//This is a TCP peer-to-peer text chat program.

//Usage:  java p2pchat address receiveport sendport


//KNOWN BUGS:

//I can't seem to get both the server and the client threads to share the CPU


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

//This class waits for a connection from another chat client and then listens

//to whatever the client has to say:

class ChatServer extends Thread {
    private Socket connectionSocket = null;
    private int port;
    private String address;
    private FileWriter logFile = null;

    public ChatServer( String address, int port /*, String fileName*/ )
    {
        this.port = port;
        this.address = address;
        //setDaemon(true);
        /*try{ logFile = new FileWriter( fileName ); } catch( Exception e ) { System.out.println( e ); };*/
        start();
    }

    public void run()
    {

        String clientData = "";

        // Create welcome socket for the client to connect to us.
        ServerSocket welcomeSocket = null;

        try{
        welcomeSocket = new ServerSocket(port);

        System.out.println( "Available for connections." );
        System.out.println( "SOCKET INFO" );
        System.out.println( "====================================" );
        System.out.println( welcomeSocket );
        System.out.println( "====================================" );
        } catch( Exception e ) {
                System.out.println( e );
        }

        while(true) {
            try
            {
            // Create a socket when there is a knock at the door
            connectionSocket = welcomeSocket.accept();
            System.out.println( "Connection established." );
            System.out.println( connectionSocket );

            BufferedReader inFromClient = new BufferedReader
            (new InputStreamReader(connectionSocket.getInputStream()));
            
            //Talk to this client as long as they want:
            do
            {
                 System.out.println( "WAITING FOR MESSAGE FROM REMOTE HOST..." );
                 System.out.flush();
                 // Read info from socket
                 clientData = inFromClient.readLine();
                 System.out.println( ">>> " + clientData );
                 yield();
             }  while( !clientData.equals( "QUIT/" ) );

             System.out.println( "Connection closed." );
             }  catch( Exception e ) {
                  System.out.println( e );
             }
       }
    }
};



//This class does all the talking:
class ChatClient extends Thread {
    private int port;
    private String address;
    private String myData = null;

    public ChatClient( String address, int port )
    {
        this.port = port;
        this.address = address;
        //setDaemon(true);
        start();
    }

    public void run()
    {
        // Create socket to hostname or IP address and port #
        // Initiates TCP connection between client and server
        Socket clientSocket = null;
        DataOutputStream outToClient = null;

        BufferedReader inFromUser =
        new BufferedReader(new InputStreamReader(System.in));


        System.out.println( "Connecting to remote host..." );

        while(true)
        {
                try{
                //Keep trying to connect if we haven't yet.
                if( clientSocket == null )
                {
                        clientSocket = new Socket(address, port);
                        outToClient = new DataOutputStream(clientSocket.getOutputStream());
                }


                if ( clientSocket!=null )
                {
                        System.out.print( ": " );
                        myData = inFromUser.readLine();
                        outToClient.writeBytes( myData );
                        outToClient.flush();
                        System.out.println( "MESSAGE SENT TO REMOTE HOST." );
                }
                } catch( Exception e ) {
                        System.out.println( e );
                }
         }
    }
};




class p2pchat {
    public static void main(String args[]) throws Exception {
        String clientSentence;
        String capitalizedSentence;
        int receiveport = Integer.parseInt(args[1]);
        int sendport = Integer.parseInt(args[2]);
        //String logFileName = args[3];
        String address = args[0];

        ChatServer serve = new ChatServer(address, receiveport /*, logFileName*/ );
        ChatClient client = new ChatClient(address, sendport);
    }
}