.newsclub.net.unix.AFUNIXSelectorProvider;
  import org.newsclub.net.unix.AFUNIXSocketAddress;
  
  import com.kohlschutter.annotations.compiletime.SuppressFBWarnings;
  
  import io.netty.bootstrap.ServerBootstrap;
  import io.netty.channel.ChannelFuture;
  import io.netty.channel.ChannelInitializer;
  import io.netty.channel.ChannelOption;
  import io.netty.channel.EventLoopGroup;
  import io.netty.channel.nio.NioEventLoopGroup;
  import io.netty.channel.socket.SocketChannel;
  import io.netty.channel.socket.nio.NioServerSocketChannel;
  
  /**
   * Echos any incoming data.
   * <p>
   * Based on example code from <a href="https://netty.io/wiki/user-guide-for-4.x.html">Netty user
   * guide for 4.x</a>
   */
  @SuppressWarnings("FutureReturnValueIgnored" /* errorprone */)
  public class EchoServer {
    private final AFSocketAddress addr;
  
    public EchoServer(AFSocketAddress addr) {
      this.addr = addr;
    }
  
    public void run() throws Exception {
      SelectorProvider provider = AFUNIXSelectorProvider.provider();
      // SelectorProvider provider = AFTIPCSelectorProvider.provider();
  
      // We need to specify our custom selector provider here (1), as well as in (3)
      EventLoopGroup bossGroup = new NioEventLoopGroup(0, (Executor) null, provider); // (1)
      EventLoopGroup workerGroup = new NioEventLoopGroup(0, (Executor) null, provider); // (1)
      try {
        ServerBootstrap b = new ServerBootstrap(); // (2)
        b.group(bossGroup, workerGroup) //
            .channelFactory(() -> new NioServerSocketChannel(provider)) // (3)
            .childHandler(new ChannelInitializer<SocketChannel>() { // (4)
              @Override
              public void initChannel(SocketChannel ch) throws Exception {
                ch.pipeline().addLast(new EchoServerHandler());
              }
            }) //
            .option(ChannelOption.SO_BACKLOG, 128) // (5)
            .childOption(ChannelOption.SO_KEEPALIVE, true); // (6)
  
        // Bind and start to accept incoming connections.
        ChannelFuture f = b.bind(addr).sync(); // (7)
  
        // Wait until the server socket is closed.
        // In this example, this does not happen, but you can do that to gracefully
        // shut down your server.
        f.channel().closeFuture().sync();
      } finally {
        workerGroup.shutdownGracefully();
        bossGroup.shutdownGracefully();
      }
    }
  
    @SuppressFBWarnings("PATH_TRAVERSAL_IN")
    public static void main(String[] args) throws Exception {
      File path = new File("/tmp/nettyecho");
      if (args.length > 0) {
        path = new File(args[0]);
      }
  
      AFUNIXSocketAddress addr = AFUNIXSocketAddress.of(path);
      System.out.println("Binding to " + addr);
  
      new EchoServer(addr).run();
      // new EchoServer(AFTIPCSocketAddress.ofService(Scope.SCOPE_CLUSTER, 128, 3)).run();
    }
  }