from datetime import datetime, timedelta import json from random import sample, shuffle from itertools import islice, cycle from collections import Counter from django.db import models from django.db.models import Q from django.contrib.auth.models import User from django.forms.models import model_to_dict from django.contrib.contenttypes.models import ContentType from taggit.managers import TaggableManager from django.utils import timezone import pytz languages = ( ("python", "Python"), ("bash", "Bash"), ("c", "C Language"), ("cpp", "C++ Language"), ("java", "Java Language"), ("scilab", "Scilab"), ) question_types = ( ("mcq", "Multiple Choice"), ("mcc", "Multiple Correct Choices"), ("code", "Code"), ("upload", "Assignment Upload"), ) enrollment_methods = ( ("default", "Enroll Request"), ("open", "Open Course"), ) test_case_types = ( ("standardtestcase", "Standard Testcase"), ("stdoutbasedtestcase", "Stdout Based Testcase"), ("mcqtestcase", "MCQ Testcase"), ) attempts = [(i, i) for i in range(1, 6)] attempts.append((-1, 'Infinite')) days_between_attempts = [(j, j) for j in range(401)] test_status = ( ('inprogress', 'Inprogress'), ('completed', 'Completed'), ) def get_assignment_dir(instance, filename): return '%s/%s' % (instance.user.roll_number, instance.assignmentQuestion.id) def get_model_class(model): ctype = ContentType.objects.get(app_label="yaksh", model=model) model_class = ctype.model_class() return model_class def has_profile(user): """ check if user has profile """ return True if hasattr(user, 'profile') else False ############################################################################### class CourseManager(models.Manager): def create_trial_course(self, user): """Creates a trial course for testing questions""" trial_course = self.create(name="trial_course", enrollment="open", creator=user, is_trial=True) trial_course.enroll(False, user) return trial_course ############################################################################### class Course(models.Model): """ Course for students""" name = models.CharField(max_length=128) enrollment = models.CharField(max_length=32, choices=enrollment_methods) active = models.BooleanField(default=True) creator = models.ForeignKey(User, related_name='creator') students = models.ManyToManyField(User, related_name='students') requests = models.ManyToManyField(User, related_name='requests') rejected = models.ManyToManyField(User, related_name='rejected') created_on = models.DateTimeField(auto_now_add=True) teachers = models.ManyToManyField(User, related_name='teachers') is_trial = models.BooleanField(default=False) objects = CourseManager() def request(self, *users): self.requests.add(*users) def get_requests(self): return self.requests.all() def enroll(self, was_rejected, *users): self.students.add(*users) if not was_rejected: self.requests.remove(*users) else: self.rejected.remove(*users) def get_enrolled(self): return self.students.all() def reject(self, was_enrolled, *users): self.rejected.add(*users) if not was_enrolled: self.requests.remove(*users) else: self.students.remove(*users) def get_rejected(self): return self.rejected.all() def is_enrolled(self, user): return user in self.students.all() def is_creator(self, user): return self.creator == user def is_teacher(self, user): return True if user in self.teachers.all() else False def is_self_enroll(self): return True if self.enrollment == enrollment_methods[1][0] else False def get_quizzes(self): return self.quiz_set.filter(is_trial=False) def activate(self): self.active = True def deactivate(self): self.active = False def add_teachers(self, *teachers): self.teachers.add(*teachers) def get_teachers(self): return self.teachers.all() def remove_teachers(self, *teachers): self.teachers.remove(*teachers) def __unicode__(self): return self.name ############################################################################### class ConcurrentUser(models.Model): concurrent_user = models.OneToOneField(User, null=False) session_key = models.CharField(null=False, max_length=40) ############################################################################### class Profile(models.Model): """Profile for a user to store roll number and other details.""" user = models.OneToOneField(User) roll_number = models.CharField(max_length=20) institute = models.CharField(max_length=128) department = models.CharField(max_length=64) position = models.CharField(max_length=64) timezone = models.CharField(max_length=64, default=pytz.utc.zone, choices=[(tz, tz) for tz in pytz.common_timezones] ) ############################################################################### class Question(models.Model): """Question for a quiz.""" # A one-line summary of the question. summary = models.CharField(max_length=256) # The question text, should be valid HTML. description = models.TextField() # Number of points for the question. points = models.FloatField(default=1.0) # The language for question. language = models.CharField(max_length=24, choices=languages) # The type of question. type = models.CharField(max_length=24, choices=question_types) # The type of evaluator test_case_type = models.CharField(max_length=24, choices=test_case_types) # Is this question active or not. If it is inactive it will not be used # when creating a QuestionPaper. active = models.BooleanField(default=True) # Tags for the Question. tags = TaggableManager(blank=True) # Snippet of code provided to the user. snippet = models.CharField(max_length=256, blank=True) # user for particular question user = models.ForeignKey(User, related_name="user") def consolidate_answer_data(self, user_answer): question_data = {} test_case_data = [] test_cases = self.get_test_cases() for test in test_cases: test_case_as_dict = test.get_field_value() test_case_data.append(test_case_as_dict) question_data['test_case_data'] = test_case_data question_data['user_answer'] = user_answer return json.dumps(question_data) def dump_into_json(self, question_ids, user): questions = Question.objects.filter(id__in=question_ids, user_id=user.id) questions_dict = [] for question in questions: test_case = question.get_test_cases() q_dict = {'summary': question.summary, 'description': question.description, 'points': question.points, 'language': question.language, 'type': question.type, 'active': question.active, 'test_case_type': question.test_case_type, 'snippet': question.snippet, 'testcase': [case.get_field_value() for case in test_case]} questions_dict.append(q_dict) return json.dumps(questions_dict, indent=2) def load_from_json(self, questions_list, user): questions = json.loads(questions_list) for question in questions: question['user'] = user test_cases = question.pop('testcase') que, result = Question.objects.get_or_create(**question) model_class = get_model_class(que.test_case_type) for test_case in test_cases: model_class.objects.get_or_create(question=que, **test_case) def get_test_cases(self, **kwargs): test_case_ctype = ContentType.objects.get(app_label="yaksh", model=self.test_case_type ) test_cases = test_case_ctype.get_all_objects_for_this_type( question=self, **kwargs ) return test_cases def get_test_case(self, **kwargs): test_case_ctype = ContentType.objects.get(app_label="yaksh", model=self.test_case_type ) test_case = test_case_ctype.get_object_for_this_type( question=self, **kwargs ) return test_case def __unicode__(self): return self.summary ############################################################################### class Answer(models.Model): """Answers submitted by the users.""" # The question for which user answers. question = models.ForeignKey(Question) # The answer submitted by the user. answer = models.TextField(null=True, blank=True) # Error message when auto-checking the answer. error = models.TextField() # Marks obtained for the answer. This can be changed by the teacher if the # grading is manual. marks = models.FloatField(default=0.0) # Is the answer correct. correct = models.BooleanField(default=False) # Whether skipped or not. skipped = models.BooleanField(default=False) def set_marks(self, marks): if marks > self.question.points: self.marks = self.question.points else: self.marks = marks def __unicode__(self): return self.answer ############################################################################### class QuizManager(models.Manager): def get_active_quizzes(self): return self.filter(active=True, is_trial=False) def create_trial_quiz(self, trial_course, user): """Creates a trial quiz for testing questions""" trial_quiz = self.create(course=trial_course, duration=1000, description="trial_questions", is_trial=True, time_between_attempts=0 ) return trial_quiz def create_trial_from_quiz(self, original_quiz_id, user, godmode): """Creates a trial quiz from existing quiz""" trial_quiz_name = "Trial_orig_id_{0}_{1}".format(original_quiz_id, "godmode" if godmode else "usermode" ) if self.filter(description=trial_quiz_name).exists(): trial_quiz = self.get(description=trial_quiz_name) else: trial_quiz = self.get(id=original_quiz_id) trial_quiz.course.enroll(False, user) trial_quiz.pk = None trial_quiz.description = trial_quiz_name trial_quiz.is_trial = True trial_quiz.time_between_attempts = 0 trial_quiz.prerequisite = None if godmode: trial_quiz.duration = 1000 trial_quiz.active = True trial_quiz.start_date_time = timezone.now() trial_quiz.end_date_time = datetime(2199, 1, 1, 0, 0, 0, 0, tzinfo=pytz.utc ) trial_quiz.save() return trial_quiz ############################################################################### class Quiz(models.Model): """A quiz that students will participate in. One can think of this as the "examination" event. """ course = models.ForeignKey(Course) # The start date of the quiz. start_date_time = models.DateTimeField("Start Date and Time of the quiz", default=timezone.now(), null=True) # The end date and time of the quiz end_date_time = models.DateTimeField("End Date and Time of the quiz", default=datetime(2199, 1, 1, tzinfo=pytz.timezone (timezone. get_current_timezone_name()) ), null=True) # This is always in minutes. duration = models.IntegerField("Duration of quiz in minutes", default=20) # Is the quiz active. The admin should deactivate the quiz once it is # complete. active = models.BooleanField(default=True) # Description of quiz. description = models.CharField(max_length=256) # Mininum passing percentage condition. pass_criteria = models.FloatField("Passing percentage", default=40) # List of prerequisite quizzes to be passed to take this quiz prerequisite = models.ForeignKey("Quiz", null=True, blank=True) # Programming language for a quiz language = models.CharField(max_length=20, choices=languages) # Number of attempts for the quiz attempts_allowed = models.IntegerField(default=1, choices=attempts) time_between_attempts = models.IntegerField("Number of Days",\ choices=days_between_attempts) is_trial = models.BooleanField(default=False) objects = QuizManager() class Meta: verbose_name_plural = "Quizzes" def is_expired(self): return not self.start_date_time <= timezone.now() < self.end_date_time def has_prerequisite(self): return True if self.prerequisite else False def __unicode__(self): desc = self.description or 'Quiz' return '%s: on %s for %d minutes' % (desc, self.start_date_time, self.duration) ############################################################################### class QuestionPaperManager(models.Manager): def _create_trial_from_questionpaper(self, original_quiz_id): """Creates a copy of the original questionpaper""" trial_questionpaper = self.get(quiz_id=original_quiz_id) trial_questions = {"fixed_questions": trial_questionpaper .fixed_questions.all(), "random_questions": trial_questionpaper .random_questions.all() } trial_questionpaper.pk = None trial_questionpaper.save() return trial_questionpaper, trial_questions def create_trial_paper_to_test_questions(self, trial_quiz, questions_list): """Creates a trial question paper to test selected questions""" if questions_list is not None: trial_questionpaper = self.create(quiz=trial_quiz, total_marks=10, ) trial_questionpaper.fixed_questions.add(*questions_list) return trial_questionpaper def create_trial_paper_to_test_quiz(self, trial_quiz, original_quiz_id): """Creates a trial question paper to test quiz.""" if self.filter(quiz=trial_quiz).exists(): trial_questionpaper = self.get(quiz=trial_quiz) else: trial_questionpaper, trial_questions = self._create_trial_from_questionpaper\ (original_quiz_id) trial_questionpaper.quiz = trial_quiz trial_questionpaper.fixed_questions\ .add(*trial_questions["fixed_questions"]) trial_questionpaper.random_questions\ .add(*trial_questions["random_questions"]) trial_questionpaper.save() return trial_questionpaper ############################################################################### class QuestionPaper(models.Model): """Question paper stores the detail of the questions.""" # Question paper belongs to a particular quiz. quiz = models.ForeignKey(Quiz) # Questions that will be mandatory in the quiz. fixed_questions = models.ManyToManyField(Question) # Questions that will be fetched randomly from the Question Set. random_questions = models.ManyToManyField("QuestionSet") # Option to shuffle questions, each time a new question paper is created. shuffle_questions = models.BooleanField(default=False) # Total marks for the question paper. total_marks = models.FloatField() objects = QuestionPaperManager() def update_total_marks(self): """ Updates the total marks for the Question Paper""" marks = 0.0 questions = self.fixed_questions.all() for question in questions: marks += question.points for question_set in self.random_questions.all(): marks += question_set.marks * question_set.num_questions self.total_marks = marks def _get_questions_for_answerpaper(self): """ Returns fixed and random questions for the answer paper""" questions = [] questions = list(self.fixed_questions.all()) for question_set in self.random_questions.all(): questions += question_set.get_random_questions() return questions def make_answerpaper(self, user, ip, attempt_num): """Creates an answer paper for the user to attempt the quiz""" ans_paper = AnswerPaper(user=user, user_ip=ip, attempt_number=attempt_num ) ans_paper.start_time = timezone.now() ans_paper.end_time = ans_paper.start_time + \ timedelta(minutes=self.quiz.duration) ans_paper.question_paper = self ans_paper.save() questions = self._get_questions_for_answerpaper() ans_paper.questions.add(*questions) ans_paper.questions_unanswered.add(*questions) return ans_paper def _is_questionpaper_passed(self, user): return AnswerPaper.objects.filter(question_paper=self, user=user, passed = True).exists() def _is_attempt_allowed(self, user): attempts = AnswerPaper.objects.get_total_attempt(questionpaper=self, user=user) return attempts != self.quiz.attempts_allowed def can_attempt_now(self, user): if self._is_attempt_allowed(user): last_attempt = AnswerPaper.objects.get_user_last_attempt(user=user, questionpaper=self) if last_attempt: time_lag = (timezone.now() - last_attempt.start_time).days return time_lag >= self.quiz.time_between_attempts else: return True else: return False def _get_prequisite_paper(self): return self.quiz.prerequisite.questionpaper_set.get() def is_prerequisite_passed(self, user): if self.quiz.has_prerequisite(): prerequisite = self._get_prequisite_paper() return prerequisite._is_questionpaper_passed(user) ############################################################################### class QuestionSet(models.Model): """Question set contains a set of questions from which random questions will be selected for the quiz. """ # Marks of each question of a particular Question Set marks = models.FloatField() # Number of questions to be fetched for the quiz. num_questions = models.IntegerField() # Set of questions for sampling randomly. questions = models.ManyToManyField(Question) def get_random_questions(self): """ Returns random questions from set of questions""" return sample(self.questions.all(), self.num_questions) ############################################################################### class AnswerPaperManager(models.Manager): def get_all_questions(self, questionpaper_id, attempt_number, status='completed'): ''' Return a dict of question id as key and count as value''' papers = self.filter(question_paper_id=questionpaper_id, attempt_number=attempt_number, status=status) all_questions = list() questions = list() for paper in papers: all_questions += paper.get_questions() for question in all_questions: questions.append(question.id) return Counter(questions) def get_all_questions_answered(self, questionpaper_id, attempt_number, status='completed'): ''' Return a dict of answered question id as key and count as value''' papers = self.filter(question_paper_id=questionpaper_id, attempt_number=attempt_number, status=status) questions_answered = list() for paper in papers: for question in filter(None, paper.get_questions_answered()): if paper.is_answer_correct(question): questions_answered.append(question.id) return Counter(questions_answered) def get_attempt_numbers(self, questionpaper_id, status='completed'): ''' Return list of attempt numbers''' attempt_numbers = self.filter( question_paper_id=questionpaper_id, status=status ).values_list('attempt_number', flat=True).distinct() return attempt_numbers def has_attempt(self, questionpaper_id, attempt_number, status='completed'): ''' Whether question paper is attempted''' return self.filter(question_paper_id=questionpaper_id, attempt_number=attempt_number, status=status).exists() def get_count(self, questionpaper_id, attempt_number, status='completed'): ''' Return count of answerpapers for a specfic question paper and attempt number''' return self.filter(question_paper_id=questionpaper_id, attempt_number=attempt_number, status=status).count() def get_question_statistics(self, questionpaper_id, attempt_number, status='completed'): ''' Return dict with question object as key and list as value The list contains two value, first the number of times a question was answered correctly, and second the number of times a question appeared in a quiz''' question_stats = {} questions_answered = self.get_all_questions_answered(questionpaper_id, attempt_number) questions = self.get_all_questions(questionpaper_id, attempt_number) all_questions = Question.objects.filter( id__in=set(questions) ).order_by('type') for question in all_questions: if question.id in questions_answered: question_stats[question] = [questions_answered[question.id], questions[question.id]] else: question_stats[question] = [0, questions[question.id]] return question_stats def _get_answerpapers_for_quiz(self, questionpaper_id, status=False): if not status: return self.filter(question_paper_id=questionpaper_id) else: return self.filter(question_paper_id=questionpaper_id, status="completed") def _get_answerpapers_users(self, answerpapers): return answerpapers.values_list('user', flat=True).distinct() def get_latest_attempts(self, questionpaper_id): papers = self._get_answerpapers_for_quiz(questionpaper_id) users = self._get_answerpapers_users(papers) latest_attempts = [] for user in users: latest_attempts.append(self._get_latest_attempt(papers, user)) return latest_attempts def _get_latest_attempt(self, answerpapers, user_id): return answerpapers.filter(user_id=user_id).order_by('-attempt_number')[0] def get_user_last_attempt(self, questionpaper, user): attempts = self.filter(question_paper=questionpaper, user=user).order_by('-attempt_number') if attempts: return attempts[0] def get_user_answerpapers(self, user): return self.filter(user=user) def get_total_attempt(self, questionpaper, user): return self.filter(question_paper=questionpaper, user=user).count() def get_users_for_questionpaper(self, questionpaper_id): return self._get_answerpapers_for_quiz(questionpaper_id, status=True)\ .values("user__id", "user__first_name", "user__last_name")\ .distinct() def get_user_all_attempts(self, questionpaper, user): return self.filter(question_paper=questionpaper, user=user)\ .order_by('-attempt_number') def get_user_data(self, user, questionpaper_id, attempt_number=None): if attempt_number is not None: papers = self.filter(user=user, question_paper_id=questionpaper_id, attempt_number=attempt_number) else: papers = self.filter(user=user, question_paper_id=questionpaper_id)\ .order_by("-attempt_number") data = {} profile = user.profile if hasattr(user, 'profile') else None data['user'] = user data['profile'] = profile data['papers'] = papers data['questionpaperid'] = questionpaper_id return data ############################################################################### class AnswerPaper(models.Model): """A answer paper for a student -- one per student typically. """ # The user taking this question paper. user = models.ForeignKey(User) questions = models.ManyToManyField(Question, related_name='questions') # The Quiz to which this question paper is attached to. question_paper = models.ForeignKey(QuestionPaper) # The attempt number for the question paper. attempt_number = models.IntegerField() # The time when this paper was started by the user. start_time = models.DateTimeField() # The time when this paper was ended by the user. end_time = models.DateTimeField() # User's IP which is logged. user_ip = models.CharField(max_length=15) # The questions unanswered questions_unanswered = models.ManyToManyField(Question, related_name='questions_unanswered') # The questions answered questions_answered = models.ManyToManyField(Question, related_name='questions_answered') # All the submitted answers. answers = models.ManyToManyField(Answer) # Teacher comments on the question paper. comments = models.TextField() # Total marks earned by the student in this paper. marks_obtained = models.FloatField(null=True, default=None) # Marks percent scored by the user percent = models.FloatField(null=True, default=None) # Result of the quiz, True if student passes the exam. passed = models.NullBooleanField() # Status of the quiz attempt status = models.CharField(max_length=20, choices=test_status,\ default='inprogress') objects = AnswerPaperManager() def current_question(self): """Returns the current active question to display.""" if self.questions_unanswered.all(): return self.questions_unanswered.all()[0] def questions_left(self): """Returns the number of questions left.""" return self.questions_unanswered.count() def completed_question(self, question_id): """ Adds the completed question to the list of answered questions and returns the next question. """ self.questions_answered.add(question_id) self.questions_unanswered.remove(question_id) return self.current_question() def skip(self, question_id): """ Skips the current question and returns the next sequentially available question. """ questions = self.questions_unanswered.all() question_cycle = cycle(questions) for question in question_cycle: if question.id==int(question_id): return question_cycle.next() def time_left(self): """Return the time remaining for the user in seconds.""" dt = timezone.now() - self.start_time try: secs = dt.total_seconds() except AttributeError: # total_seconds is new in Python 2.7. :( secs = dt.seconds + dt.days*24*3600 total = self.question_paper.quiz.duration*60.0 remain = max(total - secs, 0) return int(remain) def _update_marks_obtained(self): """Updates the total marks earned by student for this paper.""" marks = sum([x.marks for x in self.answers.filter(marks__gt=0.0)]) if not marks: self.marks_obtained = 0 else: self.marks_obtained = marks def _update_percent(self): """Updates the percent gained by the student for this paper.""" total_marks = self.question_paper.total_marks if self.marks_obtained is not None: percent = self.marks_obtained/self.question_paper.total_marks*100 self.percent = round(percent, 2) def _update_passed(self): """ Checks whether student passed or failed, as per the quiz passing criteria. """ if self.percent is not None: if self.percent >= self.question_paper.quiz.pass_criteria: self.passed = True else: self.passed = False def _update_status(self, state): """ Sets status as inprogress or completed """ self.status = state def update_marks(self, state='completed'): self._update_marks_obtained() self._update_percent() self._update_passed() self._update_status(state) self.save() def set_end_time(self, datetime): """ Sets end time """ self.end_time = datetime self.save() def get_question_answers(self): """ Return a dictionary with keys as questions and a list of the corresponding answers. """ q_a = {} for answer in self.answers.all(): question = answer.question if question in q_a: q_a[question].append(answer) else: q_a[question] = [answer] return q_a def get_questions(self): return self.questions.all() def get_questions_answered(self): return self.questions_answered.all() def get_questions_unanswered(self): return self.questions_unanswered.all() def is_answer_correct(self, question_id): ''' Return marks of a question answered''' return self.answers.filter(question_id=question_id, correct=True).exists() def is_attempt_inprogress(self): if self.status == 'inprogress': return self.time_left()> 0 def get_previous_answers(self, question): if question.type == 'code': return self.answers.filter(question=question).order_by('-id') def __unicode__(self): u = self.user return u'Question paper for {0} {1}'.format(u.first_name, u.last_name) ############################################################################### class AssignmentUpload(models.Model): user = models.ForeignKey(Profile) assignmentQuestion = models.ForeignKey(Question) assignmentFile = models.FileField(upload_to=get_assignment_dir) ################################################################################ class TestCase(models.Model): question = models.ForeignKey(Question, blank=True, null = True) class StandardTestCase(TestCase): test_case = models.TextField(blank=True) def get_field_value(self): return {"test_case": self.test_case} def __unicode__(self): return u'Question: {0} | Test Case: {1}'.format(self.question, self.test_case ) class StdoutBasedTestCase(TestCase): expected_output = models.TextField(blank=True) def get_field_value(self): return {"expected_output": self.expected_output} def __unicode__(self): return u'Question: {0} | Exp. Output: {1}'.format(self.question, self.expected_output ) class McqTestCase(TestCase): options = models.TextField() correct = models.BooleanField(default=False) def get_field_value(self): return {"options": self.options, "correct": self.correct} def __unicode__(self): return u'Question: {0} | Correct: {1}'.format(self.question, self.correct )