"""Unit tests for devx.i18n."""

from __future__ import annotations

import pytest

import devx.i18n as i18n_mod
from devx.i18n import _, configure_i18n


class TestTranslate:
    def test_returns_english_by_default(self) -> None:
        with pytest.MonkeyPatch().context() as mp:
            mp.delenv("DEVX_LANG", raising=False)
            assert _("Running tests") == "Running tests"

    def test_returns_key_when_missing(self) -> None:
        with pytest.MonkeyPatch().context() as mp:
            mp.delenv("DEVX_LANG", raising=False)
            assert _("nonexistent.key.xyz") == "nonexistent.key.xyz"

    def test_formats_kwargs(self) -> None:
        # Find a key with format placeholders
        for key, translations in i18n_mod.TRANSLATIONS.items():
            en = translations.get("en", "")
            if "{" in en:
                with pytest.MonkeyPatch().context() as mp:
                    mp.delenv("DEVX_LANG", raising=False)
                    result = _(key, **dict.fromkeys(_extract_format_keys(en), "x"))
                    assert "{" not in result
                return
        pytest.skip("No key with format placeholders found")

    def test_invalid_lang_falls_back_to_english(self) -> None:
        with pytest.MonkeyPatch().context() as mp:
            mp.setenv("DEVX_LANG", "fr")
            assert _("Running tests") == "Running tests"

    def test_bulgarian_translation(self) -> None:
        with pytest.MonkeyPatch().context() as mp:
            mp.setenv("DEVX_LANG", "bg")
            # Find a key that has a Bulgarian translation
            for key, translations in i18n_mod.TRANSLATIONS.items():
                if "bg" in translations:
                    result = _(key)
                    assert result == translations["bg"]
                    return
        pytest.skip("No Bulgarian translation found")


class TestConfigureI18n:
    def test_custom_lang_env_var(self) -> None:
        configure_i18n(lang_env_var="GRM_LANG")
        try:
            with pytest.MonkeyPatch().context() as mp:
                mp.setenv("GRM_LANG", "bg")
                mp.delenv("DEVX_LANG", raising=False)
                # Find a key with Bulgarian translation
                for key, translations in i18n_mod.TRANSLATIONS.items():
                    if "bg" in translations:
                        assert _(key) == translations["bg"]
                        return
            pytest.skip("No Bulgarian translation found")
        finally:
            configure_i18n()  # Reset to defaults

    def test_custom_translations_path_env_var(self, tmp_path) -> None:
        custom_translations = {"custom.key": {"en": "Custom Value", "bg": "Персонализирано"}}
        custom_file = tmp_path / "custom.json"
        custom_file.write_text(__import__("json").dumps(custom_translations))

        configure_i18n(translations_path_env_var="GRM_TRANSLATIONS_PATH")
        try:
            # Use i18n_mod.TRANSLATIONS (not a stale import) — other tests
            # may call importlib.reload(devx.i18n), replacing the dict object.
            translations = i18n_mod.TRANSLATIONS
            original = dict(translations)
            translations.update(custom_translations)
            try:
                with pytest.MonkeyPatch().context() as mp:
                    mp.setenv("GRM_TRANSLATIONS_PATH", str(custom_file))
                    assert _("custom.key") == "Custom Value"
            finally:
                translations.clear()
                translations.update(original)
        finally:
            configure_i18n()  # Reset to defaults

    def test_reset_to_defaults(self) -> None:
        configure_i18n(lang_env_var="GRM_LANG")
        configure_i18n()  # Reset
        assert i18n_mod._lang_env_var == "DEVX_LANG"
        assert i18n_mod._translations_path_env_var == "DEVX_TRANSLATIONS_PATH"


def _extract_format_keys(template: str) -> list[str]:
    """Extract {key} format placeholders from a template string."""
    import re

    return re.findall(r"\{(\w+)\}", template)