Disallow editing location of nodes attached to ways/relations

lib/services/map_data_submodules/nodes_from_osm_api.dart

@@ -47,44 +47,7 @@ Future<List<OsmNode>> fetchOsmApiNodes({
     
     // Parse XML response
     final document = XmlDocument.parse(response.body);
-    final nodes = <OsmNode>[];
-    
-    // Find all node elements
-    for (final nodeElement in document.findAllElements('node')) {
-      final id = int.tryParse(nodeElement.getAttribute('id') ?? '');
-      final latStr = nodeElement.getAttribute('lat');
-      final lonStr = nodeElement.getAttribute('lon');
-      
-      if (id == null || latStr == null || lonStr == null) continue;
-      
-      final lat = double.tryParse(latStr);
-      final lon = double.tryParse(lonStr);
-      if (lat == null || lon == null) continue;
-      
-      // Parse tags
-      final tags = <String, String>{};
-      for (final tagElement in nodeElement.findElements('tag')) {
-        final key = tagElement.getAttribute('k');
-        final value = tagElement.getAttribute('v');
-        if (key != null && value != null) {
-          tags[key] = value;
-        }
-      }
-      
-      // Check if this node matches any of our profiles
-      if (_nodeMatchesProfiles(tags, profiles)) {
-        nodes.add(OsmNode(
-          id: id,
-          coord: LatLng(lat, lon),
-          tags: tags,
-        ));
-      }
-      
-      // Respect maxResults limit if set
-      if (maxResults > 0 && nodes.length >= maxResults) {
-        break;
-      }
-    }
+    final nodes = _parseOsmApiResponseWithConstraints(document, profiles, maxResults);
     
     if (nodes.isNotEmpty) {
       debugPrint('[fetchOsmApiNodes] Retrieved ${nodes.length} matching surveillance nodes');
@@ -107,6 +70,93 @@ Future<List<OsmNode>> fetchOsmApiNodes({
   }
 }
 
+/// Parse OSM API XML response to create OsmNode objects with constraint information.
+List<OsmNode> _parseOsmApiResponseWithConstraints(XmlDocument document, List<NodeProfile> profiles, int maxResults) {
+  final surveillanceNodes = <int, Map<String, dynamic>>{};  // nodeId -> node data
+  final constrainedNodeIds = <int>{};
+  
+  // First pass: collect surveillance nodes
+  for (final nodeElement in document.findAllElements('node')) {
+    final id = int.tryParse(nodeElement.getAttribute('id') ?? '');
+    final latStr = nodeElement.getAttribute('lat');
+    final lonStr = nodeElement.getAttribute('lon');
+    
+    if (id == null || latStr == null || lonStr == null) continue;
+    
+    final lat = double.tryParse(latStr);
+    final lon = double.tryParse(lonStr);
+    if (lat == null || lon == null) continue;
+    
+    // Parse tags
+    final tags = <String, String>{};
+    for (final tagElement in nodeElement.findElements('tag')) {
+      final key = tagElement.getAttribute('k');
+      final value = tagElement.getAttribute('v');
+      if (key != null && value != null) {
+        tags[key] = value;
+      }
+    }
+    
+    // Check if this node matches any of our profiles
+    if (_nodeMatchesProfiles(tags, profiles)) {
+      surveillanceNodes[id] = {
+        'id': id,
+        'lat': lat,
+        'lon': lon,
+        'tags': tags,
+      };
+    }
+  }
+  
+  // Second pass: identify constrained nodes from ways
+  for (final wayElement in document.findAllElements('way')) {
+    for (final ndElement in wayElement.findElements('nd')) {
+      final ref = int.tryParse(ndElement.getAttribute('ref') ?? '');
+      if (ref != null && surveillanceNodes.containsKey(ref)) {
+        constrainedNodeIds.add(ref);
+      }
+    }
+  }
+  
+  // Third pass: identify constrained nodes from relations
+  for (final relationElement in document.findAllElements('relation')) {
+    for (final memberElement in relationElement.findElements('member')) {
+      if (memberElement.getAttribute('type') == 'node') {
+        final ref = int.tryParse(memberElement.getAttribute('ref') ?? '');
+        if (ref != null && surveillanceNodes.containsKey(ref)) {
+          constrainedNodeIds.add(ref);
+        }
+      }
+    }
+  }
+  
+  // Create OsmNode objects with constraint information
+  final nodes = <OsmNode>[];
+  for (final nodeData in surveillanceNodes.values) {
+    final nodeId = nodeData['id'] as int;
+    final isConstrained = constrainedNodeIds.contains(nodeId);
+    
+    nodes.add(OsmNode(
+      id: nodeId,
+      coord: LatLng(nodeData['lat'], nodeData['lon']),
+      tags: nodeData['tags'] as Map<String, String>,
+      isConstrained: isConstrained,
+    ));
+    
+    // Respect maxResults limit if set
+    if (maxResults > 0 && nodes.length >= maxResults) {
+      break;
+    }
+  }
+  
+  final constrainedCount = nodes.where((n) => n.isConstrained).length;
+  if (constrainedCount > 0) {
+    debugPrint('[fetchOsmApiNodes] Found $constrainedCount constrained nodes out of ${nodes.length} total');
+  }
+  
+  return nodes;
+}
+
 /// Check if a node's tags match any of the given profiles
 bool _nodeMatchesProfiles(Map<String, String> nodeTags, List<NodeProfile> profiles) {
   for (final profile in profiles) {