"""Language detection helper - tolerant to short / mixed text."""

from __future__ import annotations

from langdetect import DetectorFactory, LangDetectException, detect_langs

DetectorFactory.seed = 42


def detect_language(text: str, min_chars: int = 40) -> str | None:
    """Return ISO 639-1 language code or ``None`` if undetectable."""
    if not text or len(text.strip()) < min_chars:
        return None
    try:
        ranked = detect_langs(text)
    except LangDetectException:
        return None
    if not ranked:
        return None
    return ranked[0].lang


def has_cyrillic(text: str) -> bool:
    return any("Ѐ" <= ch <= "ӿ" for ch in text)