public async Task SendMessage(string message)
{
int studentId = Context.User.GetUserId();
ChatMessageDTO chatMessage = new ChatMessageDTO()
{
Message = message,
SentOn = DateTime.Now,
StudentId = studentId
};
StudentDTO student = await _studentService.GetStudentById(studentId);
await Clients.All.SendAsync("ReceiveMessage", student.Initials, student.Username, message, Context.User.IsAdministrator());
await _chatMessageService.Add(chatMessage);
}