Node fetch rework

lib/services/node_data_manager.dart

@@ -0,0 +1,236 @@
+import 'dart:async';
+import 'package:flutter/foundation.dart';
+import 'package:latlong2/latlong.dart';
+import 'package:flutter_map/flutter_map.dart';
+
+import '../models/node_profile.dart';
+import '../models/osm_node.dart';
+import '../app_state.dart';
+import 'overpass_service.dart';
+import 'node_spatial_cache.dart';
+import 'network_status.dart';
+import 'map_data_submodules/nodes_from_osm_api.dart';
+import 'map_data_submodules/nodes_from_local.dart';
+
+/// Coordinates node data fetching between cache, Overpass, and OSM API.
+/// Simple interface: give me nodes for this view with proper caching and error handling.
+class NodeDataManager extends ChangeNotifier {
+  static final NodeDataManager _instance = NodeDataManager._();
+  factory NodeDataManager() => _instance;
+  NodeDataManager._();
+
+  final OverpassService _overpassService = OverpassService();
+  final NodeSpatialCache _cache = NodeSpatialCache();
+  
+  /// Get nodes for the given bounds and profiles.
+  /// Returns cached data immediately if available, otherwise fetches from appropriate source.
+  Future<List<OsmNode>> getNodesFor({
+    required LatLngBounds bounds,
+    required List<NodeProfile> profiles,
+    UploadMode uploadMode = UploadMode.production,
+    bool isUserInitiated = false,
+  }) async {
+    if (profiles.isEmpty) return [];
+
+    // Handle offline mode
+    if (AppState.instance.offlineMode) {
+      if (uploadMode == UploadMode.sandbox) {
+        // Offline + Sandbox = no nodes (local cache is production data)
+        debugPrint('[NodeDataManager] Offline + Sandbox mode: returning no nodes');
+        return [];
+      } else {
+        // Offline + Production = use local cache only
+        return fetchLocalNodes(bounds: bounds, profiles: profiles);
+      }
+    }
+
+    // Handle sandbox mode (always fetch from OSM API, no caching)
+    if (uploadMode == UploadMode.sandbox) {
+      debugPrint('[NodeDataManager] Sandbox mode: fetching from OSM API');
+      return fetchOsmApiNodes(
+        bounds: bounds,
+        profiles: profiles,
+        uploadMode: uploadMode,
+        maxResults: 0,
+      );
+    }
+
+    // Production mode: check cache first
+    if (_cache.hasDataFor(bounds)) {
+      debugPrint('[NodeDataManager] Using cached data for bounds');
+      return _cache.getNodesFor(bounds);
+    }
+
+    // Not cached - need to fetch
+    if (isUserInitiated) {
+      NetworkStatus.instance.setWaiting();
+    }
+
+    try {
+      final nodes = await fetchWithSplitting(bounds, profiles);
+      
+      if (isUserInitiated) {
+        NetworkStatus.instance.setSuccess();
+      }
+      
+      notifyListeners();
+      return nodes;
+      
+    } catch (e) {
+      debugPrint('[NodeDataManager] Fetch failed: $e');
+      
+      if (isUserInitiated) {
+        if (e is RateLimitError) {
+          NetworkStatus.instance.reportOverpassIssue();
+        } else {
+          NetworkStatus.instance.setNetworkError();
+        }
+      }
+      
+      // Return whatever we have in cache for this area
+      return _cache.getNodesFor(bounds);
+    }
+  }
+
+  /// Fetch nodes with automatic area splitting if needed
+  Future<List<OsmNode>> fetchWithSplitting(
+    LatLngBounds bounds, 
+    List<NodeProfile> profiles, {
+    int splitDepth = 0,
+  }) async {
+    const maxSplitDepth = 3; // 4^3 = 64 max sub-areas
+    
+    try {
+      // Expand bounds slightly to reduce edge effects
+      final expandedBounds = _expandBounds(bounds, 1.2);
+      
+      final nodes = await _overpassService.fetchNodes(
+        bounds: expandedBounds,
+        profiles: profiles,
+      );
+      
+      // Success - cache the data for the expanded area
+      _cache.markAreaAsFetched(expandedBounds, nodes);
+      return nodes;
+      
+    } on NodeLimitError {
+      // Hit node limit or timeout - split area if not too deep
+      if (splitDepth >= maxSplitDepth) {
+        debugPrint('[NodeDataManager] Max split depth reached, giving up');
+        return [];
+      }
+      
+      debugPrint('[NodeDataManager] Splitting area (depth: $splitDepth)');
+      NetworkStatus.instance.reportSlowProgress();
+      
+      return _fetchSplitAreas(bounds, profiles, splitDepth + 1);
+      
+    } on RateLimitError {
+      // Rate limited - wait and return empty
+      debugPrint('[NodeDataManager] Rate limited, backing off');
+      await Future.delayed(const Duration(seconds: 30));
+      return [];
+    }
+  }
+
+  /// Fetch data by splitting area into quadrants
+  Future<List<OsmNode>> _fetchSplitAreas(
+    LatLngBounds bounds, 
+    List<NodeProfile> profiles,
+    int splitDepth,
+  ) async {
+    final quadrants = _splitBounds(bounds);
+    final allNodes = <OsmNode>[];
+    
+    for (final quadrant in quadrants) {
+      try {
+        final nodes = await fetchWithSplitting(quadrant, profiles, splitDepth: splitDepth);
+        allNodes.addAll(nodes);
+      } catch (e) {
+        debugPrint('[NodeDataManager] Quadrant fetch failed: $e');
+        // Continue with other quadrants
+      }
+    }
+    
+    debugPrint('[NodeDataManager] Split fetch complete: ${allNodes.length} total nodes');
+    return allNodes;
+  }
+
+  /// Split bounds into 4 quadrants
+  List<LatLngBounds> _splitBounds(LatLngBounds bounds) {
+    final centerLat = (bounds.north + bounds.south) / 2;
+    final centerLng = (bounds.east + bounds.west) / 2;
+    
+    return [
+      // Southwest
+      LatLngBounds(LatLng(bounds.south, bounds.west), LatLng(centerLat, centerLng)),
+      // Southeast  
+      LatLngBounds(LatLng(bounds.south, centerLng), LatLng(centerLat, bounds.east)),
+      // Northwest
+      LatLngBounds(LatLng(centerLat, bounds.west), LatLng(bounds.north, centerLng)),
+      // Northeast
+      LatLngBounds(LatLng(centerLat, centerLng), LatLng(bounds.north, bounds.east)),
+    ];
+  }
+
+  /// Expand bounds by given factor around center point
+  LatLngBounds _expandBounds(LatLngBounds bounds, double factor) {
+    final centerLat = (bounds.north + bounds.south) / 2;
+    final centerLng = (bounds.east + bounds.west) / 2;
+    
+    final latSpan = (bounds.north - bounds.south) * factor / 2;
+    final lngSpan = (bounds.east - bounds.west) * factor / 2;
+    
+    return LatLngBounds(
+      LatLng(centerLat - latSpan, centerLng - lngSpan),
+      LatLng(centerLat + latSpan, centerLng + lngSpan),
+    );
+  }
+
+  /// Add or update nodes in cache (for upload queue integration)
+  void addOrUpdateNodes(List<OsmNode> nodes) {
+    _cache.addOrUpdateNodes(nodes);
+    notifyListeners();
+  }
+
+  /// Remove node from cache (for deletions)
+  void removeNodeById(int nodeId) {
+    _cache.removeNodeById(nodeId);
+    notifyListeners();
+  }
+
+  /// Clear cache (when profiles change significantly)
+  void clearCache() {
+    _cache.clear();
+    notifyListeners();
+  }
+
+  /// Force refresh for current view (manual retry)
+  Future<void> refreshArea({
+    required LatLngBounds bounds,
+    required List<NodeProfile> profiles,
+    UploadMode uploadMode = UploadMode.production,
+  }) async {
+    // Clear any cached data for this area
+    _cache.clear(); // Simple: clear everything for now
+    
+    // Re-fetch
+    await getNodesFor(
+      bounds: bounds,
+      profiles: profiles,
+      uploadMode: uploadMode,
+      isUserInitiated: true,
+    );
+  }
+
+  /// NodeCache compatibility methods
+  OsmNode? getNodeById(int nodeId) => _cache.getNodeById(nodeId);
+  void removePendingEditMarker(int nodeId) => _cache.removePendingEditMarker(nodeId);
+  void removePendingDeletionMarker(int nodeId) => _cache.removePendingDeletionMarker(nodeId);
+  void removeTempNodeById(int tempNodeId) => _cache.removeTempNodeById(tempNodeId);
+  List<OsmNode> findNodesWithinDistance(LatLng coord, double distanceMeters, {int? excludeNodeId}) =>
+      _cache.findNodesWithinDistance(coord, distanceMeters, excludeNodeId: excludeNodeId);
+
+  /// Get cache statistics
+  String get cacheStats => _cache.stats.toString();
+}