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

public class Server implements Runnable {

   private Thread thread = new Thread(this);
   private ServerSocket ss;
   private Vector clientVector = new Vector();
   private int nClients = 0;
   private static int port = 2000;
   private static boolean visible = true;

   public static void main(String args[]) {
      if(args.length != 0) {
         port = Integer.parseInt(args[0]);
      }
      
      new Server();
   }

   public Server() {
      try {
         ss = new ServerSocket(port);
      } catch (IOException e) {
         System.exit(1);
      }

      thread.start();
   }

   public void run() {
      while(true) {
         Socket s = null;
         try {
	    s = ss.accept();
         } catch(IOException e) {}
         addClient(s);
      }
   }

   private synchronized void addClient(Socket s) {
      broadcast(s, "CLIENT CONNECTED: " + getHost(s));
      clientVector.addElement(s);
      new ClientHandler(s, this);
   }
        
   public synchronized void removeClient(Socket s) {
      clientVector.removeElement(s);
      broadcast(s, "CLIENT DISSCONNECTED: " + getHost(s));
   }
        
   public synchronized void broadcast(Socket sFrom, String message) {
      for(int i = 0; i < clientVector.size(); i++) {
         Socket s = (Socket)clientVector.elementAt(i);
         sendToOne(s, message);
      }
   }

   private synchronized void sendToOne(Socket s, String message) {
      try {
         PrintWriter out = new PrintWriter(s.getOutputStream(), true);
         out.println(message);
      } catch (IOException e) {}
   }

   public synchronized void who(Socket s) {
      for(int i = 0; i < clientVector.size(); i++) {
         Socket sTmp = (Socket)clientVector.elementAt(i);
         String hostTmp = getHost(sTmp);
         sendToOne(s, "WWHHOO: " + hostTmp);
      }
   }

   private String getHost(Socket socket) {
      return(socket.getInetAddress().getHostName());
   }

   private String getHost(ServerSocket ss) {
      try {
         return(ss.getInetAddress().getLocalHost().getHostName());
      } catch(UnknownHostException uhe) {
         return("FAILED: GET SERVER HOST");
      }
   }
}

class ClientHandler extends Thread {

   private Server server;
   private Socket s;

   public ClientHandler(Socket s, Server server) {
      this.s = s;
      this.server = server;
      start();
   }
        
   public void run() {
      BufferedReader in = null;
      try{
         in = new BufferedReader(new InputStreamReader(s.getInputStream()));
      } catch(IOException e) {
         server.removeClient(s);
         return;
      }

      String inputLine;
      try {
         while ((inputLine = in.readLine()) != null) {
            if(inputLine.equals("wwhhoo"))
               server.who(s);
            else
               server.broadcast(s, inputLine);   
         }
         in.close();
         s.close();
      } catch (IOException e) {}
      server.removeClient(s);
   }
}