#  Episodes.Community - Community-Driven TV Show Episode Link Sharing Site
#  Copyright (C) 2017  Evert "Diamond" Prants <evert@lunasqu.ee>, Taizo "Tsa6" Simpson <taizo@tsa6.net>
#
#  This program is free software: you can redistribute it and/or modify
#  it under the terms of the GNU Affero General Public License as
#  published by the Free Software Foundation, either version 3 of the
#  License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU Affero General Public License for more details.
#
#  You should have received a copy of the GNU Affero General Public License
#  along with this program.  If not, see <https://www.gnu.org/licenses/>.

from django.template import RequestContext
from django.shortcuts import render, get_list_or_404, get_object_or_404
from django.views import View
from django.views.generic.base import TemplateView
from django.contrib.auth.decorators import login_required
from django.conf import settings
from django.http import Http404, HttpResponseForbidden, HttpResponse, HttpResponseRedirect
from django.db.models import Case, When, Value, IntegerField, Count, F, Q
from django.contrib.auth.mixins import LoginRequiredMixin

from guardian.decorators import permission_required_or_403

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

from . import forms

import datetime

# Create your views here.

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

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

        # Get show by abbr, add episode count to the show and return only the first object
        show = get_object_or_404(Show, abbr=abbr)

        # 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, abbr, season, episode, **kwargs):
        ctx = super().get_context_data()

        # Get show by abbr
        show = get_object_or_404(Show, abbr=abbr)
        episode = get_object_or_404(Episode, show=show,season__number=season,episode=episode)

        # I acknowledge 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

# Submission form GET and POST
@login_required
def SubmissionForm(req, abbr, season, episode):
    show = get_object_or_404(Show, abbr=abbr)
    episode = get_object_or_404(Episode, show=show,season__number=season,episode=episode)
    user = req.user

    form = forms.SubmissionForm()

    # Request context
    ctx = {
        'form': form,
        'show': show,
        'episode': episode
    }

    # Get bans for this user regarding this show
    bans = Ban.objects.filter(Q(scope=show) | Q(site_wide=True), Q(expiration__gte=datetime.datetime.now()) | Q(permanent=True), user=user)

    if bans.count() > 0:
        return HttpResponseForbidden('You are banned from submitting links to this show.<br>Reason: %s'%(bans.first().reason))

    # Handle POST
    if req.method == 'POST':
        form = forms.SubmissionForm(req.POST)
        ctx['form'] = form

        if form.is_valid():
            form_data = form.cleaned_data

            # Check if the URL has already been submitted
            if Submission.objects.filter(episode=episode,url=form_data['url']).count() > 0:
                ctx['error'] = 'This URL has already been submitted!'
                return render(req, "submit.html", ctx)

            if not user.has_perm('LandingPage.can_moderate_show', show):
                # Check if there has been a submission by this user for this episode within the last 24 hours
                if Submission.objects.filter(user=user,episode=episode,timestamp__gte=datetime.datetime.now() - datetime.timedelta(hours=24)).count() > 0:
                    ctx['error'] = 'You can only submit one link for an episode in 24 hours!'
                    return render(req, "submit.html", ctx)

            new_submission = form.save(commit=False)
            new_submission.user = user
            new_submission.episode = episode
            new_submission.save()

            return HttpResponseRedirect('/show/%s/episode/%d/%d'%(abbr, episode.season.number, episode.episode))
        else:
            ctx['error'] = 'Invalid fields!'

    return render(req, "submit.html", ctx)

# Edit a submission - for moderators
@permission_required_or_403('LandingPage.can_moderate_show', (Show, 'abbr', 'abbr'), accept_global_perms=True)
def SubmissionModForm(req, abbr, submission):
    show = get_object_or_404(Show, abbr=abbr)
    submission = get_object_or_404(Submission, pk=submission)
    episode = submission.episode
    user = req.user

    form = forms.SubmissionForm(instance=submission)

    # Request context
    ctx = {
        'form': form,
        'show': show,
        'episode': episode
    }

    # Handle POST
    if req.method == 'POST':
        if 'delete' in req.POST:
            submission.delete()
            return HttpResponseRedirect('/show/%s/episode/%d/%d'%(abbr, episode.season.number, episode.episode))

        if 'delete_ban' in req.POST:
            submission.delete()
            return HttpResponseRedirect('/show/%s/create_ban?user=%s'%(abbr,submission.user.username))

        form = forms.SubmissionForm(req.POST, instance=submission)
        ctx['form'] = form

        if form.is_valid():
            form_data = form.cleaned_data
            form.save()

            return HttpResponseRedirect('/show/%s/episode/%d/%d'%(abbr, episode.season.number, episode.episode))
        else:
            ctx['error'] = 'Invalid fields!'

    return render(req, "submit_mod.html", ctx)

# Season form GET and POST
@permission_required_or_403('LandingPage.can_moderate_show', (Show, 'abbr', 'abbr'), accept_global_perms=True)
def SeasonSubmitForm(req, abbr):
    show = get_object_or_404(Show, abbr=abbr)
    user = req.user

    form = forms.SeasonForm()

    # Request context
    ctx = {
        'form': form,
        'show': show
    }

    # Handle POST
    if req.method == 'POST':
        form = forms.SeasonForm(req.POST)
        ctx['form'] = form

        if form.is_valid():
            form_data = form.cleaned_data

            # Check if the URL has already been submitted
            if Season.objects.filter(show=show,number=form_data['number']).count() > 0:
                ctx['error'] = 'This season has already been submitted!'
                return render(req, "season_add.html", ctx)

            new_season = form.save(commit=False)
            new_season.show = show
            new_season.save()

            return HttpResponseRedirect('/show/%s'%(abbr))
        else:
            ctx['error'] = 'Invalid fields!'

    return render(req, "season_add.html", ctx)

# Episode form GET and POST
@permission_required_or_403('LandingPage.can_moderate_show', (Show, 'abbr', 'abbr'), accept_global_perms=True)
def EpisodeSubmitForm(req, abbr, season):
    show = get_object_or_404(Show, abbr=abbr)
    season = get_object_or_404(Season, show=show,number=season)
    user = req.user

    form = forms.EpisodeForm()

    # Request context
    ctx = {
        'form': form,
        'season': season,
        'show': show
    }

    # Handle POST
    if req.method == 'POST':
        form = forms.EpisodeForm(req.POST)
        ctx['form'] = form

        if form.is_valid():
            form_data = form.cleaned_data

            # Check if the URL has already been submitted
            if Episode.objects.filter(show=show,episode=form_data['episode'],season=season).count() > 0:
                ctx['error'] = 'This episode has already been submitted!'
                return render(req, "episode_add.html", ctx)

            new_episode = form.save(commit=False)
            new_episode.show = show
            new_episode.season = season
            new_episode.save()

            return HttpResponseRedirect('/show/%s'%(abbr))
        else:
            ctx['error'] = 'Invalid fields!'

    return render(req, "episode_add.html", ctx)

# Vote request
# /show/{{abbr}}/vote/{{submission id}}/{{positive == 1}}
class SubmissionVoteSubmit(LoginRequiredMixin, View):
    def post (self, req, abbr, subid, positive):
        # Convert positive parameter into a boolean
        pos_bool = int(positive) == 1

        user = req.user

        # Get the submission from the database
        submission = get_object_or_404(Submission, id=subid)

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

        show = submission.episode.show

        # Get bans for this user regarding this show
        bans = Ban.objects.filter(Q(scope=show) | Q(site_wide=True), Q(expiration__gte=datetime.datetime.now()) | Q(permanent=True), user=user)

        if bans.count() > 0:
            return HttpResponseForbidden('You are banned from voting on this show.<br>Reason: %s'%(bans.first().reason))

        # 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 == pos_bool:
                vote.positive = pos_bool
                vote.save()
            else:
                vote.delete()
        else:
            new_vote = SubmissionVote(
                    user=user,
                    submission=submission,
                    positive=pos_bool
                )
            new_vote.save()

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

# Episode form GET and POST
@permission_required_or_403('LandingPage.can_create_show_ban', (Show, 'abbr', 'abbr'), accept_global_perms=True)
def BanFromShowForm(req, abbr):
    show = get_object_or_404(Show, abbr=abbr)
    user = req.user

    banTarget = get_object_or_404(User, username=req.GET.get('user', None))

    if banTarget == user:
        return HttpResponseForbidden('You cannot ban yourself!')

    if banTarget.is_staff:
        return HttpResponseForbidden('You cannot ban a staff member!')

    if banTarget.has_perm('LandingPage.can_moderate_show', show):
        return HttpResponseForbidden('You cannot ban another moderator!')

    form = forms.BanForm()

    # Request context
    ctx = {
        'form': form,
        'show': show,
        'target': banTarget
    }

    # Handle POST
    if req.method == 'POST':
        form = forms.BanForm(req.POST)
        ctx['form'] = form

        if form.is_valid():
            form_data = form.cleaned_data

            # Save
            new_ban = form.save(commit=False)

            if form_data['permanent']:
                new_ban.expiration = datetime.datetime.now()

            new_ban.site_wide = False
            new_ban.user = banTarget
            new_ban.admin = user
            new_ban.save()

            # Add show to scope
            new_ban.scope.add(show)

            # Delete all of the user's submissions for this show
            if 'delete' in req.POST:
                Submission.objects.filter(episode__show=show,user=banTarget).delete()

            return HttpResponseRedirect('/show/%s'%(abbr))
        else:
            ctx['error'] = 'Invalid fields!'

    return render(req, "create_ban.html", ctx)