public void SendMessage(int?ddCourses, string textMessage)
{
var controller = User is StudentViewModel ? "Student" : "Teacher";
var usersInCourse = _studentAppService.GetUsersForStudent(CurrentUser.Id).Where(s => s.Courses.Any(c => c.Id.Equals(ddCourses.Value)));
var users = ddCourses != null?_userAppService.GetUsersByCourse(ddCourses.Value).Where(u => !u.Id.Equals(CurrentUser.Id)).ToList() : new List <UserViewModel>();
users.AddRange(userList);
List <Message> messages = StudentMessageViewModelFactory.CreateUserMessage(users, textMessage, CurrentUser);
_messageAppService.AddMessages(messages);
userList = new List <UserViewModel>();
}