from django.contrib import messages
from django.contrib.messages.views import SuccessMessageMixin
from django.db.models import Count, Prefetch
from django.http import HttpResponseRedirect
from django.urls import reverse
from django.utils.translation import gettext_lazy as _
from django.views.generic import CreateView, DetailView, UpdateView

from .forms import ElectionCreateForm, OptionFormSet
from .models import Election, Option, Question

# TODO: access control *everywhere*


class ElectionCreateView(SuccessMessageMixin, CreateView):
    model = Election
    form_class = ElectionCreateForm
    template_name = "elections/election_create.html"
    success_message = _("Élection crée avec succès !")


class ElectionUpdateView(SuccessMessageMixin, UpdateView):
    model = Election
    fields = ["name", "description", "start_time", "end_time"]
    success_message = _("Élection modifiée avec succès !")

    def get_queryset(self):
        # On ne peut plus modifier une élection déjà comptée
        return super().get_queryset().filter(tallied=False, archived=False)


class ElectionView(DetailView):
    model = Election
    template_name = "elections/election.html"

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        if self.object.tallied:
            options_qs = Option.objects.annotate(nb_votes=Count("voters"))
            questions = self.election.question.prefetch_related(
                Prefetch("options", queryset=options_qs)
            )
            context["questions"] = questions

        return context

    def get_queryset(self):
        return super().get_queryset().filter(archived=False)


class VoteView(SuccessMessageMixin, DetailView):
    model = Question
    template_name = "elections/vote.html"

    def get_queryset(self):
        # On ne peut voter que si l'élection n'a pas été comptée
        return (
            super()
            .get_queryset()
            .filter(election__tallied=False, election__archived=False)
            .select_related("election")
        )

    def get(self, request, *args, **kwargs):
        self.object = self.get_object()
        vote_form = OptionFormSet(instance=self.object)

        return self.render_to_response(self.get_context_data(formset=vote_form))

    def post(self, request, *args, **kwargs):
        self.object = self.get_object()
        vote_form = OptionFormSet(self.request.POST, instance=self.object)

        # We record the cast votes
        for v in vote_form:
            v.record_vote(self.request.user)

        messages.success(self.request, _("Votre vote a bien été enregistré !"))

        return HttpResponseRedirect(
            reverse("election.view", args=[self.object.election.pk])
            + f"#q_{self.object.pk}"
        )