namespace _8246_Server_Application
{
    public delegate void MesageEventHandler(object sender, string msg);
    
    public class ServerApp
    {
        private string status = "Connected" ;
        NetworkStream socketStream;
        DatabaseApp databaseapp = new DatabaseApp();
        string SQLcommand = "hello";

        public event MesageEventHandler MessageHandler;
        
        public void OnMessage(string message)
        {
            if (MessageHandler != null)
            {
                MessageHandler(this, message);
            }
            
        }
        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
            
            try
            {
                //creates an instance Tcp listenter to listen for connections on port 43
                listener = new TcpListener(IPAddress.Any, 43);

                while (true)
                {
                    //begins listening for incoming connections
                    listener.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();
                    //closes the socket stream
                    socketStream.Close();
                    //closes connection
                    connection.Close();
                   
                }
                
            }
            catch (Exception e)
            {
                e.ToString();
            } 
        }
        public string doRequest()
        {
            //streamReader reads incoming connection from client
            StreamWriter sw = new StreamWriter(socketStream);
            StreamReader sr = new StreamReader(socketStream);
            //writes in coming data
           //Assigns data from the streamreader to a string
            string clientInfo = sr.ReadLine();
            int pos = clientInfo.IndexOf(" ");
            if(pos > 0)
            {
                SQLcommand = "UPDATE information SET location = 'In the Lab' WHERE username = '123456'";
                status = "Database Updated";
            }  
            else 
            {
                status = "Searched Database";
                SQLcommand = "SELECT From D";
            }
          
           sw.WriteLine(status);
           sw.Flush();
           OnMessage(databaseapp.RunDatabase());
           return SQLcommand;
        }
    }
}

public string RunDatabase()
        {
            ServerApp serverapp = new ServerApp();

            
            
            //create a connection to a Microsoft database entited Server.mdb in the C drive
            OleDbConnection aConnection = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=c:\\ACWcoursework.mdb");
        
           //creates global OleDbCommand to be used later in the program
           OleDbCommand readCommand = new OleDbCommand();
          
         
           //if user inputs anything else than database displayed in table
           readCommand = new OleDbCommand(serverapp.DoRequest(),    Connection);