public LastAnswerSheetResult GetLastAnswerSheet(string sessionToken)
{
var result = new LastAnswerSheetResult();
var userId = _checkSessionToken(sessionToken, result);
if (userId.HasValue)
{
var answerSheets = mContext.AnswerSheet
.Where(a => a.IsClosed != true && a.UserId == userId)
.OrderByDescending(a => a.Id)
.ToArray();
Models.AnswerSheet lastAnswerSheet = null;
Models.Exam lastExam = null;
foreach (var item in answerSheets)
{
var exam = mContext.Exam.FirstOrDefault(e => e.Id == item.ExamId);
if (exam != null)
{
var deadline = item.CreatedAt.AddMinutes(exam.Time);
if (deadline < DateTime.Now && lastAnswerSheet == null)
{
lastAnswerSheet = item;
lastExam = exam;
}
else
{
item.IsClosed = true;
}
}
}
mContext.SaveChanges();
result.AnswerSheet = lastAnswerSheet;
result.Exam = lastExam;
}
return(result);
}
public BasicResult MakeExam(string sessionToken, Models.Exam exam, int numberOf)
{
var result = new BasicResult();
var userId = _checkSessionToken(sessionToken, result);
if (userId.HasValue)
{
var quizzesId = mContext.Quizzes
.Where(q => q.Subject.Equals(exam.Subject))
.Select(q => q.Id)
.ToArray();
var count = quizzesId.Length;
if (count > numberOf)
{
var idies = new long[numberOf];
var random = new Random();
while (numberOf > 0)
{
var idx = quizzesId[random.Next(0, count)];
if (idies.Contains(idx) == false)
{
idies[--numberOf] = idx;
}
}
exam.Quizzes = string.Join(",", idies.Select(x => x.ToString()).ToArray());
mContext.Exam.Add(exam);
mContext.SaveChanges();
}
else
{
result.MessageError = string.Format("Số lượng câu hỏi lớn hơn số lượng câu hỏi trong CSDL.");
}
}
return(result);
}