pangolin/client/test/unit/connection_watchdog_test.dart

// connection_watchdog_test.dart — 连通看门狗(返工版,数据面 IP 探测已撤):
//   路径 A 意外内核掉线(非用户主动)→ 置「节点异常」提示;
//   路径 B 服务端判所连节点 down → 智能切节点 / 手动断开提示;健康则保持连接。
import 'dart:async';

import 'package:flutter/widgets.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:pangolin_vpn/bridge/vpn_bridge.dart';
import 'package:pangolin_vpn/bridge/vpn_bridge_provider.dart';
import 'package:pangolin_vpn/l10n/strings_zh.dart';
import 'package:pangolin_vpn/models/node.dart';
import 'package:pangolin_vpn/services/connect_api.dart';
import 'package:pangolin_vpn/state/connection_provider.dart';
import 'package:pangolin_vpn/state/nodes_provider.dart';

// 可控假桥:能手动推 VpnStatus,无内部计时器(避免 pending timer)。
class _FakeBridge implements VpnBridge {
  final _status = StreamController<VpnStatus>.broadcast();
  final _stats = StreamController<VpnStatsEvent>.broadcast();
  void emit(VpnStatus s) => _status.add(s);
  @override
  Stream<VpnStatus> get statusStream => _status.stream;
  @override
  Stream<VpnStatsEvent> get statsStream => _stats.stream;
  @override
  Future<void> start(String configJson) async {}
  @override
  Future<void> stop() async {}
  @override
  Future<VpnStatus> getStatus() async => VpnStatus.off;
  @override
  Future<void> selectOutbound(String tag) async {}
  @override
  Future<String> getActiveOutbound() async => 'auto';
  @override
  Future<void> setKillSwitch({required bool on}) async {}
  @override
  void dispose() {
    _status.close();
    _stats.close();
  }
}

// 重连时 fetchConfig 立即抛错,绕开真实网络(不留超时计时器)。
class _FakeConnectApi extends ConnectApi {
  _FakeConnectApi() : super(baseUrl: 'http://test.local', authToken: '');
  @override
  Future<String> fetchConfig({required String nodeId, required String deviceId, bool splitCN = false}) async {
    throw const ConnectApiException(statusCode: 0, messageZh: 'x', messageEn: 'x');
  }
  @override
  void dispose() {}
}

// 两节点都可用(status=up)。
class _StubNodes extends NodesNotifier {
  @override
  Future<List<Node>> build() async => const [
        Node(code: 'HK', nameZh: '香港', nameEn: 'Hong Kong', ping: 20, uuid: 'hk-uuid', host: 'hk', port: 443),
        Node(code: 'JP', nameZh: '东京', nameEn: 'Tokyo', ping: 35, uuid: 'jp-uuid', host: 'jp', port: 443),
      ];
  @override
  Future<void> refresh() async {}
}

// 当前最优节点 HK 被服务端判 down(status≠up),JP 仍可用。
class _StubNodesHKDown extends NodesNotifier {
  @override
  Future<List<Node>> build() async => const [
        Node(code: 'HK', nameZh: '香港', nameEn: 'Hong Kong', ping: 20, uuid: 'hk-uuid', host: 'hk', port: 443, status: 'down'),
        Node(code: 'JP', nameZh: '东京', nameEn: 'Tokyo', ping: 35, uuid: 'jp-uuid', host: 'jp', port: 443),
      ];
  @override
  Future<void> refresh() async {}
}

void main() {
  const t = StringsZh();

  ProviderContainer makeContainer(_FakeBridge bridge, {NodesNotifier Function()? nodes}) =>
      ProviderContainer(overrides: [
        vpnBridgeProvider.overrideWithValue(bridge),
        nodesProvider.overrideWith(nodes ?? _StubNodes.new),
        connectApiFactoryProvider.overrideWithValue((_) => _FakeConnectApi()),
        connectionProvider.overrideWith(
            (ref) => ConnectionController(ref, ref.watch(vpnBridgeProvider))),
      ]);

  // 加载节点 + 建 controller + 推 on,并让「即时首查」跑完。
  Future<void> driveOn(WidgetTester tester, ProviderContainer c, _FakeBridge bridge) async {
    c.read(nodesProvider);
    await tester.pump();
    c.read(connectionProvider);
    bridge.emit(VpnStatus.on);
    await tester.pump();
    await tester.pump();
    await tester.pump();
  }

  testWidgets('路径A:意外内核掉线(非用户主动)→ 置「节点异常」提示', (tester) async {
    final bridge = _FakeBridge();
    final c = makeContainer(bridge); // 节点都 up,排除路径B
    addTearDown(bridge.dispose);
    addTearDown(c.dispose);
    await tester.pumpWidget(UncontrolledProviderScope(container: c, child: const SizedBox()));
    await driveOn(tester, c, bridge);
    expect(c.read(connectionProvider).phase, VpnPhase.on);
    bridge.emit(VpnStatus.off); // 模拟节点数据面死 → REALITY 断 → 内核自报 off
    await tester.pump();
    final st = c.read(connectionProvider);
    expect(st.phase, VpnPhase.off, reason: '内核掉线应回 off');
    expect(st.error, t.nodeUnhealthyError, reason: '非用户主动掉线应给「节点异常」提示');
  });

  testWidgets('路径B:服务端判当前节点 down(智能)→ 切到其他可用节点', (tester) async {
    final bridge = _FakeBridge();
    final c = makeContainer(bridge, nodes: _StubNodesHKDown.new);
    addTearDown(bridge.dispose);
    addTearDown(c.dispose);
    await tester.pumpWidget(UncontrolledProviderScope(container: c, child: const SizedBox()));
    // 默认智能:有效节点取最优 HK,被判 down → 应切到 JP。
    await driveOn(tester, c, bridge);
    expect(c.read(selectedNodeCodeProvider), 'JP', reason: '智能模式应自动切到其他可用节点');
  });

  testWidgets('路径B:服务端判当前节点 down(手动)→ 断开 + 提示,不自动换', (tester) async {
    final bridge = _FakeBridge();
    final c = makeContainer(bridge, nodes: _StubNodesHKDown.new);
    addTearDown(bridge.dispose);
    addTearDown(c.dispose);
    await tester.pumpWidget(UncontrolledProviderScope(container: c, child: const SizedBox()));
    c.read(selectedNodeCodeProvider.notifier).select('HK'); // 手动选定 HK(已 down)
    await driveOn(tester, c, bridge);
    final st = c.read(connectionProvider);
    expect(st.phase, VpnPhase.off, reason: '手动模式节点 down 应断开');
    expect(st.error, t.nodeUnhealthyError, reason: '应给节点异常提示');
    expect(c.read(selectedNodeCodeProvider), 'HK', reason: '手动模式不应自动换节点');
  });

  testWidgets('节点健康 → 保持连接,不触发任何动作', (tester) async {
    final bridge = _FakeBridge();
    final c = makeContainer(bridge); // 都 up
    addTearDown(bridge.dispose);
    addTearDown(c.dispose);
    await tester.pumpWidget(UncontrolledProviderScope(container: c, child: const SizedBox()));
    c.read(selectedNodeCodeProvider.notifier).select('HK');
    await driveOn(tester, c, bridge);
    for (var i = 0; i < 3; i++) {
      await tester.pump(const Duration(seconds: 15));
      await tester.pump();
    }
    expect(c.read(connectionProvider).phase, VpnPhase.on, reason: '健康时应保持连接');
    expect(c.read(selectedNodeCodeProvider), 'HK');
    bridge.emit(VpnStatus.off); // 收尾:停看门狗/计时器
    await tester.pump();
  });
}