#ConnectionServer.java#

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;

class ConnectionServer implements Runnable { 
    // some constants 
    public static final int WAIT_AUTH = 0; 
    public static final int AUTH_DONE = 1;

    public static final String WAIT_AUTH_MSG = "Registration Number pls!\n"; 
    public static final String AUTH_DONE_MSG = "You are authorised to post\n"; 
    public static final String MSG_POSTED    = "Your message posted\n"; 

    // per connection variables
    private Socket mySocket; // connection socket per thread 
    private int currentState; 
    private String clientName; 
    private MainServer mainServer;
    int count;

    public ConnectionServer(MainServer mainServer) { 
	this.mySocket = null; // we will set this later 
	this.currentState = WAIT_AUTH; 
	this.clientName = null; 
	this.mainServer = mainServer;
	this.count=0;
	
	// who created me. He should give some interface 
    }

    public boolean handleConnection(Socket socket) { 
	this.mySocket = socket; 
	Thread newThread = new Thread(this); 
	newThread.start(); 
	return true; 
    }

    public void run() { // can not use "throws .." interface is different
	BufferedReader in=null; 
	PrintWriter out=null; 
	try { 
	    in = new 
		BufferedReader(new InputStreamReader(mySocket.getInputStream()));
	    out = new 
		PrintWriter(new OutputStreamWriter(mySocket.getOutputStream()));
		
	    String line, outline; 
	    for(line = in.readLine(); 
		line != null && !line.equals("quit"); 
		line = in.readLine()) { 	

		switch(currentState) { 
		case WAIT_AUTH: 
		    // we are waiting for login name 
		    // e number should be the line 
		    if(mainServer.isAuthorized(line)) { 
			currentState = AUTH_DONE; 
			clientName   = mainServer.getName(line); 
			outline = AUTH_DONE_MSG; 
		    }
		    else { 
			outline = WAIT_AUTH_MSG; 
		    }
		    break;
		    /*****************************/
		case AUTH_DONE: 
		    mainServer.postMSG(this.clientName + " Says: " + line);
		    ++this.count;
		    if(this.count>5) return;
		    outline = MSG_POSTED; 
		    break; 
		default: 
		    System.out.println("Undefined state"); 
		    return; 
		} // case 
		 
		out.print(outline); // Send the said message 
		out.flush(); // flush to network

	    } // for 

	    // close everything 
	    out.close(); 
	    in.close(); 
	    this.mySocket.close(); 
	} // try 	     
	catch (IOException e) { 
	    System.out.println(e); 
	} 
    }
}