"""Common exceptions raised by the program."""
from typing import Union, List


class InvalidKeyError(Exception):
    """Thrown when a config file contains an invalid key."""

    def __init__(self, keys: Union[str, List[str]]):
        """Create a new InvalidKeyError object with the given key.

        Args:
            keys: the invalid key(s)
        """
        if type(keys) == str:
            keys = [keys]

        self.message = "Invalid key(s): {}".format(", ".join(keys))

        super().__init__()


class MissingKeyError(Exception):
    """Thrown when a required key is missing from a config."""

    def __init__(self, keys: Union[str, List[str]]):
        """Create a new MissingKeyError object with the given key.

        Args:
            keys: the invalid key(s)
        """
        if type(keys) == str:
            keys = [keys]

        self.message = "Missing key(s): {}".format(", ".join(keys))

        super().__init__()


class InvalidValueError(Exception):
    """Thrown when a key contains an invalid value."""

    def __init__(self, key: str, expected: str, actual: str):
        """Create a new InvalidValueError given the arguments.

        Args:
            key: the key containing the invalid value
            expected: name of the expected type
            actual: name of the actual type
        """
        self.message = (
            f"Invalid value for key {key}: expected {expected}, "
            f"got {actual}"
        )

        super().__init__()