from django.db.models import Count
from django.shortcuts import render, get_object_or_404

from polls.models import Poll, Option, Vote


def polls(
        request,
):
    context = {}

    context["polls"] = Poll.objects.all()

    return render(
        request,
        template_name="polls/polls.html",
        context=context,
    )


def already_voted(
        user,
        poll,
):
    vote = Vote.objects.filter(
        poll=poll,
        user=user,
    )
    return vote.exists()


def poll_results(
        request,
        poll_id,
):
    context = {}

    poll = get_object_or_404(
        Poll,
        pk=poll_id,
    )

    context["poll"] = poll

    results = Vote.objects.filter(
        poll=poll,
    ).annotate(
        count=Count("option")
    )
    context["results"] = results

    return render(
        request,
        template_name="polls/poll_results.html",
        context=context,
    )


def poll_details(
        request,
        poll_id,
):
    poll = get_object_or_404(
        Poll,
        pk=poll_id,
    )

    if already_voted(
        request.user,
        poll,
    ):
        return poll_results(
            request,
            poll_id,
        )

    context = {}

    context["poll"] = poll
    context["options"] = Option.objects.filter(
        poll=poll,
    )

    return render(
        request,
        template_name="polls/poll_details.html",
        context=context,
    )


def cast_vote(
        request,
        poll_id,
        option_id,
):
    poll = get_object_or_404(
        Poll,
        pk=poll_id,
    )

    vote = Vote.objects.filter(
        poll=poll,
        user=request.user,
    )
    if vote.exists():
        return poll_results(
            request,
            poll_id=poll_id,
        )

    option = get_object_or_404(
        Option,
        pk=option_id,
    )

    vote = Vote()
    vote.poll = poll
    vote.option = option
    vote.user = request.user
    vote.save()

    return poll_results(
        request,
        poll_id=poll_id,
    )