Add network auto control feature for mobile platforms

Co-authored-by: monkeyWie <[email protected]>

ui/flutter/lib/util/network_monitor.dart

@@ -0,0 +1,107 @@
+import 'dart:async';
+import 'dart:io';
+
+import 'package:connectivity_plus/connectivity_plus.dart';
+import 'package:get/get.dart';
+
+import '../api/api.dart';
+import '../database/database.dart';
+import '../util/log_util.dart';
+
+class NetworkMonitor extends GetxService {
+  static NetworkMonitor get to => Get.find();
+
+  late final Connectivity _connectivity;
+  late StreamSubscription<List<ConnectivityResult>> _connectivitySubscription;
+  
+  final _isWiFiConnected = false.obs;
+  bool get isWiFiConnected => _isWiFiConnected.value;
+  
+  bool _wasWiFiConnected = false;
+  bool _isInitialized = false;
+
+  @override
+  Future<void> onInit() async {
+    super.onInit();
+    
+    // Only monitor network on mobile platforms
+    if (!Platform.isAndroid && !Platform.isIOS) {
+      return;
+    }
+    
+    _connectivity = Connectivity();
+    
+    // Check initial connectivity state
+    final initialResult = await _connectivity.checkConnectivity();
+    _updateWiFiStatus(initialResult);
+    _wasWiFiConnected = _isWiFiConnected.value;
+    _isInitialized = true;
+    
+    // Listen to connectivity changes
+    _connectivitySubscription = _connectivity.onConnectivityChanged.listen(
+      _onConnectivityChanged,
+      onError: (error) {
+        logError('Network monitoring error: $error');
+      },
+    );
+    
+    logInfo('Network monitor initialized');
+  }
+
+  @override
+  void onClose() {
+    _connectivitySubscription.cancel();
+    super.onClose();
+  }
+
+  void _updateWiFiStatus(List<ConnectivityResult> result) {
+    final hasWiFi = result.contains(ConnectivityResult.wifi);
+    _isWiFiConnected.value = hasWiFi;
+  }
+
+  void _onConnectivityChanged(List<ConnectivityResult> result) {
+    if (!_isInitialized) return;
+    
+    // Check if network auto control is enabled
+    final isNetworkAutoControlEnabled = Database.instance.getNetworkAutoControl();
+    if (!isNetworkAutoControlEnabled) {
+      return;
+    }
+
+    _updateWiFiStatus(result);
+    final currentlyWiFi = _isWiFiConnected.value;
+    
+    logInfo('Network changed: wasWiFi=$_wasWiFiConnected, currentlyWiFi=$currentlyWiFi');
+    
+    // WiFi to Mobile Data: pause all tasks
+    if (_wasWiFiConnected && !currentlyWiFi) {
+      _pauseAllDownloads();
+      logInfo('Switched from WiFi to mobile data - pausing all downloads');
+    }
+    // Mobile Data to WiFi: resume all tasks
+    else if (!_wasWiFiConnected && currentlyWiFi) {
+      _resumeAllDownloads();
+      logInfo('Switched from mobile data to WiFi - resuming all downloads');
+    }
+    
+    _wasWiFiConnected = currentlyWiFi;
+  }
+
+  Future<void> _pauseAllDownloads() async {
+    try {
+      await pauseAllTasks(null);
+      logInfo('Successfully paused all downloads due to network change');
+    } catch (e) {
+      logError('Failed to pause all downloads: $e');
+    }
+  }
+
+  Future<void> _resumeAllDownloads() async {
+    try {
+      await continueAllTasks(null);
+      logInfo('Successfully resumed all downloads due to network change');
+    } catch (e) {
+      logError('Failed to resume all downloads: $e');
+    }
+  }
+}