from django.shortcuts import render
from django.shortcuts import render
from django.views import View
from django.views.generic.base import TemplateView
from django.conf import settings
from django.http import Http404
from django.http import HttpResponse
from django.http import HttpResponseRedirect
from django.db.models import Case, When, Value, IntegerField, Count, F

from LandingPage.models import User
from LandingPage.models import Show
from LandingPage.models import Season
from LandingPage.models import Episode
from LandingPage.models import Submission, SubmissionVote

# Create your views here.

# Index page of a show
class IndexView(TemplateView):
    template_name = "show.html"

    def get_context_data(self, abbreviation, **kwargs):
        ctx = super().get_context_data()

        # Get show by abbreviation, add episode count to the show and return only the first object
        show = Show.objects.filter(abbr=abbreviation).first()

        # 404
        if not show:
            raise Http404("Show does not exist")

        # Get all seasons of the show and annotate episode counts onto them
        seasons = show.seasons.all()

        # Add fields to context
        ctx['show'] = show
        ctx['seasons'] = seasons

        return ctx

# Episodes page of a show
class EpisodeView(TemplateView):
    template_name = "episode.html"

    def get_context_data(self, abbreviation, season, episode, **kwargs):
        ctx = super().get_context_data()

        # Get show by abbreviation
        show = Show.objects.filter(abbr=abbreviation).first()

        # Get episode by season and episode number
        episode = Episode.objects.filter(show=show,episode=episode).first()

        # 404's
        if not show:
            raise Http404("Show does not exist")
        
        if not episode:
            raise Http404("Episode does not exist")

        # I aknowledge that this is a mess. A functional mess. But a mess nonetheless. Hey, that rhymed!
        submissions = episode.submissions.annotate(
            positives=Count(
                Case(
                    When(
                        votes__positive=True,
                        then=Value(1)
                        )
                    )
                ),
            negatives=Count('votes') - F('positives'),
            score=F('positives') - F('negatives')
        ).order_by('-score')

        # Add fields to context
        ctx['show'] = show
        ctx['episode'] = episode
        ctx['submissions'] = submissions

        return ctx

# Vote request
# /show/{{abbr}}/vote/{{submission id}}/{{positive == 1}}
class SubmissionVoteSubmit(View):
    def get (self, req, abbreviation, subid, positive):
        # Check for login status
        if not req.session['user_id']:
            r = HttpResponse('<h1>Error</h1><p>You need to be logged in to vote.  Please <a href=/login>log in</a></p>')
            r.status = 400
            return r

        user = User.objects.get(user_id=req.session['user_id'])

        # Get the submission from the database
        submission = Submission.objects.filter(id=subid).first()

        # 404
        if not submission:
            raise Http404("Submission does not exist")

        # Prevent voting for own submission
        if submission.user == user:
            r = HttpResponse('<h1>Error</h1><p>You cannot vote for your own submission.</p>')
            r.status = 400
            return r

        # Allow changing a vote from positive to negative or vice-versa. Delete vote if its a re-vote
        vote = submission.votes.filter(user=user,submission__id=submission.id).first()
        if vote:
            if not vote.positive == (int(positive) == 1):
                vote.positive = int(positive) == 1
                vote.save()
            else:
                vote.delete()
        else:
            new_vote = SubmissionVote(
                    user=user,
                    submission=submission,
                    positive=int(positive) == 1
                )
            new_vote.save()

        return HttpResponseRedirect('/show/%s/episode/%d/%d'%(abbreviation, submission.episode.season.number, submission.episode.episode))