"""Numeral-script normalization without value repair."""
from .contracts import SourceScript

WESTERN = "0123456789"
ARABIC_INDIC = "٠١٢٣٤٥٦٧٨٩"
EXTENDED_ARABIC_INDIC = "۰۱۲۳۴۵۶۷۸۹"
TRANSLATION = str.maketrans(
    ARABIC_INDIC + EXTENDED_ARABIC_INDIC + "٬٫،",
    WESTERN + WESTERN + ",.,",
)
ALLOWED = frozenset(WESTERN + "/-.,:% ")


def _source_script(text: str) -> SourceScript:
    scripts = set()
    if any(char in WESTERN for char in text):
        scripts.add("western")
    if any(char in ARABIC_INDIC for char in text):
        scripts.add("arabic_indic")
    if any(char in EXTENDED_ARABIC_INDIC for char in text):
        scripts.add("extended_arabic_indic")
    if len(scripts) > 1:
        return "mixed"
    return next(iter(scripts), "western")  # type: ignore[return-value]


def normalize_numeric_text(text: str) -> tuple[str, SourceScript]:
    stripped = text.strip()
    script = _source_script(stripped)
    normalized = stripped.translate(TRANSLATION)
    unsupported = next((char for char in normalized if char not in ALLOWED), None)
    if unsupported is not None:
        raise ValueError("unsupported character in numeric evidence")
    if not any(char.isdigit() for char in normalized):
        raise ValueError("numeric evidence contains no digits")
    return normalized, script