"""
Tests for the Internationalization (i18n) UI component (Story 7.12).
"""

import pytest
from pathlib import Path

from PyQt6.QtWidgets import QApplication
from PyQt6.QtCore import QLocale

from src.ui.i18n import (
    SupportedLanguage,
    TRANSLATIONS,
    I18nManager,
    get_i18n_manager,
    t,
)


@pytest.fixture
def app(qtbot):
    """Create QApplication for tests."""
    return QApplication.instance() or QApplication([])


@pytest.fixture
def clean_manager():
    """Create a fresh I18nManager for testing."""
    import src.ui.i18n as i18n
    i18n._i18n_manager_instance = None
    manager = I18nManager()
    return manager


class TestSupportedLanguage:
    """Tests for SupportedLanguage enum."""
    def test_language_values(self):
        """Test SupportedLanguage enum values."""
        assert SupportedLanguage.CHINESE_SIMPLIFIED.code == "zh_CN"
        assert SupportedLanguage.ENGLISH.code == "en_US"

    def test_native_names(self):
        """Test native language names."""
        assert SupportedLanguage.CHINESE_SIMPLIFIED.native_name == "简体中文"
        assert SupportedLanguage.ENGLISH.native_name == "English"

    def test_english_names(self):
        """Test English language names."""
        assert SupportedLanguage.CHINESE_SIMPLIFIED.english_name == "Chinese (Simplified)"
        assert SupportedLanguage.ENGLISH.english_name == "English"

    def test_from_locale_chinese(self):
        """Test getting language from Chinese locale."""
        locale = QLocale(QLocale.Language.Chinese, QLocale.Country.China)
        lang = SupportedLanguage.from_locale(locale)
        assert lang == SupportedLanguage.CHINESE_SIMPLIFIED

    def test_from_locale_english(self):
        """Test getting language from English locale."""
        locale = QLocale(QLocale.Language.English, QLocale.Country.UnitedStates)
        lang = SupportedLanguage.from_locale(locale)
        assert lang == SupportedLanguage.ENGLISH


class TestTranslations:
    """Tests for translation strings."""

    def test_translations_structure(self):
        """Test that translations have proper structure."""
        for key, translations in TRANSLATIONS.items():
            assert "zh_CN" in translations
            assert "en_US" in translations

    def test_common_translations_exist(self):
        """Test that common UI strings have translations."""
        # Menu items
        assert "menu.file" in TRANSLATIONS
        assert "menu.edit" in TRANSLATIONS

        # Buttons
        assert "button.ok" in TRANSLATIONS
        assert "button.cancel" in TRANSLATIONS

        # Status
        assert "status.ready" in TRANSLATIONS
        assert "status.translating" in TRANSLATIONS

    def test_translation_values(self):
        """Test specific translation values."""
        assert TRANSLATIONS["button.ok"]["zh_CN"] == "确定"
        assert TRANSLATIONS["button.ok"]["en_US"] == "OK"

        assert TRANSLATIONS["button.cancel"]["zh_CN"] == "取消"
        assert TRANSLATIONS["button.cancel"]["en_US"] == "Cancel"

    def test_formatted_translations(self):
        """Test translations with format placeholders."""
        assert "{count}" in TRANSLATIONS["msg.added_files"]["zh_CN"]
        assert "{count}" in TRANSLATIONS["msg.added_files"]["en_US"]

        assert "{path}" in TRANSLATIONS["msg.file_not_found"]["zh_CN"]
        assert "{path}" in TRANSLATIONS["msg.file_not_found"]["en_US"]


class TestI18nManager:
    """Tests for I18nManager."""

    def test_initialization(self, clean_manager):
        """Test manager initialization."""
        assert isinstance(clean_manager, I18nManager)
        # Default to Chinese
        assert clean_manager.current_language == SupportedLanguage.CHINESE_SIMPLIFIED

    def test_current_language(self, clean_manager):
        """Test current_language property."""
        assert clean_manager.current_language == SupportedLanguage.CHINESE_SIMPLIFIED

        clean_manager.set_language(SupportedLanguage.ENGLISH)
        assert clean_manager.current_language == SupportedLanguage.ENGLISH

    def test_current_locale(self, clean_manager):
        """Test current_locale property."""
        locale = clean_manager.current_locale
        assert isinstance(locale, QLocale)

    def test_set_language_chinese(self, clean_manager):
        """Test setting Chinese language."""
        clean_manager.set_language(SupportedLanguage.CHINESE_SIMPLIFIED)
        assert clean_manager.current_language == SupportedLanguage.CHINESE_SIMPLIFIED

    def test_set_language_english(self, clean_manager):
        """Test setting English language."""
        clean_manager.set_language(SupportedLanguage.ENGLISH)
        assert clean_manager.current_language == SupportedLanguage.ENGLISH

    def test_translate_chinese(self, clean_manager):
        """Test translation to Chinese."""
        clean_manager.set_language(SupportedLanguage.CHINESE_SIMPLIFIED)

        text = clean_manager.translate("button.ok")
        assert text == "确定"

        text = clean_manager.translate("button.cancel")
        assert text == "取消"

    def test_translate_english(self, clean_manager):
        """Test translation to English."""
        clean_manager.set_language(SupportedLanguage.ENGLISH)

        text = clean_manager.translate("button.ok")
        assert text == "OK"

        text = clean_manager.translate("button.cancel")
        assert text == "Cancel"

    def test_translate_with_format(self, clean_manager):
        """Test translation with format arguments."""
        clean_manager.set_language(SupportedLanguage.ENGLISH)

        text = clean_manager.translate("msg.added_files", count=5)
        assert "5" in text
        assert "file" in text

    def test_translate_unknown_key(self, clean_manager):
        """Test translating unknown key returns key itself."""
        text = clean_manager.translate("unknown.key")
        assert text == "unknown.key"

    def test_shorthand_t(self, clean_manager):
        """Test shorthand t() function."""
        clean_manager.set_language(SupportedLanguage.CHINESE_SIMPLIFIED)

        text = clean_manager.t("button.ok")
        assert text == "确定"

    def test_language_changed_signal(self, app, clean_manager, qtbot):
        """Test that language_changed signal is emitted."""
        signals = []

        def on_language_changed(lang):
            signals.append(lang)

        clean_manager.language_changed.connect(on_language_changed)
        clean_manager.set_language(SupportedLanguage.ENGLISH)

        assert len(signals) == 1
        assert signals[0] == SupportedLanguage.ENGLISH

    def test_retranslate_callback(self, clean_manager):
        """Test retranslate callbacks are called on language change."""
        callback_calls = []

        def callback():
            callback_calls.append(True)

        clean_manager.register_retranslate_callback(callback)

        # Change language
        clean_manager.set_language(SupportedLanguage.ENGLISH)

        assert len(callback_calls) == 1

        # Change again
        clean_manager.set_language(SupportedLanguage.CHINESE_SIMPLIFIED)

        assert len(callback_calls) == 2

    def test_get_language_menu(self, clean_manager):
        """Test getting language selection menu."""
        menu = clean_manager.get_language_menu()
        assert menu is not None

        # Should have actions for all languages
        assert menu.isEmpty() is False


class TestModuleLevelFunctions:
    """Tests for module-level functions."""

    def test_get_i18n_manager(self):
        """Test getting i18n manager singleton."""
        import src.ui.i18n as i18n
        i18n._i18n_manager_instance = None

        manager = get_i18n_manager()
        assert manager is not None
        assert isinstance(manager, I18nManager)

    def test_t_function(self):
        """Test module-level t() function."""
        import src.ui.i18n as i18n
        i18n._i18n_manager_instance = None
        i18n._i18n_manager_instance = I18nManager()

        # Set to Chinese
        i18n._i18n_manager_instance.set_language(SupportedLanguage.CHINESE_SIMPLIFIED)

        text = t("button.ok")
        assert text == "确定"

    def test_singleton_persistence(self):
        """Test that singleton returns same instance."""
        import src.ui.i18n as i18n
        i18n._i18n_manager_instance = None

        manager1 = get_i18n_manager()
        manager2 = get_i18n_manager()
        assert manager1 is manager2


class TestTranslationCoverage:
    """Tests to ensure translation coverage."""

    def test_all_categories(self):
        """Test translations for all UI categories."""
        # Menus
        assert any(key.startswith("menu.") for key in TRANSLATIONS)

        # Actions
        assert any(key.startswith("action.") for key in TRANSLATIONS)

        # Buttons
        assert any(key.startswith("button.") for key in TRANSLATIONS)

        # Labels
        assert any(key.startswith("label.") for key in TRANSLATIONS)

        # Status
        assert any(key.startswith("status.") for key in TRANSLATIONS)

        # Dialogs
        assert any(key.startswith("dialog.") for key in TRANSLATIONS)

        # Messages
        assert any(key.startswith("msg.") for key in TRANSLATIONS)

    def test_glossary_translations(self):
        """Test glossary-related translations."""
        assert "glossary.add_term" in TRANSLATIONS
        assert "glossary.character" in TRANSLATIONS
        assert "glossary.skill" in TRANSLATIONS

    def test_log_translations(self):
        """Test log-related translations."""
        assert "log.level_info" in TRANSLATIONS
        assert "log.level_error" in TRANSLATIONS

    def test_theme_translations(self):
        """Test theme-related translations."""
        assert "theme.light" in TRANSLATIONS
        assert "theme.dark" in TRANSLATIONS