updated apps

custom_components/powercalc/unit.py

@@ -0,0 +1,98 @@
+"""Shared helpers for parsing numeric state values and converting between units."""
+
+from __future__ import annotations
+
+from decimal import Decimal, DecimalException
+import logging
+
+from homeassistant.const import UnitOfEnergy
+from homeassistant.core import State
+from homeassistant.exceptions import HomeAssistantError, TemplateError
+from homeassistant.helpers.template import Template
+from homeassistant.util.unit_conversion import (
+    BaseUnitConverter,
+    EnergyConverter,
+    PowerConverter,
+)
+
+from custom_components.powercalc.const import UNAVAILABLE_STATES, UnitPrefix
+
+_LOGGER = logging.getLogger(__name__)
+
+# Maps a configured energy unit prefix to the resulting energy unit of measurement.
+ENERGY_UNIT_PREFIX_MAPPING: dict[str, str] = {
+    UnitPrefix.NONE: UnitOfEnergy.WATT_HOUR,
+    UnitPrefix.KILO: UnitOfEnergy.KILO_WATT_HOUR,
+    UnitPrefix.MEGA: UnitOfEnergy.MEGA_WATT_HOUR,
+    UnitPrefix.GIGA: UnitOfEnergy.GIGA_WATT_HOUR,
+    UnitPrefix.TERA: UnitOfEnergy.TERA_WATT_HOUR,
+}
+
+# Maps any energy or power unit of measurement to the converter that handles it.
+UNIT_CONVERTERS: dict[str | None, type[BaseUnitConverter]] = {
+    **dict.fromkeys(EnergyConverter.VALID_UNITS, EnergyConverter),
+    **dict.fromkeys(PowerConverter.VALID_UNITS, PowerConverter),
+}
+
+
+def parse_decimal(value: object) -> Decimal | None:
+    """Parse a numeric value into a Decimal, returning None when it is not a usable number.
+
+    Accepts a Home Assistant State (its ``state`` string is used) or a raw value of any type.
+    Unknown or unavailable states and values that are not numeric yield None instead of raising.
+    """
+    if isinstance(value, State):
+        if value.state in UNAVAILABLE_STATES:
+            return None
+        value = value.state
+    if not isinstance(value, (str, int, float, Decimal)):
+        return None
+    try:
+        return Decimal(value)
+    except DecimalException, ValueError:
+        return None
+
+
+def evaluate_to_decimal(value: object) -> Decimal | None:
+    """Evaluate a value into a Decimal, rendering it first when it is a template.
+
+    Non-template values (strings, numbers) are parsed directly. Returns None when a template
+    fails to render, or when the (rendered) value is not a usable number. Unknown/unavailable
+    renders yield None silently; any other failure is logged.
+    """
+    if isinstance(value, Template):
+        try:
+            value = value.async_render()
+        except TemplateError as ex:
+            _LOGGER.error("Could not render template %s: %s", value, ex)
+            return None
+        if value in UNAVAILABLE_STATES:
+            return None
+
+    result = parse_decimal(value)
+    if result is None:
+        _LOGGER.error("Could not convert value %s to a decimal", value)
+    return result
+
+
+def convert_to_decimal(
+    value: State | str | float | Decimal,
+    from_unit: str | None,
+    to_unit: str | None,
+) -> Decimal | None:
+    """Convert a value between energy/power units and return it as a Decimal.
+
+    Returns None when the value is not numeric or the units cannot be converted.
+    """
+    parsed = parse_decimal(value)
+    if parsed is None:
+        return None
+    if from_unit == to_unit:
+        return parsed
+    converter = UNIT_CONVERTERS.get(from_unit)
+    if converter is None:
+        return None
+    try:
+        return Decimal(str(converter.convert(float(parsed), from_unit, to_unit)))
+    except HomeAssistantError:
+        return None