/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF 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 org.apache.commons.net.telnet;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.net.ServerSocket;
  import java.net.Socket;
  
  import org.apache.commons.io.IOUtils;
  
  /**
   * Simple TCP server. Waits for connections on a TCP port in a separate thread.
   */
  public class TelnetTestSimpleServer implements Runnable {
      ServerSocket serverSocket;
      Socket clientSocket;
      Thread listener;
  
      /*
       * test of client-driven subnegotiation. <p>
       *
       * @param port   server port on which to listen.
       * @throws IOException on error
       */
      public TelnetTestSimpleServer(final int port) throws IOException {
          serverSocket = new ServerSocket(port);
  
          listener = new Thread(this);
  
          listener.start();
      }
  
      public void disconnect() {
          if (clientSocket == null) {
              return;
          }
          synchronized (clientSocket) {
              try {
                  clientSocket.notify();
              } catch (final Exception e) {
                  System.err.println("Exception in notify, " + e.getMessage());
              }
          }
      }
  
      public InputStream getInputStream() throws IOException {
          if (clientSocket != null) {
              return clientSocket.getInputStream();
          }
          return null;
      }
  
      public OutputStream getOutputStream() throws IOException {
          if (clientSocket != null) {
              return clientSocket.getOutputStream();
          }
          return null;
      }
  
      @Override
      public void run() {
          boolean bError = false;
          while (!bError) {
              try {
                  clientSocket = serverSocket.accept();
                  synchronized (clientSocket) {
                      try {
                          clientSocket.wait();
                      } catch (final Exception e) {
                          System.err.println("Exception in wait, " + e.getMessage());
                      }
                      IOUtils.close(clientSocket, e -> System.err.println("Exception in close, " + e.getMessage()));
                  }
              } catch (final IOException e) {
                  bError = true;
              }
          }
          IOUtils.closeQuietly(serverSocket, e -> System.err.println("Exception in close, " + e.getMessage()));
      }
  
      public void stop() {
          listener.interrupt();
          IOUtils.closeQuietly(serverSocket, e -> System.err.println("Exception in close, " + e.getMessage()));
     }
 }