private StudentViewModel UpdateStudentEnrollments(List <int> selectedCourses, StudentViewModel studentViewModel)
{
Student student = _StudentRepo.GetStudentById(studentViewModel.ID);
List <EnrollmentViewModel> studentExistingEnrollments = student.Enrollments.Select(e => new EnrollmentViewModel
{
EnrollmentID = e.EnrollmentID,
CourseID = e.CourseID,
StudentID = e.StudentID,
Course = new CourseViewModel {
CourseID = e.Course.CourseID, Title = e.Course.Title, Credits = e.Course.Credits
}
}).ToList();
studentViewModel.Enrollments = studentExistingEnrollments;
if (selectedCourses == null)
{
studentViewModel.Enrollments = new List <EnrollmentViewModel>();
return(studentViewModel);
}
var AvailableCourses = _StudentRepo.GetEnrollmentsAll();
var selectedCoursesHS = new HashSet <int>(selectedCourses);
var instructorCourses = new HashSet <int>
(studentExistingEnrollments.Select(e => e.Course.CourseID));
foreach (var course in AvailableCourses)
{
if (selectedCoursesHS.Contains(course.CourseID))
{
if (!instructorCourses.Contains(course.CourseID))
{
EnrollmentViewModel newEnrollment = new EnrollmentViewModel();
newEnrollment.Course = new CourseViewModel {
CourseID = course.CourseID, Title = course.Title, Credits = course.Credits
};
newEnrollment.CourseID = course.CourseID;
newEnrollment.StudentID = student.ID;
studentViewModel.Enrollments.Add(newEnrollment);
}
}
else
{
if (instructorCourses.Contains(course.CourseID))
{
EnrollmentViewModel deleteEnrollmentViewModel = studentViewModel.Enrollments.Where(e => e.Course.CourseID == course.CourseID).FirstOrDefault();
studentViewModel.Enrollments.Remove(deleteEnrollmentViewModel);
}
}
}
return(studentViewModel);
}