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

from infrasynth.security.permissions import IsAuthenticatedAndPermitted

from .models import FeatureFlag, FeatureFlagOverride
from .serializers import FeatureFlagOverrideSerializer, FeatureFlagSerializer
from .services import FeatureService
from .signals import flag_created, flag_deleted, flag_toggled, override_created, override_deleted


class FeatureFlagViewSet(viewsets.ModelViewSet):
    queryset = FeatureFlag.objects.all()
    serializer_class = FeatureFlagSerializer
    permission_classes = [IsAuthenticatedAndPermitted]

    def get_queryset(self):
        return FeatureFlag.objects.all()

    def perform_create(self, serializer):
        instance = serializer.save()
        FeatureService().invalidate(instance.slug, instance.tenant_id)
        flag_created.send(
            sender=FeatureFlag,
            tenant_id=str(instance.tenant_id) if instance.tenant_id else None,
            flag_slug=instance.slug,
            is_active=instance.is_active,
            actor_id=getattr(self.request.user, "pk", None),
        )

    def perform_update(self, serializer):
        previous_active = serializer.instance.is_active
        instance = serializer.save()
        FeatureService().invalidate(instance.slug, instance.tenant_id)
        if instance.is_active != previous_active:
            flag_toggled.send(
                sender=FeatureFlag,
                tenant_id=str(instance.tenant_id) if instance.tenant_id else None,
                flag_slug=instance.slug,
                is_active=instance.is_active,
                previous_is_active=previous_active,
                actor_id=getattr(self.request.user, "pk", None),
            )

    def perform_destroy(self, instance):
        slug = instance.slug
        tenant_id = instance.tenant_id
        FeatureService().invalidate(slug, tenant_id)
        actor_id = getattr(self.request.user, "pk", None)
        instance.delete()
        flag_deleted.send(
            sender=FeatureFlag,
            tenant_id=str(tenant_id) if tenant_id else None,
            flag_slug=slug,
            actor_id=actor_id,
        )

    @action(detail=False, methods=["get"], url_path="active")
    def active_flags(self, request):
        from django.conf import settings

        from infrasynth.tenancy.context import get_current_tenant

        fs = FeatureService()
        tenant = get_current_tenant()
        flags = fs.get_active_flags(user=request.user, tenant_id=tenant.pk if tenant is not None else None)
        # A list (not a map) so camelCase key conversion never mangles slug identifiers.
        data = {"flags": [{"slug": slug, "enabled": enabled} for slug, enabled in sorted(flags.items())]}
        config = getattr(settings, "INFRASYNTH_FEATURES", {})
        if config.get("EXPOSE_PERMISSIONS_IN_ACTIVE_ENDPOINT"):
            from infrasynth.security.services import AuthorizationService

            data["effective_permissions"] = sorted(AuthorizationService().get_effective_permissions(request.user))
        if config.get("EXPOSE_ROLES_IN_ACTIVE_ENDPOINT"):
            roles_qs = getattr(request.user, "roles", None)
            data["roles"] = list(roles_qs.values_list("slug", flat=True)) if roles_qs is not None else []
        return Response(data)

    @action(detail=False, methods=["get"], url_path="check/(?P<slug>[^/]+)")
    def check_flag(self, request, slug=None):
        from infrasynth.tenancy.context import get_current_tenant

        fs = FeatureService()
        tenant = get_current_tenant()
        enabled = fs.is_enabled(slug, user=request.user, tenant_id=tenant.pk if tenant is not None else None)
        return Response({"slug": slug, "is_enabled": enabled})


class FeatureFlagOverrideViewSet(
    mixins.CreateModelMixin,
    mixins.ListModelMixin,
    mixins.DestroyModelMixin,
    viewsets.GenericViewSet,
):
    queryset = FeatureFlagOverride.objects.all()
    serializer_class = FeatureFlagOverrideSerializer
    permission_classes = [IsAuthenticatedAndPermitted]

    def get_queryset(self):
        return FeatureFlagOverride.objects.select_related("flag", "user").all()

    def perform_create(self, serializer):
        instance = serializer.save()
        flag_slug = instance.flag.slug
        tenant_id = instance.tenant_id
        FeatureService().invalidate(flag_slug, tenant_id)
        override_created.send(
            sender=FeatureFlagOverride,
            tenant_id=str(tenant_id) if tenant_id else None,
            flag_slug=flag_slug,
            user_id=instance.user_id,
            is_enabled=instance.is_enabled,
            actor_id=getattr(self.request.user, "pk", None),
        )

    def perform_destroy(self, instance):
        flag_slug = instance.flag.slug
        tenant_id = instance.tenant_id
        user_id = instance.user_id
        FeatureService().invalidate(flag_slug, tenant_id)
        actor_id = getattr(self.request.user, "pk", None)
        instance.delete()
        override_deleted.send(
            sender=FeatureFlagOverride,
            tenant_id=str(tenant_id) if tenant_id else None,
            flag_slug=flag_slug,
            user_id=user_id,
            actor_id=actor_id,
        )