feat: Add location-based DM retries

lib/models/path_history.dart

@@ -9,6 +9,11 @@ class PathRecord {
   final int failureCount;
   final int lastRoundTripTimeMs;
   final DateTime lastUsedAt;
+  final DateTime? lastSucceededAt;
+  final double? senderLatitude;
+  final double? senderLongitude;
+  final double? recipientLatitude;
+  final double? recipientLongitude;
 
   const PathRecord({
     required this.pathBytes,
@@ -19,6 +24,11 @@ class PathRecord {
     required this.failureCount,
     required this.lastRoundTripTimeMs,
     required this.lastUsedAt,
+    required this.lastSucceededAt,
+    required this.senderLatitude,
+    required this.senderLongitude,
+    required this.recipientLatitude,
+    required this.recipientLongitude,
   });
 
   String get signature =>
@@ -36,6 +46,11 @@ class PathRecord {
     int? failureCount,
     int? lastRoundTripTimeMs,
     DateTime? lastUsedAt,
+    DateTime? lastSucceededAt,
+    double? senderLatitude,
+    double? senderLongitude,
+    double? recipientLatitude,
+    double? recipientLongitude,
   }) {
     return PathRecord(
       pathBytes: pathBytes ?? this.pathBytes,
@@ -46,6 +61,11 @@ class PathRecord {
       failureCount: failureCount ?? this.failureCount,
       lastRoundTripTimeMs: lastRoundTripTimeMs ?? this.lastRoundTripTimeMs,
       lastUsedAt: lastUsedAt ?? this.lastUsedAt,
+      lastSucceededAt: lastSucceededAt ?? this.lastSucceededAt,
+      senderLatitude: senderLatitude ?? this.senderLatitude,
+      senderLongitude: senderLongitude ?? this.senderLongitude,
+      recipientLatitude: recipientLatitude ?? this.recipientLatitude,
+      recipientLongitude: recipientLongitude ?? this.recipientLongitude,
     );
   }
 
@@ -59,6 +79,11 @@ class PathRecord {
       'failure_count': failureCount,
       'last_round_trip_time_ms': lastRoundTripTimeMs,
       'last_used_at': lastUsedAt.toIso8601String(),
+      'last_succeeded_at': lastSucceededAt?.toIso8601String(),
+      'sender_latitude': senderLatitude,
+      'sender_longitude': senderLongitude,
+      'recipient_latitude': recipientLatitude,
+      'recipient_longitude': recipientLongitude,
     };
   }
 
@@ -79,6 +104,13 @@ class PathRecord {
       lastUsedAt:
           DateTime.tryParse(json['last_used_at'] as String? ?? '') ??
           DateTime.fromMillisecondsSinceEpoch(0),
+      lastSucceededAt: DateTime.tryParse(
+        json['last_succeeded_at'] as String? ?? '',
+      ),
+      senderLatitude: (json['sender_latitude'] as num?)?.toDouble(),
+      senderLongitude: (json['sender_longitude'] as num?)?.toDouble(),
+      recipientLatitude: (json['recipient_latitude'] as num?)?.toDouble(),
+      recipientLongitude: (json['recipient_longitude'] as num?)?.toDouble(),
     );
   }
 }

lib/providers/app_provider.dart

@@ -1761,6 +1761,7 @@ class AppProvider with ChangeNotifier {
           return _prepareDirectMessageSend(
             messageId: messageId,
             contact: contact,
+            retryAttempt: retryAttempt,
           );
         };
 
@@ -1830,23 +1831,47 @@ class AppProvider with ChangeNotifier {
   Future<Contact> _prepareDirectMessageSend({
     required String messageId,
     required Contact contact,
+    required int retryAttempt,
   }) async {
     final latestContact =
         contactsProvider.findContactByKey(contact.publicKey) ?? contact;
     var session = _directMessageRouteSessions[messageId];
     if (session == null) {
-      final selection = await _pathHistoryService.getSelectionForContact(
-        latestContact,
-        autoRouteRotationEnabled: _autoRouteRotationEnabled,
-      );
+      final selection = latestContact.routeHasPath && latestContact.routeHopCount > 0
+          ? PathSelection(
+              mode: PathSelectionMode.directCurrent,
+              pathBytes: Uint8List.fromList(latestContact.routePathBytes),
+              hopCount: latestContact.routeHopCount,
+              hashSize: latestContact.routeHashSize,
+            )
+          : await _pathHistoryService.getSelectionForContact(
+              latestContact,
+              autoRouteRotationEnabled: _autoRouteRotationEnabled,
+            );
       session = _DirectMessageRouteSession(
         currentSelection: selection,
         originalRoute: ContactRouteCodec.fromContact(latestContact),
         routerFallbackAttempted: false,
       );
-      _directMessageRouteSessions[messageId] = session;
     }
 
+    if (!session.routerFallbackAttempted) {
+      final currentSignature =
+          latestContact.routeHasPath && latestContact.routeHopCount > 0
+          ? latestContact.routePathBytes
+                .map((byte) => byte.toRadixString(16).padLeft(2, '0'))
+                .join()
+          : null;
+      final selection = await _resolveDirectMessageSelectionForRetry(
+        latestContact,
+        retryAttempt: retryAttempt,
+        currentSignature: currentSignature,
+        fallbackSelection: session.currentSelection,
+      );
+      session = session.copyWith(currentSelection: selection);
+    }
+    _directMessageRouteSessions[messageId] = session;
+
     await _applyPathSelection(
       latestContact,
       session.currentSelection,
@@ -1857,6 +1882,43 @@ class AppProvider with ChangeNotifier {
         latestContact;
   }
 
+  Future<PathSelection> _resolveDirectMessageSelectionForRetry(
+    Contact contact, {
+    required int retryAttempt,
+    required String? currentSignature,
+    required PathSelection fallbackSelection,
+  }) async {
+    if (contact.routeHasPath && contact.routeHopCount > 0 && retryAttempt <= 1) {
+      return PathSelection(
+        mode: PathSelectionMode.directCurrent,
+        pathBytes: Uint8List.fromList(contact.routePathBytes),
+        hopCount: contact.routeHopCount,
+        hashSize: contact.routeHashSize,
+      );
+    }
+
+    if (retryAttempt == 2) {
+      return PathSelection.flood();
+    }
+
+    if (retryAttempt >= 3) {
+      final historicalSelection = await _pathHistoryService
+          .getLastSuccessfulDirectSelection(
+            contact,
+            excludeSignature: currentSignature,
+            senderLatitude: locationTrackingService.currentPosition?.latitude,
+            senderLongitude: locationTrackingService.currentPosition?.longitude,
+            recipientLatitude: contact.displayLocation?.latitude,
+            recipientLongitude: contact.displayLocation?.longitude,
+          );
+      if (historicalSelection != null) {
+        return historicalSelection;
+      }
+    }
+
+    return fallbackSelection;
+  }
+
   Future<void> _applyPathSelection(
     Contact contact,
     PathSelection selection, {
@@ -2031,6 +2093,10 @@ class AppProvider with ChangeNotifier {
         session.currentSelection,
         success: true,
         roundTripTimeMs: roundTripTimeMs,
+        senderLatitude: locationTrackingService.currentPosition?.latitude,
+        senderLongitude: locationTrackingService.currentPosition?.longitude,
+        recipientLatitude: contact.displayLocation?.latitude,
+        recipientLongitude: contact.displayLocation?.longitude,
       ),
     );
   }

lib/providers/helpers/message_retry_manager.dart

@@ -21,8 +21,8 @@ class MessageRetryManager {
   final Map<String, int> _pathFailureStreaks = {};
 
   /// Max retry attempts when the contact has a known path.
-  /// Official MeshCore app uses 5 (with auto-retry) or 3 (without).
-  static const int maxRetryAttemptsWithPath = 5;
+  /// Sequence: 2 direct attempts, flood, then last successful route.
+  static const int maxRetryAttemptsWithPath = 3;
 
   /// No retries for flood-only contacts (no known path).
   /// Value 0 means: don't retry at all, go straight to fallback/fail.

lib/providers/messages_provider.dart

@@ -2354,17 +2354,6 @@ class MessagesProvider with ChangeNotifier {
           return;
         }
 
-        // On the last attempt, reset the path to force flood mode
-        // (matches official MeshCore app behaviour)
-        if (_retryManager.isLastAttempt(currentMessage, contact)) {
-          debugPrint(
-            '🔄 [MessagesProvider] Last attempt — resetting path to flood for $messageId',
-          );
-          if (resetPathBeforeLastRetryCallback != null) {
-            await resetPathBeforeLastRetryCallback!(contact);
-          }
-        }
-
         if (sendMessageCallback != null) {
           final queued = await sendMessageCallback!(
             contactPublicKey: contact.publicKey,

lib/services/path_history_service.dart

@@ -1,6 +1,7 @@
 import 'dart:convert';
 
 import 'package:flutter/foundation.dart';
+import 'package:geolocator/geolocator.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 
 import '../models/contact.dart';
@@ -9,7 +10,7 @@ import '../models/path_selection.dart';
 import '../utils/log_rx_route_decoder.dart';
 
 class PathHistoryService {
-  static const String _storageKey = 'contact_path_history_v1';
+  static const String _storageKey = 'contact_path_history_v2';
   static const int _maxDirectPaths = 20;
   static const int _topRotationCount = 3;
 
@@ -59,6 +60,11 @@ class PathHistoryService {
       failureCount: existing?.failureCount ?? 0,
       lastRoundTripTimeMs: existing?.lastRoundTripTimeMs ?? 0,
       lastUsedAt: DateTime.now(),
+      lastSucceededAt: existing?.lastSucceededAt,
+      senderLatitude: existing?.senderLatitude,
+      senderLongitude: existing?.senderLongitude,
+      recipientLatitude: existing?.recipientLatitude,
+      recipientLongitude: existing?.recipientLongitude,
     );
 
     await _saveHistory(
@@ -104,6 +110,11 @@ class PathHistoryService {
       failureCount: existing?.failureCount ?? 0,
       lastRoundTripTimeMs: existing?.lastRoundTripTimeMs ?? 0,
       lastUsedAt: DateTime.now(),
+      lastSucceededAt: existing?.lastSucceededAt,
+      senderLatitude: existing?.senderLatitude,
+      senderLongitude: existing?.senderLongitude,
+      recipientLatitude: existing?.recipientLatitude,
+      recipientLongitude: existing?.recipientLongitude,
     );
 
     await _saveHistory(
@@ -172,6 +183,10 @@ class PathHistoryService {
     PathSelection selection, {
     required bool success,
     int? roundTripTimeMs,
+    double? senderLatitude,
+    double? senderLongitude,
+    double? recipientLatitude,
+    double? recipientLongitude,
   }) async {
     await initialize();
     final history = _historyFor(contactPublicKeyHex);
@@ -206,6 +221,13 @@ class PathHistoryService {
           ? (roundTripTimeMs ?? existing?.lastRoundTripTimeMs ?? 0)
           : (existing?.lastRoundTripTimeMs ?? 0),
       lastUsedAt: DateTime.now(),
+      lastSucceededAt: success ? DateTime.now() : existing?.lastSucceededAt,
+      senderLatitude: success ? senderLatitude : existing?.senderLatitude,
+      senderLongitude: success ? senderLongitude : existing?.senderLongitude,
+      recipientLatitude:
+          success ? recipientLatitude : existing?.recipientLatitude,
+      recipientLongitude:
+          success ? recipientLongitude : existing?.recipientLongitude,
     );
     await _saveHistory(
       contactPublicKeyHex,
@@ -215,6 +237,54 @@ class PathHistoryService {
     );
   }
 
+  Future<PathSelection?> getLastSuccessfulDirectSelection(
+    Contact contact, {
+    String? excludeSignature,
+    double? senderLatitude,
+    double? senderLongitude,
+    double? recipientLatitude,
+    double? recipientLongitude,
+  }) async {
+    await initialize();
+    final history = _historyFor(contact.publicKeyHex);
+    final ranked = history.directPaths
+        .where(
+          (record) =>
+              record.successCount > 0 &&
+              record.lastSucceededAt != null &&
+              record.signature != excludeSignature,
+        )
+        .toList()
+      ..sort((a, b) {
+        final locationCompare = _compareLocationFit(
+          a,
+          b,
+          senderLatitude: senderLatitude,
+          senderLongitude: senderLongitude,
+          recipientLatitude: recipientLatitude,
+          recipientLongitude: recipientLongitude,
+        );
+        if (locationCompare != 0) return locationCompare;
+        final succeededCompare = b.lastSucceededAt!.compareTo(
+          a.lastSucceededAt!,
+        );
+        if (succeededCompare != 0) return succeededCompare;
+        return _comparePathRecords(a, b);
+      });
+
+    if (ranked.isEmpty) {
+      return null;
+    }
+
+    final record = ranked.first;
+    return PathSelection(
+      mode: PathSelectionMode.directHistorical,
+      pathBytes: Uint8List.fromList(record.pathBytes),
+      hopCount: record.hopCount,
+      hashSize: record.hashSize,
+    );
+  }
+
   ContactPathHistory historyFor(String contactPublicKeyHex) {
     return _cache[contactPublicKeyHex] ??
         ContactPathHistory.empty(contactPublicKeyHex);
@@ -279,4 +349,68 @@ class PathHistoryService {
 
   String _signature(Uint8List bytes) =>
       bytes.map((byte) => byte.toRadixString(16).padLeft(2, '0')).join();
+
+  int _compareLocationFit(
+    PathRecord a,
+    PathRecord b, {
+    required double? senderLatitude,
+    required double? senderLongitude,
+    required double? recipientLatitude,
+    required double? recipientLongitude,
+  }) {
+    final aDistance = _locationDistanceScore(
+      a,
+      senderLatitude: senderLatitude,
+      senderLongitude: senderLongitude,
+      recipientLatitude: recipientLatitude,
+      recipientLongitude: recipientLongitude,
+    );
+    final bDistance = _locationDistanceScore(
+      b,
+      senderLatitude: senderLatitude,
+      senderLongitude: senderLongitude,
+      recipientLatitude: recipientLatitude,
+      recipientLongitude: recipientLongitude,
+    );
+    return aDistance.compareTo(bDistance);
+  }
+
+  double _locationDistanceScore(
+    PathRecord record, {
+    required double? senderLatitude,
+    required double? senderLongitude,
+    required double? recipientLatitude,
+    required double? recipientLongitude,
+  }) {
+    var total = 0.0;
+    var matched = false;
+
+    if (senderLatitude != null &&
+        senderLongitude != null &&
+        record.senderLatitude != null &&
+        record.senderLongitude != null) {
+      matched = true;
+      total += Geolocator.distanceBetween(
+        senderLatitude,
+        senderLongitude,
+        record.senderLatitude!,
+        record.senderLongitude!,
+      );
+    }
+
+    if (recipientLatitude != null &&
+        recipientLongitude != null &&
+        record.recipientLatitude != null &&
+        record.recipientLongitude != null) {
+      matched = true;
+      total += Geolocator.distanceBetween(
+        recipientLatitude,
+        recipientLongitude,
+        record.recipientLatitude!,
+        record.recipientLongitude!,
+      );
+    }
+
+    return matched ? total : double.infinity;
+  }
 }

test/services/path_history_service_test.dart

@@ -206,4 +206,59 @@ void main() {
       expect(history.directPaths.single.source, PathRecordSource.observed);
     },
   );
+
+  test('last successful direct path is chosen by location fit', () async {
+    final service = PathHistoryService();
+    final contact = _buildContact(
+      seed: 7,
+      pathBytes: [0xAA],
+      hopCount: 1,
+      hashSize: 1,
+    );
+
+    await service.initialize();
+    await service.recordPathResult(
+      contact.publicKeyHex,
+      PathSelection(
+        mode: PathSelectionMode.directHistorical,
+        pathBytes: Uint8List.fromList([0x11]),
+        hopCount: 1,
+        hashSize: 1,
+      ),
+      success: true,
+      roundTripTimeMs: 120,
+      senderLatitude: 46.0,
+      senderLongitude: 14.0,
+      recipientLatitude: 46.1,
+      recipientLongitude: 14.1,
+    );
+    await service.recordPathResult(
+      contact.publicKeyHex,
+      PathSelection(
+        mode: PathSelectionMode.directHistorical,
+        pathBytes: Uint8List.fromList([0x22]),
+        hopCount: 1,
+        hashSize: 1,
+      ),
+      success: true,
+      roundTripTimeMs: 90,
+      senderLatitude: 46.0001,
+      senderLongitude: 14.0001,
+      recipientLatitude: 46.1001,
+      recipientLongitude: 14.1001,
+    );
+
+    final selection = await service.getLastSuccessfulDirectSelection(
+      contact,
+      excludeSignature: 'aa',
+      senderLatitude: 46.0002,
+      senderLongitude: 14.0002,
+      recipientLatitude: 46.1002,
+      recipientLongitude: 14.1002,
+    );
+
+    expect(selection, isNotNull);
+    expect(selection!.mode, PathSelectionMode.directHistorical);
+    expect(selection.canonicalPath, '22');
+  });
 }