simple working json import and export

lib/service/storage.dart

@@ -4,6 +4,7 @@ import 'package:shared_preferences/shared_preferences.dart';
 
 import '../model/bookmark.dart';
 import '../model/collection.dart';
+import 'json_file_service.dart';
 
 class Storage {
   static const String _bookmarksKey = 'bookmarks';
@@ -163,4 +164,20 @@ class Storage {
     }
     return _prefsWithCache!;
   }
+
+  static Future<bool> exportToJsonFile() => JsonFileService.exportToJson(
+    collections: loadCollections(),
+    bookmarks: loadBookmarks(),
+  );
+
+  static Future<bool> importFromJsonFile() async {
+    final import = await JsonFileService.importFromJson();
+
+    if (import.bookmarks.isNotEmpty || import.collections.isNotEmpty) {
+      saveBookmarks(import.bookmarks);
+      saveCollections(import.collections);
+      return true;
+    }
+    return false;
+  }
 }