import java.io.*;
import java.net.*;
import java.util.*;

public class Server
{
  private ServerSocket ss;


  private Hashtable outputStreams = new Hashtable();

  public Server( int port ) throws IOException {
    listen( port );
  }

  private void listen( int port ) throws IOException {

    ss = new ServerSocket( port );

    System.out.println( "Listening on "+ss );

    while (true) {

      Socket s = ss.accept();

      System.out.println( "Connection from "+s );

      DataOutputStream dout = new DataOutputStream( s.getOutputStream() );

      outputStreams.put( s, dout );

      new ServerThread( this, s );
    }
  }

  Enumeration getOutputStreams() {
    return outputStreams.elements();
  }

  void sendToAll( String message ) {

    synchronized( outputStreams ) {

      for (Enumeration e = getOutputStreams(); e.hasMoreElements(); ) {

        DataOutputStream dout = (DataOutputStream)e.nextElement();

        try {
          dout.writeUTF( message );
        } catch( IOException ie ) { System.out.println( ie ); }
      }
    }
  }

  void removeConnection( Socket s ) {

    synchronized( outputStreams ) {

      System.out.println( "Removing connection to "+s );

      outputStreams.remove( s );

      try {
        s.close();
      } catch( IOException ie ) {
        System.out.println( "Error closing "+s );
        ie.printStackTrace();
      }
    }
  }

  static public void main( String args[] ) throws Exception {

    int port = Integer.parseInt( args[0] );

    new Server( port );
  }
}