/// 登录页 widget 测试（P3 计划 Task 3）。
///
/// 覆盖：空字段客户端校验（不发请求）、成功登录写会话并跳 /home、
/// 凭据错误/限速（429）错误码本地化文案、提交中加载态（按钮禁用防重复提交）。
/// API 层经 FakeAdapter（dio HttpClientAdapter）打桩，Provider 以 override
/// 注入测试客户端（无真实网络）。
library;

import 'dart:async';

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/core/api_client.dart';
import 'package:photo_live/core/error_codes.dart';
import 'package:photo_live/l10n/app_localizations.dart';
import 'package:photo_live/pages/login_page.dart';

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

void main() {
  late FakeSessionStore store;
  late int unauthorizedCalls;

  setUp(() {
    store = FakeSessionStore();
    unauthorizedCalls = 0;
  });

  ApiClient clientOf(FakeAdapter adapter) => ApiClient(
        sessionStore: store,
        dio: Dio(BaseOptions(baseUrl: 'http://test.local'))
          ..httpClientAdapter = adapter,
      )..onUnauthorized = () => unauthorizedCalls++;

  Future<void> pumpLoginPage(WidgetTester tester, ApiClient client) async {
    await tester.pumpWidget(
      ProviderScope(
        overrides: [apiClientProvider.overrideWith((ref) => client)],
        child: MaterialApp(
          localizationsDelegates: AppLocalizations.localizationsDelegates,
          supportedLocales: AppLocalizations.supportedLocales,
          home: const LoginPage(),
          routes: {
            '/home': (context) =>
                const Scaffold(body: Center(child: Text('HOME_MARK'))),
          },
        ),
      ),
    );
    await tester.pumpAndSettle();
  }

  Future<void> fillAndSubmit(WidgetTester tester) async {
    await tester.enterText(
      find.widgetWithText(TextFormField, 'Account'),
      'staff01',
    );
    await tester.enterText(
      find.widgetWithText(TextFormField, 'Password'),
      'pw-123456',
    );
    await tester.tap(find.text('Sign in'));
    await tester.pump(); // 触发提交（含 SnackBar 动画首帧）。
  }

  testWidgets('空字段 → 客户端校验提示，不发请求', (tester) async {
    final adapter = FakeAdapter((_) => throw StateError('不应发起请求'));
    await pumpLoginPage(tester, clientOf(adapter));

    await tester.tap(find.text('Sign in'));
    await tester.pump();

    // 测试环境默认 locale=en：账号/密码两个必填提示。
    expect(find.text('This field is required'), findsNWidgets(2));
    expect(adapter.requests, isEmpty);
  });

  testWidgets('成功 → 写会话并跳 /home', (tester) async {
    final adapter = FakeAdapter(
      (o) => o.path == '/v1/auth/password' ? (200, loginOkBody())
          : throw StateError('unexpected ${o.path}'),
    );
    await pumpLoginPage(tester, clientOf(adapter));

    await fillAndSubmit(tester);
    await tester.pumpAndSettle();

    expect(find.text('HOME_MARK'), findsOneWidget);
    expect(store.session?.token, 'tok-new');
    expect(store.session?.account, 'staff01');
    expect(
      adapter.requests.single.body,
      {'account': 'staff01', 'password': 'pw-123456'},
    );
  });

  testWidgets('凭据错误（401）→ 「账号或密码错误」文案，不驱逐通知', (tester) async {
    final adapter = FakeAdapter(
      (o) => o.path == '/v1/auth/password'
          ? (401, errorBody(ErrorCodes.authInvalidCredentials))
          : throw StateError('unexpected ${o.path}'),
    );
    await pumpLoginPage(tester, clientOf(adapter));

    await fillAndSubmit(tester);
    await tester.pumpAndSettle();

    expect(find.text('Incorrect account or password'), findsOneWidget);
    expect(store.session, isNull, reason: '登录失败不落会话');
    expect(unauthorizedCalls, 0, reason: '登录 401 不触发驱逐');
    expect(find.text('HOME_MARK'), findsNothing);
  });

  testWidgets('限速（429 AUTH_RATE_LIMITED）→ 稍后再试文案', (tester) async {
    final adapter = FakeAdapter(
      (o) => o.path == '/v1/auth/password'
          ? (429, errorBody(ErrorCodes.authRateLimited))
          : throw StateError('unexpected ${o.path}'),
    );
    await pumpLoginPage(tester, clientOf(adapter));

    await fillAndSubmit(tester);
    await tester.pumpAndSettle();

    expect(
      find.text('Too many attempts. Please try again later'),
      findsOneWidget,
    );
  });

  testWidgets('提交中 → 加载指示且按钮禁用（防重复提交）', (tester) async {
    final gate = Completer<void>();
    final adapter = FakeAdapter((o) async {
      await gate.future;
      return (200, loginOkBody());
    });
    await pumpLoginPage(tester, clientOf(adapter));

    await fillAndSubmit(tester);
    // dio 链路经真实定时器推进（fake-async 需步进时钟才抵达适配器）。
    await tester.pump(const Duration(milliseconds: 50));

    expect(find.byType(CircularProgressIndicator), findsOneWidget);
    // 加载中再点按钮（onPressed=null）不产生第二个请求。
    await tester.tap(find.byType(FilledButton), warnIfMissed: false);
    await tester.pump(const Duration(milliseconds: 50));
    expect(adapter.requests, hasLength(1));

    gate.complete();
    await tester.pumpAndSettle();
    expect(find.text('HOME_MARK'), findsOneWidget);
  });
}