feat: Search feature

lib/pages/chat_search/chat_search_page.dart

@@ -0,0 +1,95 @@
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+
+import 'package:matrix/matrix.dart';
+
+import 'package:fluffychat/pages/chat_search/chat_search_view.dart';
+import 'package:fluffychat/widgets/matrix.dart';
+
+class ChatSearchPage extends StatefulWidget {
+  final String roomId;
+  const ChatSearchPage({required this.roomId, super.key});
+
+  @override
+  ChatSearchController createState() => ChatSearchController();
+}
+
+class ChatSearchController extends State<ChatSearchPage>
+    with SingleTickerProviderStateMixin {
+  Room? get room => Matrix.of(context).client.getRoomById(widget.roomId);
+
+  final TextEditingController searchController = TextEditingController();
+  late final TabController tabController;
+
+  Timeline? timeline;
+
+  Stream<(List<Event>, String?)>? searchStream;
+
+  void restartSearch() {
+    if (tabController.index == 0 && searchController.text.isEmpty) {
+      setState(() {
+        searchStream = null;
+      });
+      return;
+    }
+    setState(() {
+      searchStream = const Stream.empty();
+    });
+    WidgetsBinding.instance.addPostFrameCallback((timeStamp) {
+      startSearch();
+    });
+  }
+
+  void startSearch({
+    String? prevBatch,
+    List<Event>? previousSearchResult,
+  }) async {
+    final timeline = this.timeline ??= await room!.getTimeline();
+
+    if (tabController.index == 0 && searchController.text.isEmpty) {
+      return;
+    }
+
+    setState(() {
+      searchStream = timeline
+          .startSearch(
+            searchTerm: tabController.index == 0 ? searchController.text : null,
+            searchFunc: switch (tabController.index) {
+              1 => (event) => event.messageType == MessageTypes.Image,
+              2 => (event) => event.messageType == MessageTypes.File,
+              int() => null,
+            },
+            prevBatch: prevBatch,
+            requestHistoryCount: 1000,
+            limit: 32,
+          )
+          .map(
+            (result) => (
+              [
+                if (previousSearchResult != null) ...previousSearchResult,
+                ...result.$1,
+              ],
+              result.$2,
+            ),
+          )
+          .asBroadcastStream();
+    });
+  }
+
+  @override
+  void initState() {
+    super.initState();
+    tabController = TabController(initialIndex: 0, length: 3, vsync: this);
+    tabController.addListener(restartSearch);
+  }
+
+  @override
+  void dispose() {
+    tabController.removeListener(restartSearch);
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) => ChatSearchView(this);
+}