from enum import Enum, EnumMeta


class OnAccess(EnumMeta):
    """
    runs a user-specified function whenever member is accessed
    """

    def __getattribute__(cls, name):
        obj = super().__getattribute__(name)
        if isinstance(obj, Enum) and obj._on_access:
            obj._on_access()
        return obj

    def __getitem__(cls, name):
        member = super().__getitem__(name)
        if member._on_access:
            member._on_access()
        return member

    def __call__(
        cls, value, names=None, *, module=None, qualname=None, type=None, start=1
    ):
        obj = super().__call__(
            value, names, module=module, qualname=qualname, type=type, start=start
        )
        if isinstance(obj, Enum) and obj._on_access:
            obj._on_access()
        return obj


class DeprecatedEnum(Enum, metaclass=OnAccess):
    def __new__(cls, value, *args):
        member = object.__new__(cls)
        member._value_ = value
        member._args = args
        member._on_access = member.deprecate if args else None
        return member

    def deprecate(self):
        args = self._args
        import warnings

        warnings.warn(
            "%s" % args,
            DeprecationWarning,
            stacklevel=3,
        )