fix: какое то уведомление при входе в незнакомые каналы

lib/backend/api.dart

@@ -266,7 +266,11 @@ class Api {
   }
 
   /// Отправляет запрос и ждёт ответ от сервера.
-  Future<Packet> sendRequest(int opcode, Map<dynamic, dynamic> payload) async {
+  Future<Packet> sendRequest(
+    int opcode,
+    Map<dynamic, dynamic> payload, {
+    bool silent = false,
+  }) async {
     final session = _session;
     if (session == null) {
       throw StateError('Нет соединения (${Opcode.name(opcode)})');
@@ -296,7 +300,7 @@ class Api {
         throw ex;
       }
       final text = _serverErrorText(packet.payload);
-      if (text != null) _errorController.add(text);
+      if (text != null && !silent) _errorController.add(text);
       final err = PacketError(
         messageFromErrorPayload(packet.payload),
         errorKey: resp.errorKey,

lib/backend/modules/chats.dart

@@ -399,7 +399,7 @@ class ChatsModule {
           'chatId': chatId,
           'messageId': msgIdNum,
           'mark': mark,
-        });
+        }, silent: true);
       } catch (_) {}
     }
 
@@ -424,7 +424,7 @@ class ChatsModule {
           'chatId': chatId,
           'messageId': msgIdNum,
           'mark': mark,
-        });
+        }, silent: true);
       } catch (_) {}
     }
 
@@ -1348,12 +1348,36 @@ class ChatsModule {
       await api.sendRequest(Opcode.chatSubscribe, {
         'chatId': chatId,
         'subscribe': subscribe,
-      });
+      }, silent: true);
     } catch (e) {
       logger.w('subscribeChat failed: $e');
     }
   }
 
+  Future<({CachedChat chat, int? subscribersCount})> joinChannel(
+    Api api,
+    String link,
+    int accountId,
+  ) async {
+    final packet = await api.sendRequest(Opcode.chatJoin, {
+      'link': link,
+    }, silent: true);
+    if (!packet.isOk) {
+      throw PacketError(messageFromErrorPayload(packet.payload));
+    }
+    final payload = packet.payload;
+    final chatMap = payload is Map ? payload['chat'] : null;
+    if (chatMap is! Map) {
+      throw const PacketError('Не удалось подписаться');
+    }
+    final cached = await cacheServerChat(chatMap, accountId);
+    if (cached == null) {
+      throw const PacketError('Не удалось подписаться');
+    }
+    final count = chatMap['participantsCount'];
+    return (chat: cached, subscribersCount: count is int ? count : null);
+  }
+
   Future<bool> ensureChatCached(Api api, int accountId, int chatId) async {
     final rows = await AppDatabase.loadChat(accountId, chatId);
     if (rows.isNotEmpty) return true;

lib/frontend/screens/chats/chat/view/composer_input.dart

@@ -46,6 +46,9 @@ class ComposerInputBar extends StatelessWidget {
     required this.contextMenuBuilder,
     required this.isMuted,
     required this.onToggleMute,
+    this.channelSubscribed = true,
+    this.channelSubscribing = false,
+    this.onSubscribe,
   });
 
   final String chatType;
@@ -73,6 +76,9 @@ class ComposerInputBar extends StatelessWidget {
   final Widget Function(BuildContext, EditableTextState) contextMenuBuilder;
   final bool isMuted;
   final VoidCallback onToggleMute;
+  final bool channelSubscribed;
+  final bool channelSubscribing;
+  final VoidCallback? onSubscribe;
 
   @override
   Widget build(BuildContext context) {
@@ -80,6 +86,49 @@ class ComposerInputBar extends StatelessWidget {
     final mutedIcon = cs.onSurfaceVariant.withValues(alpha: 0.85);
 
     if (chatType == "CHANNEL") {
+      if (!channelSubscribed) {
+        return SafeArea(
+          child: Padding(
+            padding: const EdgeInsets.symmetric(
+              horizontal: 12.0,
+              vertical: 8.0,
+            ),
+            child: GlossyPill(
+              onTap: channelSubscribing ? null : onSubscribe,
+              color: cs.primary,
+              borderRadius: BorderRadius.circular(28),
+              padding: const EdgeInsets.symmetric(vertical: 16),
+              depth: 8,
+              borderSide: BorderSide(
+                color: cs.outlineVariant.withValues(alpha: 0.5),
+                width: 0.5,
+              ),
+              child: SizedBox(
+                width: double.infinity,
+                child: Center(
+                  child: channelSubscribing
+                      ? SizedBox(
+                          width: 22,
+                          height: 22,
+                          child: CircularProgressIndicator(
+                            strokeWidth: 2,
+                            color: cs.onPrimary,
+                          ),
+                        )
+                      : Text(
+                          'Подписаться',
+                          style: TextStyle(
+                            color: cs.onPrimary,
+                            fontSize: 16,
+                            fontWeight: FontWeight.w600,
+                          ),
+                        ),
+                ),
+              ),
+            ),
+          ),
+        );
+      }
       return SafeArea(
         child: Padding(
           padding: const EdgeInsets.symmetric(horizontal: 12.0, vertical: 8.0),

lib/frontend/screens/chats/chat_screen.dart

@@ -435,6 +435,8 @@ class _ChatScreenState extends State<ChatScreen>
   late AnimationController _shimmerController;
   Timer? _shimmerStartTimer;
   bool _previewChat = false;
+  bool _subscribing = false;
+  String? _channelLink;
   bool _forwardRequestDone = false;
 
   final ChatController _chatController = ChatController();
@@ -642,6 +644,10 @@ class _ChatScreenState extends State<ChatScreen>
     if (widget.chatType != 'CHAT' && widget.chatType != 'CHANNEL') return;
     final info = await chats.getChatInfo(api, widget.chatId);
     if (!mounted) return;
+    if (widget.chatType == 'CHANNEL') {
+      final link = info?['link'];
+      if (link is String && link.isNotEmpty) _channelLink = link;
+    }
     final count = info?['participantsCount'] as int?;
     if (count != null && count != _participantsCount) {
       _participantsCount = count;
@@ -2166,6 +2172,9 @@ class _ChatScreenState extends State<ChatScreen>
                     _formatContextMenu(_messageController, ctx, state),
                 isMuted: chat?.isMuted ?? false,
                 onToggleMute: _toggleChatMute,
+                channelSubscribed: !_previewChat,
+                channelSubscribing: _subscribing,
+                onSubscribe: _subscribeChannel,
               ),
               StickerPanelView(
                 stickers: _stickers,
@@ -2754,6 +2763,39 @@ class _ChatScreenState extends State<ChatScreen>
     );
   }
 
+  Future<void> _subscribeChannel() async {
+    if (_subscribing) return;
+    setState(() => _subscribing = true);
+    try {
+      var link = _channelLink;
+      if (link == null || link.isEmpty) {
+        final info = await chats.getChatInfo(api, widget.chatId);
+        link = info?['link'] as String?;
+      }
+      if (link == null || link.isEmpty) {
+        throw const PacketError('Не удалось получить ссылку канала');
+      }
+      final result = await chats.joinChannel(api, link, _myId);
+      if (!mounted) return;
+      setState(() {
+        _previewChat = false;
+        _subscribing = false;
+        chat = result.chat;
+        _participantsCount =
+            result.subscribersCount ?? ((_participantsCount ?? 0) + 1);
+      });
+      _recomputeHeaderStatus();
+      showCustomNotification(context, 'Вы подписались на канал');
+    } catch (e) {
+      if (!mounted) return;
+      setState(() => _subscribing = false);
+      showCustomNotification(
+        context,
+        e is PacketError ? e.message : 'Не удалось подписаться',
+      );
+    }
+  }
+
   Future<void> _toggleChatMute() async {
     final current = chat;
     if (current == null) return;