from rest_framework import status, viewsets
from rest_framework.decorators import action
from rest_framework.response import Response

from apps.accounts.permissions import CanRegisterCitySite, IsExecutive, can_sync
from apps.accounts.scoping import filter_city_sites_queryset
from apps.farms.services.city_registry import ensure_hq_site_for_city
from apps.sync.models import CitySite
from apps.sync.serializers import CitySiteSerializer, CitySiteWriteSerializer


class CitySiteViewSet(viewsets.ModelViewSet):
    """
    List/read: scoped (director all; BUH managed GMs; GM own).
    Create/update/delete: GM and GM Admin.
    Sync: GM and GM Admin only (stubs until mirror pull is implemented).

    Creating a city site also attaches (or creates) an HQ Site so farm data
    appears in the executive view list.
    """

    executive_sync_action = True

    def get_queryset(self):
        qs = CitySite.objects.select_related("registered_by").all()
        return filter_city_sites_queryset(qs, self.request.user)

    def get_permissions(self):
        if self.action in {"create", "update", "partial_update", "destroy"}:
            return [CanRegisterCitySite()]
        return [IsExecutive()]

    def get_serializer_class(self):
        if self.action in {"create", "update", "partial_update"}:
            return CitySiteWriteSerializer
        return CitySiteSerializer

    def perform_create(self, serializer):
        city = serializer.save(registered_by=self.request.user)
        ensure_hq_site_for_city(city)

    def perform_update(self, serializer):
        city = serializer.save()
        if city.is_active:
            ensure_hq_site_for_city(city)

    @action(detail=True, methods=["post"], url_path="sync")
    def sync(self, request, pk=None):
        if not can_sync(request.user):
            return Response({"detail": "Sync not allowed."}, status=status.HTTP_403_FORBIDDEN)
        city = self.get_object()
        if not city.is_active:
            return Response(
                {"detail": "City site is inactive."},
                status=status.HTTP_400_BAD_REQUEST,
            )
        return Response(
            {
                "detail": "City sync not implemented yet.",
                "city_site": CitySiteSerializer(city).data,
            },
            status=status.HTTP_501_NOT_IMPLEMENTED,
        )

    @action(detail=False, methods=["post"], url_path="sync-all")
    def sync_all(self, request):
        if not can_sync(request.user):
            return Response({"detail": "Sync not allowed."}, status=status.HTTP_403_FORBIDDEN)
        cities = list(self.get_queryset().filter(is_active=True))
        return Response(
            {
                "detail": "City sync-all not implemented yet.",
                "city_count": len(cities),
                "cities": CitySiteSerializer(cities, many=True).data,
            },
            status=status.HTTP_501_NOT_IMPLEMENTED,
        )