core/homeassistant/helpers/location.py

"""Location helpers for Home Assistant."""

from typing import Optional, Sequence

from homeassistant.const import ATTR_LATITUDE, ATTR_LONGITUDE
from homeassistant.core import State
from homeassistant.util import location as loc_util


def has_location(state: State) -> bool:
    """Test if state contains a valid location.

    Async friendly.
    """
    # type ignore: https://github.com/python/mypy/issues/7207
    return (
        isinstance(state, State)  # type: ignore
        and isinstance(state.attributes.get(ATTR_LATITUDE), float)
        and isinstance(state.attributes.get(ATTR_LONGITUDE), float)
    )


def closest(
    latitude: float, longitude: float, states: Sequence[State]
) -> Optional[State]:
    """Return closest state to point.

    Async friendly.
    """
    with_location = [state for state in states if has_location(state)]

    if not with_location:
        return None

    return min(
        with_location,
        key=lambda state: loc_util.distance(
            state.attributes.get(ATTR_LATITUDE),
            state.attributes.get(ATTR_LONGITUDE),
            latitude,
            longitude,
        ),
    )