public void ConnectDoctor(string username)
        {
            business = new ConversationBusiness(_db);
            var id = Context.ConnectionId;

            var doctor = _db.Doctors.Where(x=>x.Username.Equals(username)).FirstOrDefault();
            var doctorDetail = Doctors.Where(x => x.Username.Equals(username)).FirstOrDefault();

            //Update Doctor list status
            if (doctorDetail == null)
            {
                doctorDetail = new DoctorDetail
                {
                    ConnectionId = id,
                    CountMessageUnRead = business.CountMessageUnRead(doctor),
                    ProfilePicture = doctor.ProfilePicture,
                    IsOnline = doctor.IsOnline,
                    FullName = doctor.FullName,
                    Username = doctor.Username,
                    SpeciatyField = doctor.SpecialtyField.Name
                };
                Doctors.Add(doctorDetail);
            }
            else
            {
                doctorDetail.CountMessageUnRead = business.CountMessageUnRead(doctor);
                doctorDetail.IsOnline = doctor.IsOnline;
            }

            //Add User
            UserDetail userDetail = new UserDetail
            {
                ConnectionId = id,
                CountMessageUnRead = business.CountMessageUnRead(doctor),
                ProfilePicture = doctor.ProfilePicture,
                FullName = doctor.FullName,
                Username = doctor.Username,
            };

            //Show List of Lastest contact
            var userDetailList = new List<UserDetail>();

            var conversations = _db.Conversations.Where(
                x => x.DoctorId == doctor.UserId).
                OrderByDescending(x=>x.LatestTimeFromPatient
                ).ToList();

            foreach (var conversation in conversations)
            {
                var existUser = userDetailList.Where
                    (x => x.Username == conversation.Patient.Username).FirstOrDefault();
                if (existUser == null)
                {
                    //Check user online or not
                    var connectedUser = ConnectedUsers.Where
                        (x => x.Username == conversation.Patient.Username).FirstOrDefault();
                    var IsOnline = (connectedUser != null && connectedUser.IsOnline) ? true: false;
                    UserDetail userDetailCon = new UserDetail
                    {
                        FullName = conversation.Patient.FullName,
                        LastestContent = conversation.LatestContentFromPatient,
                        LastestTime = conversation.LatestTimeFromPatient,
                        ProfilePicture = conversation.Patient.ProfilePicture,
                        Username = conversation.Patient.Username,
                        IsRead = conversation.IsRead,
                        IsOnline = IsOnline
                    };
                    userDetailList.Add(userDetailCon);
                }
            }

            ConnectedUsers.Add(userDetail);

            Debug.WriteLine("Size of userDetailList: " + userDetailList.Count);

            // send to all except caller client
            Clients.Caller.onGetConversationList(userDetailList);

            Clients.AllExcept(id).onGetDoctorList(Doctors);
        }
        public void ConnectPatient(string username)
        {
            business = new ConversationBusiness(_db);
            var id = Context.ConnectionId;
            var userDetail = ConnectedUsers.Where(x => x.Username.Equals(username)).FirstOrDefault();
            if (userDetail == null)
            {
                var user = _db.Users.Where(x => x.Username.Equals(username)).FirstOrDefault();
                ConnectedUsers.Add(new UserDetail { ConnectionId = id,
                    Username = username, CountMessageUnRead = 0,
                    FullName = user.FullName, ProfilePicture = user.ProfilePicture,
                    IsOnline = true
                });

                var DoctorListDB = _db.Doctors.ToList();
                foreach (var doctor in DoctorListDB)
                {
                    if (Doctors.Where(d => d.Username.Equals(doctor.Username)).FirstOrDefault() == null)
                    {
                        DoctorDetail doctorDetail = new DoctorDetail
                        {
                            FullName = doctor.FullName,
                            IsOnline = false,
                            SpeciatyField = doctor.SpecialtyField.Name,
                            Username = doctor.Username,
                            ProfilePicture = doctor.ProfilePicture
                        };
                        Doctors.Add(doctorDetail);
                    }
                }

                // send to caller
                Clients.Caller.onGetDoctorList(Doctors);
            }
        }