/**
 * DateServer
 * 
 * Network (socket) programming
 * socket: ip address + port (entry point)
 *         80 http, 8080 https, 3316 sql , 22 ssh (222 gburg)
 */

import java.util.Date;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.net.ServerSocket;
import java.net.Socket;

public class DateServer {

    public static void main(String[] args) throws IOException {

        String serverName = "Sunny";
        int    portNo     = 8888;

        // 1. set up a Server (socket) to monitor any requests through portNo
        ServerSocket serverSocket = new ServerSocket(portNo);

        System.out.println("Datetime server " + serverName + " is running. Waiting for clients...");    

        // 2. waiting for a client to connect
        while (true) {

            // 3. accept a client's connection request
            Socket clientSocket = serverSocket.accept();

            // on Server-side
            // data is transmitted in bytes via stream readers
            // wrap it around using PrintWriter, BufferedReader
            //      -- allow us to use basic types and Strings easily
            //receive : clientSocket.getInputStream()
            //send    : clientSocket.getOutputStream()

            // 4. send current day/time to the client

            PrintWriter    netOut = new PrintWriter(clientSocket.getOutputStream());
            BufferedReader netIn  = 
                new BufferedReader(
                    new InputStreamReader(
                        clientSocket.getInputStream()));

            // 4.5 receive client's name
            //  send a welcome message and prompt for client's name
            netOut.println("Welcome to Datetime server!");
            netOut.println("Enter your name: ");
            netOut.flush();

            String clientName = netIn.readLine();

            System.out.println("Client " + clientName + " connected");

            Date now = new Date();

            netOut.println(serverName + ": " + now.toString());
            netOut.close();  // singals end of communication

            // 5. close connection
            clientSocket.close();
        }

    }
}