/*
    * junixsocket
    *
    * Copyright 2009-2024 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.server;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.net.Socket;
  import java.net.SocketAddress;
  import java.nio.charset.StandardCharsets;
  
  import org.newsclub.net.unix.AFUNIXSocket;
  
  /**
   * A multi-threaded unix socket server that simply reads all input, byte per byte, not doing
   * anything else with it.
   *
   * @author Christian Kohlschütter
   */
  @SuppressWarnings("CatchAndPrintStackTrace" /* errorprone */)
  public final class SendFileHandleServer extends DemoServerBase {
    private final File file;
  
    public SendFileHandleServer(SocketAddress listenAddress, File file) {
      super(listenAddress);
      this.file = file;
    }
  
    @Override
    protected void doServeSocket(Socket socket) throws IOException {
      if (!(socket instanceof AFUNIXSocket)) {
        throw new UnsupportedOperationException("File handles can only be sent via UNIX sockets");
      }
      doServeSocket((AFUNIXSocket) socket);
    }
  
    private void doServeSocket(AFUNIXSocket socket) throws IOException {
      try (InputStream is = socket.getInputStream();
          OutputStream os = socket.getOutputStream();
          FileInputStream fin = new FileInputStream(file)) {
        socket.setOutboundFileDescriptors(fin.getFD());
        os.write("FD sent via ancillary message.".getBytes(StandardCharsets.UTF_8));
      }
    }
  }