// 端到端集成测试：在真实 Windows 桌面运行完整链路。
//
// 验证：RustLib.init() → 点 CONNECT → TerminalEngine（Alacritty Rust 引擎）创建
// → 连上服务端 → 命令回显（内容渲染 + 输入通路）。
//
// 运行前需先启动 Rust 服务端（cd .. && cargo run）。
// 运行：flutter test integration_test -d windows
import 'dart:async';
import 'dart:typed_data';

import 'package:flutter/foundation.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:flutter_alacritty/flutter_alacritty.dart';
import 'package:integration_test/integration_test.dart';

import 'package:rtty_desktop/main.dart' as app;
import 'package:rtty_desktop/src/terminal_screen.dart';

void main() {
  IntegrationTestWidgetsFlutterBinding.ensureInitialized();

  testWidgets('桌面端连接服务端并渲染命令输出', (WidgetTester tester) async {
    await app.main();
    await tester.pumpAndSettle();

    // 未连接提示。
    expect(find.text('AWAITING CONNECTION'), findsOneWidget);

    // 点击 CONNECT。
    await tester.tap(find.text('CONNECT'));
    await tester.pump();

    // 等待连接就绪（进入 connected 状态，提示页消失）。
    final deadline = DateTime.now().add(const Duration(seconds: 8));
    while (DateTime.now().isBefore(deadline)) {
      await tester.pump(const Duration(milliseconds: 200));
      if (find.text('AWAITING CONNECTION').evaluate().isEmpty) break;
    }
    expect(find.text('AWAITING CONNECTION'), findsNothing,
        reason: '连接后应进入终端渲染');

    // Alacritty TerminalView 应渲染。
    expect(find.byType(TerminalView), findsOneWidget,
        reason: 'Alacritty TerminalView 应渲染');

    // 通过引擎输出通路发送一条命令（模拟用户输入），验证：
    // 服务端回显 → backend.output → engine.feed → 网格渲染。
    final engine = tester.state<TerminalViewState>(find.byType(TerminalView)).widget.engine;
    final token = 'RTTY_INT_${DateTime.now().millisecondsSinceEpoch}';
    engine.write(Uint8List.fromList('echo $token\r\n'.codeUnits));

    // 轮询引擎网格，等待命令回显进入渲染。
    String? found;
    final outDeadline = DateTime.now().add(const Duration(seconds: 8));
    while (DateTime.now().isBefore(outDeadline)) {
      await tester.pump(const Duration(milliseconds: 200));
      final gridText = _gridText(engine);
      if (gridText.contains(token)) {
        found = gridText;
        break;
      }
    }
    expect(found, isNotNull, reason: '命令回显应进入引擎网格');
    debugPrint('回显捕获: ${found!.trim().split('\n').last}');

    // 输入通路也验证：TerminalView 聚焦时按键应经 engine.write → backend → 服务端。
    expect(find.byType(TerminalScreen), findsOneWidget);
  });
}

/// 从引擎镜像网格提取可视文本。
String _gridText(TerminalEngine engine) {
  final grid = engine.gridForView;
  final sb = StringBuffer();
  for (var r = 0; r < grid.rows; r++) {
    for (var c = 0; c < grid.columns; c++) {
      final cp = grid.codepointAt(r, c) as int;
      sb.writeCharCode(cp == 0 ? 32 : cp);
    }
    sb.write('\n');
  }
  return sb.toString();
}