monthly usage: delete existing rows within dates

logic and tests to delete existing rows within date range in
post monthly usage

rctab/routers/accounting/usage.py

@@ -10,7 +10,10 @@
 from fastapi.security import OAuth2PasswordBearer
 from pydantic import BaseModel
 from rctab_models.models import AllCMUsage, AllUsage, CMUsage, Usage, UserRBAC
-from sqlalchemy import select
+from sqlalchemy import delete, select
+
+# require the postgre specific insert rather than the generic sqlachemy for;
+# `post_cm_usage` fn where "excluded" and "on_conflict_do_update" are used.
 from sqlalchemy.dialects.postgresql import insert
 from sqlalchemy.inspection import inspect
 
@@ -96,6 +99,27 @@ async def insert_usage(all_usage: AllUsage) -> None:
     )
 
 
+async def delete_usage(start_date: datetime.date, end_date: datetime.date) -> None:
+    """Deletes usage(s) within a date range from the database.
+
+    Args:
+        start_date: Defines the beginning of the date range.
+        end_date: Defines the end of the date range.
+    """
+    usage_query = (
+        delete(accounting_models.usage)
+        .where(accounting_models.usage.c.date >= start_date)
+        .where(accounting_models.usage.c.date <= end_date)
+    )
+
+    logger.info("Delete usage data within a date range")
+    delete_start = datetime.datetime.now()
+
+    await database.execute(usage_query)
+
+    logger.info("Delete usage data took %s", datetime.datetime.now() - delete_start)
+
+
 @router.post("/monthly-usage", response_model=TmpReturnStatus)
 async def post_monthly_usage(
     all_usage: AllUsage, _: Dict[str, str] = Depends(authenticate_usage_app)
@@ -180,6 +204,7 @@ async def post_usage(
             unique_subscriptions = list(
                 {i.subscription_id for i in all_usage.usage_list}
             )
+            await delete_usage(all_usage.start_date, all_usage.end_date)
 
             await insert_subscriptions_if_not_exists(unique_subscriptions)
 

tests/test_routes/test_usage.py

@@ -128,23 +128,45 @@ async def test_post_usage2(
     # upload some usage data for some subset of the dates
     usage_list = [
         Usage(
-            id=str(UUID(int=0)),
+            id=str(UUID(int=3)),
             subscription_id=sub1,
-            date="2024-04-01",
+            date="2024-04-02",
             total_cost=4.0,
             invoice_section="-",
         ),
     ]
     usage_items = AllUsage(
         usage_list=usage_list,
-        start_date="2024-04-01",
-        end_date="2024-04-03",
+        start_date="2024-04-02",
+        end_date="2024-04-02",
     )
     await post_usage(usage_items, {"mock": "authentication"})
 
-    # check that some usage data was left alone and some was replaced
+    # check that the uploaded usage data replaced the existing ones
     all_usage = await get_usage()
-    assert all_usage == usage_list
+    assert set(all_usage) == {
+        Usage(
+            id=str(UUID(int=0)),
+            subscription_id=sub1,
+            date="2024-04-01",
+            total_cost=1.0,
+            invoice_section="-",
+        ),
+        Usage(
+            id=str(UUID(int=3)),
+            subscription_id=sub1,
+            date="2024-04-02",
+            total_cost=4.0,
+            invoice_section="-",
+        ),
+        Usage(
+            id=str(UUID(int=2)),
+            subscription_id=sub1,
+            date="2024-04-03",
+            total_cost=4.0,
+            invoice_section="-",
+        ),
+    }
 
 
 @pytest.mark.asyncio