fix: LOC — location filter never applied to event API calls

Root cause: SearchScreen popped with a plain city label string; the
pincode was available in search results but discarded. home_screen only
saved the display label to prefs and never updated the 'pincode' key,
so every API call always sent {pincode:'all'} regardless of selection.

GPS path had the same issue — lat/lng were obtained but thrown away
after reverse-geocoding; only the label was passed back.

Fix:
- SearchScreen now pops with Map<String,dynamic> {label, pincode,
  lat?, lng?} instead of a plain String
- Pincode results return their pincode; GPS returns actual coordinates;
  popular city chips look up the first matching pincode from the
  Kerala pincodes DB (fallback 'all' if not found)
- home_screen._openLocationSearch() saves pincode + lat/lng to prefs
  and updates _pincode/_userLat/_userLng in state
- home_screen._loadUserDataAndEvents() prefers getEventsByLocation
  (haversine) when GPS coords are saved, falls back to getEventsByPincode
- EventsService gains getEventsByLocation(lat, lng) which sends
  latitude/longitude/radius_km to the existing Django haversine endpoint
  and auto-expands radius 10→25→50→100 km until ≥ 6 events found

lib/features/events/services/events_service.dart

@@ -108,6 +108,33 @@ class EventsService {
     return [];
   }
 
+  /// Get events by GPS coordinates using haversine distance filtering.
+  /// Automatically expands radius (10 → 25 → 50 → 100 km) until ≥ 6 events found.
+  Future<List<EventModel>> getEventsByLocation(double lat, double lng, {double initialRadiusKm = 10}) async {
+    const radii = [10.0, 25.0, 50.0, 100.0];
+    for (final radius in radii) {
+      if (radius < initialRadiusKm) continue;
+      final body = {
+        'latitude': lat,
+        'longitude': lng,
+        'radius_km': radius,
+        'page': 1,
+        'page_size': 50,
+        'per_type': 5,
+      };
+      final res = await _api.post(ApiEndpoints.eventsByPincode, body: body, requiresAuth: false);
+      final list = <EventModel>[];
+      final events = res['events'] ?? res['data'] ?? [];
+      if (events is List) {
+        for (final e in events) {
+          if (e is Map<String, dynamic>) list.add(EventModel.fromJson(Map<String, dynamic>.from(e)));
+        }
+      }
+      if (list.length >= 6 || radius >= 100) return list;
+    }
+    return [];
+  }
+
   /// Events by month and year for calendar (POST to /events/events-by-month-year/)
   Future<Map<String, dynamic>> getEventsByMonthYear(String month, int year) async {
     final res = await _api.post(ApiEndpoints.eventsByMonth, body: {'month': month, 'year': year}, requiresAuth: false);

lib/screens/home_screen.dart

@@ -37,6 +37,8 @@ class _HomeScreenState extends State<HomeScreen> with SingleTickerProviderStateM
   String _username = '';
   String _location = '';
   String _pincode = 'all';
+  double? _userLat;
+  double? _userLng;
 
   final EventsService _eventsService = EventsService();
 
@@ -104,12 +106,17 @@ class _HomeScreenState extends State<HomeScreen> with SingleTickerProviderStateM
       _location = storedLocation;
     }
     _pincode = prefs.getString('pincode') ?? 'all';
+    _userLat = prefs.getDouble('user_lat');
+    _userLng = prefs.getDouble('user_lng');
 
     try {
-      // Fetch types and events in parallel for faster loading
+      // Fetch types and events in parallel for faster loading.
+      // Prefer haversine (lat/lng) when GPS coords are available; fall back to pincode.
       final results = await Future.wait([
         _events_service_getEventTypesSafe(),
-        _events_service_getEventsSafe(_pincode),
+        (_userLat != null && _userLng != null)
+            ? _events_service_getEventsByLocationSafe(_userLat!, _userLng!)
+            : _events_service_getEventsSafe(_pincode),
       ]);
       final types = results[0] as List<EventTypeModel>;
       final events = results[1] as List<EventModel>;
@@ -171,6 +178,15 @@ class _HomeScreenState extends State<HomeScreen> with SingleTickerProviderStateM
     }
   }
 
+  Future<List<EventModel>> _events_service_getEventsByLocationSafe(double lat, double lng) async {
+    try {
+      return await _eventsService.getEventsByLocation(lat, lng);
+    } catch (_) {
+      // Fallback to all events if location-based fetch fails
+      return _events_service_getEventsSafe('all');
+    }
+  }
+
   Future<void> _refresh() async {
     await _loadUserDataAndEvents();
   }
@@ -277,12 +293,31 @@ class _HomeScreenState extends State<HomeScreen> with SingleTickerProviderStateM
       transitionDuration: const Duration(milliseconds: 220),
     ));
 
-    if (selected != null && selected is String) {
+    if (selected != null && selected is Map) {
+      final label = (selected['label'] as String?) ?? 'Current Location';
+      final pincode = (selected['pincode'] as String?) ?? 'all';
+      final lat = selected['lat'] as double?;
+      final lng = selected['lng'] as double?;
+
       final prefs = await SharedPreferences.getInstance();
-      await prefs.setString('location', selected);
+      await prefs.setString('location', label);
-      setState(() {
+      await prefs.setString('pincode', pincode);
-        _location = selected;
+      if (lat != null && lng != null) {
-      });
+        await prefs.setDouble('user_lat', lat);
+        await prefs.setDouble('user_lng', lng);
+      } else {
+        await prefs.remove('user_lat');
+        await prefs.remove('user_lng');
+      }
+
+      if (mounted) {
+        setState(() {
+          _location = label;
+          _pincode = pincode;
+          _userLat = lat;
+          _userLng = lng;
+        });
+      }
       await _refresh();
     }
   }

lib/screens/search_screen.dart

@@ -106,8 +106,24 @@ class _SearchScreenState extends State<SearchScreen> {
     });
   }
 
+  /// Pop with a structured result so home_screen can update both the display
+  /// label AND the pincode / GPS coordinates used for API filtering.
+  void _selectWithPincode(String label, {String? pincode}) {
+    Navigator.of(context).pop(<String, dynamic>{
+      'label': label,
+      'pincode': pincode ?? 'all',
+    });
+  }
+
   void _selectAndClose(String location) {
-    Navigator.of(context).pop(location);
+    // Legacy path for plain strings — wrap in structured map.
+    // Tries to look up a pincode from the database for the given city name.
+    final match = _locationDb.cast<_LocationItem?>().firstWhere(
+      (loc) => loc!.city.toLowerCase() == location.toLowerCase() ||
+               loc.displayTitle.toLowerCase() == location.toLowerCase(),
+      orElse: () => null,
+    );
+    _selectWithPincode(location, pincode: match?.pincode);
   }
 
   Future<void> _useCurrentLocation() async {
@@ -122,13 +138,14 @@ class _SearchScreenState extends State<SearchScreen> {
       if (permission == LocationPermission.deniedForever || permission == LocationPermission.denied) {
         if (mounted) {
           ScaffoldMessenger.of(context).showSnackBar(const SnackBar(content: Text('Location permission denied')));
-          Navigator.of(context).pop('Current Location');
+          Navigator.of(context).pop(<String, dynamic>{'label': 'Current Location', 'pincode': 'all'});
         }
         return;
       }
 
       final pos = await Geolocator.getCurrentPosition(desiredAccuracy: LocationAccuracy.best);
 
+      String label = 'Current Location';
       try {
         final placemarks = await placemarkFromCoordinates(pos.latitude, pos.longitude);
         if (placemarks.isNotEmpty) {
@@ -137,17 +154,24 @@ class _SearchScreenState extends State<SearchScreen> {
           if ((p.subLocality ?? '').isNotEmpty) parts.add(p.subLocality!);
           if ((p.locality ?? '').isNotEmpty) parts.add(p.locality!);
           if ((p.subAdministrativeArea ?? '').isNotEmpty) parts.add(p.subAdministrativeArea!);
-          final label = parts.isNotEmpty ? parts.join(', ') : 'Current Location';
+          if (parts.isNotEmpty) label = parts.join(', ');
-          if (mounted) Navigator.of(context).pop(label);
-          return;
         }
       } catch (_) {}
 
-      if (mounted) Navigator.of(context).pop('Current Location');
+      if (mounted) {
+        // Return lat/lng so home_screen can use haversine filtering
+        Navigator.of(context).pop(<String, dynamic>{
+          'label': label,
+          'pincode': 'all',
+          'lat': pos.latitude,
+          'lng': pos.longitude,
+        });
+      }
+      return;
     } catch (e) {
       if (mounted) {
         ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text(userFriendlyError(e))));
-        Navigator.of(context).pop('Current Location');
+        Navigator.of(context).pop(<String, dynamic>{'label': 'Current Location', 'pincode': 'all'});
       }
     } finally {
       if (mounted) setState(() => _loadingLocation = false);
@@ -320,7 +344,7 @@ class _SearchScreenState extends State<SearchScreen> {
                         subtitle: loc.pincode != null && loc.pincode!.isNotEmpty
                             ? Text(loc.pincode!, style: TextStyle(color: Colors.grey[500], fontSize: 13))
                             : null,
-                        onTap: () => _selectAndClose(loc.returnValue),
+                        onTap: () => _selectWithPincode(loc.displayTitle, pincode: loc.pincode),
                       );
                     },
                   ),