Enable avoidance distance settings

lib/app_state.dart

@@ -122,6 +122,7 @@ class AppState extends ChangeNotifier {
   // Navigation search state
   bool get isNavigationSearchLoading => _navigationState.isSearchLoading;
   List<SearchResult> get navigationSearchResults => _navigationState.searchResults;
+  int get navigationAvoidanceDistance => _settingsState.navigationAvoidanceDistance;
   
   // Profile state
   List<NodeProfile> get profiles => _profileState.profiles;
@@ -645,6 +646,11 @@ class AppState extends ChangeNotifier {
     await _settingsState.setSuspectedLocationMinDistance(distance);
   }
 
+  /// Set navigation avoidance distance
+  Future<void> setNavigationAvoidanceDistance(int distance) async {
+    await _settingsState.setNavigationAvoidanceDistance(distance);
+  } 
+
   // ---------- Queue Methods ----------
   void clearQueue() {
     _uploadQueueState.clearQueue();

lib/screens/navigation_settings_screen.dart

@@ -8,6 +8,7 @@ class NavigationSettingsScreen extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final appState = context.watch<AppState>();
     final locService = LocalizationService.instance;
     
     return AnimatedBuilder(
@@ -26,48 +27,28 @@ class NavigationSettingsScreen extends StatelessWidget {
           child: Column(
             crossAxisAlignment: CrossAxisAlignment.start,
             children: [
-              // Coming soon message
-              Card(
-                child: Padding(
-                  padding: const EdgeInsets.all(16),
-                  child: Column(
-                    crossAxisAlignment: CrossAxisAlignment.start,
-                    children: [
-                      Row(
-                        children: [
-                          Icon(Icons.info_outline, color: Colors.blue),
-                          const SizedBox(width: 8),
-                          Text(
-                            'Navigation Features',
-                            style: Theme.of(context).textTheme.titleMedium?.copyWith(
-                              fontWeight: FontWeight.bold,
-                            ),
-                          ),
-                        ],
-                      ),
-                      const SizedBox(height: 8),
-                      Text(
-                        'Navigation and routing settings will be available here. Coming soon:\n\n'
-                        '• Surveillance avoidance distance\n'
-                        '• Route planning preferences\n'
-                        '• Search history management\n'
-                        '• Distance units (metric/imperial)',
-                        style: Theme.of(context).textTheme.bodyMedium,
-                      ),
-                    ],
-                  ),
-                ),
-              ),
-              
-              const SizedBox(height: 24),
-              
-              // Placeholder settings (disabled for now)
-              _buildDisabledSetting(
-                context,
-                icon: Icons.warning_outlined,
-                title: locService.t('navigation.avoidanceDistance'),
-                subtitle: locService.t('navigation.avoidanceDistanceSubtitle'),
-                value: '100 ${locService.t('navigation.meters')}',
+              ListTile(
+                leading: const Icon(Icons.social_distance),
+                title: Text(locService.t('navigation.avoidanceDistance')),
+                subtitle: Text(locService.t('navigation.avoidanceDistanceSubtitle')),
+                trailing: SizedBox(
+                  width: 80,
+                  child: TextFormField(
+                    initialValue: appState.navigationAvoidanceDistance.toString(),
+                    keyboardType: const TextInputType.numberWithOptions(signed: false, decimal: false),
+                    textInputAction: TextInputAction.done,
+                    decoration: const InputDecoration(
+                      isDense: true,
+                      contentPadding: EdgeInsets.symmetric(vertical: 6, horizontal: 8),
+                      border: OutlineInputBorder(),
+                      suffixText: 'm',
+                    ),
+                    onFieldSubmitted: (value) {
+                      final distance = int.tryParse(value) ?? 250;
+                      appState.setNavigationAvoidanceDistance(distance.clamp(0, 2000));
+                    }
+                  )
+                )
               ),
               
               const Divider(),
@@ -126,4 +107,4 @@ class NavigationSettingsScreen extends StatelessWidget {
       ),
     );
   }
-}
+}

lib/services/routing_service.dart

@@ -2,6 +2,7 @@ import 'dart:convert';
 import 'package:flutter/foundation.dart';
 import 'package:http/http.dart' as http;
 import 'package:latlong2/latlong.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 
 class RouteResult {
   final List<LatLng> waypoints;
@@ -31,6 +32,9 @@ class RoutingService {
     required LatLng end,
   }) async {
     debugPrint('[RoutingService] Calculating route from $start to $end');
+
+    final prefs = await SharedPreferences.getInstance();
+    final avoidance_distance = await prefs.getInt('navigation_avoidance_distance');
     
     final uri = Uri.parse('$_baseUrl');
     final params = {
@@ -42,6 +46,7 @@ class RoutingService {
         'longitude': end.longitude,
         'latitude': end.latitude
       },
+      'avoidance_distance': avoidance_distance,
       'enabled_profiles': [ // revise to be dynamic based on user input
         {
           'id': 'generic-ALPR',
@@ -50,7 +55,8 @@ class RoutingService {
             'surveillance:type': 'ALPR'
           }
         }
-      ]
+      ],
+      'show_exclusion_zone': false, // if true, returns a GeoJSON Feature MultiPolygon showing what areas are avoided in calculating the route
     };
     
     debugPrint('[RoutingService] alprwatch request: $uri $params');

lib/state/navigation_state.dart

@@ -224,7 +224,7 @@ class NavigationState extends ChangeNotifier {
   /// Calculate route using alprwatch
   void _calculateRoute() {
     if (_routeStart == null || _routeEnd == null) return;
-    
+
     debugPrint('[NavigationState] Calculating route with alprwatch...');
     _isCalculating = true;
     _routingError = null;

lib/state/settings_state.dart

@@ -29,6 +29,7 @@ class SettingsState extends ChangeNotifier {
   static const String _networkStatusIndicatorEnabledPrefsKey = 'network_status_indicator_enabled';
   static const String _suspectedLocationMinDistancePrefsKey = 'suspected_location_min_distance';
   static const String _pauseQueueProcessingPrefsKey = 'pause_queue_processing';
+  static const String _navigationAvoidanceDistancePrefsKey = 'navigation_avoidance_distance';
 
   bool _offlineMode = false;
   bool _pauseQueueProcessing = false;
@@ -41,6 +42,7 @@ class SettingsState extends ChangeNotifier {
   int _suspectedLocationMinDistance = 100; // meters
   List<TileProvider> _tileProviders = [];
   String _selectedTileTypeId = '';
+  int _navigationAvoidanceDistance = 250; // meters
 
   // Getters
   bool get offlineMode => _offlineMode;
@@ -54,6 +56,7 @@ class SettingsState extends ChangeNotifier {
   int get suspectedLocationMinDistance => _suspectedLocationMinDistance;
   List<TileProvider> get tileProviders => List.unmodifiable(_tileProviders);
   String get selectedTileTypeId => _selectedTileTypeId;
+  int get navigationAvoidanceDistance => _navigationAvoidanceDistance;
   
   /// Get the currently selected tile type
   TileType? get selectedTileType {
@@ -100,6 +103,11 @@ class SettingsState extends ChangeNotifier {
     
     // Load max nodes
     _maxNodes = prefs.getInt(_maxNodesPrefsKey) ?? kDefaultMaxNodes;
+
+    // Load navigation avoidance distance
+    if (prefs.containsKey(_navigationAvoidanceDistancePrefsKey)) {
+      _navigationAvoidanceDistance = prefs.getInt(_navigationAvoidanceDistancePrefsKey) ?? 250;
+    }
     
     // Load proximity alerts settings
     _proximityAlertsEnabled = prefs.getBool(_proximityAlertsEnabledPrefsKey) ?? false;
@@ -351,4 +359,14 @@ class SettingsState extends ChangeNotifier {
     }
   }
 
-}
+  // Set distance for avoidance of nodes during navigation
+  Future<void> setNavigationAvoidanceDistance(int distance) async {
+    if (_navigationAvoidanceDistance != distance) {
+      _navigationAvoidanceDistance = distance;
+      final prefs = await SharedPreferences.getInstance();
+      await prefs.setInt(_navigationAvoidanceDistancePrefsKey, distance);
+      notifyListeners();
+    }
+  }
+
+}