from django.utils.translation import gettext as _
from django.views.generic import ListView
from django.http import HttpResponse, JsonResponse, HttpResponseBadRequest, HttpResponsePermanentRedirect, HttpResponseRedirect
from django.core.paginator import Paginator
from django.core.exceptions import PermissionDenied
from django.shortcuts import render
from django.forms.models import model_to_dict
from django.db.models import Case, BooleanField, When, Q, Subquery, OuterRef, Exists, Count, IntegerField
from django.db.models.functions import Coalesce
from django.utils import timezone
from django.contrib.auth.decorators import login_required
from django.urls import reverse

import datetime

from judge import event_poster as event
from judge.jinja2.gravatar import gravatar
from judge.models import Friend

from chat_box.models import Message, Profile, Room, UserRoom, Ignore
from chat_box.utils import encrypt_url, decrypt_url

import json


class ChatView(ListView):
    context_object_name = 'message'
    template_name = 'chat/chat.html'
    title = _('Chat Box')
    
    def __init__(self):
        super().__init__()
        self.room_id = None
        self.room = None
        self.paginate_by = 50
        self.messages = None
        self.paginator = None

    def get_queryset(self):
        return self.messages

    def get(self, request, *args, **kwargs):
        request_room = kwargs['room_id']
        page = request.GET.get('page')

        if request_room:
            try:
                self.room = Room.objects.get(id=request_room)
                if not can_access_room(request, self.room):
                    return HttpResponseBadRequest()
            except Room.DoesNotExist:
                return HttpResponseBadRequest()
        else:
            request_room = None

        if request_room != self.room_id or not self.messages:
            self.room_id = request_room
            self.messages = Message.objects.filter(hidden=False, room=self.room_id)
            self.paginator = Paginator(self.messages, self.paginate_by)

        if page == None:
            update_last_seen(request, **kwargs)
            return super().get(request, *args, **kwargs)

        cur_page = self.paginator.get_page(page)

        return render(request, 'chat/message_list.html', {
            'object_list': cur_page.object_list,
            'num_pages': self.paginator.num_pages
        })

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

        context['title'] = self.title
        context['last_msg'] = event.last()
        context['status_sections'] = get_status_context(self.request)
        context['room'] = self.room_id
        context['unread_count_lobby'] = get_unread_count(None, self.request.profile)
        if self.room:
            users_room = [self.room.user_one, self.room.user_two]
            users_room.remove(self.request.profile)
            context['other_user'] =  users_room[0]
            context['other_online'] = get_user_online_status(context['other_user'])
            context['is_ignored'] = Ignore.is_ignored(self.request.profile, context['other_user'])
        else:
            context['online_count'] = get_online_count()
        context['message_template'] = {
            'author': self.request.profile,
            'id': '$id',
            'time': timezone.now(),
            'body': '$body'
        }        
        return context


def delete_message(request):
    ret = {'delete': 'done'}
    
    if request.method == 'GET':
        return JsonResponse(ret)

    if request.user.is_staff:
        try:
            messid = int(request.POST.get('message'))
            mess = Message.objects.get(id=messid)
        except:
            return HttpResponseBadRequest()
        
        mess.hidden = True
        mess.save()
        
        return JsonResponse(ret)
    
    return JsonResponse(ret)


@login_required
def post_message(request):
    ret = {'msg': 'posted'}
    if request.method != 'POST':
        return HttpResponseBadRequest()

    room = None
    if request.POST['room']:
        room = Room.objects.get(id=request.POST['room'])
    
    if not can_access_room(request, room) or request.profile.mute:
        return HttpResponseBadRequest()

    new_message = Message(author=request.profile,
                          body=request.POST['body'],
                          room=room)
    new_message.save()

    if not room:
        event.post('chat_lobby', {
            'type': 'lobby',
            'author_id': request.profile.id, 
            'message': new_message.id,
            'room': 'None',
            'tmp_id': request.POST.get('tmp_id')
        })
    else:
        for user in room.users():
            event.post('chat_' + str(user.id), {
                'type': 'private',
                'author_id': request.profile.id, 
                'message': new_message.id,
                'room': room.id,
                'tmp_id': request.POST.get('tmp_id')
            })   
    
    return JsonResponse(ret)


def can_access_room(request, room):
    return not room or room.user_one == request.profile or room.user_two == request.profile


@login_required
def chat_message_ajax(request):
    if request.method != 'GET':
        return HttpResponseBadRequest()

    try:
        message_id = request.GET['message']
    except KeyError:
        return HttpResponseBadRequest()

    try:
        message = Message.objects.filter(hidden=False).get(id=message_id)
        room = message.room
        if room and not room.contain(request.profile):
            return HttpResponse('Unauthorized', status=401)
    except Message.DoesNotExist:
        return HttpResponseBadRequest()
    return render(request, 'chat/message.html', {
        'message': message,
    })


@login_required
def update_last_seen(request, **kwargs):
    if 'room_id' in kwargs:
        room_id = kwargs['room_id']
    elif request.method == 'GET':
        room_id = request.GET.get('room')
    elif request.method == 'POST':
        room_id = request.POST.get('room')
    else:
        return HttpResponseBadRequest()

    try:
        profile = request.profile
        room = None
        if room_id:
            room = Room.objects.get(id=int(room_id))
    except Room.DoesNotExist:
        return HttpResponseBadRequest()
    except Exception as e:
        return HttpResponseBadRequest()

    if room and not room.contain(profile):
        return HttpResponseBadRequest()

    user_room, _ = UserRoom.objects.get_or_create(user=profile, room=room)
    user_room.last_seen = timezone.now()
    user_room.save()

    return JsonResponse({'msg': 'updated'})


def get_online_count():
    last_two_minutes = timezone.now()-timezone.timedelta(minutes=2)
    return Profile.objects.filter(last_access__gte=last_two_minutes).count()


def get_user_online_status(user):
    time_diff = timezone.now() - user.last_access
    is_online = time_diff <= timezone.timedelta(minutes=2)
    return is_online


def user_online_status_ajax(request):
    if request.method != 'GET':
        return HttpResponseBadRequest()

    user_id = request.GET.get('user')

    if user_id:
        try:
            user_id = int(user_id)
            user = Profile.objects.get(id=user_id)
        except Exception as e:
            return HttpResponseBadRequest()

        is_online = get_user_online_status(user)
        return render(request, 'chat/user_online_status.html', {
                'other_user': user,
                'other_online': is_online,
                'is_ignored': Ignore.is_ignored(request.profile, user)
            })
    else:
        return render(request, 'chat/user_online_status.html', {
                'online_count': get_online_count(),
            })


def get_online_status(request_user, queryset, rooms=None):
    if not queryset:
        return None
    last_two_minutes = timezone.now()-timezone.timedelta(minutes=2)
    ret = []

    if rooms:
        unread_count = get_unread_count(rooms, request_user)
        count = {}
        for i in unread_count:
            count[i['other_user']] = i['unread_count']

    for user in queryset:
        is_online = False
        if (user.last_access >= last_two_minutes):
            is_online = True
        user_dict = {'user': user, 'is_online': is_online}
        if rooms and user.id in count:
            user_dict['unread_count'] = count[user.id]
        user_dict['url'] = encrypt_url(request_user.id, user.id)
        ret.append(user_dict)
    return ret


def get_status_context(request, include_ignored=False):
    if include_ignored:
        ignored_users = Profile.objects.none()
        queryset = Profile.objects
    else:
        ignored_users = Ignore.get_ignored_users(request.profile)
        queryset = Profile.objects.exclude(id__in=ignored_users)

    last_two_minutes = timezone.now()-timezone.timedelta(minutes=2)
    recent_profile = Room.objects.filter(
            Q(user_one=request.profile) | Q(user_two=request.profile)
        ).annotate(
            last_msg_time=Subquery(
                Message.objects.filter(room=OuterRef('pk')).values('time')[:1]
            ),
            other_user=Case(
                When(user_one=request.profile, then='user_two'),
                default='user_one',
            )
        ).filter(last_msg_time__isnull=False)\
        .exclude(other_user__in=ignored_users)\
        .order_by('-last_msg_time').values('other_user', 'id')[:20]

    recent_profile_id = [str(i['other_user']) for i in recent_profile]
    joined_id = ','.join(recent_profile_id)
    recent_rooms = [int(i['id']) for i in recent_profile]
    recent_list = None
    if joined_id:
        recent_list = Profile.objects.raw(
            f'SELECT * from judge_profile where id in ({joined_id}) order by field(id,{joined_id})')
    friend_list = Friend.get_friend_profiles(request.profile).exclude(id__in=recent_profile_id)\
                    .exclude(id__in=ignored_users)\
                    .order_by('-last_access')
    admin_list = queryset.filter(display_rank='admin')\
                .exclude(id__in=friend_list).exclude(id__in=recent_profile_id)
    all_user_status = queryset\
        .filter(display_rank='user',
        last_access__gte = last_two_minutes)\
        .annotate(is_online=Case(default=True,output_field=BooleanField()))\
        .order_by('-rating').exclude(id__in=friend_list).exclude(id__in=admin_list)\
        .exclude(id__in=recent_profile_id)[:30]
    
    return [
        {
            'title': 'Recent',
            'user_list': get_online_status(request.profile, recent_list, recent_rooms),
        },
        {
            'title': 'Following',
            'user_list': get_online_status(request.profile, friend_list),
        },
        {
            'title': 'Admin',
            'user_list': get_online_status(request.profile, admin_list),
        },
        {
            'title': 'Other',
            'user_list': get_online_status(request.profile, all_user_status),
        },
    ]


@login_required
def online_status_ajax(request):
    return render(request, 'chat/online_status.html', {
            'status_sections': get_status_context(request),
            'unread_count_lobby': get_unread_count(None, request.profile),
        })


@login_required
def get_room(user_one, user_two):
    if user_one.id > user_two.id:
        user_one, user_two = user_two, user_one
    room, created = Room.objects.get_or_create(user_one=user_one, user_two=user_two)
    return room


@login_required
def get_or_create_room(request):
    if request.method == 'GET':
        decrypted_other_id = request.GET.get('other')
    elif request.method == 'POST':
        decrypted_other_id = request.POST.get('other')
    else:
        return HttpResponseBadRequest()

    request_id, other_id = decrypt_url(decrypted_other_id)

    if not other_id or not request_id or request_id != request.profile.id:
        return HttpResponseBadRequest()

    try:
        other_user = Profile.objects.get(id=int(other_id))
    except Exception:
        return HttpResponseBadRequest()

    user = request.profile
    
    if not other_user or not user:
        return HttpResponseBadRequest()
    # TODO: each user can only create <= 300 rooms
    room = get_room(other_user, user)
    for u in [other_user, user]:
        user_room, created = UserRoom.objects.get_or_create(user=u, room=room)
        if created:
            user_room.last_seen = timezone.now()
            user_room.save()

    if request.method == 'GET':
        return JsonResponse({'room': room.id, 'other_user_id': other_user.id})
    return HttpResponseRedirect(reverse('chat', kwargs={'room_id': room.id}))


def get_unread_count(rooms, user):
    if rooms:
        mess = Message.objects.filter(room=OuterRef('room'),
                                      time__gte=OuterRef('last_seen'))\
                .exclude(author=user)\
                .order_by().values('room')\
                .annotate(unread_count=Count('pk')).values('unread_count')

        return UserRoom.objects\
            .filter(user=user, room__in=rooms)\
            .annotate(
                unread_count=Coalesce(Subquery(mess, output_field=IntegerField()), 0),
                other_user=Case(
                    When(room__user_one=user, then='room__user_two'),
                    default='room__user_one',
                )
            ).filter(unread_count__gte=1).values('other_user', 'unread_count')
    else: # lobby
        mess = Message.objects.filter(room__isnull=True,
                                      time__gte=OuterRef('last_seen'))\
                .exclude(author=user)\
                .order_by().values('room')\
                .annotate(unread_count=Count('pk')).values('unread_count')

        res = UserRoom.objects\
            .filter(user=user, room__isnull=True)\
            .annotate(
                unread_count=Coalesce(Subquery(mess, output_field=IntegerField()), 0),
            ).values_list('unread_count', flat=True)

        return res[0] if len(res) else 0


@login_required
def toggle_ignore(request, **kwargs):
    user_id = kwargs['user_id']
    if not user_id:
        return HttpResponseBadRequest()
    try:
        other_user = Profile.objects.get(id=user_id)
    except:
        return HttpResponseBadRequest()

    Ignore.toggle_ignore(request.profile, other_user)
    next_url = request.GET.get('next', '/')
    return HttpResponseRedirect(next_url)


@login_required
def get_unread_boxes(request):
    if (request.method != 'GET'):
        return HttpResponseBadRequest()

    mess = Message.objects.filter(room=OuterRef('room'),
                                  time__gte=OuterRef('last_seen'))\
            .exclude(author=request.profile)\
            .order_by().values('room')\
            .annotate(unread_count=Count('pk')).values('unread_count')

    unread_boxes = UserRoom.objects\
        .filter(user=request.profile, room__isnull=False)\
        .annotate(
            unread_count=Coalesce(Subquery(mess, output_field=IntegerField()), 0),
        ).filter(unread_count__gte=1).count()

    return JsonResponse({'unread_boxes': unread_boxes})