修复：支持已确认退回的并发幂等

shierfeng-fastapi-backend/module_business/service/return_service.py

@@ -446,14 +446,13 @@ class ReturnService:
         pallet_ids: list[int],
         source_site_id: int,
         current_user: CurrentUserModel,
+        inventories: list[BizPalletInventory],
     ) -> tuple[
         list[BizPalletInventory],
         list[BizPallet],
         dict[int, BizFillingRecord | None],
-        list[int] | None,
     ]:
         ordered_ids = cls._validate_pallet_ids(pallet_ids)
-        inventories = await InventoryDao.get_inventories_for_update(query_db, ordered_ids)
         inventory_by_id = {inventory.pallet_id: inventory for inventory in inventories}
         if set(inventory_by_id) != set(ordered_ids):
             cls._raise_pallet_not_accessible(current_user, '存在不存在或库存缺失的托盘')
@@ -461,13 +460,11 @@ class ReturnService:
         ordered_inventories = [inventory_by_id[pallet_id] for pallet_id in ordered_ids]
         if any(inventory.site_id != source_site_id for inventory in ordered_inventories):
             cls._raise_pallet_not_accessible(current_user, '同一退回单托盘必须属于同一现场')
-        try:
-            await AccessService.assert_site_access(query_db, current_user, source_site_id)
-        except PermissionException:
-            cls._raise_pallet_not_accessible(current_user)
-        fresh_site_ids = await cls._site_scope(query_db, current_user)
-        if fresh_site_ids is not None and source_site_id not in fresh_site_ids:
-            cls._raise_pallet_not_accessible(current_user)
+        if any(
+            inventory.warehouse_id is not None or inventory.flow_state not in cls._REQUESTABLE_STATES
+            for inventory in ordered_inventories
+        ):
+            raise ServiceException(message='托盘当前状态不允许发起退回')
 
         pallets = await InventoryDao.get_pallets_by_ids(query_db, ordered_ids)
         pallet_by_id = {pallet.pallet_id: pallet for pallet in pallets}
@@ -485,7 +482,7 @@ class ReturnService:
         )
         for filling_id in filling_ids:
             filling_by_id[filling_id] = await OperationDao.get_active_filling_for_update(query_db, filling_id)
-        return ordered_inventories, ordered_pallets, filling_by_id, fresh_site_ids
+        return ordered_inventories, ordered_pallets, filling_by_id
 
     @classmethod
     def _validate_locked_request_pallets(
@@ -618,7 +615,7 @@ class ReturnService:
             await query_db.rollback()
 
     @classmethod
-    async def request_return_services(  # noqa: PLR0915
+    async def request_return_services(  # noqa: PLR0912, PLR0915
         cls,
         query_db: AsyncSession,
         page_object: ReturnRequestModel,
@@ -672,12 +669,18 @@ class ReturnService:
                 await query_db.rollback()
                 return cls._success('申请成功', return_id)
 
-            inventories, pallets, filling_by_id, fresh_site_ids = await cls._lock_request_pallets(
-                query_db,
-                ordered_ids,
-                page_object.source_site_id,
-                current_user,
-            )
+            inventories = await InventoryDao.get_inventories_for_update(query_db, ordered_ids)
+            try:
+                await AccessService.assert_site_access(
+                    query_db,
+                    current_user,
+                    page_object.source_site_id,
+                )
+            except PermissionException:
+                cls._raise_pallet_not_accessible(current_user)
+            fresh_site_ids = await cls._site_scope(query_db, current_user)
+            if fresh_site_ids is not None and page_object.source_site_id not in fresh_site_ids:
+                cls._raise_pallet_not_accessible(current_user)
             fresh_warehouse_ids = None if fresh_site_ids is None else []
             fresh_existing = await OperationDao.get_return_by_request_idempotency_key(
                 query_db,
@@ -693,6 +696,13 @@ class ReturnService:
                 await query_db.rollback()
                 return cls._success('申请成功', fresh_existing_id)
 
+            inventories, pallets, filling_by_id = await cls._lock_request_pallets(
+                query_db,
+                ordered_ids,
+                page_object.source_site_id,
+                current_user,
+                inventories,
+            )
             await cls._lock_new_request_route(query_db, page_object, current_user)
             cls._validate_locked_request_pallets(
                 inventories,