public async Task <StudentGetOneTestQueryResult> Handle(StudentGetOneTestQuery request, CancellationToken cancellationToken)
{
var test = await _testRepository.GetSingleTestByIdWithIncludes(request.TestId);
var testView = new StudentGetOneTestQueryResult.TestView();
_mapper.Map(test, testView);
// TODO: Change when (if) we add temporary save
if (await _enrolementRepository.GetByStudentIdAndTestId(request.UserId.Value, test.TestId) != null)
{
testView.Completed = true;
Enrolement enrolement = await _enrolementRepository.GetByStudentIdAndTestIdWithAnswrs(request.UserId.Value, request.TestId);
foreach (EnrolementAnswer studentAnswer in enrolement.EnrolementAnswers)
{
System.Diagnostics.Debug.WriteLine(studentAnswer.AnswerId);
var question = testView.Questions
.Where(q => q.QuestionId == studentAnswer.QuestionId)
.FirstOrDefault();
if (question.SelectedAnswers == null)
{
question.SelectedAnswers = new List <StudentGetOneTestQueryResult.Answer>();
}
if (!studentAnswer.Skipped)
{
question.SelectedAnswers.Add(_mapper.Map(studentAnswer.Answer, new StudentGetOneTestQueryResult.Answer()));
question.SelectedAnswers.ToList().ForEach(a => a.Text = "");
}
}
}
else
{
testView.Questions
.ToList()
.ForEach(q =>
{
q.SelectedAnswers = new List <StudentGetOneTestQueryResult.Answer>();
q.Answers.ToList().ForEach(a => a.Correct = false);
});
}
var sorted = await SortQuestions(testView);
var isolated = testView.Questions.Where(q => !sorted.Contains(q)).ToList();
sorted.AddRange(isolated);
testView.Questions = sorted;
return(new StudentGetOneTestQueryResult
{
Test = testView
});
}
public async Task <List <StudentGetOneTestQueryResult.Question> > SortQuestions(StudentGetOneTestQueryResult.TestView test)
{
var knowledgeSpace = await _knowledgeSpaceRepository.GetSingleKnowledgeSpaceByIdWidthIncludes(test.KnowledgeSpaceId);
var edges = knowledgeSpace.Edges.ToList();
var sortedQuestions = new List <StudentGetOneTestQueryResult.Question>();
var leaves = edges.Where(edge => !edges.Any(e => e.ProblemSourceId == edge.ProblemTargetId)).Select(e => e.ProblemTargetId).Distinct().ToList();
TravereseGraph(leaves, edges, sortedQuestions, test);
return(sortedQuestions);
}
public void TravereseGraph(List <int?> nodes, List <Edge> edges, List <StudentGetOneTestQueryResult.Question> questions, StudentGetOneTestQueryResult.TestView test)
{
foreach (var node in nodes)
{
var parents = edges.Where(e => e.ProblemTargetId == node).Select(e => e.ProblemSourceId).ToList();
if (!parents.Any())
{
questions.AddRange(test.Questions.Where(q => q.ProblemId == node).ToList());
edges.RemoveAll(e => e.ProblemSourceId == node);
continue;
}
TravereseGraph(parents, edges, questions, test);
questions.AddRange(test.Questions.Where(q => q.ProblemId == node).ToList());
edges.RemoveAll(e => e.ProblemSourceId == node);
}
}
