#  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, redirect, 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, Max
from django.contrib.auth.mixins import LoginRequiredMixin
from django.shortcuts import render
from django.core.paginator import Paginator, PageNotAnInteger, EmptyPage
from django.utils.text import slugify

from guardian.decorators import permission_required_or_403

from LandingPage.models import Show, DiscussionBoard, DiscussionReply, DiscussionVote, Ban
from . import forms

import datetime
import re

class Boards(TemplateView):

    template_name = "boards.html"

    def get_context_data(self, abbr, **kwargs):
        ctx = super().get_context_data()
        show = get_object_or_404(Show, abbr=abbr)

        page = self.request.GET.get('page', 1)

        boards_list = DiscussionBoard.objects.filter(show=show).annotate(
            num_replies=Count('replies'),
            recency=Case(
                        When(
                            num_replies=0,
                            then=Max('timestamp')
                        ),
                        When(
                            num_replies__gt=0,
                            then=Max('replies__timestamp')
                        )
                    ),
            ).order_by('-recency')
        paginator = Paginator(boards_list, getattr(settings, "DISCUSSIONS_PER_PAGE", 26))

        try:
            boards = paginator.page(page)
        except PageNotAnInteger:
            boards = paginator.page(1)
        except EmptyPage:
            boards = paginator.page(paginator.num_pages)
        
        ctx['boards'] = boards
        ctx['show'] = show

        return ctx

class Board(TemplateView):

    template_name = "board.html"

    def get_context_data(self, abbr, bid, **kwargs):
        ctx = super().get_context_data()
        show = get_object_or_404(Show, abbr=abbr)
        board = get_object_or_404(DiscussionBoard, pk=bid)

        page = self.request.GET.get('page', 1)
        find = self.request.GET.get('findReply', None)

        reply_list = DiscussionReply.objects.filter(board=board).order_by('timestamp').annotate(
            positives=Count(
                Case(
                    When(
                        votes__positive=True,
                        then=Value(1)
                        )
                    )
                ),
            negatives=Count('votes') - F('positives'),
            score=F('positives') - F('negatives')
        )
        perpage = getattr(settings, "DISCUSSIONS_REPLIES_PER_PAGE", 10)
        paginator = Paginator(reply_list, perpage)

        if find and find.isnumeric():
            item = get_object_or_404(DiscussionReply, pk=find)
            if item.board == board:
                found = DiscussionReply.objects.filter(timestamp__lt=item.timestamp,board=board).count()
                page = int(found / perpage) + 1
                index = int(found % perpage) + 1
                ctx['url'] = '/show/%s/discuss/board/%d-%s?page=%d#reply-%d'%(abbr, board.pk, slugify(board.title), page, index)

                return ctx

        try:
            replies = paginator.page(page)
        except PageNotAnInteger:
            replies = paginator.page(1)
        except EmptyPage:
            replies = paginator.page(paginator.num_pages)

        ctx['board'] = board
        ctx['replies'] = replies
        ctx['show'] = show
        ctx['form'] = forms.ReplyForm()

        return ctx

    def render_to_response(self, context):
        if 'url' in context:
            return redirect(context['url'])

        return super(Board, self).render_to_response(context)

# Board form GET and POST
@login_required
def BoardForm(req, abbr):
    show = get_object_or_404(Show, abbr=abbr)
    user = req.user

    form = forms.BoardForm()

    # Request context
    ctx = {
        'form': form,
        'show': 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 discussing this show.<br>Reason: %s'%(bans.first().reason))

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

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

            # Check if the Title has already been posted
            if DiscussionBoard.objects.filter(show=show,title=form_data['title']).count() > 0:
                ctx['error'] = 'A board with this title already exists!'
                return render(req, "boards_new.html", ctx)

            if not user.has_perm('LandingPage.can_moderate_board', show):
                # Check if there has been a board by this user for this show within the last 24 hours
                if DiscussionBoard.objects.filter(user=user,show=show,timestamp__gte=datetime.datetime.now() - datetime.timedelta(hours=24)).count() > 8:
                    ctx['error'] = 'You can only create 8 boards for a show in 24 hours!'
                    return render(req, "boards_new.html", ctx)

            new_board = form.save(commit=False)
            new_board.user = user
            new_board.show = show
            new_board.save()

            new_post = DiscussionReply(user=user,board=new_board,body=form_data['body'])
            new_post.save()

            return HttpResponseRedirect('/show/%s/discuss/board/%d-%s'%(abbr, new_board.pk, slugify(form_data['title'])))
        else:
            ctx['error'] = 'Invalid fields!'

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

# Reply form GET and POST
@login_required
def BoardReplyForm(req, abbr, bid):
    show = get_object_or_404(Show, abbr=abbr)
    board = get_object_or_404(DiscussionBoard, pk=bid)
    user = req.user

    form = forms.ReplyForm()

    # Request context
    ctx = {
        'form': form,
        'board': board,
        'show': 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 discussing this show.<br>Reason: %s'%(bans.first().reason))

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

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

            # Body Content Filter
            real_content = re.sub(r'[\s\W]+', '', form_data['body'])
            err_res = False
            if len(real_content) < 10:
                ctx['error'] = 'The content is too small! Please write more meaningful replies.'
                err_res = True
            elif len(real_content) > 4000:
                ctx['error'] = 'The content body is too large! Please write less in a single reply.'
                err_res = True

            # TODO: Apply word filtering here
            # TODO: Apply markdown

            if err_res:
                return render(req, "board_reply.html", ctx)

            new_reply = form.save(commit=False)
            new_reply.user = user
            new_reply.board = board
            new_reply.save()

            return HttpResponseRedirect('/show/%s/discuss/board/%d-%s?findReply=%d'%(abbr, board.pk, slugify(board.title), new_reply.pk))
        else:
            ctx['error'] = 'Invalid fields!'

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

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

        user = req.user

        # Get the reply from the database
        reply = get_object_or_404(DiscussionReply, id=replyid)

        # Prevent voting for own reply
        if reply.user == user:
            return HttpResponse('<h1>Error</h1><p>You cannot vote for your own reply.</p><p>'
                                '<a href="/show/%s/discuss/board/%d-%s">Return to board</a></p>' 
                                % (abbr, reply.board.pk, slugify(reply.board.title)), status=400)

        show = reply.board.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\'s discussion boards.<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 = reply.votes.filter(user=user,reply=reply).first()
        if vote:
            if not vote.positive == pos_bool:
                vote.positive = pos_bool
                vote.save()
            else:
                vote.delete()
        else:
            new_vote = DiscussionVote(
                    user=user,
                    reply=reply,
                    positive=pos_bool
                )
            new_vote.save()

        return HttpResponseRedirect('/show/%s/discuss/board/%d-%s?findReply=%d'%(abbr, reply.board.pk, slugify(reply.board.title), reply.pk))