from django.shortcuts import get_object_or_404, render

# Create your views here.

from django.http import HttpResponse, HttpResponseRedirect
from django.template import loader
from django.urls import reverse
from django.views import generic

from .models import Choice, Question

from django.http import Http404

from django.utils import timezone

## simple index
#def index(request):
#  return HttpResponse("Hello, world. You're at the polls index.")

## meaningful index
#def index(request):
#  latest_question_list = Question.objects.order_by('-pub_date')[:5]
#  output = ', '.join([q.question_text for q in latest_question_list])
#  return HttpResponse(output)

## meaningful and templated index
#def index(request):
#  latest_question_list = Question.objects.order_by('-pub_date')[:5]
#  template = loader.get_template('polls/index.html')
#  context = {
#    'latest_question_list': latest_question_list,
#  }
#  return HttpResponse(template.render(context, request))

## meaningful, templated and easy to write index
## and then we no longer need to import loader and HttpResponse
#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)

class IndexView(generic.ListView):
  template_name = 'polls/index.html'
  context_object_name = 'latest_question_list'

## has bug
#  def get_queryset(self):
#    """Return the last five published questions."""
#    return Question.objects.order_by('-pub_date')[:5]

# refactor
  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]

## simple detail
#def detail(request, question_id):
#  return HttpResponse("You're looking at question %s." % question_id)

## meaningful detail
#def detail(request, question_id):
#  try:
#    question = Question.objects.get(pk=question_id)
#  except Question.DoesNotExist:
#    raise Http404("Question does not exist")
#  return render(request, 'polls/detail.html', {'question': question})

## meaningful and easy to write detail
#def detail(request, question_id):
#  question = get_object_or_404(Question, pk=question_id)
#  return render(request, 'polls/detail.html', {'question': question})

## refactor detail view
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())

#def results(request, question_id):
#  response = "You're looking at the results of question %s."
#  return HttpResponse(response % question_id)

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

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

#def vote(request, question_id):
#  return HttpResponse("You're voting on question %s." % question_id)


# #real implementation of vote
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()
    # Always return an HttpResponseRedirect after successfully dealing
    # with POST data. This prevents data from being posted twice if a
    # user hits the Back button
    return HttpResponseRedirect(reverse('polls:results', args=(question.id,)))