private async Task <List <Document> > getDocumentsForStudent(Exam exam, Student student, string ip)
{
List <Document> documents;
if (!await db.Assignments.AnyAsync(a => a.StudentId == student.Id && db.Documents.Any(d =>
d.Id == a.DocumentId && db.Questions.Any(q =>
q.Id == d.QuestionId && q.ExamId == exam.Id))))
{
//we need to do this in one student at a time, so if multiple students hit the server
//at the same time, we'll still process them sequentially
await slim.WaitAsync();
try
{
//now that we know we haven't already given you documents
//figure out which documents to hand over
documents = await AssignmentHandler.GetStudentDocuments(db, student, exam, ip, random);
await saveDocuments(student, ip, documents);
}
finally
{
slim.Release();
}
}
else
{
//send them the same files again
documents = await db.Documents.Where(d => db.Assignments.Any(a =>
a.DocumentId == d.Id && a.StudentId == student.Id && db.Questions.Any(q =>
d.QuestionId == q.Id && db.Exams.Any(e => e.Id == q.ExamId && e.Id == exam.Id)))).ToListAsync();
await saveDocuments(student, ip, documents);
}
return(documents);
}
