Fix handling of missing period statistics in Anglian Water coordinator (#167427)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

homeassistant/components/anglian_water/coordinator.py

@@ -92,6 +92,7 @@ class AnglianWaterUpdateCoordinator(DataUpdateCoordinator[None]):
                 _LOGGER.debug("Updating statistics for the first time")
                 usage_sum = 0.0
                 last_stats_time = None
+                allow_update_last_stored_hour = False
             else:
                 if not meter.readings or len(meter.readings) == 0:
                     _LOGGER.debug("No recent usage statistics found, skipping update")
@@ -107,6 +108,7 @@ class AnglianWaterUpdateCoordinator(DataUpdateCoordinator[None]):
                     continue
                 start = dt_util.as_local(parsed_read_at) - timedelta(hours=1)
                 _LOGGER.debug("Getting statistics at %s", start)
+                stats: dict[str, list[Any]] = {}
                 for end in (start + timedelta(seconds=1), None):
                     stats = await get_instance(self.hass).async_add_executor_job(
                         statistics_during_period,
@@ -127,15 +129,28 @@ class AnglianWaterUpdateCoordinator(DataUpdateCoordinator[None]):
                             "Not found, trying to find oldest statistic after %s",
                             start,
                         )
-                assert stats
 
-                def _safe_get_sum(records: list[Any]) -> float:
-                    if records and "sum" in records[0]:
-                        return float(records[0]["sum"])
-                    return 0.0
+                if not stats or not stats.get(usage_statistic_id):
+                    _LOGGER.debug(
+                        "Could not find existing statistics during period lookup for %s, "
+                        "falling back to last stored statistic",
+                        usage_statistic_id,
+                    )
+                    allow_update_last_stored_hour = True
+                    last_records = last_stat[usage_statistic_id]
+                    usage_sum = float(last_records[0].get("sum") or 0.0)
+                    last_stats_time = last_records[0]["start"]
+                else:
+                    allow_update_last_stored_hour = False
+                    records = stats[usage_statistic_id]
 
-                usage_sum = _safe_get_sum(stats.get(usage_statistic_id, []))
-                last_stats_time = stats[usage_statistic_id][0]["start"]
+                    def _safe_get_sum(records: list[Any]) -> float:
+                        if records and "sum" in records[0]:
+                            return float(records[0]["sum"])
+                        return 0.0
+
+                    usage_sum = _safe_get_sum(records)
+                    last_stats_time = records[0]["start"]
 
             usage_statistics = []
 
@@ -148,7 +163,13 @@ class AnglianWaterUpdateCoordinator(DataUpdateCoordinator[None]):
                     )
                     continue
                 start = dt_util.as_local(parsed_read_at) - timedelta(hours=1)
-                if last_stats_time is not None and start.timestamp() <= last_stats_time:
+                if last_stats_time is not None and (
+                    start.timestamp() < last_stats_time
+                    or (
+                        start.timestamp() == last_stats_time
+                        and not allow_update_last_stored_hour
+                    )
+                ):
                     continue
                 usage_state = max(0, read["consumption"] / 1000)
                 usage_sum = max(0, read["read"])

tests/components/anglian_water/test_coordinator.py

@@ -1,6 +1,7 @@
 """Tests for the Anglian Water coordinator."""
 
-from unittest.mock import AsyncMock
+from datetime import timedelta
+from unittest.mock import AsyncMock, patch
 
 from pyanglianwater.meter import SmartMeter
 import pytest
@@ -162,3 +163,92 @@ async def test_coordinator_invalid_readings(
         "Could not parse read_at time also-invalid-date, skipping reading"
         in caplog.text
     )
+
+
+async def test_coordinator_subsequent_run_missing_period_statistics(
+    recorder_mock: Recorder,
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+    mock_smart_meter: SmartMeter,
+    mock_anglian_water_client: AsyncMock,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Test the coordinator handles missing period lookup statistics."""
+    coordinator = AnglianWaterUpdateCoordinator(
+        hass, mock_anglian_water_client, mock_config_entry
+    )
+    await coordinator._async_update_data()
+    await async_wait_recording_done(hass)
+
+    # Correct the latest already-stored reading. Fallback should still update
+    # this hour instead of skipping it.
+    mock_smart_meter.readings[-1] = {
+        "read_at": "2024-06-01T14:00:00",
+        "consumption": 35,
+        "read": 70,
+    }
+
+    # Add a new later reading to ensure fallback also accepts newer entries.
+    mock_smart_meter.readings.append(
+        {"read_at": "2024-06-01T15:00:00", "consumption": 20, "read": 90}
+    )
+
+    with patch(
+        "homeassistant.components.anglian_water.coordinator.statistics_during_period",
+        return_value={},
+    ):
+        await coordinator._async_update_data()
+    await async_wait_recording_done(hass)
+
+    assert "Could not find existing statistics during period lookup" in caplog.text
+
+    statistic_id = f"anglian_water:{ACCOUNT_NUMBER}_testsn_usage"
+    stats = await hass.async_add_executor_job(
+        get_last_statistics, hass, 1, statistic_id, True, {"sum"}
+    )
+    assert stats[statistic_id][0]["sum"] >= 70
+
+    parsed_read_at = dt_util.parse_datetime("2024-06-01T14:00:00")
+    assert parsed_read_at is not None
+    corrected_start = dt_util.as_local(parsed_read_at) - timedelta(hours=1)
+
+    corrected_stats = await hass.async_add_executor_job(
+        statistics_during_period,
+        hass,
+        corrected_start,
+        corrected_start + timedelta(seconds=1),
+        {
+            statistic_id,
+        },
+        "hour",
+        None,
+        {"sum"},
+    )
+    assert corrected_stats[statistic_id][0]["sum"] == 70
+
+
+async def test_coordinator_period_statistics_without_sum(
+    recorder_mock: Recorder,
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+    mock_anglian_water_client: AsyncMock,
+) -> None:
+    """Test period lookup records without sum are handled safely."""
+    coordinator = AnglianWaterUpdateCoordinator(
+        hass, mock_anglian_water_client, mock_config_entry
+    )
+    await coordinator._async_update_data()
+    await async_wait_recording_done(hass)
+
+    statistic_id = f"anglian_water:{ACCOUNT_NUMBER}_testsn_usage"
+    with patch(
+        "homeassistant.components.anglian_water.coordinator.statistics_during_period",
+        return_value={statistic_id: [{"start": 0.0}]},
+    ):
+        await coordinator._async_update_data()
+    await async_wait_recording_done(hass)
+
+    stats = await hass.async_add_executor_job(
+        get_last_statistics, hass, 1, statistic_id, True, {"sum"}
+    )
+    assert stats[statistic_id]