"""Locale files: same keys everywhere, and a real fallback.

``Translator`` returns the key itself when a string is missing, which is silent
in production — a label would simply read ``axes.nope``. The studio suite guards
this by comparing key sets; the same guard applies here.
"""

from __future__ import annotations

import json
from pathlib import Path

import pytest

from orisys_autocal.preferences import load_preferences

LOCALES = Path(__file__).resolve().parents[1] / "config" / "locales"
LANGUAGES = ("zh_CN", "en_US")


def _load(language: str) -> dict:
    return json.loads((LOCALES / f"{language}.json").read_text(encoding="utf-8"))


def _flatten(node: dict, prefix: str = "") -> set[str]:
    keys: set[str] = set()
    for key, value in node.items():
        path = f"{prefix}{key}"
        if isinstance(value, dict):
            keys |= _flatten(value, f"{path}.")
        else:
            keys.add(path)
    return keys


def test_every_locale_file_exists():
    for language in LANGUAGES:
        assert (LOCALES / f"{language}.json").is_file(), language


def test_locales_have_identical_key_sets():
    reference = _flatten(_load("zh_CN"))
    for language in LANGUAGES[1:]:
        other = _flatten(_load(language))
        assert other == reference, {
            f"{language}_only": sorted(other - reference),
            f"zh_CN_only": sorted(reference - other),
        }


def test_no_translation_is_empty_where_a_label_is_expected():
    """A blank string renders as an empty widget, which looks like a bug."""
    for language in LANGUAGES:
        for key, value in _walk(_load(language)):
            assert str(value).strip(), f"{language}: {key} is blank"


def test_the_product_name_is_localised():
    """The window title is Chinese in zh_CN and English in en_US."""
    assert _load("zh_CN")["app"]["title"] != _load("en_US")["app"]["title"]


@pytest.mark.parametrize("language", LANGUAGES)
def test_every_locale_loads_through_the_translator(language):
    from orisys_app_shared.i18n import Translator

    translator = Translator(LOCALES, locale=language)
    for key in sorted(_flatten(_load(language))):
        assert translator.t(key) != key, f"{language}: {key} did not resolve"


def test_the_default_preferences_file_matches_the_schema_shape():
    """A shipped default that names a key the app does not have is dead weight."""
    shipped = json.loads(
        (LOCALES.parent / "preferences.default.json").read_text(encoding="utf-8")
    )
    schema = load_preferences()
    for key in shipped:
        assert key in schema, f"preferences.default.json has an unknown key: {key}"


def test_the_shipped_defaults_carry_the_controller_task_number():
    """Re-initialisation names a task; if this key is missing every re-init is wrong."""
    from orisys_autocal.motion import DEFAULT_BAS_TASK

    shipped = json.loads(
        (LOCALES.parent / "preferences.default.json").read_text(encoding="utf-8")
    )
    assert shipped["bas_task"] == DEFAULT_BAS_TASK == 4


def _walk(node, prefix: str = ""):
    for key, value in node.items():
        path = f"{prefix}{key}"
        if isinstance(value, dict):
            yield from _walk(value, f"{path}.")
        else:
            yield path, value