feat: locking group with bill request

services/deal.py

@@ -7,7 +7,7 @@ from starlette import status
 
 import models.deal
 import models.secondary
-from models import User, Service, Client, DealProductService, deal_relations
+from models import User, Service, Client, DealProductService, deal_relations, GroupBillRequest
 from models.deal import *
 from models.deal_group import DealGroup
 from schemas.client import ClientDetailsSchema
@@ -1150,6 +1150,10 @@ class DealService(BaseService):
 
     async def add_to_group(self, user: User, request: DealAddToGroupRequest) -> DealAddToGroupResponse:
         try:
+            group_bill_request = await self.session.get(GroupBillRequest, request.group_id)
+            if group_bill_request:
+                raise Exception("Нельзя добавить сделку, так как на группу выставлен счёт.")
+
             # changing status if needed
             deal_id = await self.session.scalar(
                 select(deal_relations.c.deal_id)