import 'package:dsh_workbench/main.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_test/flutter_test.dart';

void main() {
  TestWidgetsFlutterBinding.ensureInitialized();
  const channel = MethodChannel('dsh.workbench/gecko/42');
  final calls = <String>[];
  var canGoBack = true;
  final systemCalls = <String>[];

  setUp(() {
    calls.clear();
    systemCalls.clear();
    canGoBack = true;
    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
        .setMockMethodCallHandler(channel, (call) async {
          calls.add(call.method);
          return call.method == 'goBack' ? canGoBack : null;
        });
    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
        .setMockMethodCallHandler(SystemChannels.platform, (call) async {
          systemCalls.add(call.method);
          return null;
        });
  });

  tearDown(() {
    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
        .setMockMethodCallHandler(channel, null);
    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
        .setMockMethodCallHandler(SystemChannels.platform, null);
  });

  Future<void> emit(String method, [Object? value]) async {
    await TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
        .handlePlatformMessage(
          channel.name,
          const StandardMethodCodec().encodeMethodCall(
            MethodCall(method, value),
          ),
          (_) {},
        );
  }

  testWidgets('返回键优先回退 Gecko 历史，之后退出应用', (tester) async {
    await tester.pumpWidget(const DshApp());
    tester.widget<AndroidView>(find.byType(AndroidView)).onPlatformViewCreated!(
      42,
    );
    await tester.pump();
    final pop = tester.widget<PopScope>(
      find.byWidgetPredicate((w) => w is PopScope),
    );
    pop.onPopInvokedWithResult!(false, null);
    await tester.pump();
    expect(calls.last, 'goBack');
    expect(systemCalls, isNot(contains('SystemNavigator.pop')));
    canGoBack = false;
    pop.onPopInvokedWithResult!(false, null);
    await tester.pump();
    expect(systemCalls, contains('SystemNavigator.pop'));
    await tester.pumpWidget(const SizedBox());
  });

  testWidgets('Gecko 页面事件、错误及重试通过独立通道连接', (tester) async {
    await tester.pumpWidget(const DshApp());
    final view = tester.widget<AndroidView>(find.byType(AndroidView));
    expect(view.viewType, 'dsh.workbench/gecko');
    view.onPlatformViewCreated!(42);
    await tester.pump();
    expect(calls, ['load']);
    expect(find.text('正在加载…'), findsOneWidget);

    await emit('onPageFinished');
    await tester.pump();
    expect(find.text('正在加载…'), findsNothing);

    await emit('onLoadError', '连接已断开');
    await tester.pump();
    expect(find.text('连接已断开'), findsOneWidget);
    await tester.tap(find.text('重试'));
    await tester.pump();
    expect(calls.last, 'reload');
    expect(find.text('正在加载…'), findsOneWidget);

    await emit('onPageStarted');
    await emit('onPageFinished');
    await emit('onDownloadError', '空间不足');
    await tester.pump();
    expect(find.text('下载失败：空间不足'), findsOneWidget);
    await tester.pumpWidget(const SizedBox());
    await emit('onPageStarted');
    expect(tester.takeException(), isNull);
  });
}