from django.shortcuts import render

# Create your views here.
from django.http import HttpResponse,HttpResponseRedirect
from .models import Question,Choice
from django.utils import timezone
from django.template import loader
from django.shortcuts import get_object_or_404, render
from django.urls import reverse
from django.views import generic
from django.http import HttpResponse, JsonResponse
from django.views.decorators.csrf import csrf_exempt
from rest_framework.parsers import JSONParser
from polls.models import Question
from polls.serializer import QuestionSerializer
from django.core import serializers

class IndexView(generic.ListView):
    template_name = 'polls/index.html'
    context_object_name = 'latest_question_list'
    def get_queryset(self):
        """Return the last five published questions."""
        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 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,)))

@csrf_exempt
def Question_list(request):
    """
    List all code snippets, or create a new snippet.
    """
    if request.method == 'GET':
        Questions = Question.objects.all()
        serializer = QuestionSerializer(Questions, many=True)
        return JsonResponse(serializer.data, safe=False)

    elif request.method == 'POST':
        data = JSONParser().parse(request)
        serializer = QuestionSerializer(data=data)
        if serializer.is_valid():
            serializer.save()
            return JsonResponse(serializer.data, status=201)
        return JsonResponse(serializer.errors, status=400)
@csrf_exempt
def Question_detail(request, pk):
    """
    Retrieve, update or delete a code snippet.
    """
    try:
        Questions = Question.objects.get(pk=pk)
    except Questions.DoesNotExist:
        return HttpResponse(status=404)

    if request.method == 'GET':
        serializer = QuestionSerializer(Questions)
        return JsonResponse(serializer.data)

    elif request.method == 'PUT':
        data = JSONParser().parse(request)
        serializer = QuestionSerializer(Questions, data=data)
        if serializer.is_valid():
            serializer.save()
            return JsonResponse(serializer.data)
        return JsonResponse(serializer.errors, status=400)

    elif request.method == 'DELETE':
        Questions.delete()
        return HttpResponse(status=204)
@csrf_exempt
def Question_json(request):
    question_json=serializers.serialize("json",Question.objects.all())
    return HttpResponse(question_json, content_type="application/json")
