add changeset comment tracking and message notification bubble on startup

lib/state/messages_state.dart

@@ -1,22 +1,28 @@
 import 'package:flutter/material.dart';
 import '../services/osm_messages_service.dart';
+import '../services/changeset_comments_service.dart';
 import 'settings_state.dart';
 
-/// State management for OSM message notifications
+/// State management for OSM message and changeset comment notifications
 class MessagesState extends ChangeNotifier {
   final OSMMessagesService _messagesService = OSMMessagesService();
+  final ChangesetCommentsService _changesetCommentsService = ChangesetCommentsService();
   
   int? _unreadCount;
+  int? _unreadChangesetId; // ID of a changeset with unread comments, if any
   bool _isChecking = false;
   
   // Getters
   int? get unreadCount => _unreadCount;
   bool get hasUnreadMessages => (_unreadCount ?? 0) > 0;
+  bool get hasUnreadChangesetComments => _unreadChangesetId != null;
+  bool get hasUnreadNotifications => hasUnreadMessages || hasUnreadChangesetComments;
   bool get isChecking => _isChecking;
   
-  /// Check for unread messages
+  /// Check for unread messages and changeset comments
   Future<void> checkMessages({
     required String? accessToken,
+    required String? username,
     required UploadMode uploadMode,
     bool forceRefresh = false,
   }) async {
@@ -26,18 +32,29 @@ class MessagesState extends ChangeNotifier {
     notifyListeners();
     
     try {
-      final count = await _messagesService.getUnreadMessageCount(
-        accessToken: accessToken,
-        uploadMode: uploadMode,
-        forceRefresh: forceRefresh,
-      );
+      final results = await Future.wait([
+        _messagesService.getUnreadMessageCount(
+          accessToken: accessToken,
+          uploadMode: uploadMode,
+          forceRefresh: forceRefresh,
+        ),
+        _changesetCommentsService.getUnreadChangesetId(
+          username: username,
+          uploadMode: uploadMode,
+          forceRefresh: forceRefresh,
+        ),
+      ]);
       
-      if (_unreadCount != count) {
+      final count = results[0] as int?;
+      final unreadChangesetId = results[1] as int?;
+      
+      if (_unreadCount != count || _unreadChangesetId != unreadChangesetId) {
         _unreadCount = count;
+        _unreadChangesetId = unreadChangesetId;
         notifyListeners();
       }
     } catch (e) {
-      // Silently handle errors - messages are not critical
+      // Silently handle errors - notifications are not critical
       debugPrint('MessagesState: Error checking messages: $e');
     } finally {
       _isChecking = false;
@@ -45,6 +62,26 @@ class MessagesState extends ChangeNotifier {
     }
   }
   
+  /// URL of the changeset with unread comments, on OSM's website, or null
+  /// if there are no unread changeset comments.
+  String? getUnreadChangesetUrl(UploadMode uploadMode) {
+    final id = _unreadChangesetId;
+    if (id == null) return null;
+    return _changesetCommentsService.getChangesetUrl(id, uploadMode);
+  }
+  
+  /// Mark changeset comments as read (called when user views the changeset on OSM)
+  Future<void> markChangesetCommentsRead({
+    required String? username,
+    required UploadMode uploadMode,
+  }) async {
+    await _changesetCommentsService.markRead(username: username, uploadMode: uploadMode);
+    if (_unreadChangesetId != null) {
+      _unreadChangesetId = null;
+      notifyListeners();
+    }
+  }
+  
   /// Get the URL to view messages
   String getMessagesUrl(UploadMode uploadMode) {
     return _messagesService.getMessagesUrl(uploadMode);
@@ -53,7 +90,9 @@ class MessagesState extends ChangeNotifier {
   /// Clear message state (when user logs out or changes mode)
   void clearMessages() {
     _unreadCount = null;
+    _unreadChangesetId = null;
     _messagesService.clearCache();
+    _changesetCommentsService.clearCache();
     notifyListeners();
   }
-}
+}