Reset energy-added when a new charge session is detected

custom_components/teslafi/const.py

@@ -20,6 +20,8 @@
 DELAY_LOCKS = timedelta(seconds=15)
 DELAY_WAKEUP = timedelta(seconds=30)
 
+TESLAFI_DATE_FORMAT = "%Y-%m-%d %H:%M:%S"
+
 ATTRIBUTION = "Data provided by Tesla and TeslaFi"
 
 SHIFTER_STATES = {

custom_components/teslafi/coordinator.py

@@ -1,7 +1,8 @@
 """TeslaFi data update coordinator"""
 
-from datetime import timedelta
-from typing_extensions import override
+from datetime import datetime, timedelta
+from typing import override
+
 from homeassistant.core import HomeAssistant, callback
 from homeassistant.helpers.update_coordinator import DataUpdateCoordinator
 
@@ -23,7 +24,8 @@ class TeslaFiCoordinator(DataUpdateCoordinator[TeslaFiVehicle]):
     _vehicle: TeslaFiVehicle
     data: TeslaFiVehicle
 
-    _override_next_refresh: timedelta = None
+    _last_charge_reset: datetime | None = None
+    _override_next_refresh: timedelta | None = None
 
     def __init__(
         self,
@@ -33,6 +35,7 @@ def __init__(
         self._client = client
         self.data = None
         self._vehicle = TeslaFiVehicle({})
+        self._last_charge_reset = None
         # TODO: implement custom Debouncer to ensure no more than 2x per min,
         #  as per API rate limit?
         super().__init__(
@@ -55,6 +58,11 @@ def schedule_refresh_in(self, delta: timedelta):
         self._override_next_refresh = delta
         self._schedule_refresh()
 
+    @property
+    def last_charge_reset(self) -> datetime | None:
+        """Last charge reset time."""
+        return self._last_charge_reset
+
     @override
     @callback
     def _schedule_refresh(self) -> None:
@@ -78,9 +86,11 @@ async def _refresh(self) -> TeslaFiVehicle:
         """Refresh"""
         current = await self._client.last_good()
         LOGGER.debug("Last good: %s", current)
+
+        self._infer_charge_session(prev=self.data, current=current)
+
         self._vehicle.update_non_empty(current)
-        last_remote_update = self._vehicle.get("Date")
-        LOGGER.debug("Remote data last updated %s", last_remote_update)
+        LOGGER.debug("Remote data last updated %s", self._vehicle.last_remote_update)
 
         assert current.vin
         assert self._vehicle.vin
@@ -101,3 +111,19 @@ async def _refresh(self) -> TeslaFiVehicle:
             self._override_next_refresh = None
 
         return self._vehicle
+
+    def _infer_charge_session(
+        self,
+        prev: TeslaFiVehicle,
+        current: TeslaFiVehicle,
+    ):
+        if prev and current and prev != current:
+            if not prev.is_plugged_in and current.is_plugged_in:
+                LOGGER.info("Vehicle is newly plugged in: resetting charge session")
+                self._last_charge_reset = current.last_remote_update
+            elif (
+                current.charge_session_number
+                and prev.charge_session_number != current.charge_session_number
+            ):
+                LOGGER.info("New charge session detected")
+                self._last_charge_reset = current.last_remote_update

custom_components/teslafi/model.py

@@ -2,12 +2,14 @@
 
 from collections import UserDict
 from dataclasses import dataclass
+from datetime import datetime
+import logging
 
 from typing_extensions import deprecated
 
 from homeassistant.const import UnitOfPressure
 
-from .const import SHIFTER_STATES, VIN_YEARS
+from .const import SHIFTER_STATES, TESLAFI_DATE_FORMAT, VIN_YEARS
 from .util import (
     _convert_to_bool,
     _int_or_none,
@@ -18,6 +20,8 @@
 
 NAN: float = float("NaN")
 
+LOGGER = logging.getLogger(__package__)
+
 CHARGER_CONNECTED_STATES = [
     "charging",
     "complete",
@@ -92,6 +96,19 @@ def name(self) -> str:
             or f"{self.model_year} {self.car_type} {self.vin[-4:]}"
         )
 
+    @property
+    def last_remote_update(self) -> datetime | None:
+        """Last remote update."""
+        try:
+            return (
+                datetime.strptime(s, TESLAFI_DATE_FORMAT)
+                if (s := self.get("Date", None))
+                else None
+            )
+        except ValueError:
+            LOGGER.warning("Failed to parse TeslaFi date: %s", s)
+            return None
+
     @property
     def car_type(self) -> str | None:
         """Car type (model). E.g. 'model3', etc."""
@@ -158,6 +175,11 @@ def charging_state(self) -> str | None:
         """
         return _lower_or_none(self.get("charging_state", None))
 
+    @property
+    def charge_session_number(self) -> int | None:
+        """The current charge session number."""
+        return n if (n := _int_or_none(self.get("chargeNumber"))) != 0 else None
+
     @property
     def is_plugged_in(self) -> bool | None:
         """Whether the vehicle is plugged in."""

custom_components/teslafi/sensor.py

@@ -1,5 +1,7 @@
 """Sensors"""
 
+from datetime import datetime
+from functools import cached_property
 from typing import override
 
 from homeassistant.components.sensor import (
@@ -133,6 +135,7 @@
         device_class=SensorDeviceClass.ENERGY,
         entity_registry_visible_default=False,
         state_class=SensorStateClass.TOTAL,
+        last_reset=None,
         available=lambda u, d, h: u and d.is_plugged_in,
     ),
     TeslaFiSensorEntityDescription(
@@ -255,6 +258,15 @@ def _handle_coordinator_update(self) -> None:
             fixed := self.entity_description.fix_unit(self.coordinator.data, self.hass)
         ):
             self._attr_native_unit_of_measurement = fixed
+
+        if self.entity_description.key == "charge_energy_added":
+            if self.entity_description.state_class == SensorStateClass.TOTAL and (
+                last_reset := self.coordinator.last_charge_reset
+            ):
+                self._attr_last_reset = last_reset
+            else:
+                self._attr_last_reset = None
+
         return super()._handle_coordinator_update()
 
     @property