Goodwe reset to 0 at midnight (#76793)

* reset at midnight

* fix styling

* Update sensor.py

* Update homeassistant/components/goodwe/sensor.py

Co-authored-by: Erik Montnemery <erik@montnemery.com>

* fix missing import

* Only reset if inverter is offline at midnight

* fix issort

* Add detailed explanation

Co-authored-by: Erik Montnemery <erik@montnemery.com>

homeassistant/components/goodwe/sensor.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 
 from collections.abc import Callable
 from dataclasses import dataclass
+from datetime import timedelta
 from typing import Any, cast
 
 from goodwe import Inverter, Sensor, SensorKind
@@ -23,19 +24,28 @@ from homeassistant.const import (
     POWER_WATT,
     TEMP_CELSIUS,
 )
-from homeassistant.core import HomeAssistant
+from homeassistant.core import HomeAssistant, callback
 from homeassistant.helpers.entity import DeviceInfo, EntityCategory
 from homeassistant.helpers.entity_platform import AddEntitiesCallback
+from homeassistant.helpers.event import async_track_point_in_time
 from homeassistant.helpers.update_coordinator import (
     CoordinatorEntity,
     DataUpdateCoordinator,
 )
+import homeassistant.util.dt as dt_util
 
 from .const import DOMAIN, KEY_COORDINATOR, KEY_DEVICE_INFO, KEY_INVERTER
 
 # Sensor name of battery SoC
 BATTERY_SOC = "battery_soc"
 
+# Sensors that are reset to 0 at midnight.
+# The inverter is only powered by the solar panels and not mains power, so it goes dead when the sun goes down.
+# The "_day" sensors are reset to 0 when the inverter wakes up in the morning when the sun comes up and power to the inverter is restored.
+# This makes sure daily values are reset at midnight instead of at sunrise.
+# When the inverter has a battery connected, HomeAssistant will not reset the values but let the inverter reset them by looking at the unavailable state of the inverter.
+DAILY_RESET = ["e_day", "e_load_day"]
+
 _MAIN_SENSORS = (
     "ppv",
     "house_consumption",
@@ -167,6 +177,7 @@ class InverterSensor(CoordinatorEntity, SensorEntity):
             self._attr_device_class = SensorDeviceClass.BATTERY
         self._sensor = sensor
         self._previous_value = None
+        self._stop_reset = None
 
     @property
     def native_value(self):
@@ -190,3 +201,32 @@ class InverterSensor(CoordinatorEntity, SensorEntity):
         return cast(GoodweSensorEntityDescription, self.entity_description).available(
             self
         )
+
+    @callback
+    def async_reset(self, now):
+        """Reset the value back to 0 at midnight."""
+        if not self.coordinator.last_update_success:
+            self._previous_value = 0
+            self.coordinator.data[self._sensor.id_] = 0
+            self.async_write_ha_state()
+        next_midnight = dt_util.start_of_local_day(dt_util.utcnow() + timedelta(days=1))
+        self._stop_reset = async_track_point_in_time(
+            self.hass, self.async_reset, next_midnight
+        )
+
+    async def async_added_to_hass(self):
+        """Schedule reset task at midnight."""
+        if self._sensor.id_ in DAILY_RESET:
+            next_midnight = dt_util.start_of_local_day(
+                dt_util.utcnow() + timedelta(days=1)
+            )
+            self._stop_reset = async_track_point_in_time(
+                self.hass, self.async_reset, next_midnight
+            )
+        await super().async_added_to_hass()
+
+    async def async_will_remove_from_hass(self):
+        """Remove reset task at midnight."""
+        if self._sensor.id_ in DAILY_RESET and self._stop_reset is not None:
+            self._stop_reset()
+        await super().async_will_remove_from_hass()