from __future__ import annotations

from ragcore.ingestion.language import (
    detect_language,
    normalize_language_tag,
    resolve_document_language,
)

_DUTCH = (
    "Dit is een handleiding voor het herstarten van de dienst. Controleer eerst "
    "of de gateway niet bereikbaar is en wacht daarna tien seconden voordat de "
    "schakelaar opnieuw wordt omgezet. Het systeem moet daarna weer normaal werken."
)
_ENGLISH = (
    "This is the runbook for restarting the service. First confirm that the "
    "gateway is not reachable and then wait ten seconds before you cycle the "
    "breaker again. The system should be healthy after that and the alert clears."
)
_FRENCH = (
    "Ce document décrit la procédure pour redémarrer le service. Vérifiez d'abord "
    "que la passerelle n'est pas joignable et attendez ensuite dix secondes avant "
    "de basculer le disjoncteur. Le système doit être de nouveau disponible."
)
_GERMAN = (
    "Dieses Dokument beschreibt das Neustarten des Dienstes. Prüfen Sie zuerst, "
    "ob das Gateway nicht erreichbar ist, und warten Sie danach zehn Sekunden, "
    "bevor der Schalter wieder umgelegt wird. Das System muss danach laufen."
)


def test_detects_each_supported_language() -> None:
    assert detect_language(_DUTCH) == "nl"
    assert detect_language(_ENGLISH) == "en"
    assert detect_language(_FRENCH) == "fr"
    assert detect_language(_GERMAN) == "de"


def test_short_or_codeish_content_stays_undetected() -> None:
    assert detect_language("restart") is None
    assert detect_language("SELECT id FROM documents WHERE space_id = $1;") is None


def test_normalize_language_tag_reduces_locales() -> None:
    assert normalize_language_tag("nl-BE") == "nl"
    assert normalize_language_tag("EN_us") == "en"
    assert normalize_language_tag("not a tag!") is None


def test_resolution_priority_is_explicit_then_detected_then_fallback() -> None:
    assert resolve_document_language(explicit_locale="fr-FR", text=_DUTCH) == "fr"
    assert resolve_document_language(explicit_locale=None, text=_DUTCH) == "nl"
    assert resolve_document_language(explicit_locale="??", text="x") == "en"