private async Task SaveAnswers(QuestionAnswerDto answer)
{
CourseInstanceQuestion courseInstanceQuestionEntity = await _context.FindAsync <CourseInstanceQuestion>(answer.IdCourseInstanceQuestion);
//Check if already answered.
if (courseInstanceQuestionEntity.AnsweredAt.HasValue && courseInstanceQuestionEntity.AnswerShown)
{
return;
}
IList <CourseInstanceQuestionOption> options = await _context.CourseInstancesQuestionOption
.Where(x => x.CourseInstanceQuestion.Id == courseInstanceQuestionEntity.Id)
.OrderBy(x => x.Id)
.Include(x => x.QuestionOption).ToListAsync();
if (options.Count != answer.Answers.Count)
{
throw new InvalidOperationException($"Num options in client-answer and database do not match");
}
for (int i = 0; i < options.Count; i++)
{
CourseInstanceQuestionOption optionInstanceEntity = options[i];
bool thisAnswer = answer.Answers[i];
bool optioncorrect = optionInstanceEntity.QuestionOption.IsTrue == thisAnswer;
optionInstanceEntity.Checked = thisAnswer;
optionInstanceEntity.Correct = optioncorrect;
}
courseInstanceQuestionEntity.Correct = options.All(x => x.Correct);
courseInstanceQuestionEntity.AnsweredAt = DateTime.Now;
await SaveChangesAsync();
}
private async Task <CourseInstanceDto> GetNextQuestion(CourseInstance courseInstanceEntity)
{
CourseInstanceDto result = new CourseInstanceDto();
result.IdCourse = courseInstanceEntity.IdCourse;
result.IdCourseInstance = courseInstanceEntity.Id;
Course courseEntity = await _context.FindAsync <Course>(courseInstanceEntity.IdCourse);
result.NumQuestionsAlreadyAsked = await _context.CourseInstancesQuestion.Where(x => x.CourseInstance.Id == courseInstanceEntity.Id)
.CountAsync();
result.NumQuestionsTotal = courseEntity.NumQuestionsToAsk;
//Possible Quetions Query
IQueryable <int> questionIds = PossibleQuestionsQuery(courseInstanceEntity.Id, courseEntity.Language);
int count = await questionIds.CountAsync();
if (count == 0 || result.NumQuestionsAlreadyAsked >= courseEntity.NumQuestionsToAsk)
{
result.IdCourseInstanceQuestion = 0;
result.NumQuestionsTotal = result.NumQuestionsAlreadyAsked;
result.Done = true;
await EndCourseAsync(courseInstanceEntity.Id);
}
else
{
if (count <= result.NumQuestionsTotal - result.NumQuestionsAlreadyAsked)
{
result.NumQuestionsTotal = result.NumQuestionsAlreadyAsked + count;
}
int quesitonNo = _random.Next(0, count - 1);
int questionId = await questionIds.Skip(quesitonNo).FirstAsync();
Question questionEntity = await _context.FindAsync <Question>(questionId);
//Course instance question
CourseInstanceQuestion courseInstanceQuestionEntity = new CourseInstanceQuestion
{
CourseInstance = courseInstanceEntity,
Question = questionEntity,
Number = result.NumQuestionsAlreadyAsked + 1,
};
await _context.AddAsync(courseInstanceQuestionEntity);
//Course instance question options
IList <QuestionOption> options = await _context.QuestionOptions.Where(option => option.Question.Id == questionEntity.Id).ToListAsync();
foreach (QuestionOption questionOptionEntity in options)
{
CourseInstanceQuestionOption courseInstanceQuestionOptionEntity = new CourseInstanceQuestionOption();
courseInstanceQuestionOptionEntity.QuestionOption = questionOptionEntity;
courseInstanceQuestionOptionEntity.CourseInstanceQuestion = courseInstanceQuestionEntity;
courseInstanceQuestionEntity.CourseInstancesQuestionOption.Add(courseInstanceQuestionOptionEntity);
await _context.AddAsync(courseInstanceQuestionOptionEntity);
}
await SaveChangesAsync();
result.IdCourseInstanceQuestion = courseInstanceQuestionEntity.Id;
}
return(result);
}
