/*
 * SampleServer.java
 */

/**
 *
 * @author  Peter Sutton
 */
import java.io.*;
import java.net.*;
import java.util.Vector;
import java.util.ListIterator;

public class SampleServer {
    private Vector clientList;
    
    class ClientThread extends Thread {
        private SampleServer server;
        private Socket socket;
        private PrintWriter out;
        private BufferedReader in;
        
        public ClientThread(SampleServer server, Socket socket) 
		throws IOException {
	    this.server = server;
            this.socket = socket;
            out = new PrintWriter(socket.getOutputStream(), true);
            in = new BufferedReader(new InputStreamReader(
		    socket.getInputStream()));
        }
         
        public void run() {
            try {
                /* Now receive lines and turn them into uppercase and send
		** them back
		*/
                String line;
                while((line = in.readLine()) != null) {
		    line = line.toUpperCase();
		    out.println(line);
                }
		close();
            }
            catch (SocketException e) {
                close();
            }
            catch (IOException e) {
                e.printStackTrace();
            }
        }

	public void close() {
	    try {
		System.err.println("Disconnection.");
		out.close();
		in.close();
		socket.close();
		server.disconnected(this);
	    }
	    catch (IOException e) {
		e.printStackTrace();
	    }
	}
    }
       
    public SampleServer() {
        clientList = new Vector();
    }


    public static void main(String[] args) {
        // An argument is expected - a port number to listen on - check for it
        if(args.length != 1) {
            System.err.println("Expected port number on command line");
            System.exit(1);
        }
        SampleServer chatServer = new SampleServer();
        int port = Integer.parseInt(args[0]);
        ServerSocket serverSocket = null;

        // Wait for connections
        try {
            serverSocket = new ServerSocket(port);
            System.err.println("Listening on port " + port);
            while(true) {
                // Wait for a connection to come in
                Socket connectionSocket = serverSocket.accept();
                // Start a new thread to deal with it
                chatServer.addClient(connectionSocket);
            }
        }
        catch (IOException e) {
            e.printStackTrace();
        }
        
    }   
    
    public int numClients() {
        return clientList.size();
    }
    
    public void addClient(Socket connectionSocket) throws IOException {
        ClientThread clientThread = new ClientThread(this, connectionSocket);
        clientList.add(clientThread);
        clientThread.start();
    }
    
    public void disconnected(ClientThread gone) {
        clientList.remove(gone);
    }
}