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

from netbox.api.viewsets import NetBoxModelViewSet

from ..engine.resolver import Resolver
from ..models import Service, ServiceTemplate
from .serializers import ServiceSerializer, ServiceTemplateSerializer


class ServiceTemplateViewSet(NetBoxModelViewSet):
    queryset = ServiceTemplate.objects.all()
    serializer_class = ServiceTemplateSerializer


class ServiceViewSet(NetBoxModelViewSet):
    queryset = Service.objects.all()
    serializer_class = ServiceSerializer

    @action(detail=True, methods=["post"])
    def resolve(self, request, pk=None):
        """Resolve a service's requirement tree.

        Request body: ``{"mode": "dry_run" | "commit"}``
        """
        service = self.get_object()
        mode = request.data.get("mode", "dry_run")

        resolver = Resolver()
        try:
            result = resolver.resolve(service, mode=mode, user=request.user)
        except Exception as exc:
            return Response(
                {"error": str(exc)},
                status=status.HTTP_400_BAD_REQUEST,
            )

        planned_data = []
        for node_name, obj in result.planned_objects:
            ct = obj.__class__._meta
            planned_data.append({
                "node": node_name,
                "object_type": f"{ct.app_label}.{ct.model_name}",
                "object_id": obj.pk,
                "object": str(obj),
            })

        response_data = {
            "mode": mode,
            "succeeded": result.succeeded,
            "total_planned": result.total_planned,
            "total_current": result.total_current,
            "to_add": len(result.to_add),
            "to_remove": len(result.to_remove),
            "planned": planned_data,
            "errors": result.errors,
            "warnings": result.warnings,
            "summary": result.summary,
        }

        return Response(response_data)