"""News app views."""
from django.conf import settings
from django.db.transaction import on_commit
from django.shortcuts import get_object_or_404
from rest_framework import generics, permissions, status
from rest_framework.response import Response

from gallery.tasks import delete_image
from news import filters, models, serializers
from rating.tasks import add_rating
from utils.permissions import IsCountryAdmin, IsContentPageManager


class NewsMixinView:
    """News mixin."""

    permission_classes = (permissions.AllowAny,)
    serializer_class = serializers.NewsBaseSerializer

    def get_queryset(self, *args, **kwargs):
        from django.conf import settings
        """Override get_queryset method."""

        qs = models.News.objects.published().with_base_related() \
            .order_by('-is_highlighted', '-created')
        country_code = self.request.country_code
        if country_code:

            #  temp code
            # Temporary stub for international news logic
            # (по договорённости с заказчиком на демонстрации 4 ноября
            # здесь будет 6 фиксированных новостей)
            # TODO replace this stub with actual logic
            if hasattr(settings, 'HARDCODED_INTERNATIONAL_NEWS_IDS'):
                if country_code and country_code != 'www' and country_code != 'main':
                    qs = qs.by_country_code(country_code)
                else:
                    qs = models.News.objects.filter(
                            id__in=settings.HARDCODED_INTERNATIONAL_NEWS_IDS)
                return qs
            # temp code

            qs = qs.by_country_code(country_code)
        return qs


class NewsListView(NewsMixinView, generics.ListAPIView):
    """News list view."""

    serializer_class = serializers.NewsListSerializer
    filter_class = filters.NewsListFilterSet


class NewsDetailView(NewsMixinView, generics.RetrieveAPIView):
    """News detail view."""

    lookup_field = 'slug'
    serializer_class = serializers.NewsDetailWebSerializer

    def get_queryset(self):
        """Override get_queryset method."""
        return super().get_queryset().with_extended_related()


class NewsTypeListView(generics.ListAPIView):
    """NewsType list view."""

    pagination_class = None
    permission_classes = (permissions.AllowAny, )
    queryset = models.NewsType.objects.all()
    serializer_class = serializers.NewsTypeSerializer


class NewsBackOfficeMixinView:
    """News back office mixin view."""

    permission_classes = (permissions.IsAuthenticated,)
    queryset = models.News.objects.with_base_related() \
        .order_by('-is_highlighted', '-created')


class NewsBackOfficeLCView(NewsBackOfficeMixinView,
                           generics.ListCreateAPIView):
    """Resource for a list of news for back-office users."""

    serializer_class = serializers.NewsBackOfficeBaseSerializer
    create_serializers_class = serializers.NewsBackOfficeDetailSerializer
    permission_classes = [IsCountryAdmin|IsContentPageManager]

    def get_serializer_class(self):
        """Override serializer class."""
        if self.request.method == 'POST':
            return self.create_serializers_class
        return super().get_serializer_class()

    def get_queryset(self):
        """Override get_queryset method."""
        return super().get_queryset().with_extended_related()


class NewsBackOfficeGalleryCreateDestroyView(NewsBackOfficeMixinView,
                                             generics.CreateAPIView,
                                             generics.DestroyAPIView):
    """Resource for a create gallery for news for back-office users."""
    serializer_class = serializers.NewsBackOfficeGallerySerializer

    def get_object(self):
        """
        Returns the object the view is displaying.
        """
        news_qs = self.filter_queryset(self.get_queryset())

        news = get_object_or_404(news_qs, pk=self.kwargs['pk'])
        gallery = get_object_or_404(news.news_gallery, image_id=self.kwargs['image_id'])

        # May raise a permission denied
        self.check_object_permissions(self.request, gallery)

        return gallery

    def create(self, request, *args, **kwargs):
        """Overridden create method"""
        super().create(request, *args, **kwargs)
        return Response(status=status.HTTP_201_CREATED)

    def destroy(self, request, *args, **kwargs):
        """Override destroy method."""
        gallery_obj = self.get_object()
        if settings.USE_CELERY:
            on_commit(lambda: delete_image.delay(image_id=gallery_obj.image.id,
                                                 completely=False))
        else:
            on_commit(lambda: delete_image(image_id=gallery_obj.image.id,
                                           completely=False))
        # Delete an instances of NewsGallery model
        gallery_obj.delete()
        return Response(status=status.HTTP_204_NO_CONTENT)


class NewsBackOfficeGalleryListView(NewsBackOfficeMixinView, generics.ListAPIView):
    """Resource for returning gallery for news for back-office users."""
    serializer_class = serializers.NewsImageSerializer

    def get_object(self):
        """Override get_object method."""
        qs = super(NewsBackOfficeGalleryListView, self).get_queryset()
        news = get_object_or_404(qs, pk=self.kwargs['pk'])

        # May raise a permission denied
        self.check_object_permissions(self.request, news)

        return news

    def get_queryset(self):
        """Override get_queryset method."""
        return self.get_object().gallery.all()


class NewsBackOfficeRUDView(NewsBackOfficeMixinView,
                            generics.RetrieveUpdateDestroyAPIView):
    """Resource for detailed information about news for back-office users."""

    serializer_class = serializers.NewsBackOfficeDetailSerializer
    permission_classes = [IsCountryAdmin|IsContentPageManager]

    def get(self, request, pk, *args, **kwargs):
        add_rating(remote_addr=request.META.get('REMOTE_ADDR'),
                   pk=pk, model='news', app_label='news')
        return self.retrieve(request, *args, **kwargs)