dialog replace or merge imported bookmarks

app/lib/features/geckoview/features/bookmarks/presentation/dialogs/import_bookmarks_dialog.dart

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2024-2025 Fabian Freund.
+ *
+ * This file is part of WebLibre
+ * (see https://weblibre.eu).
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+import 'package:flutter/material.dart';
+
+Future<bool?> showImportBookmarksDialog(BuildContext context) {
+  return showDialog<bool?>(
+    context: context,
+    builder: (BuildContext context) {
+      return AlertDialog(
+        title: const Text('Import Bookmarks'),
+        content: const Text(
+          'Do you want to erase all existing bookmarks before importing?\n\n'
+          'Choose "Replace" to delete existing bookmarks, or "Merge" to keep them.',
+        ),
+        actions: <Widget>[
+          TextButton(
+            onPressed: () {
+              Navigator.pop(context, false);
+            },
+            child: const Text('Merge'),
+          ),
+          TextButton(
+            onPressed: () {
+              Navigator.pop(context, true);
+            },
+            child: const Text('Replace'),
+          ),
+        ],
+      );
+    },
+  );
+}

app/lib/features/geckoview/features/bookmarks/presentation/screens/bookmark_list.dart

@@ -33,6 +33,7 @@ import 'package:weblibre/core/routing/routes.dart';
 import 'package:weblibre/features/geckoview/features/bookmarks/domain/entities/bookmark_item.dart';
 import 'package:weblibre/features/geckoview/features/bookmarks/domain/providers/bookmarks.dart';
 import 'package:weblibre/features/geckoview/features/bookmarks/domain/repositories/bookmarks.dart';
+import 'package:weblibre/features/geckoview/features/bookmarks/presentation/dialogs/import_bookmarks_dialog.dart';
 import 'package:weblibre/presentation/hooks/listenable_callback.dart';
 import 'package:weblibre/presentation/hooks/menu_controller.dart';
 import 'package:weblibre/presentation/widgets/failure_widget.dart';
@@ -359,12 +360,18 @@ class BookmarkListScreen extends HookConsumerWidget {
         return;
       }
 
+      if (!context.mounted) return;
+
+      // Ask user if they want to erase existing bookmarks
+      final shouldReplace = await showImportBookmarksDialog(context);
+      if (shouldReplace == null) return; // User cancelled dialog
+
       final content = await File(file.path!).readAsString();
       final repository = ref.read(bookmarksRepositoryProvider.notifier);
 
       final count = format == 'json'
-          ? await repository.importFromJSON(content)
-          : await repository.importFromHTML(content);
+          ? await repository.importFromJSON(content, replace: shouldReplace)
+          : await repository.importFromHTML(content, replace: shouldReplace);
 
       if (context.mounted) {
         showInfoMessage(context, 'Imported $count bookmarks successfully');

app/lib/features/geckoview/features/bookmarks/utils/bookmark_html_utils.dart

@@ -387,7 +387,12 @@ class _BookmarkImporter {
 
   Future<int> _importBookmarks() async {
     if (_isImportDefaults) {
-      await _service.eraseEverything(BookmarkRoot.root);
+      // Delete bookmarks from each root folder (except root itself to avoid errors)
+      for (final root in BookmarkRoot.values) {
+        if (root != BookmarkRoot.root) {
+          await _service.eraseEverything(root);
+        }
+      }
     }
 
     final bookmarkTrees = _getBookmarkTrees();

app/lib/features/geckoview/features/bookmarks/utils/bookmark_json_utils.dart

@@ -64,7 +64,12 @@ class BookmarkJSONUtils {
 
     // If replacing, erase existing bookmarks first
     if (replace) {
-      await _service.eraseEverything(BookmarkRoot.root);
+      // Delete bookmarks from each root folder (except root itself to avoid errors)
+      for (final root in BookmarkRoot.values) {
+        if (root != BookmarkRoot.root) {
+          await _service.eraseEverything(root);
+        }
+      }
     }
 
     final folderIdToGuidMap = <String, String>{};