Add plan variety change tracking

backend/apps/plans/views.py

@@ -10,6 +10,7 @@ from .serializers import (
     RiceTransplantPlanSerializer,
     RiceTransplantPlanWriteSerializer,
 )
+from .services import update_plan_with_variety_tracking
 from apps.fields.models import Field
 
 
@@ -120,15 +121,23 @@ class PlanViewSet(viewsets.ModelViewSet):
         updated = 0
         created = 0
         for field_id in field_ids:
-            plan, was_created = Plan.objects.update_or_create(
-                field_id=field_id,
-                year=year,
-                defaults={'crop': crop, 'variety': variety}
-            )
-            if was_created:
+            plan = Plan.objects.filter(field_id=field_id, year=year).first()
+            if plan is None:
+                Plan.objects.create(
+                    field_id=field_id,
+                    year=year,
+                    crop=crop,
+                    variety=variety,
+                )
                 created += 1
-            else:
-                updated += 1
+                continue
+
+            update_plan_with_variety_tracking(
+                plan,
+                crop=crop,
+                variety=variety,
+            )
+            updated += 1
 
         return Response({'created': created, 'updated': updated, 'total': created + updated})