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

public class SimpleChatServer
{
  /**
   * A thread class for each client connecting
   */
  class ClientThread implements Runnable {
    Socket s;
    SimpleChatServer server;
    public ClientThread(Socket s, SimpleChatServer server) {
      this.s = s;
      this.server=server;
      server.broadcast(s.getInetAddress() + " joined");
    }
    
    /**
     * The run() method is started with Thread.start()
     */
    public void run() {
      String input=null;

      try {
        /* Read lines from this client */
        BufferedReader in =
          new BufferedReader(new InputStreamReader(s.getInputStream()));

        while( (input = in.readLine()) != null) {
          /* Unless clients wants to quit, send message to all
           * connected clients...
           */
          if (! input.equals("bye")) {
            server.broadcast(s.getInetAddress() + ": " + input);
            System.out.println("Got: " + input + " from " + s);
          } else {
            break;
          }
        }
        
      } catch(IOException e) {
        System.err.println("Error in client thread: " + e);
      } finally {
        /* Don't keep this connection */
        System.out.println("Removing connection to " + s);
        server.dropConnection(s);
      }       
    }
  } // End inner class
  
  /* Keep sockets in a Vector - Vector is thread safe */
  private Vector<Socket> sockets = new Vector<Socket>();

  /* A way to remove logged out (or lost) connections */
  private void dropConnection(Socket s) {
    sockets.remove(s);
    try {
      s.close();
    } catch(IOException e) {
      System.err.println("Error closing " + s + ": " + e);
    }
  }
  
  /* Send message to all connected clients */
  private void broadcast(String msg) {

    try {
      System.out.println(msg.length());
      if (msg == null || msg.endsWith("]: ")) {
        return; // Don't write empty lines
      }
      
      PrintWriter out;
      for (Socket s : sockets) {
        out = new PrintWriter(s.getOutputStream(), true);
        out.println(msg);
      }
      
    } catch(IOException ioe) {
      System.err.println("Error writing to clients: " + ioe);
    }
  }
  
  /* Main listen loop handling connections */
  private void listen() {

    try {
      ServerSocket server = new ServerSocket(1066);
      while (true) {
        /* Whenever a client connects, welcome it
         * and save the connection 
         */
        Socket s = server.accept();
        sockets.add(s);
        /* Log this connection on the server side */
        System.out.println(new Date() +
                           " - Got connection from: " +
                           s.getInetAddress());

        /* Greeting to new client */
        PrintWriter out = new PrintWriter(s.getOutputStream(), true);
        String input = null;
        out.println("HELLO - log out with 'bye'");
        /* Let a new thread handle i/o for this client */
        new Thread(new ClientThread(s, this)).start();
      }
      
    } catch(IOException e) {
      System.err.println("Error in Server: " + e.getMessage());
      e.printStackTrace();
    }
  }
  
  public static void main(String[] args) {
    /* Start this server */
    new SimpleChatServer().listen();
  }
  
}