chat search now lists local and server-side hits like the file search, and jumping to old messages pages in history with a progress banner and keeps the hit marked

lib/api/marianumcloud/search/search_chat_messages.dart

@@ -0,0 +1,37 @@
+import 'dart:io';
+
+import 'package:http/http.dart' as http;
+
+import '../nextcloud_ocs.dart';
+import 'search_chat_messages_response.dart';
+
+/// Wraps Talk's `talk-message-current` search provider, which searches the
+/// whole server-side history of one conversation. The conversation is picked
+/// via `from`, the route the provider would be opened from in the web UI.
+class SearchChatMessages {
+  Future<SearchChatMessagesResponse> run({
+    required String chatToken,
+    required String term,
+    int limit = 25,
+    Object? cursor,
+  }) async {
+    final endpoint = NextcloudOcs.uri(
+      'search/providers/talk-message-current/search',
+      queryParameters: {
+        'term': term,
+        'from': '/call/$chatToken',
+        'limit': limit.toString(),
+        if (cursor != null) 'cursor': cursor.toString(),
+      },
+    );
+    final response = await http.get(endpoint, headers: NextcloudOcs.headers());
+    if (response.statusCode != HttpStatus.ok) {
+      throw Exception(
+        'Chat search failed with ${response.statusCode}: ${response.body}',
+      );
+    }
+    final data =
+        NextcloudOcs.decode(response.body)['data'] as Map<String, dynamic>;
+    return SearchChatMessagesResponse.fromJson(data, term: term);
+  }
+}