photo-live/apps/mobile/test/app/locale_test.dart

/// App 内语言切换测试（P3 计划 Task 10）。
///
/// 覆盖：
/// - 启动：持久档位注入 Notifier → 首帧即对应语言（无闪变）；
/// - 切换：setChoice → MaterialApp 即刻重建（登录页文案随切）+ 写持久层；
/// - 解析矩阵（system 档）：系统 zh → zh、系统 en → en、系统其他 →
///   回退模板语言 zh（l10n.yaml template=app_zh.arb）；
/// - 显式选择优先于系统 locale；
/// - 持久值解析容错（null/非法值/存储异常 → system）。
library;

import 'package:dio/dio.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:photo_live/app/app.dart';
import 'package:photo_live/app/locale_controller.dart';
import 'package:photo_live/core/api_client.dart';

import '../helpers/fakes.dart';

/// 写入即抛的存储替身（持久化失败容错断言用）。
class ThrowingWriteLocaleStore extends FakeLocaleStore {
  @override
  Future<void> write(String value) async => throw StateError('disk full');
}

void main() {
  group('持久值解析（纯逻辑）', () {
    test('fromPersisted：合法值/空值/非法值', () {
      expect(AppLocaleChoice.fromPersisted('system'), AppLocaleChoice.system);
      expect(AppLocaleChoice.fromPersisted('zh'), AppLocaleChoice.zh);
      expect(AppLocaleChoice.fromPersisted('en'), AppLocaleChoice.en);
      expect(AppLocaleChoice.fromPersisted(null), AppLocaleChoice.system);
      expect(AppLocaleChoice.fromPersisted('fr'), AppLocaleChoice.system,
          reason: '未来档位/手改损坏的旧值一律回退 system');
    });

    test('readPersisted：读取异常 → system（启动不因存储故障卡死）', () async {
      final store = ThrowingWriteLocaleStore();
      final choice = await LocaleSettings.readPersisted(store);
      expect(choice, AppLocaleChoice.system);
    });

    test('setChoice 写失败不回滚本次会话状态', () async {
      final container = ProviderContainer(
        overrides: [
          localeSettingsProvider.overrideWith(
            () => LocaleSettings(store: ThrowingWriteLocaleStore()),
          ),
        ],
      );
      addTearDown(container.dispose);
      await container
          .read(localeSettingsProvider.notifier)
          .setChoice(AppLocaleChoice.en);
      expect(container.read(localeSettingsProvider), AppLocaleChoice.en);
    });
  });

  group('PhotoLiveApp 语言接线（widget）', () {
    late FakeSessionStore session;
    late ApiClient client;

    setUp(() {
      // 无会话：App 停在登录页（文案断言载体）；客户端拒绝一切请求
      //（语言测试不触网，仅为满足 Provider 依赖图）。
      session = FakeSessionStore();
      client = ApiClient(
        sessionStore: session,
        dio: Dio(BaseOptions(baseUrl: 'http://test.local'))
          ..httpClientAdapter =
              FakeAdapter((o) => throw StateError('不应发起请求: ${o.path}')),
      );
    });

    Future<ProviderContainer> pumpApp(
      WidgetTester tester, {
      AppLocaleChoice initial = AppLocaleChoice.system,
      FakeLocaleStore? localeStore,
    }) async {
      final store = localeStore ?? FakeLocaleStore();
      await tester.pumpWidget(
        ProviderScope(
          overrides: [
            ...pageTestOverrides(session: session, client: client),
            localeSettingsProvider.overrideWith(
              () => LocaleSettings(initial: initial, store: store),
            ),
          ],
          child: const PhotoLiveApp(),
        ),
      );
      await tester.pumpAndSettle();
      return ProviderScope.containerOf(
        tester.element(find.byType(PhotoLiveApp)),
      );
    }

    testWidgets('持久档位 zh → 首帧中文文案', (tester) async {
      final store = FakeLocaleStore()..value = 'zh';
      await pumpApp(tester,
          initial: AppLocaleChoice.zh, localeStore: store);
      expect(find.text('登录'), findsOneWidget);
      expect(find.text('Sign in'), findsNothing);
    });

    testWidgets('切换 en → 登录页即刻英文 + 持久化 en', (tester) async {
      final store = FakeLocaleStore();
      final container = await pumpApp(tester,
          initial: AppLocaleChoice.zh, localeStore: store);
      expect(find.text('登录'), findsOneWidget);

      await container
          .read(localeSettingsProvider.notifier)
          .setChoice(AppLocaleChoice.en);
      await tester.pumpAndSettle();

      expect(find.text('Sign in'), findsOneWidget,
          reason: 'MaterialApp 已随 provider 重建');
      expect(find.text('登录'), findsNothing);
      expect(store.writes, ['en'], reason: '写入持久层');
    });

    testWidgets('切换回 system → 交还系统 locale', (tester) async {
      tester.platformDispatcher.localesTestValue = const [Locale('en')];
      addTearDown(tester.platformDispatcher.clearLocalesTestValue);
      final container = await pumpApp(tester, initial: AppLocaleChoice.zh);
      expect(find.text('登录'), findsOneWidget);

      await container
          .read(localeSettingsProvider.notifier)
          .setChoice(AppLocaleChoice.system);
      await tester.pumpAndSettle();

      expect(find.text('Sign in'), findsOneWidget, reason: '系统 en 接管');
    });

    testWidgets('解析矩阵：system + 系统 zh → zh', (tester) async {
      tester.platformDispatcher.localesTestValue = const [Locale('zh')];
      addTearDown(tester.platformDispatcher.clearLocalesTestValue);
      await pumpApp(tester);
      expect(find.text('登录'), findsOneWidget);
    });

    testWidgets('解析矩阵：system + 系统 en → en', (tester) async {
      tester.platformDispatcher.localesTestValue = const [Locale('en')];
      addTearDown(tester.platformDispatcher.clearLocalesTestValue);
      await pumpApp(tester);
      expect(find.text('Sign in'), findsOneWidget);
    });

    testWidgets('解析矩阵：system + 系统其他（fr）→ 回退模板语言 zh',
        (tester) async {
      // Localizations 解析用 platformDispatcher.locales（首选语言列表），
      // 单值 localeTestValue 不影响它——须整体注入列表。
      tester.platformDispatcher.localesTestValue = const [Locale('fr')];
      addTearDown(tester.platformDispatcher.clearLocalesTestValue);
      await pumpApp(tester);
      expect(find.text('登录'), findsOneWidget,
          reason: '不依赖 supportedLocales 排序（默认解析会回退 en）');
    });

    testWidgets('显式选择优先于系统 locale（选 en + 系统 zh → en）',
        (tester) async {
      tester.platformDispatcher.localesTestValue = const [Locale('zh')];
      addTearDown(tester.platformDispatcher.clearLocalesTestValue);
      await pumpApp(tester, initial: AppLocaleChoice.en);
      expect(find.text('Sign in'), findsOneWidget);
    });
  });
}