feat(chat): 正在输入指示器 — 点对点复刻 iOS + 性能改进

## 新增
- TypingIndicatorManager: 内存态管理器，精准Timer替代iOS 1s轮询
- TypingInputSender: per-chatId 节流(3s)/防抖(2s)，修复iOS跨chat竞态
- WS chat_input/chat_typing 帧处理（mode2 + ctl 双路径）

## UI
- ChatDetailPage AppBar 绿色副标题显示"正在输入…"
- ChatPage 列表 snippet 绿色输入状态优先于 lastMsg
- 群聊不发送 typing 事件（对齐 iOS gate）

## 改进 (vs iOS)
- Timer 仅在有 entry 时启动，空时 null（零空转）
- per-chatId 隔离节流/防抖（iOS 全局共享有竞态 bug）
- msgIdx 守卫防止乱序帧覆盖 lastMsg

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/im_app/lib/app/router/app_route_name.dart

@@ -17,7 +17,7 @@
 /// // 带参数导航（extra 传对象，适合列表点入详情等已有数据的场景）
 /// context.push(
 ///   AppRouteName.chatDetail.path,
-///   extra: (conversationId: '42', title: '技术支持'),
+///   extra: (conversationId: '42', title: '技术支持', chatType: 1),
 /// );
 ///
 /// // 带路径参数导航（路径中内嵌 id，适合需要直接链接或分享的场景）
@@ -60,7 +60,7 @@ enum AppRouteName {
   settings('/settings'),
 
   // ── Chat 子路由 ──────────────────────────────────────────────────────────
-  // extra: ({String conversationId, String title})
+  // extra: ({String conversationId, String title, int chatType})
   chatDetail('/chat/detail'),
   // 路径参数形式：导航用 AppRouteName.chatDetailByIdPath(id)，不直接用 .path
   chatDetailById('/chat/:id'),

apps/im_app/lib/app/router/app_router.dart

@@ -134,11 +134,12 @@ final routerProvider = Provider<GoRouter>((ref) {
         parentNavigatorKey: _rootKey,
         path: AppRouteName.chatDetail.path,
         builder: (context, state) {
-          final extra =
-              state.extra as ({String conversationId, String title});
+          final extra = state.extra
+              as ({String conversationId, String title, int chatType});
           return ChatDetailPage(
             conversationId: extra.conversationId,
             title: extra.title,
+            chatType: extra.chatType,
           );
         },
       ),

apps/im_app/lib/core/services/typing_indicator_manager.dart

@@ -0,0 +1,302 @@
+import 'dart:async';
+
+/// 输入状态枚举 — 对齐 Flutter ChatInputState / iOS ChatInputState
+///
+/// state=1 → typing, state=2 → noTyping (clear), 3-7 → media sending
+enum ChatInputState {
+  typing(1),
+  noTyping(2),
+  sendImage(3),
+  sendVideo(4),
+  sendDocument(5),
+  sendAlbum(6),
+  sendVoice(7);
+
+  const ChatInputState(this.value);
+  final int value;
+
+  static ChatInputState? fromValue(int v) {
+    for (final s in values) {
+      if (s.value == v) return s;
+    }
+    return null;
+  }
+
+  /// 过期秒数：文字输入 5s，媒体发送 30s（对齐 iOS/Flutter）
+  Duration get expiry {
+    switch (this) {
+      case sendImage:
+      case sendVideo:
+      case sendDocument:
+      case sendAlbum:
+      case sendVoice:
+        return const Duration(seconds: 30);
+      default:
+        return const Duration(seconds: 5);
+    }
+  }
+
+  /// 中文展示文本
+  String get displayText {
+    switch (this) {
+      case typing:
+        return '正在输入…';
+      case sendImage:
+        return '正在发送图片…';
+      case sendVideo:
+        return '正在发送视频…';
+      case sendDocument:
+        return '正在发送文件…';
+      case sendAlbum:
+        return '正在发送相册…';
+      case sendVoice:
+        return '正在发送语音…';
+      case noTyping:
+        return '';
+    }
+  }
+}
+
+/// 单条输入条目
+class _TypingEntry {
+  _TypingEntry({
+    required this.userId,
+    required this.username,
+    required this.state,
+    required this.expiresAt,
+  });
+
+  final int userId;
+  final String username;
+  final ChatInputState state;
+  final DateTime expiresAt;
+}
+
+/// 正在输入状态管理器 — 对齐 iOS TypingIndicatorManager + 性能优化
+///
+/// ## 对齐 iOS 行为
+/// - WS 收到 chat_input/chat_typing 时调用 [handleTypingEvent]
+/// - 收到真实消息时调用 [clearTyping] 立即清除（不等 5s 过期）
+/// - 文字输入 5s 过期，媒体发送 30s 过期
+/// - 单聊显示 "正在输入…"，群聊显示 "Alice 正在输入…" / "N 人正在输入…"
+///
+/// ## 性能改进（vs iOS）
+/// - **无常驻 Timer**：仅在有 entry 时启动清理 timer，空时自动取消
+/// - **精准调度**：timer 对齐最近过期时间，不是每秒轮询
+/// - **按 chatId 通知**：[typingTextStream] 返回指定 chat 的 Stream，
+///   只有该 chat 的状态变化才触发，避免全局重建
+class TypingIndicatorManager {
+  /// [chatId → [userId → _TypingEntry]]
+  final Map<int, Map<int, _TypingEntry>> _typing = {};
+
+  /// 每个 chatId 一个 StreamController，按需创建
+  final Map<int, StreamController<String?>> _controllers = {};
+
+  /// 全局通知（用于聊天列表等需要监听所有 chat 的场景）
+  final StreamController<void> _globalNotifier =
+      StreamController<void>.broadcast();
+
+  Timer? _purgeTimer;
+
+  // ── 接收侧 ──────────────────────────────────────────────────────────────
+
+  /// 处理 WS 收到的 chat_input/chat_typing 事件
+  ///
+  /// [senderId], [chatId], [stateValue] 从 WS 帧解析。
+  /// [username] 用于群聊显示名。
+  void handleTypingEvent({
+    required int chatId,
+    required int senderId,
+    required String username,
+    required int stateValue,
+  }) {
+    final state = ChatInputState.fromValue(stateValue);
+    if (state == null) return;
+
+    if (state == ChatInputState.noTyping) {
+      _typing[chatId]?.remove(senderId);
+      if (_typing[chatId]?.isEmpty == true) _typing.remove(chatId);
+    } else {
+      _typing.putIfAbsent(chatId, () => {});
+      _typing[chatId]![senderId] = _TypingEntry(
+        userId: senderId,
+        username: username,
+        state: state,
+        expiresAt: DateTime.now().add(state.expiry),
+      );
+    }
+
+    _notify(chatId);
+    _schedulePurge();
+  }
+
+  /// 收到真实消息时立即清除该发送者的输入状态
+  /// （对齐 iOS: TypingIndicatorManager.clearTyping + .didReceiveChatMessage）
+  void clearTyping({required int chatId, required int senderId}) {
+    if (_typing[chatId]?.remove(senderId) != null) {
+      if (_typing[chatId]?.isEmpty == true) _typing.remove(chatId);
+      _notify(chatId);
+    }
+  }
+
+  // ── 查询侧 ──────────────────────────────────────────────────────────────
+
+  /// 单聊：返回第一个活跃输入者的状态文本，排除自己
+  /// 对齐 iOS displayText(for:excludingUserId:)
+  String? displayText({required int chatId, required int myUserId}) {
+    final entries = _typing[chatId]?.values;
+    if (entries == null || entries.isEmpty) return null;
+    for (final e in entries) {
+      if (e.userId != myUserId && e.state != ChatInputState.noTyping) {
+        return e.state.displayText;
+      }
+    }
+    return null;
+  }
+
+  /// 群聊：多人输入显示规则
+  /// - 1 人 → "Alice 正在输入…"
+  /// - 2-3 人 → "Alice、Bob 正在输入…"
+  /// - 4+ 人 → "N 人正在输入…"
+  /// 对齐 iOS groupDisplayText(for:groupId:excludingUserId:)
+  String? groupDisplayText({required int chatId, required int myUserId}) {
+    final entries = _typing[chatId]?.values;
+    if (entries == null || entries.isEmpty) return null;
+    final active = entries
+        .where((e) => e.userId != myUserId && e.state != ChatInputState.noTyping)
+        .toList();
+    if (active.isEmpty) return null;
+
+    switch (active.length) {
+      case 1:
+        final name = active[0].username.isNotEmpty
+            ? active[0].username
+            : '用户${active[0].userId}';
+        return '$name ${active[0].state.displayText}';
+      case 2:
+      case 3:
+        final names = active
+            .map((e) => e.username.isNotEmpty ? e.username : '用户${e.userId}')
+            .join('、');
+        return '$names 正在输入…';
+      default:
+        return '${active.length} 人正在输入…';
+    }
+  }
+
+  /// 返回指定 chatId 的输入状态 Stream
+  ///
+  /// 每次该 chatId 的输入状态变化时发出新的显示文本（null = 无人输入）。
+  /// 懒创建 StreamController，dispose 时自动清理。
+  Stream<String?> typingTextStream({
+    required int chatId,
+    required int myUserId,
+    bool isGroup = false,
+  }) {
+    final ctrl = _controllers.putIfAbsent(
+      chatId,
+      () => StreamController<String?>.broadcast(),
+    );
+    // 立即发出当前状态
+    final current = isGroup
+        ? groupDisplayText(chatId: chatId, myUserId: myUserId)
+        : displayText(chatId: chatId, myUserId: myUserId);
+    return ctrl.stream.transform(
+      StreamTransformer.fromHandlers(
+        handleData: (data, sink) => sink.add(data),
+      ),
+    ).transform(_StartWithTransformer(current));
+  }
+
+  /// 全局变化通知（聊天列表用）
+  Stream<void> get globalChangeStream => _globalNotifier.stream;
+
+  // ── 内部 ────────────────────────────────────────────────────────────────
+
+  void _notify(int chatId) {
+    // 通知该 chatId 的订阅者
+    final ctrl = _controllers[chatId];
+    if (ctrl != null && !ctrl.isClosed) {
+      // 不知道订阅者的 myUserId / isGroup，所以传 null 让 UI 层自己查
+      ctrl.add(null); // sentinel — UI 层重新查询 displayText
+    }
+    // 通知全局订阅者
+    if (!_globalNotifier.isClosed) {
+      _globalNotifier.add(null);
+    }
+  }
+
+  /// 智能清理调度 — 对齐最近过期时间，非 1s 轮询
+  ///
+  /// iOS 问题：1s Timer 永远运行，即使 typing 为空。
+  /// 改进：找到最近过期的 entry，只在那个时间点触发一次清理。
+  void _schedulePurge() {
+    _purgeTimer?.cancel();
+
+    if (_typing.isEmpty) {
+      _purgeTimer = null;
+      return;
+    }
+
+    // 找最近过期时间
+    DateTime? earliest;
+    for (final chatEntries in _typing.values) {
+      for (final entry in chatEntries.values) {
+        if (earliest == null || entry.expiresAt.isBefore(earliest)) {
+          earliest = entry.expiresAt;
+        }
+      }
+    }
+    if (earliest == null) return;
+
+    final delay = earliest.difference(DateTime.now());
+    // 至少 100ms 防止 busy-loop
+    final safeDuration =
+        delay.isNegative ? const Duration(milliseconds: 100) : delay;
+
+    _purgeTimer = Timer(safeDuration, _purgeExpired);
+  }
+
+  void _purgeExpired() {
+    final now = DateTime.now();
+    final changedChats = <int>{};
+
+    for (final chatId in _typing.keys.toList()) {
+      final entries = _typing[chatId]!;
+      final before = entries.length;
+      entries.removeWhere((_, entry) => entry.expiresAt.isBefore(now));
+      if (entries.isEmpty) _typing.remove(chatId);
+      if ((entries.length) != before) changedChats.add(chatId);
+    }
+
+    for (final chatId in changedChats) {
+      _notify(chatId);
+    }
+
+    // 如果还有 entry，继续调度下一次
+    _schedulePurge();
+  }
+
+  /// 释放资源
+  void dispose() {
+    _purgeTimer?.cancel();
+    for (final ctrl in _controllers.values) {
+      ctrl.close();
+    }
+    _controllers.clear();
+    _globalNotifier.close();
+    _typing.clear();
+  }
+}
+
+/// 在 Stream 前插入一个初始值
+class _StartWithTransformer<T> extends StreamTransformerBase<T, T> {
+  _StartWithTransformer(this._initial);
+  final T _initial;
+
+  @override
+  Stream<T> bind(Stream<T> stream) async* {
+    yield _initial;
+    yield* stream;
+  }
+}

apps/im_app/lib/core/services/typing_input_sender.dart

@@ -0,0 +1,110 @@
+import 'dart:async';
+import 'dart:convert';
+
+import 'package:flutter/foundation.dart';
+
+import 'package:im_app/core/services/socket_manager.dart';
+
+/// 发送侧"正在输入" WS 事件管理器
+///
+/// 对齐 iOS `TypingInputSender.swift`:
+/// - 节流 3s：用户输入时最多每 3s 发一次 {typ:1}
+/// - 防抖 2s：用户停止输入 2s 后自动发 {typ:0}
+/// - 消息发送 / 文本清空时立即发 {typ:0}
+///
+/// ## 改进（vs iOS TypingInputSender.swift）
+///
+/// iOS 版用全局单一 `lastTypingSentAt` / `stopTask`，当用户在 3s 内切换聊天时
+/// 会导致：chat A 的 stop timer 被 chat B 覆盖，chat A 输入状态无法正常清除。
+/// Flutter 版改为 **per-chatId** 节流/防抖，彻底消除跨 chat 竞态。
+///
+/// WS 发送格式（对齐 iOS TypingInputSender.sendAction）：
+/// ```json
+/// {"action": "ACTION_SENDINPUT_MSG", "chat_id": N, "typ": 1}  // 开始输入
+/// {"action": "ACTION_SENDINPUT_MSG", "chat_id": N, "typ": 0}  // 停止输入
+/// ```
+class TypingInputSender {
+  TypingInputSender({required SocketManager socketManager})
+      : _socketManager = socketManager;
+
+  final SocketManager _socketManager;
+
+  /// 节流间隔：最多每 3s 发一次 typ=1（对齐 iOS inputThrottleInterval = 3.0）
+  static const _throttleInterval = Duration(seconds: 3);
+
+  /// 停止输入防抖：最后一次击键 2s 后发 typ=0（对齐 iOS inputStopDelay = 2.0）
+  static const _stopDelay = Duration(seconds: 2);
+
+  /// Per-chatId 节流时间戳（防止跨 chat 竞态）
+  final Map<int, DateTime> _lastSentAt = {};
+
+  /// Per-chatId 停止计时器
+  final Map<int, Timer> _stopTimers = {};
+
+  /// 用户输入文本变化时调用
+  ///
+  /// [text] 为当前输入框全文。
+  /// - 非空：节流发 typ=1 + 重置 2s 停止计时
+  /// - 空（清空输入框）：立即发 typ=0
+  ///
+  /// 对齐 iOS ChatViewModel.onComposerTextChanged
+  void onTextChanged({required int chatId, required String text}) {
+    final isTyping = text.trim().isNotEmpty;
+
+    if (isTyping) {
+      // 重置该 chat 的 2s 停止计时
+      _stopTimers[chatId]?.cancel();
+      _stopTimers[chatId] = Timer(_stopDelay, () {
+        _sendAction(chatId: chatId, typ: 0);
+        _lastSentAt.remove(chatId);
+        _stopTimers.remove(chatId);
+      });
+
+      // 节流：该 chat 距上次发送不足 3s 则跳过
+      final now = DateTime.now();
+      final lastSent = _lastSentAt[chatId];
+      if (lastSent != null && now.difference(lastSent) < _throttleInterval) {
+        return;
+      }
+      _lastSentAt[chatId] = now;
+      _sendAction(chatId: chatId, typ: 1);
+    } else {
+      // 文本清空 → 立即停止
+      _stopTimers[chatId]?.cancel();
+      _stopTimers.remove(chatId);
+      if (_lastSentAt.containsKey(chatId)) {
+        _lastSentAt.remove(chatId);
+        _sendAction(chatId: chatId, typ: 0);
+      }
+    }
+  }
+
+  /// 消息发送成功后调用 — 立即发 typ=0
+  ///
+  /// 对齐 iOS TypingInputSender.notifyStopTyping
+  void notifyStopTyping({required int chatId}) {
+    _stopTimers[chatId]?.cancel();
+    _stopTimers.remove(chatId);
+    _lastSentAt.remove(chatId);
+    _sendAction(chatId: chatId, typ: 0);
+  }
+
+  void _sendAction({required int chatId, required int typ}) {
+    final payload = {
+      'action': 'ACTION_SENDINPUT_MSG',
+      'chat_id': chatId,
+      'typ': typ,
+    };
+    final text = jsonEncode(payload);
+    _socketManager.sendString(text);
+    debugPrint('[TypingInputSender] chat=$chatId typ=$typ');
+  }
+
+  void dispose() {
+    for (final timer in _stopTimers.values) {
+      timer.cancel();
+    }
+    _stopTimers.clear();
+    _lastSentAt.clear();
+  }
+}

apps/im_app/lib/core/services/ws_message_service.dart

@@ -4,6 +4,7 @@ import 'package:flutter/foundation.dart';
 import 'package:networks_sdk/networks_sdk.dart';
 
 import 'package:im_app/core/services/socket_manager.dart';
+import 'package:im_app/core/services/typing_indicator_manager.dart';
 import 'package:im_app/data/remote/fetch_history_request.dart';
 import 'package:im_app/domain/repositories/chat_repository.dart';
 import 'package:im_app/domain/repositories/message_repository.dart';
@@ -31,6 +32,7 @@ class WsMessageService {
   final NetworksSdkApi _apiClient;
   final MessageRepository _messageRepo;
   final ChatRepository _chatRepo;
+  final TypingIndicatorManager _typingManager;
 
   StreamSubscription<Map<String, dynamic>>? _sub;
 
@@ -39,10 +41,12 @@ class WsMessageService {
     required NetworksSdkApi apiClient,
     required MessageRepository messageRepo,
     required ChatRepository chatRepo,
+    required TypingIndicatorManager typingManager,
   })  : _socketManager = socketManager,
         _apiClient = apiClient,
         _messageRepo = messageRepo,
-        _chatRepo = chatRepo;
+        _chatRepo = chatRepo,
+        _typingManager = typingManager;
 
   // ── 生命周期 ──────────────────────────────────────────────────────────────
 
@@ -65,6 +69,26 @@ class WsMessageService {
 
   Future<void> _handleFrame(Map<String, dynamic> frame) async {
     try {
+      // ── chat_input / chat_typing — 正在输入状态 ─────────────────────────
+      // mode2: {"chat_input": {"r": [{"send_id": N, "chat_id": N, "username": "Alice", "state": N}]}}
+      // ctl:   {"ctl": "chat_input", "r": [...]}
+      // 对齐 iOS MessageReceiver.handleChatInput
+      final typingPayload = frame['chat_input'] as Map<String, dynamic>?
+          ?? frame['chat_typing'] as Map<String, dynamic>?;
+      if (typingPayload != null) {
+        _handleTypingFrame(typingPayload);
+      }
+      // ctl 路径
+      final ctl = frame['ctl'] as String?;
+      if (ctl == 'chat_input' || ctl == 'chat_typing') {
+        final ctlData = frame['data'] as List<dynamic>?
+            ?? frame['r'] as List<dynamic>?;
+        if (ctlData != null) {
+          _handleTypingFrame({'r': ctlData});
+        }
+      }
+
+      // ── chat.r — 新消息通知 ────────────────────────────────────────────
       final chatPayload = frame['chat'] as Map<String, dynamic>?;
       if (chatPayload == null) return;
 
@@ -79,6 +103,12 @@ class WsMessageService {
         final msgIdx = (entry['msg_idx'] as num?)?.toInt();
         if (chatId == null || msgIdx == null) continue;
 
+        // 收到真实消息 → 清除发送者的输入状态（对齐 iOS .didReceiveChatMessage）
+        final sendId = (entry['send_id'] as num?)?.toInt();
+        if (sendId != null) {
+          _typingManager.clearTyping(chatId: chatId, senderId: sendId);
+        }
+
         await _fetchAndSaveMessages(chatId: chatId, anchorIdx: msgIdx);
         await _updateChatMeta(chatId: chatId, entry: entry);
       }
@@ -87,6 +117,40 @@ class WsMessageService {
     }
   }
 
+  /// 处理 chat_input/chat_typing 帧
+  void _handleTypingFrame(Map<String, dynamic> payload) {
+    final rList = payload['r'] as List<dynamic>?;
+    if (rList == null) return;
+
+    for (final item in rList) {
+      final entry = item as Map<String, dynamic>?;
+      if (entry == null) continue;
+
+      // 兼容 Int / String 类型（对齐 iOS handleChatInput 的 flatMap(Int.init)）
+      final senderId = _parseInt(entry['send_id']);
+      final chatId = _parseInt(entry['chat_id']);
+      final stateValue = _parseInt(entry['state']) ?? _parseInt(entry['typ']);
+      final username = entry['username'] as String? ?? '';
+
+      if (senderId == null || chatId == null || stateValue == null) continue;
+
+      _typingManager.handleTypingEvent(
+        chatId: chatId,
+        senderId: senderId,
+        username: username,
+        stateValue: stateValue,
+      );
+    }
+  }
+
+  /// 安全解析 int — 兼容 int / String / num（对齐 iOS Int ?? String→Int）
+  static int? _parseInt(dynamic value) {
+    if (value is int) return value;
+    if (value is num) return value.toInt();
+    if (value is String) return int.tryParse(value);
+    return null;
+  }
+
   /// 通过 HTTP 拉取消息并写入 DB
   Future<void> _fetchAndSaveMessages({
     required int chatId,
@@ -109,6 +173,9 @@ class WsMessageService {
   }
 
   /// 更新聊天列表中对应 Chat 的 lastMsg / lastTyp / msgIdx
+  ///
+  /// 包含 msgIdx 守卫：如果帧中的 msgIdx 小于 DB 已有值，说明是乱序到达的旧帧，
+  /// 跳过更新防止 lastMsg 被旧数据覆盖。
   Future<void> _updateChatMeta({
     required int chatId,
     required Map<String, dynamic> entry,
@@ -121,6 +188,11 @@ class WsMessageService {
       final lastTyp = (entry['typ'] as num?)?.toInt();
       final msgIdx = (entry['msg_idx'] as num?)?.toInt();
 
+      // 防止乱序帧覆盖新数据（Codex review #4）
+      if (msgIdx != null && existing.msgIdx != null && msgIdx < existing.msgIdx!) {
+        return;
+      }
+
       await _chatRepo.updateChat(
         existing.copyWith(
           lastMsg: lastMsg ?? existing.lastMsg,

apps/im_app/lib/features/chat/di/chat_service_providers.dart

@@ -2,6 +2,8 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 
 import 'package:im_app/app/di/app_providers.dart';
 import 'package:im_app/app/di/network_provider.dart';
+import 'package:im_app/core/services/typing_indicator_manager.dart';
+import 'package:im_app/core/services/typing_input_sender.dart';
 import 'package:im_app/core/services/ws_message_service.dart';
 import 'package:im_app/features/chat/di/chat_provider.dart';
 import 'package:im_app/features/chat/di/message_provider.dart';
@@ -20,6 +22,40 @@ import 'package:im_app/features/chat/usecases/send_video_usecase.dart';
 /// WS 消息服务在 Provider 创建时自动调用 `start()`，
 /// Provider dispose 时调用 `stop()`，生命周期与 Riverpod 容器绑定。
 
+// ── TypingIndicatorManager ────────────────────────────────────────────────────
+
+/// 输入状态管理器 Provider — 全局单例
+///
+/// 维护 [chatId → [userId → TypingEntry]] 的内存 Map。
+/// WS 帧由 [WsMessageService] 转发到此。
+/// UI 通过 [typingTextProvider] 订阅指定 chat 的输入状态。
+final typingIndicatorManagerProvider = Provider<TypingIndicatorManager>((ref) {
+  final manager = TypingIndicatorManager();
+  ref.onDispose(manager.dispose);
+  return manager;
+});
+
+/// 输入状态全局变化流 — 聊天列表监听此 Provider 触发重建
+///
+/// 每次任何 chat 的输入状态变化时 emit，ChatPage 通过 ref.watch 自动重建列表。
+/// 值无意义（只用作触发器），轻量级且不产生 GC 压力。
+final typingChangeProvider = StreamProvider<void>((ref) {
+  return ref.watch(typingIndicatorManagerProvider).globalChangeStream;
+});
+
+// ── TypingInputSender ────────────────────────────────────────────────────────
+
+/// 发送侧输入状态 Provider — 3s 节流 + 2s 防抖
+///
+/// 由 ChatDetailPage 的 TextField.onChanged 调用。
+final typingInputSenderProvider = Provider<TypingInputSender>((ref) {
+  final sender = TypingInputSender(
+    socketManager: ref.read(socketManagerProvider),
+  );
+  ref.onDispose(sender.dispose);
+  return sender;
+});
+
 // ── WsMessageService ──────────────────────────────────────────────────────────
 
 /// WS 消息服务 Provider
@@ -32,6 +68,7 @@ final wsMessageServiceProvider = Provider<WsMessageService>((ref) {
     apiClient: ref.read(networkSdkApiProvider),
     messageRepo: ref.read(messageRepositoryProvider),
     chatRepo: ref.read(chatRepositoryProvider),
+    typingManager: ref.read(typingIndicatorManagerProvider),
   );
 
   service.start();

apps/im_app/lib/features/chat/presentation/chat_list_view_model.dart

@@ -25,7 +25,11 @@ class ChatListViewModel extends Notifier<void> {
     final title = chat.name ?? 'Chat $chatId';
     context.push(
       AppRouteName.chatDetail.path,
-      extra: (conversationId: chatId.toString(), title: title),
+      extra: (
+        conversationId: chatId.toString(),
+        title: title,
+        chatType: chat.typ ?? 1,
+      ),
     );
   }
 

apps/im_app/lib/features/chat/presentation/chat_view_model.dart

@@ -17,7 +17,7 @@ class ChatViewModel extends Notifier<void> {
   void pushChatDetailWithExtra(BuildContext context) {
     context.push(
       AppRouteName.chatDetail.path,
-      extra: (conversationId: '42', title: 'extra 传参'),
+      extra: (conversationId: '42', title: 'extra 传参', chatType: 1),
     );
   }
 

apps/im_app/lib/features/chat/view/chat_detail_page.dart

@@ -1,23 +1,24 @@
+import 'dart:async';
+
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
 import 'package:im_app/app/di/app_providers.dart';
 import 'package:im_app/domain/entities/message.dart';
+import 'package:im_app/features/chat/di/chat_service_providers.dart';
 import 'package:im_app/features/chat/di/message_provider.dart';
 import 'package:im_app/features/chat/presentation/chat_detail_view_model.dart';
+import 'package:im_app/features/chat/view/widgets/attachment_panel_sheet.dart';
 import 'package:im_app/features/chat/view/widgets/audio_message_bubble.dart';
+import 'package:im_app/features/chat/view/widgets/emoji_panel.dart';
 import 'package:im_app/features/chat/view/widgets/file_message_bubble.dart';
 import 'package:im_app/features/chat/view/widgets/image_grid_bubble.dart';
 import 'package:im_app/features/chat/view/widgets/image_message_bubble.dart';
-import 'package:image_picker/image_picker.dart';
-
-import 'package:im_app/features/chat/di/chat_service_providers.dart';
-import 'package:im_app/features/chat/view/widgets/attachment_panel_sheet.dart';
-import 'package:im_app/features/chat/view/widgets/emoji_panel.dart';
 import 'package:im_app/features/chat/view/widgets/image_picker_sheet.dart';
 import 'package:im_app/features/chat/view/widgets/red_envelope_bubble.dart';
 import 'package:im_app/features/chat/view/widgets/sticker_message_bubble.dart';
 import 'package:im_app/features/chat/view/widgets/video_message_bubble.dart';
+import 'package:image_picker/image_picker.dart';
 
 /// 聊天详情页（#28 / #35 / #37）
 ///
@@ -63,23 +64,68 @@ class _ChatDetailPageState extends ConsumerState<ChatDetailPage> {
   final _inputCtrl = TextEditingController();
   final _scrollCtrl = ScrollController();
 
+  /// 当前输入状态显示文本（"正在输入…" / null）
+  String? _typingText;
+  StreamSubscription<String?>? _typingSub;
+
   @override
   void initState() {
     super.initState();
     _chatId = int.tryParse(widget.conversationId) ?? 0;
+    _inputCtrl.addListener(_onTextChanged);
+  }
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    // 订阅输入状态 Stream（首次 + 依赖变化时重建）
+    if (_typingSub == null) {
+      final uid = ref.read(authNotifierProvider).currentUid ?? 0;
+      final mgr = ref.read(typingIndicatorManagerProvider);
+      final isGroup = widget.chatType == 2;
+      _typingSub = mgr
+          .typingTextStream(chatId: _chatId, myUserId: uid, isGroup: isGroup)
+          .listen((text) {
+        // Stream sentinel: text == null → 重新查询 displayText
+        final uid = ref.read(authNotifierProvider).currentUid ?? 0;
+        final actual = isGroup
+            ? mgr.groupDisplayText(chatId: _chatId, myUserId: uid)
+            : mgr.displayText(chatId: _chatId, myUserId: uid);
+        if (actual != _typingText) {
+          setState(() => _typingText = actual);
+        }
+      });
+    }
   }
 
   @override
   void dispose() {
+    _typingSub?.cancel();
+    _inputCtrl.removeListener(_onTextChanged);
     _inputCtrl.dispose();
     _scrollCtrl.dispose();
     super.dispose();
   }
 
+  /// TextField 输入变化 → 发送输入状态（仅单聊）
+  ///
+  /// 对齐 iOS ChatView.swift:1052 — 单聊"对方正在输入"，群聊不发送
+  void _onTextChanged() {
+    if (widget.chatType == 2) return; // 群聊不发送 typing 事件
+    ref.read(typingInputSenderProvider).onTextChanged(
+          chatId: _chatId,
+          text: _inputCtrl.text,
+        );
+  }
+
   void _send() {
     final text = _inputCtrl.text.trim();
     if (text.isEmpty) return;
     _inputCtrl.clear();
+    // 消息发出 → 立即停止输入状态（仅单聊）
+    if (widget.chatType != 2) {
+      ref.read(typingInputSenderProvider).notifyStopTyping(chatId: _chatId);
+    }
     ref
         .read(chatDetailViewModelProvider(_chatId).notifier)
         .sendMessage(text);
@@ -214,7 +260,24 @@ class _ChatDetailPageState extends ConsumerState<ChatDetailPage> {
     final currentUid = ref.watch(authNotifierProvider).currentUid ?? 0;
 
     return Scaffold(
-      appBar: AppBar(title: Text(widget.title)),
+      appBar: AppBar(
+        title: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Text(widget.title),
+            // 正在输入副标题（绿色，对齐 iOS ChatNavToolbar typing 参数）
+            if (_typingText != null)
+              Text(
+                _typingText!,
+                style: TextStyle(
+                  fontSize: 12,
+                  color: Colors.green.shade600,
+                  fontWeight: FontWeight.w400,
+                ),
+              ),
+          ],
+        ),
+      ),
       body: Column(
         children: [
           // ── 消息列表 ────────────────────────────────────────────────────────

apps/im_app/lib/features/chat/view/chat_page.dart

@@ -1,8 +1,10 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
+import 'package:im_app/app/di/app_providers.dart';
 import 'package:im_app/domain/entities/chat.dart';
 import 'package:im_app/features/chat/di/chat_provider.dart';
+import 'package:im_app/features/chat/di/chat_service_providers.dart';
 import 'package:im_app/features/chat/presentation/chat_list_view_model.dart';
 
 /// 聊天列表页
@@ -16,6 +18,8 @@ class ChatPage extends ConsumerWidget {
   Widget build(BuildContext context, WidgetRef ref) {
     final vm = ref.watch(chatListViewModelProvider.notifier);
     final chatsAsync = ref.watch(allChatsProvider);
+    // 监听输入状态变化 → 触发列表重建（对齐 iOS @Published typing 全局更新）
+    ref.watch(typingChangeProvider);
 
     return Scaffold(
       appBar: AppBar(
@@ -45,20 +49,29 @@ class ChatPage extends ConsumerWidget {
   }
 }
 
-class _ChatTile extends StatelessWidget {
+class _ChatTile extends ConsumerWidget {
   const _ChatTile({required this.chat, required this.vm});
 
   final Chat chat;
   final ChatListViewModel vm;
 
   @override
-  Widget build(BuildContext context) {
+  Widget build(BuildContext context, WidgetRef ref) {
     final name = chat.name ?? 'Chat ${chat.chatId ?? chat.id}';
     final lastMsg = chat.lastMsg ?? '';
     final unread = chat.unreadNum ?? 0;
     final sendTime = chat.lastTime;
     final timeStr = sendTime != null ? _formatTime(sendTime) : '';
 
+    // 正在输入状态（对齐 iOS ConversationCell.typingText）
+    final chatId = chat.chatId ?? chat.id;
+    final myUid = ref.watch(authNotifierProvider).currentUid ?? 0;
+    final typingMgr = ref.watch(typingIndicatorManagerProvider);
+    final isGroup = (chat.typ ?? 1) == 2;
+    final typingText = isGroup
+        ? typingMgr.groupDisplayText(chatId: chatId, myUserId: myUid)
+        : typingMgr.displayText(chatId: chatId, myUserId: myUid);
+
     return ListTile(
       leading: CircleAvatar(
         backgroundColor: Theme.of(context).colorScheme.primaryContainer,
@@ -86,14 +99,24 @@ class _ChatTile extends StatelessWidget {
       subtitle: Row(
         children: [
           Expanded(
-            child: Text(
-              lastMsg,
-              maxLines: 1,
-              overflow: TextOverflow.ellipsis,
-              style: Theme.of(context).textTheme.bodySmall?.copyWith(
-                    color: Theme.of(context).colorScheme.outline,
+            child: typingText != null
+                // 输入状态优先显示（绿色，对齐 iOS onlineGreen）
+                ? Text(
+                    typingText,
+                    maxLines: 1,
+                    overflow: TextOverflow.ellipsis,
+                    style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                          color: Colors.green.shade600,
+                        ),
+                  )
+                : Text(
+                    lastMsg,
+                    maxLines: 1,
+                    overflow: TextOverflow.ellipsis,
+                    style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                          color: Theme.of(context).colorScheme.outline,
+                        ),
                   ),
-            ),
           ),
           if (unread > 0)
             Container(