/// <summary>
/// This method adds a Course with the information from the CourseViewModel
/// </summary>
/// <param name="newCourse">Course containing all the information needed to add a new course</param>
/// <returns></returns>
public CourseDetailsDTO AddCourse(CourseViewModel newCourse)
{
// Check if the course exists
var courseTemplate = _db.CourseTemplates.SingleOrDefault(x => x.TemplateID == newCourse.CourseID);
if (courseTemplate == null)
{
throw new TemplateCourseNotFoundException();
}
Entities.Course course = new Entities.Course
{
ID = _db.Courses.Any() ? _db.Courses.Max(x => x.ID) + 1 : 1,
TemplateID = courseTemplate.ID,
Semester = newCourse.Semester,
StartDate = newCourse.StartDate,
EndDate = newCourse.EndDate
};
_db.Courses.Add(course);
_db.SaveChanges();
return(new CourseDetailsDTO
{
ID = course.ID,
TemplateID = courseTemplate.TemplateID,
Name = courseTemplate.Name,
Description = courseTemplate.Description,
Semester = course.Semester,
StartDate = newCourse.StartDate,
EndDate = newCourse.EndDate,
StudentCount = _db.StudentEnrollment.Count(x => x.CourseID == course.ID)
});
}
/// <summary>
/// adds a new instance of a course to the database
/// </summary>
/// <param name="model"></param>
/// <returns></returns>
public CourseDTO AddNewCourse(CourseViewModel model)
{
//check if course already in database
//add the course
var newCourse = new Course
{
TemplateID = model.TemplateID,
Semester = model.Semester,
StartDate = model.StartDate,
EndDate = model.EndDate,
MaxStudents = model.MaxStudents
};
_db.Courses.Add(newCourse);
_db.SaveChanges();
//find the Name of the course
var courseTemplate = (from ct in _db.CourseTemplates
where ct.TemplateID == model.TemplateID
select ct).SingleOrDefault();
var result = new CourseDTO
{
ID = newCourse.ID,
Name = courseTemplate.Name,
StartDate = newCourse.StartDate,
StudentCount = 0
};
return result;
}
/// <summary>
/// Deletes a course
/// Note : This is a course not a course template.
/// </summary>
/// <param name="id">The ID of the course to delete</param>
public void DeleteCourse(int id)
{
// Get the course
Entities.Course course = _db.Courses.SingleOrDefault(x => x.ID == id);
if (course == null)
{
throw new CourseNotFoundException();
}
using (var transaction = _db.Database.BeginTransaction())
{
try
{
// Remove all the students from the course
foreach (Entities.StudentEnrollment enrollment in _db.StudentEnrollment.Where(x => x.CourseID == course.ID))
{
_db.StudentEnrollment.Remove(enrollment);
_db.SaveChanges();
}
_db.Courses.Remove(course); // Remove the course
_db.SaveChanges();
transaction.Commit();
}
catch (Exception)
{
transaction.Rollback();
throw new DeleteFromDatabaseException();
}
}
}
/// <summary>
/// Updates a course that already exists
/// Note that this edits a Course, not a CourseTemplate.
/// Only start and end date are editable
/// </summary>
/// <param name="courseID">The ID of the course to edit</param>
/// <param name="updateCourse">a course with the information to edit</param>
/// <returns></returns>
public CourseDetailsDTO UpdateCourse(int courseID, UpdateCourseViewModel updateCourse)
{
// Get the course, throw exception if the course is not found
Entities.Course course = _db.Courses.SingleOrDefault(x => x.ID == courseID);
if (course == null)
{
throw new CourseNotFoundException();
}
// Check if the course tamplate exists
var courseTemplate = _db.CourseTemplates.SingleOrDefault(x => x.ID == course.TemplateID);
if (courseTemplate == null)
{
throw new TemplateCourseNotFoundException();
}
// Update the start and end date based on the view model
course.StartDate = updateCourse.StartDate;
course.EndDate = updateCourse.EndDate;
// If all is successfull, we save our changes
_db.SaveChanges();
return(new CourseDetailsDTO
{
ID = course.ID,
TemplateID = courseTemplate.TemplateID,
Name = courseTemplate.Name,
Description = courseTemplate.Description,
Semester = course.Semester,
StartDate = updateCourse.StartDate,
EndDate = updateCourse.EndDate,
StudentCount = _db.StudentEnrollment.Count(x => x.CourseID == course.ID),
Students = (from sr in _db.StudentEnrollment
join s in _db.Students on sr.StudentID equals s.ID
where sr.CourseID == course.ID
select new StudentDTO
{
SSN = s.SSN,
Name = s.Name
}).ToList()
});
}
/// <summary>
/// Gets a student with the given SSN and that is registered in the given course
/// </summary>
/// <param name="courseID">The id of the course</param>
/// <param name="newStudent">The student</param>
/// <returns>The student</returns>
public StudentDTO GetStudentInCourse(int courseID, string studentSSN)
{
Entities.Course course = _db.Courses.SingleOrDefault(x => x.ID == courseID);
if (course == null)
{
throw new CourseNotFoundException();
}
StudentDTO student = (from s in _db.Students
join sr in _db.StudentEnrollment on s.ID equals sr.StudentID
where sr.CourseID == course.ID && s.SSN == studentSSN
select new StudentDTO
{
SSN = s.SSN,
Name = s.Name
}).SingleOrDefault();
if (student == null)
{
throw new StudentNotFoundException();
}
return(student);
}
/// <summary>
/// Method that adds a new course to the database.
/// The attributes needed to add a new course are given with a view model class.
/// </summary>
/// <param name="model">Add course view model (ViewModel class)</param>
/// <returns>The newly added course (DTO class)</returns>
public CourseDTO CreateCourse(AddCourseViewModel model)
{
var courseTemplate = _db.CourseTemplates.SingleOrDefault(x => x.TemplateID == model.TemplateID);
if (courseTemplate == null)
{
throw new AppInternalServerException();
}
var course = new Course
{
TemplateID = model.TemplateID,
StartDate = model.StartDate,
EndDate = model.EndDate,
Semester = model.Semester,
MaxStudents = model.MaxStudents
};
_db.Courses.Add(course);
_db.SaveChanges();
var result = new CourseDTO
{
ID = course.ID,
Name = course.TemplateID,
StartDate = course.StartDate,
StudentCount = 0
};
return result;
}
/// <summary>
/// This method adds a Course with the information from the CourseViewModel
/// </summary>
/// <param name="newCourse">Course containing all the information needed to add a new course</param>
/// <returns></returns>
public CourseDetailsDTO AddCourse(CourseViewModel newCourse)
{
// Check if the course exists
var courseTemplate = _db.CourseTemplates.SingleOrDefault(x => x.TemplateID == newCourse.TemplateID);
if (courseTemplate == null)
{
throw new TemplateCourseNotFoundException();
}
Entities.Course course = new Entities.Course
{
ID = _db.Courses.Any() ? _db.Courses.Max(x => x.ID) + 1 : 1,
TemplateID = courseTemplate.ID,
Semester = newCourse.Semester,
StartDate = newCourse.StartDate,
EndDate = newCourse.EndDate,
MaxStudents = newCourse.MaxStudents
};
_db.Courses.Add(course);
_db.SaveChanges();
return new CourseDetailsDTO
{
ID = course.ID,
TemplateID = courseTemplate.TemplateID,
Name = courseTemplate.Name,
Description = courseTemplate.Description,
Semester = course.Semester,
StartDate = newCourse.StartDate,
EndDate = newCourse.EndDate,
StudentCount = _db.StudentEnrollment.Count(x => x.CourseID == course.ID
&& x.IsActive == true
&& x.IsOnWaitingList == false),
Students = (from sr in _db.StudentEnrollment
join s in _db.Students on sr.StudentID equals s.ID
where sr.CourseID == course.ID
&& sr.IsActive == true
&& sr.IsOnWaitingList == false
select new StudentDTO
{
SSN = s.SSN,
Name = s.Name
}).ToList()
};
}
/// <summary>
/// Adds a course.
/// </summary>
/// <param name="courseVM">The course view model.</param>
/// <returns>Returns the course DTO. Or null if there's no matching course template.</returns>
public CourseDTO AddCourse(CourseViewModel courseVM)
{
//Find the name for the course
string courseName = (from c in _context.Courses
join ct in _context.CourseTemplates
on c.TemplateID equals ct.TemplateID
where ct.TemplateID == courseVM.TemplateID
select ct.Name).FirstOrDefault();
if (string.IsNullOrEmpty(courseName))
{
return null; //If there is no course with the given templateID, we return null..
}
Course course = new Course { TemplateID = courseVM.TemplateID, StartDate = courseVM.StartDate, EndDate = courseVM.EndDate, Semester = courseVM.Semester };
_context.Courses.Add(course);
_context.SaveChanges();
//EF is brilliant.. adds the ID to the Course..
return new CourseDTO { ID = course.ID, Name = courseName, Semester = course.Semester, StartDate = course.StartDate };
}
/// <summary>
/// This method adds a Course with the information from the CourseViewModel
/// </summary>
/// <param name="newCourse">Course containing all the information needed to add a new course</param>
/// <returns></returns>
public CourseDetailsDTO AddCourse(CourseViewModel newCourse)
{
// Check if the course exists
var courseTemplate = _db.CourseTemplates.SingleOrDefault(x => x.TemplateID == newCourse.CourseID);
if (courseTemplate == null)
{
throw new TemplateCourseNotFoundException();
}
Entities.Course course = new Entities.Course
{
ID = _db.Courses.Any() ? _db.Courses.Max(x => x.ID) + 1 : 1,
TemplateID = courseTemplate.ID,
Semester = newCourse.Semester,
StartDate = newCourse.StartDate,
EndDate = newCourse.EndDate
};
_db.Courses.Add(course);
_db.SaveChanges();
return new CourseDetailsDTO
{
ID = course.ID,
TemplateID = courseTemplate.TemplateID,
Name = courseTemplate.Name,
Description = courseTemplate.Description,
Semester = course.Semester,
StartDate = newCourse.StartDate,
EndDate = newCourse.EndDate,
StudentCount = _db.StudentEnrollment.Count(x => x.CourseID == course.ID)
};
}
/// <summary>
/// Adds a course.
/// </summary>
/// <exception cref="AppObjectNotFoundException">Thrown if we can't find a course with the given templateID.</exception>
/// <param name="courseVM">The course view model.</param>
/// <returns>Returns the course DTO.</returns>
public CourseDTO AddCourse(CourseViewModel courseVM)
{
//Find the name for the course
string courseName = _context.CourseTemplates.Where(ct => ct.TemplateID == courseVM.TemplateID).Select(ct => ct.Name).SingleOrDefault();
if (string.IsNullOrEmpty(courseName))
{
throw new AppObjectNotFoundException();
}
Course course = new Course { TemplateID = courseVM.TemplateID, StartDate = courseVM.StartDate, EndDate = courseVM.EndDate, Semester = courseVM.Semester, MaxStudents = courseVM.MaxStudents };
_context.Courses.Add(course);
_context.SaveChanges();
//EF is brilliant.. adds the ID to the Course..
return new CourseDTO { ID = course.ID, Name = courseName, Semester = course.Semester, StartDate = course.StartDate, MaxStudents = course.MaxStudents };
}
