from django.db.models import Q
from quiz.models import Question


def get_session_questions(session):
    """Helper to get filtered questions for a session"""
    questions = Question.objects.all()

    if session.course:
        questions = questions.filter(exam__course=session.course)

    if session.tags.exists():
        questions = questions.filter(tags__in=session.tags.all())

    if session.exams.exists():
        questions = questions.filter(exam__in=session.exams.all())

    if session.question_types:
        q_objs = Q()
        if 'single' in session.question_types:
            q_objs |= ~Q(correct_answer__contains=',')
        if 'multi' in session.question_types:
            q_objs |= Q(correct_answer__contains=',')

        if q_objs:
            questions = questions.filter(q_objs)

    return questions.distinct()