from django.contrib.auth.decorators import login_required
from django.core.exceptions import PermissionDenied
from django.shortcuts import get_object_or_404, render, redirect
from django.utils.decorators import method_decorator
from django.views.generic import (
    DetailView,
    ListView,
    TemplateView,
    FormView,
    CreateView,
    UpdateView,
)
from django.contrib import messages
from django.db import transaction

from accounts.decorators import lecturer_required
from .models import Course, Progress, Sitting, EssayQuestion, Quiz, MCQuestion, Question
from .forms import (
    QuizAddForm,
    MCQuestionForm,
    MCQuestionFormSet,
    QuestionForm,
    EssayForm,
)


@method_decorator([login_required, lecturer_required], name="dispatch")
class QuizCreateView(CreateView):
    model = Quiz
    form_class = QuizAddForm

    def get_context_data(self, *args, **kwargs):
        context = super(QuizCreateView, self).get_context_data(**kwargs)
        context["course"] = Course.objects.get(slug=self.kwargs["slug"])
        if self.request.POST:
            context["form"] = QuizAddForm(self.request.POST)
            # context['quiz'] = self.request.POST.get('quiz')
        else:
            context["form"] = QuizAddForm(
                initial={"course": Course.objects.get(slug=self.kwargs["slug"])}
            )
        return context

    def form_valid(self, form, **kwargs):
        context = self.get_context_data()
        form = context["form"]
        with transaction.atomic():
            self.object = form.save()
            if form.is_valid():
                form.instance = self.object
                form.save()
                return redirect(
                    "mc_create", slug=self.kwargs["slug"], quiz_id=form.instance.id
                )
        return super(QuizCreateView, self).form_invalid(form)


@method_decorator([login_required, lecturer_required], name="dispatch")
class QuizUpdateView(UpdateView):
    model = Quiz
    form_class = QuizAddForm

    def get_context_data(self, *args, **kwargs):
        context = super(QuizUpdateView, self).get_context_data(**kwargs)
        context["course"] = Course.objects.get(slug=self.kwargs["slug"])
        quiz = Quiz.objects.get(pk=self.kwargs["pk"])
        if self.request.POST:
            context["form"] = QuizAddForm(self.request.POST, instance=quiz)
        else:
            context["form"] = QuizAddForm(instance=quiz)
        return context

    def form_valid(self, form, **kwargs):
        context = self.get_context_data()
        course = context["course"]
        form = context["form"]
        with transaction.atomic():
            self.object = form.save()
            if form.is_valid():
                form.instance = self.object
                form.save()
                return redirect("quiz_index", course.slug)
        return super(QuizUpdateView, self).form_invalid(form)


@login_required
@lecturer_required
def quiz_delete(request, slug, pk):
    quiz = Quiz.objects.get(pk=pk)
    course = Course.objects.get(slug=slug)
    quiz.delete()
    messages.success(request, f"successfuly deleted.")
    return redirect("quiz_index", quiz.course.slug)


@method_decorator([login_required, lecturer_required], name="dispatch")
class MCQuestionCreate(CreateView):
    model = MCQuestion
    form_class = MCQuestionForm

    def get_context_data(self, **kwargs):
        context = super(MCQuestionCreate, self).get_context_data(**kwargs)
        context["course"] = Course.objects.get(slug=self.kwargs["slug"])
        context["quiz_obj"] = Quiz.objects.get(id=self.kwargs["quiz_id"])
        context["quizQuestions"] = Question.objects.filter(
            quiz=self.kwargs["quiz_id"]
        ).count()
        if self.request.POST:
            context["form"] = MCQuestionForm(self.request.POST)
            context["formset"] = MCQuestionFormSet(self.request.POST)
        else:
            context["form"] = MCQuestionForm(initial={"quiz": self.kwargs["quiz_id"]})
            context["formset"] = MCQuestionFormSet()

        return context

    def form_valid(self, form):
        context = self.get_context_data()
        formset = context["formset"]
        course = context["course"]
        if formset.is_valid():
            with transaction.atomic():
                form.instance.question = self.request.POST.get("content")
                self.object = form.save()
                formset.instance = self.object
                formset.save()
                if "another" in self.request.POST:
                    return redirect(
                        "mc_create",
                        slug=self.kwargs["slug"],
                        quiz_id=self.kwargs["quiz_id"],
                    )
                return redirect("quiz_index", course.slug)
        else:
            return self.form_invalid(form)
        return super(MCQuestionCreate, self).form_invalid(form)


@login_required
def quiz_list(request, slug):
    quizzes = Quiz.objects.filter(course__slug=slug).order_by("-timestamp")
    course = Course.objects.get(slug=slug)
    return render(
        request, "quiz/quiz_list.html", {"quizzes": quizzes, "course": course}
    )
    # return render(request, 'quiz/quiz_list.html', {'quizzes': quizzes})


@method_decorator([login_required, lecturer_required], name="dispatch")
class QuizMarkerMixin(object):
    @method_decorator(login_required)
    # @method_decorator(permission_required('quiz.view_sittings'))
    def dispatch(self, *args, **kwargs):
        return super(QuizMarkerMixin, self).dispatch(*args, **kwargs)


# @method_decorator([login_required, lecturer_required], name='get_queryset')
class SittingFilterTitleMixin(object):
    def get_queryset(self):
        queryset = super(SittingFilterTitleMixin, self).get_queryset()
        quiz_filter = self.request.GET.get("quiz_filter")
        if quiz_filter:
            queryset = queryset.filter(quiz__title__icontains=quiz_filter)

        return queryset


@method_decorator([login_required], name="dispatch")
class QuizUserProgressView(TemplateView):
    template_name = "progress.html"

    def dispatch(self, request, *args, **kwargs):
        return super(QuizUserProgressView, self).dispatch(request, *args, **kwargs)

    def get_context_data(self, **kwargs):
        context = super(QuizUserProgressView, self).get_context_data(**kwargs)
        progress, _ = Progress.objects.get_or_create(user=self.request.user)
        context["cat_scores"] = progress.list_all_cat_scores
        context["exams"] = progress.show_exams()
        context["exams_counter"] = progress.show_exams().count()
        return context


@method_decorator([login_required, lecturer_required], name="dispatch")
class QuizMarkingList(QuizMarkerMixin, SittingFilterTitleMixin, ListView):
    model = Sitting

    # def get_context_data(self, **kwargs):
    #     context = super(QuizMarkingList, self).get_context_data(**kwargs)
    #     context['queryset_counter'] = super(QuizMarkingList, self).get_queryset().filter(complete=True).filter(course__allocated_course__lecturer__pk=self.request.user.id).count()
    #     context['marking_list'] = super(QuizMarkingList, self).get_queryset().filter(complete=True).filter(course__allocated_course__lecturer__pk=self.request.user.id)
    #     return context
    def get_queryset(self):
        if self.request.user.is_superuser:
            queryset = super(QuizMarkingList, self).get_queryset().filter(complete=True)
        else:
            queryset = (
                super(QuizMarkingList, self)
                .get_queryset()
                .filter(
                    quiz__course__allocated_course__lecturer__pk=self.request.user.id
                )
                .filter(complete=True)
            )

        # search by user
        user_filter = self.request.GET.get("user_filter")
        if user_filter:
            queryset = queryset.filter(user__username__icontains=user_filter)

        return queryset


@method_decorator([login_required, lecturer_required], name="dispatch")
class QuizMarkingDetail(QuizMarkerMixin, DetailView):
    model = Sitting

    def post(self, request, *args, **kwargs):
        sitting = self.get_object()

        q_to_toggle = request.POST.get("qid", None)
        if q_to_toggle:
            q = Question.objects.get_subclass(id=int(q_to_toggle))
            if int(q_to_toggle) in sitting.get_incorrect_questions:
                sitting.remove_incorrect_question(q)
            else:
                sitting.add_incorrect_question(q)

        return self.get(request)

    def get_context_data(self, **kwargs):
        context = super(QuizMarkingDetail, self).get_context_data(**kwargs)
        context["questions"] = context["sitting"].get_questions(with_answers=True)
        return context


# @method_decorator([login_required, student_required], name='dispatch')
@method_decorator([login_required], name="dispatch")
class QuizTake(FormView):
    form_class = QuestionForm
    template_name = "question.html"
    result_template_name = "result.html"
    # single_complete_template_name = 'single_complete.html'

    def dispatch(self, request, *args, **kwargs):
        self.quiz = get_object_or_404(Quiz, slug=self.kwargs["slug"])
        self.course = get_object_or_404(Course, pk=self.kwargs["pk"])
        quizQuestions = Question.objects.filter(quiz=self.quiz).count()
        course = get_object_or_404(Course, pk=self.kwargs["pk"])

        if quizQuestions <= 0:
            messages.warning(request, f"Question set of the quiz is empty. try later!")
            return redirect("quiz_index", self.course.slug)

        if self.quiz.draft and not request.user.has_perm("quiz.change_quiz"):
            raise PermissionDenied

        self.sitting = Sitting.objects.user_sitting(
            request.user, self.quiz, self.course
        )

        if self.sitting is False:
            # return render(request, self.single_complete_template_name)
            messages.info(
                request,
                f"You have already sat this exam and only one sitting is permitted",
            )
            return redirect("quiz_index", self.course.slug)

        return super(QuizTake, self).dispatch(request, *args, **kwargs)

    def get_form(self, *args, **kwargs):
        self.question = self.sitting.get_first_question()
        self.progress = self.sitting.progress()

        if self.question.__class__ is EssayQuestion:
            form_class = EssayForm
        else:
            form_class = self.form_class

        return form_class(**self.get_form_kwargs())

    def get_form_kwargs(self):
        kwargs = super(QuizTake, self).get_form_kwargs()

        return dict(kwargs, question=self.question)

    def form_valid(self, form):
        self.form_valid_user(form)
        if self.sitting.get_first_question() is False:
            return self.final_result_user()

        self.request.POST = {}

        return super(QuizTake, self).get(self, self.request)

    def get_context_data(self, **kwargs):
        context = super(QuizTake, self).get_context_data(**kwargs)
        context["question"] = self.question
        context["quiz"] = self.quiz
        context["course"] = get_object_or_404(Course, pk=self.kwargs["pk"])
        if hasattr(self, "previous"):
            context["previous"] = self.previous
        if hasattr(self, "progress"):
            context["progress"] = self.progress
        return context

    def form_valid_user(self, form):
        progress, _ = Progress.objects.get_or_create(user=self.request.user)
        guess = form.cleaned_data["answers"]
        is_correct = self.question.check_if_correct(guess)

        if is_correct is True:
            self.sitting.add_to_score(1)
            progress.update_score(self.question, 1, 1)
        else:
            self.sitting.add_incorrect_question(self.question)
            progress.update_score(self.question, 0, 1)

        if self.quiz.answers_at_end is not True:
            self.previous = {
                "previous_answer": guess,
                "previous_outcome": is_correct,
                "previous_question": self.question,
                "answers": self.question.get_choices(),
                "question_type": {self.question.__class__.__name__: True},
            }
        else:
            self.previous = {}

        self.sitting.add_user_answer(self.question, guess)
        self.sitting.remove_first_question()

    def final_result_user(self):
        results = {
            "course": get_object_or_404(Course, pk=self.kwargs["pk"]),
            "quiz": self.quiz,
            "score": self.sitting.get_current_score,
            "max_score": self.sitting.get_max_score,
            "percent": self.sitting.get_percent_correct,
            "sitting": self.sitting,
            "previous": self.previous,
            "course": get_object_or_404(Course, pk=self.kwargs["pk"]),
        }

        self.sitting.mark_quiz_complete()

        if self.quiz.answers_at_end:
            results["questions"] = self.sitting.get_questions(with_answers=True)
            results["incorrect_questions"] = self.sitting.get_incorrect_questions

        if (
            self.quiz.exam_paper is False
            or self.request.user.is_superuser
            or self.request.user.is_lecturer
        ):
            self.sitting.delete()

        return render(self.request, self.result_template_name, results)