public bool RemoveInstructorFromCourse(string userId, string instructorEmail, string courseName)
{
var result = false;
try
{
var log = UpdateLog(userId, DatabaseOperation.edit, TableName.Course, courseName);
if (!log)
{
throw new Exception();
}
var instructor = db.Users.FirstOrDefault(x => x.Email == instructorEmail);
Course course = db.Courses.FirstOrDefault(x => x.Name == courseName);
ApplicationUserCourse applicationUserCourse = db.ApplicationUserCourses.FirstOrDefault(x => x.ApplicationUserId == instructor.Id);
db.ApplicationUserCourses.Remove(applicationUserCourse);
course.ApplicationUsers.Remove(applicationUserCourse);
instructor.Courses.Remove(applicationUserCourse);
db.SaveChanges();
result = true;
return(result);
}
catch (Exception)
{
return(result);
}
}
public bool RegisterForCourse(string userId, string courseName, string studentId)
{
try
{
var log = UpdateLog(userId, DatabaseOperation.add, TableName.Course, courseName);
if (!log)
{
throw new Exception();
}
var student = db.Users.Find(studentId);
var result = db.Courses.FirstOrDefault(x => x.Name == courseName);
if (result == null || student == null)
{
throw new Exception();
}
result.Capacity--;
ApplicationUserCourse application = new ApplicationUserCourse();
application.CourseId = result.Id;
application.Course = result;
application.ApplicationUserId = student.Id;
application.ApplicationUser = student;
application.DateJoined = DateTime.Now;
db.ApplicationUserCourses.Add(application);
db.SaveChanges();
return(true);
}
catch (Exception)
{
return(false);
}
}
public bool AddStudentsToCourse(string userId, List <string> studentEmails, string courseName)
{
var result = false;
try
{
var log = UpdateLog(userId, DatabaseOperation.add, TableName.Course, courseName);
if (!log)
{
throw new Exception();
}
var course = db.Courses.FirstOrDefault(x => x.Name == courseName);
if (course == null || course.Capacity < studentEmails.Count())
{
throw new Exception();
}
var length = db.ApplicationUserCourses.Count();
var students = db.Users.Where(x => studentEmails.Contains(x.Email)).ToList();
foreach (var student in students)
{
ApplicationUserCourse applicationUserCourse = new ApplicationUserCourse();
applicationUserCourse.ApplicationUserId = student.Id;
applicationUserCourse.CourseId = course.Id;
applicationUserCourse.Course = course;
applicationUserCourse.ApplicationUser = student;
applicationUserCourse.DateJoined = DateTime.Now;
course.ApplicationUsers.Add(applicationUserCourse);
}
db.SaveChanges();
if (length + studentEmails.Count() != db.ApplicationUserCourses.Count())
{
throw new Exception();
}
// if there is an error in updated database then i should delete any updated data.
result = true;
}
catch (Exception)
{
result = false;
}
return(result);
}
public bool AddStudentToACourse(string userId, string studentEmail, string courseName)
{
bool result = false;
try
{
var log = UpdateLog(userId, DatabaseOperation.add, TableName.Course, courseName);
if (!log)
{
throw new Exception();
}
var student = db.Users.FirstOrDefault(x => x.Email == studentEmail);
var course = db.Courses.FirstOrDefault(x => x.Name == courseName);
if (student == null || course == null)
{
throw new Exception();
}
var length = db.ApplicationUserCourses.Count();
ApplicationUserCourse applicationUserCourse = new ApplicationUserCourse();
applicationUserCourse.ApplicationUserId = student.Id;
applicationUserCourse.CourseId = course.Id;
applicationUserCourse.Course = course;
applicationUserCourse.ApplicationUser = student;
applicationUserCourse.DateJoined = DateTime.Now;
course.ApplicationUsers.Add(applicationUserCourse);
db.SaveChanges();
if (length + 1 == db.ApplicationUserCourses.Count())
{
result = true;
}
return(result);
}
catch (Exception)
{
return(result);
}
}
public bool RemoveStudentFromCourse(string userId, string courseName, string studentEmail)
{
var result = false;
try
{
var log = UpdateLog(userId, DatabaseOperation.edit, TableName.Course, courseName);
if (!log)
{
throw new Exception();
}
var student = db.Users.FirstOrDefault(x => x.Email == studentEmail);
Course course = db.Courses.FirstOrDefault(x => x.Name == courseName);
if (student == null || course == null)
{
throw new Exception();
}
ApplicationUserCourse applicationUserCourse = db.ApplicationUserCourses.FirstOrDefault(x => x.CourseId == course.Id && x.ApplicationUserId == student.Id);
db.ApplicationUserCourses.Remove(applicationUserCourse);
course.ApplicationUsers.Remove(applicationUserCourse);
var users = db.Users.Where(x => x.Courses.Contains(applicationUserCourse)).ToList();
users.ForEach(user =>
{
user.Courses.Remove(applicationUserCourse);
});
result = true;
}
catch (Exception)
{
}
return(result);
}
public bool AddInstructorToCourse(string userId, string courseName, string instructorId)
{
// course can contain multiple instructors.
var result = false;
try
{
var log = UpdateLog(userId, DatabaseOperation.add, TableName.Course, courseName);
if (!log)
{
throw new Exception();
}
var instructor = db.Users.Find(instructorId);
Course course = db.Courses.FirstOrDefault(x => x.Name == courseName);
if (instructor == null || course == null || instructor.Type == null)
{
throw new Exception();
}
ApplicationUserCourse applicationUserCourse = new ApplicationUserCourse();
applicationUserCourse.ApplicationUserId = instructor.Id;
applicationUserCourse.ApplicationUser = instructor;
applicationUserCourse.CourseId = course.Id;
applicationUserCourse.Course = course;
applicationUserCourse.DateJoined = DateTime.Now;
course.ApplicationUsers.Add(applicationUserCourse);
db.SaveChanges();
result = true;
return(result);
}
catch (Exception)
{
return(result);
}
}
