/// <summary>
/// Replaces the course with the given id's StartDate and EndDate with the given information
/// If course is not found exception is thrown.
/// </summary>
/// <param name="id">The ID of the course to update</param>
/// <param name="model">The course object to update with</param>
public CourseDTO UpdateCourse(int id, UpdateCourseViewModel model)
{
// Finds the course asked for
var course = _db.Courses.SingleOrDefault(x => x.ID == id);
if (course == null)
{
throw new AppObjectNotFoundException();
}
course.StartDate = model.StartDate;
course.EndDate = model.EndDate;
_db.SaveChanges();
// Check if there is a template available for the course
var templateId = _db.CourseTemplates.SingleOrDefault(x => x.TemplateID == course.TemplateID);
if (templateId == null)
{
throw new AppServerErrorException();
}
// Check how many students are enrolled in the class
var studentCount = (from cr in _db.CourseRegistrations
where course.ID == cr.ID
select cr.StudentID).ToList().Count();
// Construct a new CourseDTO to return to the client
var updatedCourse = new CourseDTO
{
ID = course.ID,
EndDate = course.EndDate,
StartDate = course.StartDate,
Name = templateId.Name,
Semester = course.Semester,
StudentCount = studentCount
};
return updatedCourse;
}
/// <summary>
/// Adds a course with a pre existing CourseTemplate to the database,
/// If there is no template available an exception is thrown,
/// Or if the course object is not valid an exception is thrown
/// </summary>
/// <param name="course">A course object containing the information to create the new course</param>
/// <returns>The course object</returns>
public CourseDTO AddCourse(AddCourseViewModel course)
{
//Check if there is a template for the course
var courseTemplate = _db.CourseTemplates.SingleOrDefault(x => x.TemplateID == course.TemplateID);
if (courseTemplate == null)
{
throw new AppObjectNotFoundException();
}
//Create a new Course object to add to the database
var newCourse = new Course
{
EndDate = course.EndDate,
StartDate = course.StartDate,
TemplateID = course.TemplateID,
MaxStudents = course.MaxStudents,
Semester = course.Semester
};
if (newCourse == null)
{
throw new AppBadRequestException();
}
//Add the new course to the database
_db.Courses.Add(newCourse);
_db.SaveChanges();
// Get the course object for the ID of the returned CourseDTO
var courseId = _db.Courses.SingleOrDefault(x => x.ID == newCourse.ID);
if (courseId == null)
{
// If the course is not found, there are inconsistancies
// in the database:
throw new AppServerErrorException();
}
var studentCount = (from cr in _db.CourseRegistrations
where courseId.ID == cr.ID
where cr.Active
select cr.StudentID).ToList().Count();
//Make a new CourseDTO to return to the client
var courseDto = new CourseDTO
{
ID = courseId.ID,
StartDate = course.StartDate,
EndDate = course.EndDate,
Name = courseTemplate.Name,
Semester = course.Semester,
StudentCount = studentCount
};
if (courseDto == null)
{
throw new AppBadRequestException();
}
return courseDto;
}