Truncate exported final shifts to match the requested period (#2924)

When calculating on-call load, if an involved shift extends outside the
requested time span you can get unexpected results. Truncate the
returned events times to keep the details for the specified start/end
dates.

CHANGELOG.md

@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Performance and UX tweaks to integrations page ([#2869](https://github.com/grafana/oncall/pull/2869))
 - Expand users details in filter swaps internal endpoint ([#2921](https://github.com/grafana/oncall/pull/2921))
+- Truncate exported final shifts to match the requested period ([#2924](https://github.com/grafana/oncall/pull/2924))
 
 ### Fixed
 

engine/apps/public_api/tests/test_schedules.py

@@ -969,7 +969,7 @@ def test_oncall_shifts_export_from_ical_schedule(
     client = APIClient()
 
     url = reverse("api-public:schedules-final-shifts", kwargs={"pk": schedule.public_primary_key})
-    response = client.get(f"{url}?start_date=2023-07-01&end_date=2023-08-01", format="json", HTTP_AUTHORIZATION=token)
+    response = client.get(f"{url}?start_date=2023-07-01&end_date=2023-07-31", format="json", HTTP_AUTHORIZATION=token)
     assert response.status_code == status.HTTP_200_OK
 
     expected_on_call_times = {
@@ -1006,11 +1006,51 @@ def test_oncall_shifts_export_from_api_schedule(
     client = APIClient()
 
     url = reverse("api-public:schedules-final-shifts", kwargs={"pk": schedule.public_primary_key})
-    response = client.get(f"{url}?start_date=2023-07-01&end_date=2023-08-01", format="json", HTTP_AUTHORIZATION=token)
+    response = client.get(f"{url}?start_date=2023-07-01&end_date=2023-07-31", format="json", HTTP_AUTHORIZATION=token)
     assert response.status_code == status.HTTP_200_OK
 
     expected_on_call_times = {
         user1.public_primary_key: 32,  # daily 2h * 16d
         user2.public_primary_key: 30,  # daily 2h * 15d
     }
     assert_expected_shifts_export_response(response, (user1, user2), expected_on_call_times)
+
+
+@pytest.mark.django_db
+def test_oncall_shifts_export_truncate_events(
+    make_organization_and_user_with_token,
+    make_user,
+    make_schedule,
+    make_on_call_shift,
+):
+    organization, _, token = make_organization_and_user_with_token()
+    user1 = make_user(organization=organization)
+
+    user1_public_primary_key = user1.public_primary_key
+    schedule = make_schedule(organization, schedule_class=OnCallScheduleWeb)
+
+    # 24h shifts starting 9am on Mo, We and Fr
+    start_date = timezone.datetime(2023, 1, 1, 9, 0, 0, tzinfo=pytz.UTC)
+    make_on_call_shift(
+        organization=organization,
+        schedule=schedule,
+        shift_type=CustomOnCallShift.TYPE_ROLLING_USERS_EVENT,
+        frequency=CustomOnCallShift.FREQUENCY_DAILY,
+        priority_level=1,
+        interval=1,
+        by_day=["MO", "WE", "FR"],
+        start=start_date,
+        rolling_users=[{user1.pk: user1_public_primary_key}],
+        rotation_start=start_date,
+        duration=timezone.timedelta(hours=24),
+    )
+
+    client = APIClient()
+
+    # request shifts on a Tu (ie. 00:00 - 09:00)
+    url = reverse("api-public:schedules-final-shifts", kwargs={"pk": schedule.public_primary_key})
+    response = client.get(f"{url}?start_date=2023-01-03&end_date=2023-01-03", format="json", HTTP_AUTHORIZATION=token)
+    assert response.status_code == status.HTTP_200_OK
+
+    expected_on_call_times = {user1_public_primary_key: 9}
+    assert_expected_shifts_export_response(response, (user1,), expected_on_call_times)

engine/apps/public_api/views/schedules.py

@@ -145,7 +145,7 @@ def final_shifts(self, request, pk):
 
         datetime_start = datetime.datetime.combine(start_date, datetime.time.min, tzinfo=pytz.UTC)
         datetime_end = datetime_start + datetime.timedelta(
-            days=days_between_start_and_end - 1, hours=23, minutes=59, seconds=59
+            days=days_between_start_and_end, hours=23, minutes=59, seconds=59
         )
 
         final_schedule_events: ScheduleEvents = schedule.final_events(datetime_start, datetime_end)
@@ -158,8 +158,9 @@ def final_shifts(self, request, pk):
                 "user_pk": user["pk"],
                 "user_email": user["email"],
                 "user_username": user["display_name"],
-                "shift_start": event["start"],
-                "shift_end": event["end"],
+                # truncate shift start/end exceeding the requested period
+                "shift_start": event["start"] if event["start"] >= datetime_start else datetime_start,
+                "shift_end": event["end"] if event["end"] <= datetime_end else datetime_end,
             }
             for event in final_schedule_events
             for user in event["users"]