"""General utilities for apps."""

import enum
import os


class AreaError(Exception):
    """Error raised when area configuration is invalid or missing."""


class Area(enum.Enum):
    """The area we are running."""

    Test = "Test"
    Live = "Live"


def from_env() -> Area:
    """Load AREA from environment variable.

    Raises:
        AreaError: if AREA is not defined
    """
    var = os.getenv("AREA", "Test")
    if var == "Test":
        return Area.Test
    if var == "Live":
        return Area.Live
    msg = "AREA not defined"
    raise AreaError(msg)