"""Identity normalization helpers for organization source ingestion."""

from __future__ import annotations

import re

VALID_INN_LENGTHS = frozenset({10, 12})
VALID_KPP_LENGTH = 9
VALID_OGRN_LENGTH = 13
VALID_OGRIP_LENGTH = 15


def digits(value: str | None) -> str:
    """Return only decimal digits from a source identity value."""
    return re.sub(r"\D+", "", str(value or ""))


def normalize_identity_fields(
    *,
    inn: str | None = "",
    kpp: str | None = "",
    ogrn: str | None = "",
    ogrip: str | None = "",
) -> tuple[str, str, str, str]:
    """Normalize parser identity values to canonical Organization constraints."""
    inn_digits = digits(inn)
    kpp_digits = digits(kpp)
    ogrn_digits = digits(ogrn)
    ogrip_digits = digits(ogrip)
    has_legal_entity_inn = len(inn_digits) == 10
    has_entrepreneur_inn = len(inn_digits) == 12

    normalized_ogrip = ""
    if len(ogrip_digits) == VALID_OGRIP_LENGTH and not has_legal_entity_inn:
        normalized_ogrip = ogrip_digits
    elif len(ogrn_digits) == VALID_OGRIP_LENGTH and not has_legal_entity_inn:
        normalized_ogrip = ogrn_digits

    normalized_inn = inn_digits if len(inn_digits) in VALID_INN_LENGTHS else ""
    normalized_kpp = (
        ""
        if normalized_ogrip or has_entrepreneur_inn
        else kpp_digits
        if len(kpp_digits) == VALID_KPP_LENGTH
        else ""
    )
    normalized_ogrn = (
        ""
        if normalized_ogrip or has_entrepreneur_inn
        else ogrn_digits
        if len(ogrn_digits) == VALID_OGRN_LENGTH
        else ""
    )
    return normalized_inn, normalized_kpp, normalized_ogrn, normalized_ogrip