From 46815be370c74cbf1716ff8f601922f1879ded3a Mon Sep 17 00:00:00 2001
From: Erwin Douna <e.douna@gmail.com>
Date: Wed, 30 Sep 2026 09:19:01 +0200
Subject: [PATCH] Log MELCloud Home telemetry unavailability once (#183649)

---
 .../components/melcloud_home/coordinator.py   | 54 ++++++++++++-------
 tests/components/melcloud_home/test_init.py   | 42 +++++++++++++++
 2 files changed, 77 insertions(+), 19 deletions(-)

diff --git a/homeassistant/components/melcloud_home/coordinator.py b/homeassistant/components/melcloud_home/coordinator.py
index 51a59aeebec7..1cf1f5ce4461 100644
--- a/homeassistant/components/melcloud_home/coordinator.py
+++ b/homeassistant/components/melcloud_home/coordinator.py
@@ -5,7 +5,7 @@ from collections.abc import Callable, Coroutine
 from dataclasses import dataclass
 from datetime import datetime, timedelta
 import logging
-from typing import override
+from typing import Any, override
 
 from aiomelcloudhome import ATAUnit, ATWUnit, MELCloudHome, UserContext
 from aiomelcloudhome.exceptions import (
@@ -180,35 +180,51 @@ class MelCloudHomeTelemetryCoordinator(
             update_interval=TELEMETRY_UPDATE_INTERVAL,
         )
         self.client = client
+        self._unavailable_telemetry: set[tuple[str, str]] = set()
+
+    async def _async_fetch_telemetry[_T](
+        self, name: str, unit_id: str, coroutine: Coroutine[Any, Any, _T]
+    ) -> _T | None:
+        """Fetch telemetry for a unit, logging once when it becomes unavailable."""
+        key = (name, unit_id)
+        try:
+            result = await coroutine
+        except (
+            MelCloudHomeAuthenticationError,
+            MelCloudHomeConnectionError,
+            MelCloudHomeTimeoutError,
+        ):
+            if key not in self._unavailable_telemetry:
+                self._unavailable_telemetry.add(key)
+                _LOGGER.info("%s for %s is unavailable", name, unit_id)
+            return None
+        if key in self._unavailable_telemetry:
+            self._unavailable_telemetry.remove(key)
+            _LOGGER.info("%s for %s is available again", name, unit_id)
+        return result
 
     async def _async_get_energy(
         self, unit_id: str, start_of_month: datetime, now: datetime
     ) -> float | None:
         """Fetch energy telemetry for a unit without failing the whole update."""
-        try:
-            energy = await self.client.get_energy_telemetry(
+        energy = await self._async_fetch_telemetry(
+            "Energy telemetry",
+            unit_id,
+            self.client.get_energy_telemetry(
                 unit_id, from_dt=start_of_month, to_dt=now, interval="Day"
-            )
-        except (
-            MelCloudHomeAuthenticationError,
-            MelCloudHomeConnectionError,
-            MelCloudHomeTimeoutError,
-        ):
-            _LOGGER.warning("Failed to fetch energy telemetry for %s:", unit_id)
+            ),
+        )
+        if energy is None:
             return None
         return sum(float(e.value) for e in energy)
 
     async def _async_get_outdoor_temperature(self, unit_id: str) -> float | None:
         """Fetch outdoor temperature for a unit without failing the whole update."""
-        try:
-            return await self.client.get_outdoor_temperature(unit_id)
-        except (
-            MelCloudHomeAuthenticationError,
-            MelCloudHomeConnectionError,
-            MelCloudHomeTimeoutError,
-        ):
-            _LOGGER.warning("Failed to fetch outdoor temperature for %s", unit_id)
-            return None
+        return await self._async_fetch_telemetry(
+            "Outdoor temperature",
+            unit_id,
+            self.client.get_outdoor_temperature(unit_id),
+        )
 
     @override
     async def _async_update_data(self) -> MelCloudHomeTelemetryData:
diff --git a/tests/components/melcloud_home/test_init.py b/tests/components/melcloud_home/test_init.py
index 0e968a386e03..be2c9bfc7f4c 100644
--- a/tests/components/melcloud_home/test_init.py
+++ b/tests/components/melcloud_home/test_init.py
@@ -346,3 +346,45 @@ async def test_outdoor_temperature_update_cycle_fails(
     await hass.async_block_till_done(wait_background_tasks=True)
 
     assert telemetry_coordinator.data.outdoor_temperature["ata-unit-uuid-1"] is not None
+
+
+@pytest.mark.parametrize(
+    ("method", "name"),
+    [
+        pytest.param("get_energy_telemetry", "Energy telemetry", id="energy"),
+        pytest.param(
+            "get_outdoor_temperature", "Outdoor temperature", id="outdoor_temperature"
+        ),
+    ],
+)
+async def test_telemetry_unavailable_logged_once(
+    hass: HomeAssistant,
+    mock_melcloud_client: AsyncMock,
+    mock_config_entry: MockConfigEntry,
+    freezer: FrozenDateTimeFactory,
+    caplog: pytest.LogCaptureFixture,
+    method: str,
+    name: str,
+) -> None:
+    """Test a failing telemetry fetch is logged once, and once when it recovers."""
+    await setup_integration(hass, mock_config_entry)
+    unavailable = f"{name} for ata-unit-uuid-1 is unavailable"
+    available = f"{name} for ata-unit-uuid-1 is available again"
+
+    getattr(mock_melcloud_client, method).side_effect = MelCloudHomeConnectionError
+    for _ in range(2):
+        freezer.tick(TELEMETRY_UPDATE_INTERVAL)
+        async_fire_time_changed(hass)
+        await hass.async_block_till_done(wait_background_tasks=True)
+
+    assert caplog.text.count(unavailable) == 1
+    assert available not in caplog.text
+
+    getattr(mock_melcloud_client, method).side_effect = None
+    for _ in range(2):
+        freezer.tick(TELEMETRY_UPDATE_INTERVAL)
+        async_fire_time_changed(hass)
+        await hass.async_block_till_done(wait_background_tasks=True)
+
+    assert caplog.text.count(unavailable) == 1
+    assert caplog.text.count(available) == 1