from django.http import HttpResponse, HttpResponseRedirect
from django.shortcuts import render, get_object_or_404
from django.urls import reverse
from django.views import generic
from django.utils import timezone

from .models import Question, Choice

'''
FBV Views
def index(request):
    latest_question_list = Question.objects.order_by('-pub_date')[:5]
    context = {
        'latest_question_list': latest_question_list
    }
    return render(request, 'polls/index.html', context)

def detail(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    return render(request, 'polls/detail.html', {'question': question})

def results(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    return render(request, 'polls/results.html', {'question': question})

'''


class IndexView(generic.ListView):
    template_name = 'polls/index.html'
    """
    The default context variable is <question>_list, (queryset)
    so we override it providing context_object_name
    """
    context_object_name = 'latest_question_list'

    def get_queryset(self):
        """
        Return the last five published questions.
        NOT including those set to be published in the future.
        """
        return Question.objects.filter(
            pub_date__lte=timezone.now()
        ).order_by('-pub_date')[:5]


class DetailView(generic.DetailView):
    model = Question
    template_name = 'polls/detail.html'

    def get_queryset(self):
        """
        Excludes any questions that aren't published yet.
        """
        return Question.objects.filter(pub_date__lte=timezone.now())


class ResultsView(generic.DetailView):
    model = Question
    template_name = 'polls/results.html'

    def get_queryset(self):
        """
        Excludes any questions that aren't published yet.
        """
        return Question.objects.filter(pub_date__lte=timezone.now())


def vote(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    try:
        selected_choice = question.choice_set.get(pk=request.POST['choice'])
    except (KeyError, Choice.DoesNotExist):
        # Redisplay the question voting form
        return render(request, 'polls/detail.html', {
            'question': question,
            'error_message': "You didn't select a choice.",
        })
    else:
        selected_choice.votes += 1
        selected_choice.save()
        # Return HttpResponseRedirect after successfully dealing with POST
        # Prevents data from being posted twice (user hits back)
        return HttpResponseRedirect(reverse('polls:results',
                                            args=(question.id,)))
