From bfde7133ca9f3213167570e9353490a716e47c9d Mon Sep 17 00:00:00 2001
From: klockky <anikitin2000@inbox.ru>
Date: Sat, 16 May 2026 07:59:56 +0300
Subject: [PATCH] =?UTF-8?q?refactor(network):=20VPN=20bypass=20as=20fallba?=
 =?UTF-8?q?ck=20=E2=80=94=20try=20VPN=20first,=20bypass=20only=20on=20fail?=
 =?UTF-8?q?ure?=
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---
 lib/core/transport/connection.dart | 68 ++++++++++++++++++++++--------
 lib/core/transport/vpn_bypass.dart | 48 ++++++---------------
 2 files changed, 62 insertions(+), 54 deletions(-)

diff --git a/lib/core/transport/connection.dart b/lib/core/transport/connection.dart
index 72c250a..dfee30a 100644
--- a/lib/core/transport/connection.dart
+++ b/lib/core/transport/connection.dart
@@ -35,29 +35,38 @@ class Connection {
     _setState(SocketState.connecting);
 
     try {
-      try {
-        await VpnBypassService.instance.applyIfNeeded();
-      } catch (e) {
-        logger.w('VPN bypass: пропущено ($e)');
-      }
-
       final proxySettings = await ProxyConfig.load();
-      RawSocket rawSocket;
 
-      if (proxySettings.isEnabled) {
-        final connector = ProxyConnector(proxySettings);
-        rawSocket = await connector.connect(host, port);
-        logger.i('Подключено через прокси ${proxySettings.type.name}');
-      } else {
-        rawSocket = await RawSocket.connect(host, port);
+      // Обход VPN — только запасной путь: сначала обычное подключение
+      // (через VPN, если он поднят), и лишь при неудаче — мимо туннеля.
+      final bypassArmed = await VpnBypassService.instance.shouldArm();
+      if (bypassArmed) {
+        await VpnBypassService.instance.restoreDefault();
       }
 
-      _socket = await RawSecureSocket.secure(
-        rawSocket,
-        host: host,
-        onBadCertificate: (_) => true,
-      );
+      RawSecureSocket socket;
+      try {
+        socket = await _openSecureSocket(
+          host,
+          port,
+          proxySettings,
+          timeout: bypassArmed ? const Duration(seconds: 8) : null,
+        );
+      } catch (e) {
+        if (!bypassArmed) rethrow;
+        final r = await VpnBypassService.instance.bind();
+        if (!r.bound) {
+          logger.w('VPN bypass: обходить нечего (${r.reason})');
+          rethrow;
+        }
+        logger.w(
+          'Подключение через VPN не удалось ($e) — '
+          'идём в обход → ${r.boundInterface} (${r.transport})',
+        );
+        socket = await _openSecureSocket(host, port, proxySettings);
+      }
 
+      _socket = socket;
       _setState(SocketState.connected);
       logger.i('Подключено к $host:$port');
 
@@ -90,6 +99,29 @@ class Connection {
     }
   }
 
+  Future<RawSecureSocket> _openSecureSocket(
+    String host,
+    int port,
+    ProxySettings proxySettings, {
+    Duration? timeout,
+  }) async {
+    RawSocket rawSocket;
+    if (proxySettings.isEnabled) {
+      final connector = ProxyConnector(proxySettings);
+      rawSocket = await connector.connect(host, port);
+      logger.i('Подключено через прокси ${proxySettings.type.name}');
+    } else {
+      rawSocket = timeout == null
+          ? await RawSocket.connect(host, port)
+          : await RawSocket.connect(host, port, timeout: timeout);
+    }
+    return RawSecureSocket.secure(
+      rawSocket,
+      host: host,
+      onBadCertificate: (_) => true,
+    );
+  }
+
   void write(Uint8List data) {
     if (_socket == null || !isConnected) {
       throw StateError('Нельзя писать: сокет не подключён');
diff --git a/lib/core/transport/vpn_bypass.dart b/lib/core/transport/vpn_bypass.dart
index 3798253..2eeb729 100644
--- a/lib/core/transport/vpn_bypass.dart
+++ b/lib/core/transport/vpn_bypass.dart
@@ -53,33 +53,21 @@ class VpnBypassService {
     await prefs.setBool(prefKey, value);
   }
 
-  /// Вызывается перед каждым (ре)коннектом.
-  Future<VpnBypassResult> applyIfNeeded() async {
-    if (!_supported) {
-      return const VpnBypassResult(
-        enabled: false,
-        reason: 'unsupported_platform',
-      );
-    }
-
-    if (!await isEnabled()) {
-      await _restoreDefault();
-      return const VpnBypassResult(enabled: false);
-    }
-
-    final tunDetected = await _hasTunInterface();
-    if (!tunDetected) {
-      await _restoreDefault();
-      logger.i('VPN bypass: tun-интерфейс не найден — маршрут по умолчанию');
-      return const VpnBypassResult(enabled: true, tunDetected: false);
-    }
+  /// true — обход включён, платформа поддерживается и виден VPN-туннель.
+  Future<bool> shouldArm() async {
+    if (!_supported) return false;
+    if (!await isEnabled()) return false;
+    return _hasTunInterface();
+  }
 
+  /// Привязывает процесс к non-VPN сети (wlan*/rmnet*).
+  Future<VpnBypassResult> bind() async {
     try {
       final res = await _channel
           .invokeMapMethod<String, dynamic>('bindToNonVpnNetwork');
       final bound = res?['bound'] == true;
       _bound = bound;
-      final result = VpnBypassResult(
+      return VpnBypassResult(
         enabled: true,
         tunDetected: true,
         bound: bound,
@@ -87,22 +75,9 @@ class VpnBypassService {
         transport: res?['transport'] as String?,
         reason: res?['reason'] as String?,
       );
-      if (bound) {
-        logger.i(
-          'VPN bypass: трафик направлен мимо VPN → '
-          '${result.boundInterface} (${result.transport})',
-        );
-      } else {
-        logger.w('VPN bypass: не удалось обойти VPN (${result.reason})');
-      }
-      return result;
     } on PlatformException catch (e) {
       logger.e('VPN bypass: ошибка платформы: ${e.message}');
-      return VpnBypassResult(
-        enabled: true,
-        tunDetected: true,
-        reason: e.code,
-      );
+      return VpnBypassResult(enabled: true, tunDetected: true, reason: e.code);
     } on MissingPluginException {
       return const VpnBypassResult(
         enabled: true,
@@ -137,7 +112,8 @@ class VpnBypassService {
     }
   }
 
-  Future<void> _restoreDefault() async {
+  /// Возвращает маршрутизацию процесса к системной (через VPN, если он есть).
+  Future<void> restoreDefault() async {
     if (!_bound) return;
     try {
       await _channel.invokeMethod('unbindNetwork');