using System;
using System.Net.Sockets;
using System.IO;
using System.Threading;
using System.Net;

namespace _8246_ACW_Coursework
{
        class ServerApp
        {
            public void runServer()
            {
                //creates a TcpListener Object to listen for incoming connections
                TcpListener listener;
                //creates a socket to send and recieve data
                Socket connection;
                //creates a network stream
                NetworkStream socketStream;

                for (;;)
                {
                    try 
                    {
                        //creates an instance Tcp listenter to listen for connections on port 43
                        listener = new TcpListener(43);
                        //begins listening for incoming connections
                        listener.Start();
                        while (true)
                        {
                            //starts new thread
                            Thread thread = new Thread(runServer);
                            thread.Start();
                            //accepts socket if request is made to connect
                            connection = listener.AcceptSocket();
                            //sets a network stream instance to the connection socket
                            socketStream = new NetworkStream(connection);
                            //calls method doRequest which takes a socketstream    and handles its request
                            doRequest(socketStream);
                            //closes the socket stream
                            socketStream.Close();
                            //closes connection
                            connection.Close();
                        }
                    }
                    catch (Exception e)
                    {
                        e.ToString();
                    }
                }
            }
            public string doRequest(NetworkStream socketStream)
            {
                //streamReader reads incoming connection from client
                StreamReader sr = new StreamReader(socketStream);
                //writes in coming data
                StreamWriter sw = new StreamWriter(socketStream);
                //Assigns data from the streamreader to a string
                string streamReader = sr.ReadLine();
                return streamReader;
            }
        }
    }

using System;
using System.Text;
using System.Net.Sockets;
using System.Threading;
using System.IO;

namespace _8246_ACW_Coursework
{
    public class ClientApp
    {
        //creates a new instance of the clientform windows form application
        static ClientServerGUI clientform = new ClientServerGUI();
        
        //variables
        public static string address,
                             sendData,
                             updateData,
                             userName;
        private static string space = " ";   
        public static int port;
    
        //method which connects to the server and returns information back to the forms class
        public static string SendData() 
        {
            TcpClient client = new TcpClient();
            //calls the TCP client and connects to the address and port passed in by the User from GUI
            client.Connect(address, port);
            //Creates a stream writer instance so user can send data to server
            StreamWriter sw = new StreamWriter(client.GetStream());
            //reads the information sent back from the server
            StreamReader sr = new StreamReader(client.GetStream());
            
            //if statement evalutes to see if the user has selected to update the server
            //" " = update server
            //"" = do not update the server
            if(updateData.Equals(""))
            {
                space = "";
            }
            else if(!updateData.Equals(""))
            {
                space = " ";
            }
            //Refrences stream writer, username variable passed in from GUI
            //space variable provides update function: "" = dont update. " " = update database.
            sw.WriteLine(userName + space + updateData);
            sw.Flush();
            //data send back from the server assigned to string variable 
            string recieved = sr.ReadLine();
            return recieved;

        }
    }
}