// Server.java -- generic network server
//
// author :  Scott W. Matey
//


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


public class Server extends Object implements Runnable {

  Vector conns = new Vector ();
  ServerSocket sock;

  // Constructor
  public Server (int port) {
    try {
      sock = new ServerSocket (port);
      log ("Socket on port " +
	   String.valueOf(sock.getLocalPort()) +
           "\n");
      } 
    catch (Exception e) {
      System.err.println ("Server() exception:\n" + e);
      System.exit(-1);
      }
    }

  // Listen for connections on server socket
  public void run () {
    while (true) {
      try {
        new ServerConnection (this, sock.accept ());
        }
      catch (Exception e) {
        System.err.println ("Server.listen() exception:\n" + e);
        System.exit(-1);
        }
      }
    }


  // Internal bookkeeping methods; don't mess with these.

  void connect (ServerConnection c) {
    conns.addElement (c);
    notifyConnect (c);
    }

  void disconnect (ServerConnection c) {
    conns.removeElement (c);
    notifyDisconnect (c);
    }

  void log (String s) {
    System.out.print (s);
    }

  void broadcast (String s) {
    log (s);
    for (Enumeration e = conns.elements() ; e.hasMoreElements() ;) {
      ((ServerConnection)(e.nextElement())).print (s);
      }
    }


  // These may be overridden by subclasses.

  public boolean readHandshake (ServerConnection c) {
    return true;
    }

  public void notifyConnect (ServerConnection c) {
    broadcast ("[New connection from " +
                c.socket.getInetAddress().toString() +
                "]\n");
    }

  public void notifyDisconnect (ServerConnection c) {
    broadcast ("[Closing connection from " +
                c.socket.getInetAddress().toString() +
                "]\n");
    }

  public void notifyInput (String s) {
    }

  }