severConsole.cs

using System;
using System.Runtime.Remoting;
using System.Runtime.Remoting.Channels;
using System.Runtime.Remoting.Channels.Tcp;
using OperClassSpace;
using ServerAppSpace;
using ServerClassSpace;
using LinkedList;

namespace Server
{
    class ProgramServer : IServerApp
    {
        private LinkedList.LinkedList userList = new LinkedList.LinkedList();
        private static int _globalPortNo = 10000;

        [STAThread]
        public static void Main(string[] args)
        {
            var channel = new TcpChannel(9001);
            ChannelServices.RegisterChannel(channel);

            var remService = new ServerClass();
            var obj = RemotingServices.Marshal(remService, "TcpService");

            var frmMain = new ProgramServer();

            // marshaling
            remService.TheMainServer = frmMain;

            Console.WriteLine("Server start!");
            Console.WriteLine("please press enter...");
            Console.ReadLine();

            // Сервер закрывается

            frmMain.DropClients();

            while (frmMain.userList.IsListEmpty() == false) ;//well...this part may arise question marks...when we called DropClients() method,
            //the clients will logoff the server but if the server closes before the clients loggedoff completely, clients will create exception...
            //so we will wait until all clients logs off...
            RemotingServices.Unmarshal(obj);
            RemotingServices.Disconnect(remService);
        }

        private void InvokeOper(string msg, int MsgOrUser, string receiveruser)     //This module calls the related client or clients...it will send them msg info, userlist info or both...
        {
            if (receiveruser == null)       //all users will be notified
            {
                switch (MsgOrUser)
                {
                    case 1:         //only message will be send...
                        {
                            for (userList.Init(); userList.More(); userList.Next())
                            {
                                ListItem item = userList.GetCurrent();
                                string receivermach = userList.ReadItemValue(item);
                                string receiverport = userList.ReadItemValue(userList.GotoSubitem(item, 1));

                                var clientobj =
                                    (OperClass)Activator.GetObject
                                    (
                                    typeof(OperClass),
                                    "tcp://" + receivermach + ":" + receiverport + "/TcpClient"     //====>>>> Portno here
                                    );

                                clientobj.UpdateOper(msg, null, 1);
                            }

                            break;
                        }
                    case 2:         //only userlist will be sent....because the userlist is a shared data among all clients, it will always be sent to all of the clients.
                        {
                            string usernamestring = "";
                            for (userList.Init(); userList.More(); userList.Next())
                            {
                                usernamestring += (userList.ReadItemValue(userList.GotoSubitem(userList.GetCurrent(), 2))) + ":";
                            }

                            for (userList.Init(); userList.More(); userList.Next())
                            {
                                ListItem item = userList.GetCurrent();
                                string receivermach = userList.ReadItemValue(item);
                                string receiverport = userList.ReadItemValue(userList.GotoSubitem(item, 1));

                                var clientobj =
                                    (OperClass)Activator.GetObject
                                    (
                                    typeof(OperClass),
                                    "tcp://" + receivermach + ":" + receiverport + "/TcpClient"     //====>>>> Portno here
                                    );

                                clientobj.UpdateOper(null, usernamestring, 2);
                            }
                            break;
                        }
                    case 3:         //both message and userlist info will be send....
                        {
                            string usernamestring = "";
                            for (userList.Init(); userList.More(); userList.Next())         //usernameString is the collection of all usernames separated with ":"
                            {
                                usernamestring += (userList.ReadItemValue(userList.GotoSubitem(userList.GetCurrent(), 2))) + ":";   //usernames of all online clients are collected here to pass to the client.
                            }

                            for (userList.Init(); userList.More(); userList.Next())     //iterates through the userList
                            {
                                ListItem item = userList.GetCurrent();
                                string receiverMach = userList.ReadItemValue(item);
                                string receiverPort = userList.ReadItemValue(userList.GotoSubitem(item, 1));
                                //                          string dareceiverUser = userList.ReadItemValue(userList.GotoSubitem(item, 2));


                                OperClass clientobj =
                                    (OperClass)Activator.GetObject
                                    (
                                    typeof(OperClass),
                                    "tcp://" + receiverMach + ":" + receiverPort + "/TcpClient"     //====>>>> Portno here
                                    );

                                clientobj.UpdateOper(msg, usernamestring, 3);       //msg is taken as a parameter.
                                clientobj.UpdateOper(msg, usernamestring, 3);       //msg is taken as a parameter.
                            }
                            break;
                        }
                }

            }
            else                            //message will be sent only to the receiveruser....
            {
                ListItem ptr = userList.SearchSubitem(2, receiveruser); //gets the list adress of the receiver.

                string receivermach = userList.ReadItemValue(ptr);
                string receiverport = userList.ReadItemValue(userList.GotoSubitem(ptr, 1));

                var clientobj =
                    (OperClass)Activator.GetObject
                    (
                    typeof(OperClass),
                    "tcp://" + receivermach + ":" + receiverport + "/TcpClient"     //====>>>> Portno here
                    );

                clientobj.UpdateOper(msg, null, 1);
            }
        }

        private void DropClients()
        {
            throw new NotImplementedException();
        }

        public void RegisterUser(string machinename, string portno, string username)
        {
            ListItem item = userList.AddItem(null, 0, machinename);                     //adds user to the linked list that i provided...
            userList.AddItem(item, 3, portno); //
            userList.AddItem(item, 3, username); //


            Console.WriteLine(username + " has logged in");

            string tempmsg = username + " has logged in";

            InvokeOper(tempmsg, 3, null);
        }

        public void UnRegisterUser(string machinename, string username)
        {
            int count = 0;

            ListItem ptr = null;
            ptr = userList.SearchSubitem(2, username); //gets the list adress of the receiver.

            if (ptr != null)
                count = userList.DeleteItem(machinename, ptr);

            if (count > 0)
                userList.RenumberList(count);

            string tempmsg = username + " вышел";
            Console.WriteLine(tempmsg);

            InvokeOper(tempmsg, 3, null);
        }

        public void SendMsg(string sendermachine, string senderusername, string receiverusername, bool isGlobal, string msgString)      //sends message
        {
            if (isGlobal == false)      //to the receiver user only
            {
                msgString = DateTime.Now.ToString() + "\n" + senderusername + ": " + msgString;

                ListItem ptr = userList.SearchSubitem(2, receiverusername); //gets the list adress of the receiver.
                string receiverMach = userList.ReadItemValue(ptr);

                InvokeOper(msgString, 1, receiverusername);
            }
            else                        //global message...all users will receive the message
            {
                msgString = DateTime.Now.ToString() + "\n" + "(GLOBAL) " + senderusername + ": " + msgString;
                InvokeOper(msgString, 1, null);
            }
        }

        public string GetMsgs(string machinename)
        {
            throw new NotImplementedException();
        }

        public int ServerGivePortNo()                       //assigns a port no. for each new client...
        {
            return _globalPortNo++;
        }

        public bool UserNameExists(string username)     //checks if the username exists or not
        {
            ListItem ptr = null;
            ptr = userList.SearchSubitem(2, username);      //gets the list adress of the receiver.

            if (ptr != null)
                return true;

            return false;
        }
    }
}