"""Custom resolvers for Kedro project."""

import os
from typing import Dict, Optional
from copy import deepcopy

from dotenv import load_dotenv

load_dotenv()


def env(key: str, default: str = None) -> Optional[str]:
    """Load a variable from the environment.

    See <https://omegaconf.readthedocs.io/en/latest/custom_resolvers.html#custom-resolvers>

    Args:
        key (str): Key to load.
        default (str): Default value to use instead

    Returns:
        str: Value of the key
    """
    try:
        value = os.environ.get(key, default)
        if value is None:
            raise KeyError()
        return value
    except KeyError:
        raise KeyError(f"Environment variable '{key}' not found or default value {default} is None")