"""JARVIS quality of life utilities."""


class Singleton(object):
    REQUIRED = []
    OPTIONAL = {}

    def __new__(cls, *args: list, **kwargs: dict):
        """Create a new singleton."""
        inst = cls.__dict__.get("inst")
        if inst is not None:
            return inst

        inst = object.__new__(cls)
        inst.init(*args, **kwargs)
        inst._validate()
        cls.__inst__ = inst

        return inst

    def _validate(self) -> None:
        for key in self.REQUIRED:
            if not getattr(self, key, None):
                raise ValueError(f"Missing required key: {key}")

    def init(self, **kwargs: dict) -> None:
        """Initialize the object."""
        for key, value in kwargs.items():
            setattr(self, key, value)

        for key, value in self.OPTIONAL.items():
            if not getattr(self, key, None):
                setattr(self, key, value)