implemented in-chat search with text highlighting, added search navigation UI, and integrated scrollable list for message jumping

lib/view/pages/talk/chat_view.dart

@@ -1,5 +1,8 @@
+import 'dart:math' as math;
+
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:scrollable_positioned_list/scrollable_positioned_list.dart';
 
 import '../../../api/marianumcloud/talk/chat/get_chat_response.dart';
 import '../../../api/marianumcloud/talk/room/get_room_response.dart';
@@ -10,9 +13,11 @@ import '../../../state/app/modules/chat/bloc/chat_state.dart';
 import '../../../theming/app_theme.dart';
 import '../../../widget/clickable_app_bar.dart';
 import '../../../widget/user_avatar.dart';
+import 'data/chat_search_controller.dart';
 import 'details/chat_info.dart';
 import 'talk_navigator.dart';
 import 'widgets/chat_bubble.dart';
+import 'widgets/chat_search_app_bar.dart';
 import 'widgets/chat_textfield.dart';
 
 class ChatView extends StatefulWidget {
@@ -32,14 +37,139 @@ class ChatView extends StatefulWidget {
 }
 
 class _ChatViewState extends State<ChatView> {
-  final ScrollController _listController = ScrollController();
+  final ItemScrollController _itemScrollController = ItemScrollController();
+  final TextEditingController _searchTextController = TextEditingController();
+  final Map<int, int> _matchIndices = {};
+
+  bool _searchActive = false;
+  String _searchQuery = '';
+  List<ChatSearchMatch> _matches = const [];
+  int _activeMatchIndex = 0;
+  GetChatResponse? _matchesComputedFor;
+  String? _matchesComputedQuery;
+
+  @override
+  void dispose() {
+    _searchTextController.dispose();
+    super.dispose();
+  }
+
+  @override
+  void didUpdateWidget(covariant ChatView oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (widget.room.token != oldWidget.room.token && _searchActive) {
+      _exitSearchMode();
+    }
+  }
 
   void _refresh() {
     context.read<ChatBloc>().setToken(widget.room.token);
   }
 
+  void _enterSearchMode() {
+    setState(() {
+      _searchActive = true;
+      _searchQuery = '';
+      _matches = const [];
+      _activeMatchIndex = 0;
+      _matchesComputedFor = null;
+      _matchesComputedQuery = null;
+      _searchTextController.clear();
+    });
+  }
+
+  void _exitSearchMode() {
+    setState(() {
+      _searchActive = false;
+      _searchQuery = '';
+      _matches = const [];
+      _activeMatchIndex = 0;
+      _matchIndices.clear();
+      _matchesComputedFor = null;
+      _matchesComputedQuery = null;
+      _searchTextController.clear();
+    });
+  }
+
+  void _onSearchChanged(String q) {
+    final chatResponse = context.read<ChatBloc>().state.data?.chatResponse;
+    setState(() {
+      _searchQuery = q;
+      _activeMatchIndex = 0;
+      if (chatResponse != null) {
+        _recomputeMatches(chatResponse);
+      } else {
+        _matches = const [];
+        _matchesComputedFor = null;
+        _matchesComputedQuery = null;
+      }
+    });
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      if (mounted && _matches.isNotEmpty) _scrollToActiveMatch();
+    });
+  }
+
+  void _recomputeMatches(GetChatResponse response) {
+    _matches = ChatSearchController.findMatches(response, _searchQuery);
+    _activeMatchIndex = _activeMatchIndex.clamp(
+      0,
+      math.max(0, _matches.length - 1),
+    );
+    _matchesComputedFor = response;
+    _matchesComputedQuery = _searchQuery;
+  }
+
+  void _goToPreviousMatch() {
+    if (_matches.isEmpty) return;
+    setState(() {
+      _activeMatchIndex = (_activeMatchIndex + 1) % _matches.length;
+    });
+    WidgetsBinding.instance.addPostFrameCallback(
+      (_) => _scrollToActiveMatch(),
+    );
+  }
+
+  void _goToNextMatch() {
+    if (_matches.isEmpty) return;
+    setState(() {
+      _activeMatchIndex =
+          (_activeMatchIndex - 1 + _matches.length) % _matches.length;
+    });
+    WidgetsBinding.instance.addPostFrameCallback(
+      (_) => _scrollToActiveMatch(),
+    );
+  }
+
+  void _scrollToActiveMatch() {
+    if (_matches.isEmpty) return;
+    if (!_itemScrollController.isAttached) return;
+    final id = _matches[_activeMatchIndex].messageId;
+    final idx = _matchIndices[id];
+    if (idx == null) return;
+    _itemScrollController.scrollTo(
+      index: idx,
+      alignment: 0.4,
+      duration: const Duration(milliseconds: 350),
+      curve: Curves.easeInOut,
+    );
+  }
+
   List<Widget> _buildMessages(GetChatResponse response) {
+    if (_searchActive &&
+        (response != _matchesComputedFor ||
+            _searchQuery != _matchesComputedQuery)) {
+      _recomputeMatches(response);
+    }
+
+    final matchIds = _matches.map((m) => m.messageId).toSet();
+    final activeId = _matches.isNotEmpty
+        ? _matches[_activeMatchIndex].messageId
+        : null;
+    final highlightQuery =
+        _searchActive && _searchQuery.trim().isNotEmpty ? _searchQuery : null;
+
     final messages = <Widget>[];
+    final chronologicalMatchIndex = <int, int>{};
     var lastDate = DateTime.now();
     for (final element in response.sortByTimestamp()) {
       final elementDate = DateTime.fromMillisecondsSinceEpoch(
@@ -65,6 +195,15 @@ class _ChatViewState extends State<ChatView> {
         );
       }
 
+      final isMatch = matchIds.contains(element.id);
+      final highlight = isMatch
+          ? (element.id == activeId
+              ? SearchHighlight.active
+              : SearchHighlight.secondary)
+          : SearchHighlight.none;
+
+      if (isMatch) chronologicalMatchIndex[element.id] = messages.length;
+
       messages.add(
         ChatBubble(
           context: context,
@@ -76,6 +215,8 @@ class _ChatViewState extends State<ChatView> {
           refetch: ({bool renew = false}) => _refresh(),
           isRead: element.id <= commonRead,
           selfId: widget.selfId,
+          highlightQuery: highlightQuery,
+          matchHighlight: highlight,
         ),
       );
     }
@@ -94,16 +235,37 @@ class _ChatViewState extends State<ChatView> {
           refetch: ({bool renew = false}) => _refresh(),
         ),
       );
+      chronologicalMatchIndex.updateAll((_, v) => v + 1);
     }
 
+    final total = messages.length;
+    _matchIndices
+      ..clear()
+      ..addEntries(
+        chronologicalMatchIndex.entries.map(
+          (e) => MapEntry(e.key, (total - 1) - e.value),
+        ),
+      );
+
     return messages;
   }
 
   @override
   Widget build(BuildContext context) => Scaffold(
     backgroundColor: const Color(0xffefeae2),
-    appBar: ClickableAppBar(
+    appBar: _searchActive
-      onTap: () => TalkNavigator.pushSplitView(context, ChatInfo(widget.room)),
+        ? ChatSearchAppBar(
+            controller: _searchTextController,
+            matchCount: _matches.length,
+            activeIndex: _matches.isEmpty ? -1 : _activeMatchIndex,
+            onChanged: _onSearchChanged,
+            onClose: _exitSearchMode,
+            onPrevious: _matches.isEmpty ? null : _goToPreviousMatch,
+            onNext: _matches.isEmpty ? null : _goToNextMatch,
+          )
+        : ClickableAppBar(
+            onTap: () =>
+                TalkNavigator.pushSplitView(context, ChatInfo(widget.room)),
             appBar: AppBar(
               title: Row(
                 children: [
@@ -118,6 +280,13 @@ class _ChatViewState extends State<ChatView> {
                   ),
                 ],
               ),
+              actions: [
+                IconButton(
+                  icon: const Icon(Icons.search),
+                  tooltip: 'In Chat suchen',
+                  onPressed: _enterSearchMode,
+                ),
+              ],
             ),
           ),
     body: DecoratedBox(
@@ -137,11 +306,16 @@ class _ChatViewState extends State<ChatView> {
               isReady: (state) =>
                   state.chatResponse != null &&
                   state.currentToken == widget.room.token,
-              child: (state, _) => ListView(
+              child: (state, _) {
+                final items =
+                    _buildMessages(state.chatResponse!).reversed.toList();
+                return ScrollablePositionedList.builder(
                   reverse: true,
-                controller: _listController,
+                  itemScrollController: _itemScrollController,
-                children: _buildMessages(state.chatResponse!).reversed.toList(),
+                  itemCount: items.length,
-              ),
+                  itemBuilder: (ctx, idx) => items[idx],
+                );
+              },
             ),
           ),
           ColoredBox(

lib/view/pages/talk/data/chat_message.dart

@@ -1,12 +1,12 @@
 import 'package:cached_network_image/cached_network_image.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_linkify/flutter_linkify.dart';
 
 import '../../../../api/marianumcloud/talk/chat/get_chat_response.dart';
 import '../../../../api/marianumcloud/talk/chat/rich_object_string_processor.dart';
 import '../../../../model/account_data.dart';
 import '../../../../model/endpoint_data.dart';
 import '../../../../utils/url_opener.dart';
+import '../widgets/highlighted_linkify.dart';
 
 class ChatMessage {
   String originalMessage;
@@ -27,8 +27,13 @@ class ChatMessage {
     );
   }
 
-  Widget getWidget() {
+  Widget getWidget({String? highlightQuery, TextStyle? style}) {
-    var contentWidget = Linkify(text: content, onOpen: UrlOpener.onOpen);
+    var contentWidget = HighlightedLinkify(
+      text: content,
+      onOpen: UrlOpener.onOpen,
+      highlight: highlightQuery,
+      style: style,
+    );
 
     if (originalData?['object']?.type == RichObjectStringObjectType.talkPoll) {
       return ListTile(

lib/view/pages/talk/data/chat_search_controller.dart

@@ -0,0 +1,49 @@
+import '../../../../api/marianumcloud/talk/chat/get_chat_response.dart';
+import '../../../../api/marianumcloud/talk/chat/rich_object_string_processor.dart';
+import '../../../../api/marianumcloud/talk/room/get_room_response.dart';
+
+class ChatSearchMatch {
+  final int messageId;
+  final int timestamp;
+
+  const ChatSearchMatch({required this.messageId, required this.timestamp});
+}
+
+class ChatSearchController {
+  static List<ChatSearchMatch> findMatches(
+    GetChatResponse response,
+    String query,
+  ) {
+    final q = query.trim().toLowerCase();
+    if (q.isEmpty) return const [];
+
+    final matches = <ChatSearchMatch>[];
+    for (final element in response.sortByTimestamp()) {
+      if (element.systemMessage.contains('reaction')) continue;
+      if (element.systemMessage.contains('poll_voted')) continue;
+
+      final haystackText = RichObjectStringProcessor.parseToString(
+        element.message,
+        element.messageParameters,
+      ).toLowerCase();
+
+      var matched = haystackText.contains(q);
+      if (!matched &&
+          element.messageType != GetRoomResponseObjectMessageType.system) {
+        matched = element.actorDisplayName.toLowerCase().contains(q);
+      }
+
+      if (matched) {
+        matches.add(
+          ChatSearchMatch(
+            messageId: element.id,
+            timestamp: element.timestamp,
+          ),
+        );
+      }
+    }
+
+    matches.sort((a, b) => b.timestamp.compareTo(a.timestamp));
+    return matches;
+  }
+}

lib/view/pages/talk/widgets/bubble.dart

@@ -27,6 +27,7 @@ class BubbleStyle {
   const BubbleStyle({
     this.color,
     this.borderWidth = 0,
+    this.borderColor,
     this.elevation = 0,
     this.margin = const BubbleEdges.only(),
     this.padding = const BubbleEdges.all(8),
@@ -37,12 +38,25 @@ class BubbleStyle {
 
   final Color? color;
   final double borderWidth;
+  final Color? borderColor;
   final double elevation;
   final BubbleEdges margin;
   final BubbleEdges padding;
   final Alignment alignment;
   final BubbleNip nip;
   final double borderRadius;
+
+  BubbleStyle copyWith({double? borderWidth, Color? borderColor}) => BubbleStyle(
+    color: color,
+    borderWidth: borderWidth ?? this.borderWidth,
+    borderColor: borderColor ?? this.borderColor,
+    elevation: elevation,
+    margin: margin,
+    padding: padding,
+    alignment: alignment,
+    nip: nip,
+    borderRadius: borderRadius,
+  );
 }
 
 /// The "nip" is faked by flattening one corner so the bubble anchors to
@@ -88,7 +102,7 @@ class Bubble extends StatelessWidget {
           borderRadius: radius,
           border: style.borderWidth > 0
               ? Border.all(
-                  color: Theme.of(context).dividerColor,
+                  color: style.borderColor ?? Theme.of(context).dividerColor,
                   width: style.borderWidth,
                 )
               : null,

lib/view/pages/talk/widgets/chat_bubble.dart

@@ -18,6 +18,9 @@ import 'bubble.dart';
 import 'chat_bubble_poll.dart';
 import 'chat_bubble_reactions.dart';
 import 'chat_message_options_dialog.dart';
+import 'highlighted_linkify.dart';
+
+enum SearchHighlight { none, secondary, active }
 
 class ChatBubble extends StatefulWidget {
   final BuildContext context;
@@ -33,6 +36,9 @@ class ChatBubble extends StatefulWidget {
 
   final void Function({bool renew}) refetch;
 
+  final String? highlightQuery;
+  final SearchHighlight matchHighlight;
+
   const ChatBubble({
     required this.context,
     required this.isSender,
@@ -41,6 +47,8 @@ class ChatBubble extends StatefulWidget {
     required this.refetch,
     this.isRead = false,
     this.selfId,
+    this.highlightQuery,
+    this.matchHighlight = SearchHighlight.none,
     super.key,
   });
 
@@ -142,14 +150,30 @@ class _ChatBubbleState extends State<ChatBubble>
 
   BubbleStyle _getStyle() {
     final styles = ChatBubbleStyles(context);
+    final BubbleStyle base;
     if (widget.bubbleData.messageType !=
         GetRoomResponseObjectMessageType.comment) {
-      return styles.getSystemStyle();
+      base = styles.getSystemStyle();
-    }
+    } else {
-    return widget.isSender
+      base = widget.isSender
           ? styles.getSelfStyle(false)
           : styles.getRemoteStyle(false);
     }
+    switch (widget.matchHighlight) {
+      case SearchHighlight.none:
+        return base;
+      case SearchHighlight.secondary:
+        return base.copyWith(
+          borderWidth: 1.5,
+          borderColor: Theme.of(context).colorScheme.primary.withValues(alpha: 0.45),
+        );
+      case SearchHighlight.active:
+        return base.copyWith(
+          borderWidth: 3,
+          borderColor: Theme.of(context).colorScheme.primary,
+        );
+    }
+  }
 
   void _showOptionsDialog() => showChatMessageOptionsDialog(
     context,
@@ -196,15 +220,29 @@ class _ChatBubbleState extends State<ChatBubble>
             GetRoomResponseObjectMessageType.deletedComment;
 
     final parent = widget.bubbleData.parent;
+    final actorBaseStyle = TextStyle(
+      color: Theme.of(context).primaryColor,
+      fontWeight: FontWeight.bold,
+    );
     final actorText = Text(
       widget.bubbleData.actorDisplayName,
       textAlign: TextAlign.start,
       overflow: TextOverflow.ellipsis,
-      style: TextStyle(
+      style: actorBaseStyle,
-        color: Theme.of(context).primaryColor,
-        fontWeight: FontWeight.bold,
-      ),
     );
+    final actorWidget = (widget.highlightQuery?.trim().isNotEmpty ?? false)
+        ? Text.rich(
+            TextSpan(
+              children: buildHighlightedSpans(
+                text: widget.bubbleData.actorDisplayName,
+                query: widget.highlightQuery,
+                baseStyle: actorBaseStyle,
+              ),
+            ),
+            textAlign: TextAlign.start,
+            overflow: TextOverflow.ellipsis,
+          )
+        : actorText;
 
     final timeText = Text(
       DateTime.fromMillisecondsSinceEpoch(
@@ -252,8 +290,16 @@ class _ChatBubbleState extends State<ChatBubble>
               style: _getStyle(),
               child: _BubbleContent(
                 actorText: actorText,
+                actorWidget: actorWidget,
                 timeText: timeText,
-                messageWidget: message.getWidget(),
+                messageWidget: message.getWidget(
+                  highlightQuery: widget.highlightQuery,
+                  style:
+                      widget.bubbleData.messageType ==
+                          GetRoomResponseObjectMessageType.system
+                      ? Theme.of(context).textTheme.bodySmall
+                      : null,
+                ),
                 parent: parent,
                 bubbleData: widget.bubbleData,
                 isSender: widget.isSender,
@@ -282,6 +328,7 @@ class _ChatBubbleState extends State<ChatBubble>
 
 class _BubbleContent extends StatelessWidget {
   final Text actorText;
+  final Widget actorWidget;
   final Text timeText;
   final Widget messageWidget;
   final GetChatResponseObject? parent;
@@ -298,6 +345,7 @@ class _BubbleContent extends StatelessWidget {
 
   const _BubbleContent({
     required this.actorText,
+    required this.actorWidget,
     required this.timeText,
     required this.messageWidget,
     required this.parent,
@@ -323,7 +371,7 @@ class _BubbleContent extends StatelessWidget {
     ),
     child: Stack(
       children: [
-        if (showActorDisplayName) Positioned(top: 0, left: 0, child: actorText),
+        if (showActorDisplayName) Positioned(top: 0, left: 0, child: actorWidget),
         Padding(
           padding: EdgeInsets.only(
             bottom: showBubbleTime ? 18 : 0,

lib/view/pages/talk/widgets/chat_search_app_bar.dart

@@ -0,0 +1,67 @@
+import 'package:flutter/material.dart';
+
+class ChatSearchAppBar extends StatelessWidget implements PreferredSizeWidget {
+  final TextEditingController controller;
+  final int matchCount;
+  final int activeIndex;
+  final ValueChanged<String> onChanged;
+  final VoidCallback onClose;
+  final VoidCallback? onPrevious;
+  final VoidCallback? onNext;
+
+  const ChatSearchAppBar({
+    required this.controller,
+    required this.matchCount,
+    required this.activeIndex,
+    required this.onChanged,
+    required this.onClose,
+    required this.onPrevious,
+    required this.onNext,
+    super.key,
+  });
+
+  @override
+  Size get preferredSize => const Size.fromHeight(kToolbarHeight);
+
+  @override
+  Widget build(BuildContext context) {
+    final counterText = matchCount == 0
+        ? '0/0'
+        : '${activeIndex + 1}/$matchCount';
+    return AppBar(
+      leading: IconButton(
+        icon: const Icon(Icons.arrow_back),
+        onPressed: onClose,
+      ),
+      title: TextField(
+        controller: controller,
+        autofocus: true,
+        textInputAction: TextInputAction.search,
+        decoration: const InputDecoration(
+          hintText: 'In Chat suchen…',
+          border: InputBorder.none,
+        ),
+        onChanged: onChanged,
+      ),
+      actions: [
+        Center(
+          child: Padding(
+            padding: const EdgeInsets.symmetric(horizontal: 4),
+            child: Text(
+              counterText,
+              style: const TextStyle(fontSize: 12),
+            ),
+          ),
+        ),
+        IconButton(
+          icon: const Icon(Icons.keyboard_arrow_up),
+          onPressed: onPrevious,
+        ),
+        IconButton(
+          icon: const Icon(Icons.keyboard_arrow_down),
+          onPressed: onNext,
+        ),
+      ],
+    );
+  }
+}

lib/view/pages/talk/widgets/highlighted_linkify.dart

@@ -0,0 +1,140 @@
+import 'package:flutter/gestures.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_linkify/flutter_linkify.dart';
+import 'package:linkify/linkify.dart' as linkify_pkg;
+
+const TextStyle kSearchHighlightStyle = TextStyle(
+  backgroundColor: Color(0xFFFFD54F),
+  color: Colors.black,
+);
+
+List<TextSpan> buildHighlightedSpans({
+  required String text,
+  required String? query,
+  required TextStyle baseStyle,
+  TextStyle highlightStyle = kSearchHighlightStyle,
+  GestureRecognizer? recognizer,
+}) {
+  final q = query?.trim().toLowerCase();
+  if (q == null || q.isEmpty) {
+    return [TextSpan(text: text, style: baseStyle, recognizer: recognizer)];
+  }
+
+  final spans = <TextSpan>[];
+  final lower = text.toLowerCase();
+  var cursor = 0;
+  while (cursor < text.length) {
+    final hit = lower.indexOf(q, cursor);
+    if (hit < 0) {
+      spans.add(
+        TextSpan(
+          text: text.substring(cursor),
+          style: baseStyle,
+          recognizer: recognizer,
+        ),
+      );
+      break;
+    }
+    if (hit > cursor) {
+      spans.add(
+        TextSpan(
+          text: text.substring(cursor, hit),
+          style: baseStyle,
+          recognizer: recognizer,
+        ),
+      );
+    }
+    final end = hit + q.length;
+    spans.add(
+      TextSpan(
+        text: text.substring(hit, end),
+        style: baseStyle.merge(highlightStyle),
+        recognizer: recognizer,
+      ),
+    );
+    cursor = end;
+  }
+  return spans;
+}
+
+class HighlightedLinkify extends StatefulWidget {
+  final String text;
+  final String? highlight;
+  final LinkCallback? onOpen;
+  final TextStyle? style;
+  final TextStyle? linkStyle;
+
+  const HighlightedLinkify({
+    required this.text,
+    this.highlight,
+    this.onOpen,
+    this.style,
+    this.linkStyle,
+    super.key,
+  });
+
+  @override
+  State<HighlightedLinkify> createState() => _HighlightedLinkifyState();
+}
+
+class _HighlightedLinkifyState extends State<HighlightedLinkify> {
+  final List<TapGestureRecognizer> _recognizers = [];
+
+  @override
+  void dispose() {
+    for (final r in _recognizers) {
+      r.dispose();
+    }
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    for (final r in _recognizers) {
+      r.dispose();
+    }
+    _recognizers.clear();
+
+    final defaultStyle = widget.style ??
+        Theme.of(context).textTheme.bodyMedium ??
+        DefaultTextStyle.of(context).style;
+    final linkStyle = (widget.linkStyle ??
+            const TextStyle(color: Colors.blue, decoration: TextDecoration.underline))
+        .merge(defaultStyle.copyWith(color: null, decoration: null));
+    const linkHighlight = TextStyle(
+      backgroundColor: Color(0xFFFFD54F),
+      color: Colors.black,
+      decoration: TextDecoration.underline,
+    );
+
+    final elements = linkify_pkg.linkify(widget.text);
+    final spans = <InlineSpan>[];
+
+    for (final el in elements) {
+      if (el is LinkableElement) {
+        final recognizer = TapGestureRecognizer()
+          ..onTap = () => widget.onOpen?.call(el);
+        _recognizers.add(recognizer);
+        spans.addAll(
+          buildHighlightedSpans(
+            text: el.text,
+            query: widget.highlight,
+            baseStyle: linkStyle,
+            highlightStyle: linkHighlight,
+            recognizer: recognizer,
+          ),
+        );
+      } else {
+        spans.addAll(
+          buildHighlightedSpans(
+            text: el.text,
+            query: widget.highlight,
+            baseStyle: defaultStyle,
+          ),
+        );
+      }
+    }
+
+    return Text.rich(TextSpan(children: spans));
+  }
+}

pubspec.yaml

@@ -38,7 +38,9 @@ dependencies:
   workmanager: ^0.9.0+3
   intl: ^0.20.2
   flutter_linkify: ^6.0.0
+  linkify: ^5.0.0
   flutter_local_notifications: ^21.0.0
+  scrollable_positioned_list: ^0.3.8
   flutter_split_view: ^0.1.2
   flutter_svg: ^2.0.10
   freezed_annotation: ^3.1.0

test/view/talk/chat_search_controller_test.dart

@@ -0,0 +1,163 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:marianum_mobile/api/marianumcloud/talk/chat/get_chat_response.dart';
+import 'package:marianum_mobile/api/marianumcloud/talk/room/get_room_response.dart';
+import 'package:marianum_mobile/view/pages/talk/data/chat_search_controller.dart';
+
+GetChatResponseObject _msg({
+  required int id,
+  required int timestamp,
+  String actorDisplayName = 'Anyone',
+  String message = '',
+  String systemMessage = '',
+  GetRoomResponseObjectMessageType type =
+      GetRoomResponseObjectMessageType.comment,
+  Map<String, RichObjectString>? params,
+}) =>
+    GetChatResponseObject(
+      id,
+      'token',
+      GetRoomResponseObjectMessageActorType.user,
+      'actor-id',
+      actorDisplayName,
+      timestamp,
+      systemMessage,
+      type,
+      true,
+      '',
+      message,
+      params,
+      null,
+      null,
+      null,
+    );
+
+GetChatResponse _response(List<GetChatResponseObject> messages) =>
+    GetChatResponse(messages.toSet());
+
+void main() {
+  group('ChatSearchController.findMatches', () {
+    test('empty query returns no matches', () {
+      final response = _response([
+        _msg(id: 1, timestamp: 100, message: 'Hallo'),
+      ]);
+      expect(ChatSearchController.findMatches(response, ''), isEmpty);
+      expect(ChatSearchController.findMatches(response, '   '), isEmpty);
+    });
+
+    test('matches message text case-insensitively', () {
+      final response = _response([
+        _msg(id: 1, timestamp: 100, message: 'Hallo Welt'),
+        _msg(id: 2, timestamp: 200, message: 'nichts hier'),
+      ]);
+      final matches = ChatSearchController.findMatches(response, 'WELT');
+      expect(matches.length, 1);
+      expect(matches.first.messageId, 1);
+    });
+
+    test('matches actor display name', () {
+      final response = _response([
+        _msg(
+          id: 1,
+          timestamp: 100,
+          actorDisplayName: 'Lisa Maier',
+          message: 'irgendwas',
+        ),
+        _msg(
+          id: 2,
+          timestamp: 200,
+          actorDisplayName: 'Tom Weber',
+          message: 'auch was',
+        ),
+      ]);
+      final matches = ChatSearchController.findMatches(response, 'lisa');
+      expect(matches.length, 1);
+      expect(matches.first.messageId, 1);
+    });
+
+    test('system messages match on text but not on actor', () {
+      final response = _response([
+        _msg(
+          id: 1,
+          timestamp: 100,
+          actorDisplayName: 'Lisa',
+          message: 'Lisa ist beigetreten',
+          type: GetRoomResponseObjectMessageType.system,
+        ),
+      ]);
+      // Match on text content
+      expect(
+        ChatSearchController.findMatches(response, 'beigetreten').length,
+        1,
+      );
+      // Actor name alone (not in text) should not match for system messages
+      final actorOnlyResponse = _response([
+        _msg(
+          id: 1,
+          timestamp: 100,
+          actorDisplayName: 'Lisa',
+          message: 'jemand ist beigetreten',
+          type: GetRoomResponseObjectMessageType.system,
+        ),
+      ]);
+      expect(
+        ChatSearchController.findMatches(actorOnlyResponse, 'lisa'),
+        isEmpty,
+      );
+    });
+
+    test('reaction and poll_voted system messages are filtered out', () {
+      final response = _response([
+        _msg(
+          id: 1,
+          timestamp: 100,
+          message: 'Treffer',
+          systemMessage: 'reaction',
+          type: GetRoomResponseObjectMessageType.system,
+        ),
+        _msg(
+          id: 2,
+          timestamp: 200,
+          message: 'Treffer',
+          systemMessage: 'poll_voted',
+          type: GetRoomResponseObjectMessageType.system,
+        ),
+        _msg(id: 3, timestamp: 300, message: 'Treffer'),
+      ]);
+      final matches = ChatSearchController.findMatches(response, 'Treffer');
+      expect(matches.length, 1);
+      expect(matches.first.messageId, 3);
+    });
+
+    test('rich object parameters are searchable (e.g. file names)', () {
+      final response = _response([
+        _msg(
+          id: 1,
+          timestamp: 100,
+          message: '{file}',
+          params: {
+            'file': RichObjectString(
+              RichObjectStringObjectType.file,
+              '42',
+              'hausaufgaben.pdf',
+              null,
+              null,
+            ),
+          },
+        ),
+      ]);
+      final matches = ChatSearchController.findMatches(response, 'hausaufgab');
+      expect(matches.length, 1);
+      expect(matches.first.messageId, 1);
+    });
+
+    test('matches are sorted newest first', () {
+      final response = _response([
+        _msg(id: 1, timestamp: 100, message: 'X'),
+        _msg(id: 2, timestamp: 300, message: 'X'),
+        _msg(id: 3, timestamp: 200, message: 'X'),
+      ]);
+      final matches = ChatSearchController.findMatches(response, 'x');
+      expect(matches.map((m) => m.messageId).toList(), [2, 3, 1]);
+    });
+  });
+}