/// <summary>
/// Method that adds a student to a course with a given ID.
/// The attributes needed to add a student to a course are given with
/// a view model class.
/// </summary>
/// <param name="id">ID of the course</param>
/// <param name="model">Add student view model (ViewModel class)</param>
/// <returns>The student that was added to the course (DTO class)</returns>
public StudentDTO AddStudentToCourse(int id, AddStudentViewModel model)
{
var course = _db.Courses.SingleOrDefault(x => x.ID == id);
var student = _db.Students.SingleOrDefault(x => x.SSN == model.SSN);
if (course == null || student == null)
{
throw new AppObjectNotFoundException();
}
var studentInCourse = _db.CourseStudents.SingleOrDefault(x => x.CourseID == id && x.StudentID == student.ID && x.IsActive == true);
if(studentInCourse != null)
{
throw new AppObjectIllegalAddException();
}
if (course.MaxStudents <= GetStudentsInCourse(id).Count)
{
throw new AppMaxReachedException();
}
var studentInWaitingList = _db.WaitingLists.SingleOrDefault(x => x.CourseID == id && x.StudentID == student.ID);
if(studentInWaitingList != null)
{
_db.WaitingLists.Remove(studentInWaitingList);
}
var courseStudent = _db.CourseStudents.SingleOrDefault(x => x.CourseID == id && x.StudentID == student.ID && x.IsActive == false);
if(courseStudent != null)
{
courseStudent.IsActive = true;
}
else
{
var newCourseStudent = new CourseStudent
{
CourseID = course.ID,
StudentID = student.ID,
IsActive = true
};
_db.CourseStudents.Add(newCourseStudent);
}
_db.SaveChanges();
var result = new StudentDTO
{
Name = student.Name,
SSN = student.SSN
};
return result;
}
/// <summary>
/// Method that returns a student with a given SSN in a
/// course with a given ID.
/// </summary>
/// <param name="id">ID of the course</param>
/// <param name="SSN">SSN of the student</param>
/// <returns>Single student (DTO class)</returns>
public StudentDTO GetStudentInCourse(int id, string SSN)
{
var course = _db.Courses.SingleOrDefault(x => x.ID == id);
var student = _db.Students.SingleOrDefault(x => x.SSN == SSN);
var courseStudent = _db.CourseStudents.SingleOrDefault(x => x.CourseID == id && x.StudentID == student.ID && x.IsActive == true);
if (course == null || student == null || courseStudent == null)
{
throw new AppObjectNotFoundException();
}
var result = new StudentDTO
{
Name = student.Name,
SSN = student.SSN
};
return result;
}