"""Load global config."""
from pathlib import Path
from typing import Union

from yaml import load

from jarvis_core.util import Singleton

try:
    from yaml import CLoader as Loader
except ImportError:
    from yaml import Loader


DEFAULT_PATH = Path("config.yaml")


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

    @classmethod
    def from_yaml(cls, filepath: Union[Path, str] = DEFAULT_PATH) -> "Config":
        """Load the yaml config file."""
        if inst := cls.__dict__.get("inst"):
            return inst

        if isinstance(filepath, str):
            filepath = Path(filepath)

        with filepath.open() as f:
            raw = f.read()

        y = load(raw, Loader=Loader)
        return cls(**y)

    @classmethod
    def reload(cls) -> bool:
        """Reload the config."""
        return cls.__dict__.pop("inst", None) is None