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"""Unit system helper class and methods."""
from __future__ import annotations
from numbers import Number
from homeassistant.const import (
CONF_UNIT_SYSTEM_IMPERIAL,
CONF_UNIT_SYSTEM_METRIC,
LENGTH,
LENGTH_KILOMETERS,
LENGTH_MILES,
MASS,
MASS_GRAMS,
MASS_KILOGRAMS,
MASS_OUNCES,
MASS_POUNDS,
PRESSURE,
PRESSURE_PA,
PRESSURE_PSI,
TEMP_CELSIUS,
TEMP_FAHRENHEIT,
TEMPERATURE,
UNIT_NOT_RECOGNIZED_TEMPLATE,
VOLUME,
VOLUME_GALLONS,
VOLUME_LITERS,
)
from homeassistant.util import (
distance as distance_util,
pressure as pressure_util,
temperature as temperature_util,
volume as volume_util,
)
# mypy: disallow-any-generics
LENGTH_UNITS = distance_util.VALID_UNITS
MASS_UNITS: tuple[str, ...] = (MASS_POUNDS, MASS_OUNCES, MASS_KILOGRAMS, MASS_GRAMS)
PRESSURE_UNITS = pressure_util.VALID_UNITS
VOLUME_UNITS = volume_util.VALID_UNITS
TEMPERATURE_UNITS: tuple[str, ...] = (TEMP_FAHRENHEIT, TEMP_CELSIUS)
def is_valid_unit(unit: str, unit_type: str) -> bool:
"""Check if the unit is valid for it's type."""
if unit_type == LENGTH:
units = LENGTH_UNITS
elif unit_type == TEMPERATURE:
units = TEMPERATURE_UNITS
elif unit_type == MASS:
units = MASS_UNITS
elif unit_type == VOLUME:
units = VOLUME_UNITS
elif unit_type == PRESSURE:
units = PRESSURE_UNITS
else:
return False
return unit in units
class UnitSystem:
"""A container for units of measure."""
def __init__(
self,
name: str,
temperature: str,
length: str,
volume: str,
mass: str,
pressure: str,
) -> None:
"""Initialize the unit system object."""
errors: str = ", ".join(
UNIT_NOT_RECOGNIZED_TEMPLATE.format(unit, unit_type)
for unit, unit_type in (
(temperature, TEMPERATURE),
(length, LENGTH),
(volume, VOLUME),
(mass, MASS),
(pressure, PRESSURE),
)
if not is_valid_unit(unit, unit_type)
)
if errors:
raise ValueError(errors)
self.name = name
self.temperature_unit = temperature
self.length_unit = length
self.mass_unit = mass
self.pressure_unit = pressure
self.volume_unit = volume
@property
def is_metric(self) -> bool:
"""Determine if this is the metric unit system."""
return self.name == CONF_UNIT_SYSTEM_METRIC
def temperature(self, temperature: float, from_unit: str) -> float:
"""Convert the given temperature to this unit system."""
if not isinstance(temperature, Number):
raise TypeError(f"{temperature!s} is not a numeric value.")
return temperature_util.convert(temperature, from_unit, self.temperature_unit)
def length(self, length: float | None, from_unit: str) -> float:
"""Convert the given length to this unit system."""
if not isinstance(length, Number):
raise TypeError(f"{length!s} is not a numeric value.")
# type ignore: https://github.com/python/mypy/issues/7207
return distance_util.convert( # type: ignore
length, from_unit, self.length_unit
)
def pressure(self, pressure: float | None, from_unit: str) -> float:
"""Convert the given pressure to this unit system."""
if not isinstance(pressure, Number):
raise TypeError(f"{pressure!s} is not a numeric value.")
# type ignore: https://github.com/python/mypy/issues/7207
return pressure_util.convert( # type: ignore
pressure, from_unit, self.pressure_unit
)
def volume(self, volume: float | None, from_unit: str) -> float:
"""Convert the given volume to this unit system."""
if not isinstance(volume, Number):
raise TypeError(f"{volume!s} is not a numeric value.")
# type ignore: https://github.com/python/mypy/issues/7207
return volume_util.convert(volume, from_unit, self.volume_unit) # type: ignore
def as_dict(self) -> dict[str, str]:
"""Convert the unit system to a dictionary."""
return {
LENGTH: self.length_unit,
MASS: self.mass_unit,
PRESSURE: self.pressure_unit,
TEMPERATURE: self.temperature_unit,
VOLUME: self.volume_unit,
}
METRIC_SYSTEM = UnitSystem(
CONF_UNIT_SYSTEM_METRIC,
TEMP_CELSIUS,
LENGTH_KILOMETERS,
VOLUME_LITERS,
MASS_GRAMS,
PRESSURE_PA,
)
IMPERIAL_SYSTEM = UnitSystem(
CONF_UNIT_SYSTEM_IMPERIAL,
TEMP_FAHRENHEIT,
LENGTH_MILES,
VOLUME_GALLONS,
MASS_POUNDS,
PRESSURE_PSI,
)