import typing

from marshmallow.validate import Regexp
import regex


class UnicodeRegexp(Regexp):
    """Customized validator to support extended Unicode constructions with regex lib.

    Supports constructions like '\p{L}' (any letter of any language), that
    the standard python re module doesn't.

    .. note::

        Uses `regex.match`, which searches for a match at the beginning of a string.

    :param pattern: The regular expression string to use. Can also be a compiled
        regular expression pattern.
    :param flags: The regexp flags to use, for example re.IGNORECASE. Ignored
        if ``pattern`` is not a string.
    :param error: Error message to raise in case of a validation error.
        Can be interpolated with `{input}` and `{pattern}`.
    """

    def __init__(
        self,
        pattern: str | bytes | typing.Pattern,
        flags: int = 0,
        *,
        error: str | None = None,
    ):
        self.regex = (
            regex.compile(pattern, flags)
            if isinstance(pattern, (str, bytes))
            else pattern
        )
        self.error = error or self.default_message