Stabilize profile sync and network persistence

lib/common/request.dart

@@ -57,7 +57,7 @@ class Request {
         throw Exception('Redirect detected, but no location header was found.');
       }
 
-      print('↪️ Redirecting to: $newUrl');
+      commonPrint.log('Redirecting to: $newUrl');
       final finalResponse = await _dio.get<Uint8List>(
         newUrl,
         options: Options(
@@ -121,36 +121,52 @@ class Request {
   };
 
   Future<Result<IpInfo?>> checkIp({CancelToken? cancelToken}) async {
-    var failureCount = 0;
-    final futures = _ipInfoSources.entries.map((source) async {
-      final completer = Completer<Result<IpInfo?>>();
-      final future = Dio().get<Map<String, dynamic>>(
+    final futures = _ipInfoSources.entries.map(
+      (source) => _checkIpFromSource(source, cancelToken: cancelToken),
+    ).toList();
+    await for (final ipInfo in Stream.fromFutures(futures)) {
+      if (cancelToken?.isCancelled == true) {
+        return Result.error("cancelled");
+      }
+      if (ipInfo != null) {
+        cancelToken?.cancel();
+        return Result.success(ipInfo);
+      }
+    }
+    return Result.success(null);
+  }
+
+  Future<IpInfo?> _checkIpFromSource(
+    MapEntry<String, IpInfo Function(Map<String, dynamic>)> source, {
+    CancelToken? cancelToken,
+  }) async {
+    try {
+      final response = await Dio(
+        BaseOptions(
+          connectTimeout: const Duration(seconds: 5),
+          receiveTimeout: const Duration(seconds: 5),
+        ),
+      ).get<Map<String, dynamic>>(
         source.key,
         cancelToken: cancelToken,
         options: Options(
           responseType: ResponseType.json,
         ),
       );
-      future.then((res) {
-        if (res.statusCode == HttpStatus.ok && res.data != null) {
-          completer.complete(Result.success(source.value(res.data!)));
-        } else {
-          failureCount++;
-          if (failureCount == _ipInfoSources.length) {
-            completer.complete(Result.success(null));
-          }
-        }
-      }).catchError((e) {
-        failureCount++;
-        if (e == DioExceptionType.cancel) {
-          completer.complete(Result.error("cancelled"));
-        }
-      });
-      return completer.future;
-    });
-    final res = await Future.any(futures);
-    cancelToken?.cancel();
-    return res;
+      if (response.statusCode != HttpStatus.ok || response.data == null) {
+        return null;
+      }
+      return source.value(response.data!);
+    } on DioException catch (e) {
+      if (CancelToken.isCancel(e)) {
+        return null;
+      }
+      commonPrint.log('Failed to check IP from ${source.key}: $e');
+      return null;
+    } catch (e) {
+      commonPrint.log('Failed to parse IP info from ${source.key}: $e');
+      return null;
+    }
   }
 
   Future<bool> pingHelper() async {

lib/models/profile.dart

@@ -233,12 +233,13 @@ extension ProfileExtension on Profile {
   }
 
   Future<Profile> saveFile(Uint8List bytes) async {
-    final message = await clashCore.validateConfig(utf8.decode(bytes));
+    final content = utf8.decode(bytes);
+    final message = await clashCore.validateConfig(content);
     if (message.isNotEmpty) {
       throw message;
     }
     final file = await getFile();
-    await file.writeAsBytes(bytes);
+    await _writeProfileFileAtomically(file, bytes);
     return copyWith(lastUpdateDate: DateTime.now());
   }
 
@@ -248,7 +249,22 @@ extension ProfileExtension on Profile {
       throw message;
     }
     final file = await getFile();
-    await file.writeAsString(value);
+    await _writeProfileFileAtomically(file, utf8.encode(value));
     return copyWith(lastUpdateDate: DateTime.now());
   }
+
+  Future<void> _writeProfileFileAtomically(File file, List<int> bytes) async {
+    final tempFile = File(
+      '${file.path}.tmp.${DateTime.now().microsecondsSinceEpoch}',
+    );
+    try {
+      await tempFile.writeAsBytes(bytes, flush: true);
+      await tempFile.rename(file.path);
+    } catch (_) {
+      if (await tempFile.exists()) {
+        await tempFile.delete();
+      }
+      rethrow;
+    }
+  }
 }

lib/pages/send_to_tv_page.dart

@@ -18,43 +18,87 @@ class SendToTvPage extends ConsumerStatefulWidget {
 }
 
 class _SendToTvPageState extends ConsumerState<SendToTvPage> {
+  static const _syncType = 'flclashx_tv_sync';
+
   final MobileScannerController _scannerController = MobileScannerController();
   bool _isScanComplete = false;
 
   Future<void> _handleQrCode(BarcodeCapture capture) async {
     if (_isScanComplete) return;
-    setState(() {
-      _isScanComplete = true;
-    });
 
+    if (capture.barcodes.isEmpty) {
+      return;
+    }
     final rawValue = capture.barcodes.first.rawValue;
-    if (rawValue == null) return;
+    if (rawValue == null) {
+      return;
+    }
 
     try {
-      final data = jsonDecode(rawValue);
-      if (data['type'] == 'flclashx_tv_sync') {
-        final ip = data['ip'];
-        final port = data['port'];
-        final tvUrl = 'http://$ip:$port/add-profile';
-        final dio = Dio(BaseOptions(
-          connectTimeout: const Duration(seconds: 5),
-          receiveTimeout: const Duration(seconds: 5),
-        ));
-        await dio.post(
-          tvUrl,
-          data: {'url': widget.profileUrl},
-        );
-        _showResultDialog(appLocalizations.successTitle,
-            appLocalizations.sentSuccessfullyMessage);
+      final endpoint = _parseSyncEndpoint(rawValue);
+      if (endpoint == null) {
+        return;
       }
+      setState(() {
+        _isScanComplete = true;
+      });
+      final dio = Dio(BaseOptions(
+        connectTimeout: const Duration(seconds: 5),
+        receiveTimeout: const Duration(seconds: 5),
+      ));
+      await dio.post(
+        endpoint,
+        data: {'url': widget.profileUrl},
+      );
+      if (!mounted) return;
+      _showResultDialog(
+        appLocalizations.successTitle,
+        appLocalizations.sentSuccessfullyMessage,
+      );
     } catch (e) {
+      commonPrint.log('Error sending profile to TV: $e');
+      if (!mounted) return;
+      setState(() {
+        _isScanComplete = true;
+      });
       _showResultDialog(
-          appLocalizations.errorTitle, appLocalizations.invalidQrMessage);
-      print('Error sending to TV: $e');
+        appLocalizations.errorTitle,
+        appLocalizations.invalidQrMessage,
+      );
+    }
+  }
+
+  String? _parseSyncEndpoint(String rawValue) {
+    final dynamic payload;
+    try {
+      payload = jsonDecode(rawValue);
+    } catch (_) {
+      return null;
+    }
+    if (payload is! Map<String, dynamic>) {
+      return null;
+    }
+    if (payload['type'] != _syncType) {
+      return null;
+    }
+    final ip = payload['ip'];
+    final port = payload['port'];
+    if (ip is! String || ip.isEmpty || port is! int) {
+      return null;
+    }
+    if (port < 1 || port > 65535) {
+      return null;
     }
+    return Uri(
+      scheme: 'http',
+      host: ip,
+      port: port,
+      path: '/add-profile',
+    ).toString();
   }
 
   void _showResultDialog(String title, String content) {
+    if (!mounted) return;
     showDialog(
       context: context,
       builder: (_) => AlertDialog(

lib/views/profiles/receive_profile_dialog.dart

@@ -17,6 +17,9 @@ class ReceiveProfileDialog extends StatefulWidget {
 }
 
 class _ReceiveProfileDialogState extends State<ReceiveProfileDialog> {
+  static const _syncType = 'flclashx_tv_sync';
+  static const _syncPort = 8899;
+
   HttpServer? _server;
   String? _qrData;
   bool _isLoading = true;
@@ -30,43 +33,64 @@ class _ReceiveProfileDialogState extends State<ReceiveProfileDialog> {
   Future<void> _startServerAndGenerateQr() async {
     try {
       final ip = await NetworkInfo().getWifiIP();
-      const port = 8899;
+      if (ip == null || ip.isEmpty) {
+        throw StateError('Could not get IP address');
+      }
 
       final router = shelf_router.Router();
       router.post('/add-profile', (shelf.Request request) async {
-        final body = await request.readAsString();
-        final json = jsonDecode(body);
-        final url = json['url'] as String?;
+        final url = await _readProfileUrl(request);
 
         if (url != null && url.isNotEmpty) {
-          print('Received subscription link: $url');
+          commonPrint.log('Received subscription link from TV sync');
           if (mounted) Navigator.of(context).pop(url);
           return shelf.Response.ok('Link received by TV');
         }
         return shelf.Response.badRequest(body: 'URL not found');
       });
 
-      _server = await shelf_io.serve(router.call, ip!, port);
-      print('Server started at http://${_server?.address.host}:${_server?.port}');
+      _server = await shelf_io.serve(router.call, ip, _syncPort);
+      commonPrint.log(
+        'TV sync server started at http://${_server?.address.host}:${_server?.port}',
+      );
 
+      if (!mounted) return;
       setState(() {
         _qrData = jsonEncode({
-          'type': 'flclashx_tv_sync',
+          'type': _syncType,
           'ip': _server?.address.host,
           'port': _server?.port,
         });
         _isLoading = false;
       });
     } catch (e) {
-      print('Error starting server: $e');
+      commonPrint.log('Error starting TV sync server: $e');
       if (mounted) Navigator.of(context).pop();
     }
   }
 
+  Future<String?> _readProfileUrl(shelf.Request request) async {
+    try {
+      final body = await request.readAsString();
+      final payload = jsonDecode(body);
+      if (payload is! Map<String, dynamic>) {
+        return null;
+      }
+      final url = payload['url'];
+      if (url is! String || url.trim().isEmpty) {
+        return null;
+      }
+      return url.trim();
+    } catch (e) {
+      commonPrint.log('Invalid TV sync request: $e');
+      return null;
+    }
+  }
+
   @override
   void dispose() {
     _server?.close(force: true);
-    print('Server stopped');
+    commonPrint.log('TV sync server stopped');
     super.dispose();
   }
 
@@ -107,4 +131,4 @@ class _ReceiveProfileDialogState extends State<ReceiveProfileDialog> {
       ],
     );
   }
-}
+}