// Server program for Gnat Chat to receive a Message object from client
// and send to other client.  
// Has two threads for each side of the communication.
// October 30, 2008 CS479  Dan Hyde

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

public class ChatServer {

    public ChatServer() {

	ServerSocket server = null;
	Socket connect1 = null;
	Socket connect2 = null;
	ObjectOutputStream out1 = null;
	ObjectOutputStream out2 = null;
	ObjectInputStream in1 = null;
	ObjectInputStream in2 = null;
	Thread thread1 = null;
	Thread thread2 = null;

	// port 5000
	try {
	    server = new ServerSocket(5000, 100);
	} catch (IOException e) {
	    System.err.println("Error in socket " + e);
	}

	while (true) {
	    try {
		System.out.println("\n--- Welcome to Gnat Chat Server ---" +
				   "\n\nWaiting for first client ....");
		connect1 = server.accept();
		System.out.println("Connection received from " +
				   connect1.getInetAddress().getHostName());
		
		try{
		    out1 = new ObjectOutputStream(connect1.getOutputStream());
		    in1  = new ObjectInputStream(connect1.getInputStream());
		} catch ( IOException e5 ){
		    System.err.println("Error in connection " + e5);
		    System.exit(0);
		}

		System.out.println("Waiting for second client ....");
		connect2 = server.accept();
		System.out.println("Connection received from " +
				   connect2.getInetAddress().getHostName());

		try{
		    out2 = new ObjectOutputStream(connect2.getOutputStream());
		    in2  = new ObjectInputStream( connect2.getInputStream());
		} catch (IOException e5){
		    System.err.println("Error in connection " + e5);
		    System.exit(0);
		}

		// start a new thread
		thread1 = new OneSideThread(in1, out2, connect1);
		
		// start a new second thread
		thread2 = new OneSideThread(in2, out1, connect2);
		
	    }
	    catch (IOException e5){
		System.err.println("Error in connection " + e5.getMessage());
	    }

	    // wait for shut down
	    try {
		thread1.join();
		thread2.join();		    
	    } catch (InterruptedException e3) {
		System.err.println(e3.getMessage());
	    }

	    // close streams and sockets 
	    try {
		in1.close();
		out1.close();
		connect1.close();
		System.out.println("Connection closed from " +
				   connect1.getInetAddress().getHostName());
		in2.close();
		out2.close();
		connect2.close();
		System.out.println("Connection closed from " +
				   connect2.getInetAddress().getHostName());
	    } catch (IOException e5) {
		System.err.println("Error in connection " + e5);
		System.exit(0);
	    }
	}
    }

    public static void main (String args []) 
    {
	ChatServer app = new ChatServer();
    }
}

// Thread that handles one side of the communication through the server.
class OneSideThread extends Thread {

    private ObjectInputStream in = null;;
    private ObjectOutputStream out = null;
    private Socket theSocket = null;

    public OneSideThread(ObjectInputStream inP, ObjectOutputStream outP, 
			Socket inSocket) { 
	
	in = inP;
	out = outP;
	theSocket = inSocket;

	this.start();  // call run()
    }

    public void run() {

	Message mess = new Message();
	boolean shutDown = false;

	    do {
		try {

		    mess = (Message) in.readObject();
		    shutDown = mess.getShutDown();
		    out.writeObject(mess);

		} catch (ClassNotFoundException e3) {
		    System.err.println("Class not found " + e3);
		    System.exit(0);
		} catch (IOException e4){
		    System.err.println("Error in I/O " + e4);
		    System.exit(0);
		}

	    } while(!shutDown);
    }
}