Google Calendar Integration - consider current oncall shifts for autogeneration of shift swap requests (#4160)

# What this PR does

Fixes issue where you create a Google Calendar OOO that overlaps with an
in-progress oncall shift (currently we only consider future/upcoming
shifts).

Related to https://github.com/grafana/oncall-private/issues/2555

## Checklist

- [x] Unit, integration, and e2e (if applicable) tests updated
- [x] Documentation added (or `pr:no public docs` PR label added if not
required)
- [x] Added the relevant release notes label (see labels prefixed w/
`release:`). These labels dictate how your PR will
    show up in the autogenerated release notes.

engine/apps/google/tasks.py

@@ -41,16 +41,16 @@ def sync_out_of_office_calendar_events_for_user(google_oauth2_user_pk: int) -> N
         )
 
         for schedule in users_schedules:
-            _, _, upcoming_shifts = schedule.shifts_for_user(
+            _, current_shifts, upcoming_shifts = schedule.shifts_for_user(
                 user,
                 start_time_utc,
                 datetime_end=end_time_utc,
             )
 
-            if upcoming_shifts:
+            if current_shifts or upcoming_shifts:
                 logger.info(
-                    f"Found {len(upcoming_shifts)} upcoming shift(s) for user {user_id} "
-                    f"during the out of office event {event_id}"
+                    f"Found {len(current_shifts)} current shift(s) and {len(upcoming_shifts)} upcoming shift(s) "
+                    f"for user {user_id} during the out of office event {event_id}"
                 )
 
                 shift_swap_request_exists = ShiftSwapRequest.objects.filter(
@@ -78,7 +78,9 @@ def sync_out_of_office_calendar_events_for_user(google_oauth2_user_pk: int) -> N
                 else:
                     logger.info(f"Shift swap request already exists for user {user_id} schedule {schedule.pk}")
             else:
-                logger.info(f"No upcoming shifts found for user {user_id} during the out of office event {event_id}")
+                logger.info(
+                    f"No current or upcoming shifts found for user {user_id} during the out of office event {event_id}"
+                )
 
 
 @shared_dedicated_queue_retry_task(autoretry_for=(Exception,), retry_backoff=True)

engine/apps/google/tests/test_sync_out_of_office_calendar_events_for_user.py

@@ -56,10 +56,16 @@ def _create_mock_google_calendar_event(start_time: datetime.datetime, end_time:
     }
 
 
+def _get_utc_now():
+    return datetime.datetime.now(tz=datetime.timezone.utc)
+
+
+def _adjust_datetime(dt):
+    return dt.replace(second=0, microsecond=0)
+
+
 def _create_event_start_and_end_times(start_days_in_future=5, end_time_minutes_past_start=50):
-    start_time = (
-        datetime.datetime.now(tz=datetime.timezone.utc) + datetime.timedelta(days=start_days_in_future)
-    ).replace(second=0, microsecond=0)
+    start_time = _adjust_datetime(_get_utc_now() + datetime.timedelta(days=start_days_in_future))
     end_time = start_time + datetime.timedelta(minutes=end_time_minutes_past_start)
 
     return start_time, end_time
@@ -259,6 +265,29 @@ def test_sync_out_of_office_calendar_events_for_user_no_upcoming_shifts(
     assert ShiftSwapRequest.objects.filter(beneficiary=user).count() == 0
 
 
+@patch("apps.google.client.build")
+@pytest.mark.django_db
+def test_sync_out_of_office_calendar_events_for_user_considers_current_shifts(
+    mock_google_api_client_build,
+    test_setup,
+):
+    in_five_minutes = _adjust_datetime(_get_utc_now() + datetime.timedelta(minutes=5))
+    in_ten_minutes = in_five_minutes + datetime.timedelta(minutes=5)
+
+    mock_google_api_client_build.return_value.events.return_value.list.return_value.execute.return_value = {
+        "items": [
+            _create_mock_google_calendar_event(in_five_minutes, in_ten_minutes),
+        ],
+    }
+
+    google_oauth2_user, _ = test_setup([])
+    user = google_oauth2_user.user
+
+    tasks.sync_out_of_office_calendar_events_for_user(google_oauth2_user.pk)
+
+    assert ShiftSwapRequest.objects.filter(beneficiary=user).count() == 1
+
+
 @patch("apps.google.client.build")
 @pytest.mark.django_db
 def test_sync_out_of_office_calendar_events_for_user_preexisting_shift_swap_request(