content: /*
   * The MIT License (MIT)
   *
   * Copyright (c) 2011-2021 Broad Institute, Aiden Lab, Rice University, Baylor College of Medicine
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   *  FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
   *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   *  THE SOFTWARE.
   */
  
  package juicebox;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.net.ServerSocket;
  import java.net.Socket;
  
  class CommandListener implements Runnable {
  
      private static CommandListener listener;
      private final Thread listenerThread;
      private final HiC hic;
      private int port = -1;
      private ServerSocket serverSocket = null;
      private Socket clientSocket = null;
      private boolean halt = false;
  
      private CommandListener(int port, HiC hic) throws IOException {
          this.port = port;
          this.hic = hic;
          listenerThread = new Thread(this);
          serverSocket = new ServerSocket(port);
      }
  
      public static synchronized void start(HiC hic) {
  
          // Grab the first available port
          int port = 0;
          for (int p = 30000; p <= 30000 + CommandBroadcaster.numPorts - 1; p++) {
              try {
                  listener = new CommandListener(p, hic);
                  listener.listenerThread.start();
                  port = p;
                  break;
              } catch (IOException e) {
                  // Expected condition -- port in use
              }
          }
          CommandBroadcaster.selfPort = port;
      }
  
      public static synchronized void halt() {
          if (listener != null) {
              listener.halt = true;
              listener.listenerThread.interrupt();
              listener.closeSockets();
              listener = null;
          }
      }
  
      /**
       * Loop forever, processing client requests synchronously.  The server is single threaded.
       */
      public void run() {
  
          CommandExecutor cmdExe = new CommandExecutor(hic);
          System.out.println("Listening on port " + port);
  
          try {
              while (!halt) {
                  clientSocket = serverSocket.accept();
                  processClientRequest(cmdExe);
                  if (clientSocket != null) {
                      try {
                          clientSocket.close();
                          clientSocket = null;
                      } catch (IOException e) {
                          System.err.println("Error in client socket loop" + e.getLocalizedMessage());
                      }
                  }
              }
          } catch (IOException e) {
              e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
          }
  
      }
  
      /**
       * Process a client request
       *
       * @param cmdExe
       * @throws IOException
       */
      private void processClientRequest(CommandExecutor cmdExe) throws IOException {
  
          BufferedReader in = null;
  
          try {
              in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()), HiCGlobals.bufferSize);
              String cmd;
              while (!halt && (cmd = in.readLine()) != null) {
                  if (cmd.equalsIgnoreCase("halt")) {
                      halt = true;
                      return;
                  }
                  cmdExe.execute(cmd);
              }
          } catch (IOException e) {
              System.err.println("Error processing client session" + e.getLocalizedMessage());
          } finally {
              if (in != null) in.close();
          }
      }
  
      private void closeSockets() {
          if (clientSocket != null) {
              try {
                  clientSocket.close();
                  clientSocket = null;
              } catch (IOException e) {
                  System.err.println("Error closing clientSocket" + e.getLocalizedMessage());
              }
          }
  
          if (serverSocket != null) {
              try {
                  serverSocket.close();
                  serverSocket = null;
              } catch (IOException e) {
                  System.err.println("Error closing server socket" + e.getLocalizedMessage());
              }
          }
      }
  
  }
  