/// <summary>
/// Adds a student to waiting list of specific course given by ID
/// </summary>
/// <param name="id">ID of the course</param>
/// <param name="model">A model containing the SSN of the student</param>
/// <returns>A personDTO of the student</returns>
public StudentDTO AddStudentToWaitingList(int id, AddStudentViewModel model)
{
// Validate
var courseEntity = _db.Courses.SingleOrDefault(x => x.ID == id);
if (courseEntity == null)
{
throw new AppObjectNotFoundException();
}
//verify that the person exists!
var person = _db.Persons.SingleOrDefault(x => x.SSN == model.SSN);
if (person == null)
{
throw new AppObjectNotFoundException();
}
//check if student already in course
var studentAlreadyInCourse = (from cs in _db.CourseStudents
where cs.CourseID == id
&& person.ID == cs.PersonID
select cs).SingleOrDefault();
if (studentAlreadyInCourse != null)
{
throw new DuplicateEntryException();
}
//make sure person is not currently on the waiting list
var onWaitingList = (from cwl in _db.CourseWaitingList
where cwl.CourseID == id
&& person.ID == cwl.PersonID
select cwl).SingleOrDefault();
if(onWaitingList != null)
{
throw new DuplicateEntryException();
}
var waitingEntity = new CourseWaitingList
{
CourseID = id,
PersonID = person.ID
};
_db.CourseWaitingList.Add(waitingEntity);
_db.SaveChanges();
var result = new StudentDTO
{
SSN = model.SSN,
Name = person.Name
};
return result;
}
public IHttpActionResult AddStudentToWaitingList(int id, AddStudentViewModel model)
{
if(ModelState.IsValid)
{
try
{
var result = _service.AddStudentToWaitingList(id, model);
return Content(HttpStatusCode.OK, result);
}
catch (AppObjectNotFoundException)
{
return StatusCode(HttpStatusCode.NotFound);
}
catch(DuplicateEntryException)
{
return StatusCode(HttpStatusCode.PreconditionFailed);
}
}
else
{
return StatusCode(HttpStatusCode.PreconditionFailed);
}
}
/// <summary>
/// Adds a student to a given course
/// </summary>
/// <param name="id"></param>
/// <param name="model"></param>
/// <returns></returns>
public StudentDTO AddStudentToCourse(int id, AddStudentViewModel model)
{
var course = _db.Courses.SingleOrDefault(x => x.ID == id);
//if course doesn't exist an error will be thrown. Not possible to add student to non existing courses
if (course == null)
{
throw new AppObjectNotFoundException();
}
//verify that the person exists!
var person = _db.Persons.SingleOrDefault(x => x.SSN == model.SSN);
if(person == null)
{
throw new AppObjectNotFoundException();
}
//count students in the course
var countStudents = _db.CourseStudents.Count(x => x.CourseID == course.ID);
//stop adding new students if course is full
if(countStudents >= course.MaxStudents)
{
throw new MaxStudentException();
}
//check if student already in course
var studentAlreadyInCourse = (from cs in _db.CourseStudents
where cs.CourseID == id
&& person.ID == cs.PersonID
select cs).SingleOrDefault();
if (studentAlreadyInCourse != null)
{
throw new DuplicateEntryException();
}
//check if person is on the waitinglist
var isOnWaitList = (from cwl in _db.CourseWaitingList
//join p in _db.Persons on cwl.PersonID equals p.ID
where cwl.CourseID == id
&& person.ID == cwl.PersonID
select cwl).SingleOrDefault();
//person is on the waitinglist
if(isOnWaitList != null)
{
_db.CourseWaitingList.Remove(isOnWaitList);
_db.SaveChanges();
}
//Actually add the record
var courseStudent = new CourseStudent
{
PersonID = person.ID,
CourseID = course.ID
};
_db.CourseStudents.Add(courseStudent);
_db.SaveChanges();
//3.Figure out what to return.
var returnValue = new StudentDTO
{
Name = person.Name,
SSN = person.SSN
};
return returnValue;
}
public IHttpActionResult AddStudentToCourse(int id, AddStudentViewModel model)
{
// Validation
if (ModelState.IsValid)
{
try
{
// Add student to the course and return the StudentDTO
var result = _service.AddStudentToCourse(id, model);
return Content(HttpStatusCode.Created, result);
}
catch(AppObjectNotFoundException)
{
return StatusCode(HttpStatusCode.NotFound);
}
catch (MaxStudentException)
{
return StatusCode(HttpStatusCode.PreconditionFailed);
}
catch (DuplicateEntryException)
{
return StatusCode(HttpStatusCode.PreconditionFailed);
}
}
else
{
return StatusCode(HttpStatusCode.PreconditionFailed);
}
}
