multi-byte paths

lib/helpers/path_helper.dart

@@ -1,3 +1,4 @@
+import 'package:flutter/foundation.dart';
 import '../models/contact.dart';
 import '../connector/meshcore_protocol.dart';
 
@@ -8,24 +9,56 @@ class PathHelper {
         .join(',');
   }
 
+  /// Resolves path bytes to contact names, supporting multi-byte hash widths.
+  /// 
+  /// Groups path bytes according to [hashByteWidth]:
+  /// - 1: Single byte per hop (256 unique nodes)
+  /// - 2: Two bytes per hop (65K unique nodes)
+  /// - 3: Three bytes per hop (16M unique nodes)
   static String resolvePathNames(
     List<int> pathBytes,
     List<Contact> allContacts,
+    int hashByteWidth,
   ) {
-    return pathBytes
-        .map((b) {
-          final hex = b.toRadixString(16).padLeft(2, '0').toUpperCase();
-          final matches = allContacts
-              .where(
-                (c) =>
-                    c.publicKey.first == b &&
-                    (c.type == advTypeRepeater || c.type == advTypeRoom),
-              )
-              .toList();
-          if (matches.isEmpty) return hex;
-          if (matches.length == 1) return matches.first.name;
-          return matches.map((c) => c.name).join(' | ');
-        })
-        .join(' \u2192 ');
+    if (pathBytes.isEmpty) return '';
+    
+    final width = hashByteWidth.clamp(1, 8);
+    final parts = <String>[];
+    
+    // Group bytes according to width
+    for (int i = 0; i < pathBytes.length; i += width) {
+      final endIdx = (i + width).clamp(0, pathBytes.length);
+      final hopBytes = pathBytes.sublist(i, endIdx);
+      
+      if (hopBytes.isEmpty) continue;
+      
+      // Format hex for display
+      final hex = hopBytes
+          .map((b) => b.toRadixString(16).padLeft(2, '0').toUpperCase())
+          .join('');
+      
+      // Find matching contacts by comparing public key prefix
+      final matches = allContacts
+          .where((c) {
+            if (c.publicKey.length < hopBytes.length) return false;
+            if (c.type != advTypeRepeater && c.type != advTypeRoom) return false;
+            // Compare bytes using listEquals for multi-byte support
+            return listEquals(
+              c.publicKey.sublist(0, hopBytes.length),
+              hopBytes,
+            );
+          })
+          .toList();
+      
+      if (matches.isEmpty) {
+        parts.add(hex);
+      } else if (matches.length == 1) {
+        parts.add(matches.first.name);
+      } else {
+        parts.add(matches.map((c) => c.name).join(' | '));
+      }
+    }
+    
+    return parts.join(' \u2192 ');
   }
 }

lib/screens/channel_message_path_screen.dart

@@ -42,9 +42,14 @@ class ChannelMessagePathScreen extends StatelessWidget {
             : primaryPathTmp;
         final hops = _buildPathHops(primaryPath, connector, l10n);
         final hasHopDetails = primaryPath.isNotEmpty;
+        
+        // Convert path byte length to hop count based on device width
+        final width = connector.pathHashByteWidth.clamp(1, 8);
+        final observedHopCount = primaryPath.length ~/ width;
+        
         final observedLabel = _formatObservedHops(
-          primaryPath.length,
-          message.pathLength,
+          observedHopCount,
+          message.pathLength != null ? message.pathLength! ~/ width : null,
           l10n,
         );
         final extraPaths = _otherPaths(primaryPath, message.pathVariants);
@@ -886,6 +891,7 @@ class _PathHop {
   final Contact? contact;
   final LatLng? position;
   final AppLocalizations l10n;
+  final Uint8List? hopBytes;
 
   const _PathHop({
     required this.index,
@@ -893,12 +899,15 @@ class _PathHop {
     required this.contact,
     required this.position,
     required this.l10n,
+    this.hopBytes,
   });
 
   bool get hasLocation => position != null;
 
   String get displayLabel {
-    final prefixLabel = _formatPrefix(prefix);
+    final prefixLabel = hopBytes != null && hopBytes!.isNotEmpty
+        ? hopBytes!.map((b) => b.toRadixString(16).padLeft(2, '0')).join('').toUpperCase()
+        : _formatPrefix(prefix);
     return '($prefixLabel) ${_resolveName(contact, l10n)}';
   }
 }
@@ -916,19 +925,30 @@ List<_PathHop> _buildPathHops(
   AppLocalizations l10n,
 ) {
   if (pathBytes.isEmpty) return const [];
-  final candidatesByPrefix = <int, List<Contact>>{};
+  
+  final width = connector.pathHashByteWidth.clamp(1, 8);
+  final candidatesByHashBytes = <List<int>, List<Contact>>{};
   final allContacts = connector.allContacts;
+  
+  // Build lookup map using hash byte sequences
   for (final contact in allContacts) {
     if (contact.publicKey.isEmpty) continue;
     if (contact.type != advTypeRepeater && contact.type != advTypeRoom) {
       continue;
     }
-    final prefix = contact.publicKey.first;
-    candidatesByPrefix.putIfAbsent(prefix, () => <Contact>[]).add(contact);
+    // Extract the hash bytes that match the device width
+    final keyBytes = contact.publicKey.sublist(
+      0,
+      min(width, contact.publicKey.length),
+    );
+    candidatesByHashBytes.putIfAbsent(keyBytes, () => <Contact>[]).add(contact);
   }
-  for (final candidates in candidatesByPrefix.values) {
+  
+  // Sort candidates by last seen
+  for (final candidates in candidatesByHashBytes.values) {
     candidates.sort((a, b) => b.lastSeen.compareTo(a.lastSeen));
   }
+  
   final startPoint =
       (connector.selfLatitude != null && connector.selfLongitude != null)
       ? LatLng(connector.selfLatitude!, connector.selfLongitude!)
@@ -938,10 +958,17 @@ List<_PathHop> _buildPathHops(
   var lastDistance = 0.0;
   var bestDistance = 0.0;
   final hops = <_PathHop>[];
-  for (var i = 0; i < pathBytes.length; i++) {
-    final searchPoint = i == 0 ? startPoint : previousPosition;
-    final candidates = candidatesByPrefix[pathBytes[i]];
+  
+  // Process path in hop-sized chunks
+  for (var hopIdx = 0; hopIdx * width < pathBytes.length; hopIdx++) {
+    final startByte = hopIdx * width;
+    final endByte = min(startByte + width, pathBytes.length);
+    final hopBytes = pathBytes.sublist(startByte, endByte);
+    
+    final searchPoint = hopIdx == 0 ? startPoint : previousPosition;
+    final candidates = candidatesByHashBytes[hopBytes.toList()];
     Contact? contact;
+    
     if (candidates != null && candidates.isNotEmpty) {
       var bestIndex = 0;
       if (searchPoint != null) {
@@ -965,7 +992,7 @@ List<_PathHop> _buildPathHops(
       }
       contact = candidates.removeAt(bestIndex);
       if (candidates.isEmpty) {
-        candidatesByPrefix.remove(pathBytes[i]);
+        candidatesByHashBytes.remove(hopBytes.toList());
       }
     }
 
@@ -973,11 +1000,12 @@ List<_PathHop> _buildPathHops(
     if (resolvedPosition != null) {
       previousPosition = resolvedPosition;
     }
+    
     // If the best candidate is much farther than the previous hop, it's likely not the correct match.
     if (lastDistance + bestDistance > 50000 &&
         candidates != null &&
         candidates.isNotEmpty) {
-      i--;
+      hopIdx--;
       lastDistance = bestDistance;
       continue;
     }
@@ -985,11 +1013,12 @@ List<_PathHop> _buildPathHops(
 
     hops.add(
       _PathHop(
-        index: i + 1,
-        prefix: pathBytes[i],
+        index: hopIdx + 1,
+        prefix: hopBytes.isNotEmpty ? hopBytes[0] : 0,
         contact: contact,
         position: resolvedPosition,
         l10n: l10n,
+        hopBytes: hopBytes,
       ),
     );
   }

lib/screens/chat_screen.dart

@@ -1111,7 +1111,11 @@ class _ChatScreenState extends State<ChatScreen> {
     final allContacts = connector.allContacts;
 
     final formattedPath = PathHelper.formatPathHex(pathBytes);
-    final resolvedNames = PathHelper.resolvePathNames(pathBytes, allContacts);
+    final resolvedNames = PathHelper.resolvePathNames(
+      pathBytes,
+      allContacts,
+      connector.pathHashByteWidth,
+    );
 
     showDialog(
       context: context,

lib/widgets/path_management_dialog.dart

@@ -79,7 +79,11 @@ class _PathManagementDialogState extends State<_PathManagementDialog> {
     final allContacts = connector.allContacts;
 
     final formattedPath = PathHelper.formatPathHex(pathBytes);
-    final resolvedNames = PathHelper.resolvePathNames(pathBytes, allContacts);
+    final resolvedNames = PathHelper.resolvePathNames(
+      pathBytes,
+      allContacts,
+      connector.pathHashByteWidth,
+    );
 
     showDialog(
       context: context,
@@ -150,6 +154,7 @@ class _PathManagementDialogState extends State<_PathManagementDialog> {
       initialPath: pathForInput.isEmpty ? null : pathForInput,
       currentPathLabel: currentContact.pathLabel(l10n),
       onRefresh: connector.isConnected ? connector.getContacts : null,
+      pathHashByteWidth: connector.pathHashByteWidth,
     );
 
     if (result != null && context.mounted) {

lib/widgets/path_selection_dialog.dart

@@ -12,6 +12,7 @@ class PathSelectionDialog extends StatefulWidget {
   final String? initialPath;
   final String? currentPathLabel;
   final VoidCallback? onRefresh;
+  final int pathHashByteWidth;
 
   const PathSelectionDialog({
     super.key,
@@ -20,6 +21,7 @@ class PathSelectionDialog extends StatefulWidget {
     this.initialPath,
     this.currentPathLabel,
     this.onRefresh,
+    this.pathHashByteWidth = 1,
   });
 
   @override
@@ -32,6 +34,7 @@ class PathSelectionDialog extends StatefulWidget {
     String? initialPath,
     String? currentPathLabel,
     VoidCallback? onRefresh,
+    int pathHashByteWidth = 1,
   }) {
     return showDialog<Uint8List?>(
       context: context,
@@ -41,6 +44,7 @@ class PathSelectionDialog extends StatefulWidget {
         initialPath: initialPath,
         currentPathLabel: currentPathLabel,
         onRefresh: onRefresh,
+        pathHashByteWidth: pathHashByteWidth,
       ),
     );
   }
@@ -73,10 +77,12 @@ class _PathSelectionDialogState extends State<PathSelectionDialog> {
   }
 
   void _updateTextFromContacts() {
+    final width = widget.pathHashByteWidth.clamp(1, 8);
+    final hexCharsPerHop = width * 2;
     final pathParts = _selectedContacts
         .map((contact) {
-          if (contact.publicKeyHex.length >= 2) {
-            return contact.publicKeyHex.substring(0, 2);
+          if (contact.publicKeyHex.length >= hexCharsPerHop) {
+            return contact.publicKeyHex.substring(0, hexCharsPerHop);
           }
           return '';
         })
@@ -112,6 +118,9 @@ class _PathSelectionDialogState extends State<PathSelectionDialog> {
       return;
     }
 
+    final width = widget.pathHashByteWidth.clamp(1, 8);
+    final expectedHexLen = width * 2; // 2 hex chars per byte
+    
     // Parse comma-separated hex prefixes
     final pathIds = path
         .split(',')