from rest_framework import viewsets, filters
from django_filters.rest_framework import DjangoFilterBackend

from apps.compliance.permissions import IsOpsOrAdmin

from .models import ProcessingBatch
from .serializers import ProcessingBatchListSerializer, ProcessingBatchDetailSerializer, ProcessingBatchWriteSerializer


class ProcessingBatchViewSet(viewsets.ModelViewSet):
    queryset = ProcessingBatch.objects.prefetch_related("qc_results", "shipments", "documents").all()
    # The buyer portal reads batches through the ORM (apps/buyer/views.py), not
    # this API, so nothing outside ops/admin needs it — including for reads. That
    # closes the hole where a buyer could PATCH a batch's status.
    permission_classes = [IsOpsOrAdmin]
    filter_backends = [DjangoFilterBackend, filters.SearchFilter, filters.OrderingFilter]
    filterset_fields = ["status", "grade"]
    search_fields = ["batch_reference"]
    ordering_fields = ["created_at", "harvest_date"]
    ordering = ["-created_at"]

    def get_serializer_class(self):
        if self.action == "list":
            return ProcessingBatchListSerializer
        if self.action in ("create", "update", "partial_update"):
            return ProcessingBatchWriteSerializer
        return ProcessingBatchDetailSerializer

    def perform_create(self, serializer):
        serializer.save(created_by=self.request.user)