from django.shortcuts import render
from django.shortcuts import get_object_or_404
from django.shortcuts import HttpResponseRedirect

from django.core.urlresolvers import reverse


from django.http import HttpResponse
from django.http import Http404


from django.template import RequestContext, loader

from polls.models import Poll
from polls.models import Choice

# Create your views here.

def index(request):

    # easiest way of rendering a page with a template
    latest_poll_list = Poll.objects.order_by('-pub_date')[:5]
    context = {'latest_poll_list': latest_poll_list}
    return render(request, 'polls/index.html', context)


    # complicated way of returning a template formatted page 
    # latest_poll_list = Poll.objects.order_by('-pub_date')[:5]
    # template= loader.get_template('polls/index.html')
    # context = RequestContext(request, {
        # 'latest_poll_list':latest_poll_list,
    # })
    # return HttpResponse(template.render(context))



    # original naive response
    # latest_poll_list = Poll.objects.order_by('-pub_date')[:5]
    # output = ', '.join([p.question for p in latest_poll_list])
    # return HttpResponse(output)
    
def detail(request, poll_id):

    # efficient way of checking for valid poll_id
    poll = get_object_or_404(Poll, pk=poll_id)
    return render(request, 'polls/detail.html', {'poll': poll})



    # error checking for item not existing (long way)
    # try:
        # poll = Poll.objects.get(pk=poll_id)
    # except Poll.DoesNotExist:
        # raise Http404
    # return render(request, 'polls/detail.html', {'poll': poll})




    # old way with hardcoded message
    # return HttpResponse("You're looking at poll %s." % poll_id)

    
def results(request, poll_id):
    poll = get_object_or_404(Poll, pk=poll_id)
    return render (request,'polls/results.html', {'poll': poll})

    # naive http response
    # return HttpResponse("You're looking at the results of poll %s." % poll_id)

def vote(request, poll_id):
    p = get_object_or_404(Poll, pk=poll_id)
    try:
        selected_choice = p.choice_set.get(pk=request.POST['choice'])
    except (KeyError, Choice.DoesNotExist):
        # Redisplay the poll voting form
        return render(request,'polls/detail.html',{
            'poll': p,
            '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=(p.id,)))


    # naive http response
    # return HttpResponse("You're voting on poll %s." % poll_id)

