"""Small display-text normalizers for model and persisted proposal content."""

from __future__ import annotations

import re
from typing import Any


_LITERAL_UNICODE_ESCAPE = re.compile(r"(?<!\\)\\u([0-9a-fA-F]{4})")


def decode_literal_unicode_escapes(value: Any) -> Any:
    """Decode only literal ``\\uXXXX`` sequences accidentally returned as text.

    JSON parsing normally handles Unicode escapes. This is deliberately narrow so a
    user-entered path or other ordinary backslash content is not reinterpreted.
    """
    if isinstance(value, str):
        return _LITERAL_UNICODE_ESCAPE.sub(
            lambda match: chr(int(match.group(1), 16)), value
        )
    if isinstance(value, list):
        return [decode_literal_unicode_escapes(item) for item in value]
    if isinstance(value, dict):
        return {key: decode_literal_unicode_escapes(item) for key, item in value.items()}
    return value