import 'dart:async';
import 'dart:convert' show base64Encode;
import 'dart:io' show File;
import 'dart:math' as math;
import 'dart:ui' as ui;
import 'package:file_picker/file_picker.dart';
import 'package:geolocator/geolocator.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/services.dart';
import 'package:komet/backend/modules/chat_preview.dart';
import 'package:komet/backend/modules/chats.dart';
import 'package:komet/backend/modules/comments.dart';
import 'package:komet/backend/modules/file_uploader.dart';
import 'package:komet/backend/modules/upload_notification_service.dart';
import 'package:komet/backend/modules/media_send.dart';
import 'package:komet/backend/modules/webapp.dart';
import 'package:komet/frontend/screens/webapp/open_mini_app.dart';
import 'package:komet/frontend/widgets/sending_clock_icon.dart';
import 'package:komet/core/media/desktop_video_probe.dart';
import 'package:komet/core/media/gallery_source.dart';
import 'package:komet/core/utils/format.dart';
import 'package:komet/frontend/screens/chats/chat_info_screen.dart';
import 'package:komet/frontend/screens/contacts/open_contact_profile.dart';
import 'package:komet/frontend/screens/chats/chat_list_screen.dart';
import 'package:komet/frontend/screens/chats/poll_create_screen.dart';
import 'package:komet/frontend/widgets/animated_text_swap.dart';
import 'package:komet/frontend/widgets/custom_notification.dart';
import 'package:komet/frontend/widgets/chat_menu_overlay.dart';
import 'package:material_symbols_icons/symbols.dart';
import '../../../main.dart';
import '../../../l10n/app_localizations.dart';
import '../../../backend/api.dart';
import '../../../backend/modules/messages.dart';
import '../../../backend/modules/contacts.dart';
import '../../../backend/modules/animoji.dart';
import '../../../models/animoji.dart';
import '../../../backend/modules/complaints.dart';
import '../../../core/calls/call_controller.dart';
import '../../../core/media/rlottie/rlottie.dart';
import '../calls/call_screen.dart';
import '../../../core/protocol/opcode_map.dart';
import '../../../core/protocol/packet.dart';
import '../../../core/push/push_service.dart';
import '../../../core/storage/app_database.dart';
import '../../../core/storage/chat_activity_store.dart';
import '../../../core/crypto/chat_crypto_service.dart';
import '../../../core/crypto/encrypted_photo.dart';
import '../../../core/crypto/message_decryption_cache.dart';
import '../../../core/storage/chat_encryption_store.dart';
import '../../../core/storage/chat_wallpaper_store.dart';
import '../../../core/storage/draft_store.dart';
import '../../../core/storage/archived_chats_store.dart';
import '../../../core/cache/info_cache.dart';
import '../../../core/cache/message_session_cache.dart';
import '../../../core/utils/haptics.dart';
import '../../../core/utils/emoji_keyword_index.dart';
import '../../../core/utils/logger.dart';
import '../../../core/config/app_cache_extent.dart';
import '../../../core/config/app_colors.dart';
import '../../../core/config/app_message_actions_style.dart';
import '../../../core/config/app_swipe_back_desktop.dart';
import 'chat/chat_prank_controller.dart';
import 'chat/chat_controller.dart';
import 'chat/voice_record_controller.dart';
import 'chat/video_note_controller.dart';
import 'chat/command_panel_controller.dart';
import 'chat/sticker_panel_controller.dart';
import 'chat/chat_search_controller.dart';
import 'chat/message_search_result.dart';
import 'chat/upload_status.dart';
import 'chat/view/search_view.dart';
import 'chat/view/composer_input.dart';
import 'chat/view/sticker_panel_view.dart';
import 'chat/view/command_panel_view.dart';
import 'chat/view/mention_panel_view.dart';
import 'chat/mention_panel_controller.dart';
import 'chat/view/selection_bar.dart';
import 'chat/view/chat_header.dart';
import 'chat/view/shimmer_loading.dart';
import '../../../core/config/app_commands.dart';
import '../../../core/config/app_visual_style.dart';
import '../../../core/config/app_chat_chrome.dart';
import 'package:komet/core/config/app_composer_background.dart';
import 'package:komet/core/config/app_frost.dart';
import 'package:komet/core/config/app_composer_style.dart';
import '../../../core/config/komet_settings.dart';
import '../../../models/attachment.dart';
import '../../../models/sticker.dart';
import '../../commands/command_registry.dart';
import '../../commands/slash_command.dart';
import '../../widgets/rich_message_controller.dart';
import '../../../core/utils/text_format.dart';
import '../../widgets/confirm_dialog.dart';
import '../../widgets/connection_status.dart';
import '../../widgets/message_bubble.dart';
import '../../widgets/photo_viewer.dart';
import '../../widgets/message_actions_overlay.dart';
import '../../widgets/lottie_image.dart';
import '../../widgets/attachment_panel.dart';
import '../../widgets/attachment/attachment_sheet.dart';
import '../../widgets/sticker_pack_sheet.dart';
import '../../widgets/small_spinner.dart';
import '../../widgets/swipe_to_pop.dart';
import '../../widgets/swipe_route.dart';
import '../../widgets/directional_drag_recognizer.dart';
import '../../widgets/reload_on_reconnect.dart';
import '../../widgets/schedule_time_picker.dart';
import '../../widgets/chat_wallpaper_sheet.dart';
import '../../widgets/chat_wallpaper_view.dart';
import '../../widgets/glossy_pill.dart';
import '../../widgets/liquid_glass.dart';
import 'scheduled_messages_screen.dart';
import 'chat_encryption_screen.dart';
import 'chat_wallpaper_preview_screen.dart';
import 'chat/retain_offset_physics.dart';
import 'profile_action_sheets.dart';

class _DateSeparatorItem {
  final DateTime date;
  final GlobalKey key;
  _DateSeparatorItem(this.date, this.key);
}

class _MessageItem {
  final CachedMessage message;
  final int index;
  const _MessageItem(this.message, this.index);
}

class _UnreadSeparatorItem {
  const _UnreadSeparatorItem();
}

class _FrostedPanel extends StatelessWidget {
  final Color tint;
  final Border? border;
  final double sigma;
  final BackdropKey? backdropKey;
  final Widget child;

  const _FrostedPanel({
    required this.tint,
    this.border,
    this.sigma = AppFrost.panelSigma,
    this.backdropKey,
    required this.child,
  });

  @override
  Widget build(BuildContext context) {
    return GlassSurface(
      frostTint: tint,
      frostSigma: sigma,
      border: border,
      backdropKey: backdropKey,
      child: child,
    );
  }
}

class _MeasureSize extends StatefulWidget {
  final Widget child;
  final ValueChanged<double> onHeight;

  const _MeasureSize({required this.onHeight, required this.child});

  @override
  State<_MeasureSize> createState() => _MeasureSizeState();
}

class _MeasureSizeState extends State<_MeasureSize> {
  final GlobalKey _key = GlobalKey();
  double _last = -1;

  void _report() {
    if (!mounted) return;
    final height = _key.currentContext?.size?.height;
    if (height == null) return;
    if ((height - _last).abs() > 0.5) {
      _last = height;
      widget.onHeight(height);
    }
  }

  void _scheduleReport() {
    WidgetsBinding.instance.addPostFrameCallback((_) => _report());
  }

  @override
  Widget build(BuildContext context) {
    _scheduleReport();
    return NotificationListener<SizeChangedLayoutNotification>(
      onNotification: (_) {
        _scheduleReport();
        return true;
      },
      child: SizeChangedLayoutNotifier(
        child: SizedBox(key: _key, child: widget.child),
      ),
    );
  }
}

class ForwardRequest {
  final int sourceChatId;
  final String sourceChatName;
  final String sourceChatIconUrl;
  final String sourceChatType;
  final List<CachedMessage> messages;

  ForwardRequest({
    required this.sourceChatId,
    required this.sourceChatName,
    required this.sourceChatIconUrl,
    required this.sourceChatType,
    required List<CachedMessage> messages,
  }) : messages = List.unmodifiable(messages);

  ForwardRequest withMessages(List<CachedMessage> value) => ForwardRequest(
    sourceChatId: sourceChatId,
    sourceChatName: sourceChatName,
    sourceChatIconUrl: sourceChatIconUrl,
    sourceChatType: sourceChatType,
    messages: value,
  );
}

class ReplyRequest {
  final int sourceChatId;
  final CachedMessage message;

  const ReplyRequest({required this.sourceChatId, required this.message});
}

class ChatScreen extends StatefulWidget {
  final int chatId;
  final String name;
  final String imageUrl;
  final String chatType;
  final bool? channelSubscribed;
  final bool embedded;
  final VoidCallback? onClose;
  final ForwardRequest? forwardRequest;
  final ReplyRequest? replyRequest;
  final String? initialMessageId;
  final int? initialMessageTime;
  final String? commentPostId;
  final CachedMessage? postMessage;
  final String? botStartPayload;
  final String? initialText;

  const ChatScreen({
    super.key,
    required this.chatId,
    required this.name,
    required this.imageUrl,
    required this.chatType,
    this.channelSubscribed,
    this.embedded = false,
    this.onClose,
    this.forwardRequest,
    this.replyRequest,
    this.initialMessageId,
    this.initialMessageTime,
    this.commentPostId,
    this.postMessage,
    this.botStartPayload,
    this.initialText,
  });

  static final List<_ChatScreenState> _open = [];

  static bool startBotInVisibleChat(int chatId, String startPayload) {
    for (final screen in _open.reversed) {
      if (screen.widget.chatId != chatId) continue;
      if (!screen.mounted || !screen._isRouteCurrent) continue;
      unawaited(screen._sendBotStart(startPayload));
      return true;
    }
    return false;
  }

  @override
  State<ChatScreen> createState() => _ChatScreenState();
}

class _ChatScreenState extends State<ChatScreen>
    with TickerProviderStateMixin, WidgetsBindingObserver, ReloadOnReconnect {
  final RichMessageController _messageController = RichMessageController();
  final FocusNode _messageFocusNode = FocusNode();
  double _keyboardReserve = 0;
  bool _keyboardWasOpen = false;
  bool _keyboardBeforeStickers = false;
  final ScrollController _scrollController = ScrollController();
  bool _userDidScroll = false;
  String? _pinnedMessageId;
  double _pinnedAlignment = 0;
  int? _unreadAnchorTime;
  bool _awaitingPosition = false;
  bool _navigatingToTarget = false;
  bool _initialPositionDone = false;
  bool _positioningInFlight = false;
  bool _initialTargetHandled = false;
  int _historyAutoloadSuppressCount = 0;
  bool get _historyAutoloadSuppressed => _historyAutoloadSuppressCount > 0;
  int _readMarkTime = 0;
  Timer? _readMarkTimer;
  final GlobalKey _listKey = GlobalKey();
  final Object _profileHeroTag = UniqueKey();
  final ValueNotifier<bool> _hasText = ValueNotifier(false);
  bool _isLoading = true;
  bool _encryptionEnabled = false;
  final ValueNotifier<bool> _showAttachmentPanel = ValueNotifier(false);
  late final StickerPanelController _stickers;
  final ValueNotifier<UploadStatus> _uploadStatus = ValueNotifier(
    const UploadStatus(),
  );
  StreamSubscription<UploadEvent>? _uploadSub;
  StreamSubscription<Packet>? _pushSub;
  StreamSubscription<MessageEvent>? _messageEventSub;
  StreamSubscription<Map<String, CommentsInfo>>? _commentsInfoSub;
  StreamSubscription<CommentAddedEvent>? _commentSub;
  final Map<String, int> _commentCounts = {};
  final Set<String> _commentCountsRequested = {};
  bool get _commentsMode => widget.commentPostId != null;
  bool _commentsLoadingMore = false;
  bool _commentsHasMore = true;
  StreamSubscription<SessionState>? _connSub;
  final Map<String, ValueNotifier<Map<String, dynamic>?>> _reactionNotifiers =
      {};
  final ValueNotifier<ReactionAnimationEvent?> _reactionAnimation =
      ValueNotifier(null);
  int _reactionAnimationToken = 0;
  final Map<String, ValueNotifier<List<double>>> _photoUploadProgress = {};
  final ValueNotifier<int> _scheduledCount = ValueNotifier(0);

  late final VoiceRecordController _voiceRec = VoiceRecordController(
    contextOf: () => context,
    isMounted: () => mounted,
    myId: () => _myId,
    onRecorded: _sendVoice,
  );

  late final VideoNoteController _note = VideoNoteController(
    contextOf: () => context,
    isMounted: () => mounted,
    onRecorded: _sendVideoNote,
    formatElapsed: formatVoiceElapsed,
  );

  StreamSubscription<MediaSendEvent>? _mediaSendSub;

  ValueListenable<List<double>>? _photoProgressFor(CachedMessage m) =>
      _photoUploadProgress[m.id] ?? MediaSendService.instance.progressFor(m.id);

  ValueNotifier<Map<String, dynamic>?> _reactionNotifierFor(CachedMessage m) {
    final existing = _reactionNotifiers[m.id];
    if (existing != null) return existing;
    final info = m.payload?['reactionInfo'];
    final notifier = ValueNotifier<Map<String, dynamic>?>(
      info is Map ? Map<String, dynamic>.from(info) : null,
    );
    _reactionNotifiers[m.id] = notifier;
    return notifier;
  }

  void _reactToMessage(CachedMessage message, String emoji) {
    if (message.isControl || message.id.startsWith('temp_')) return;
    final notifier = _reactionNotifierFor(message);
    final previous = notifier.value;
    final applied = _applyLocalReaction(previous, emoji);
    notifier.value = applied;
    final isToggleOff = applied == null || applied['yourReaction'] == null;
    unawaited(_sendReaction(message, emoji, isToggleOff, previous));
  }

  Future<void> _sendReaction(
    CachedMessage message,
    String emoji,
    bool isToggleOff,
    Map<String, dynamic>? previous,
  ) async {
    ({bool ok, Map<String, dynamic>? info}) result;
    try {
      result = isToggleOff
          ? await messagesModule.cancelReaction(widget.chatId, message.id)
          : await messagesModule.setReaction(widget.chatId, message.id, emoji);
    } catch (_) {
      result = (ok: false, info: null);
    }
    if (!mounted) return;
    final notifier = _reactionNotifiers[message.id];
    if (notifier == null) return;
    if (!result.ok) {
      notifier.value = previous;
      Haptics.error();
      showCustomNotification(context, 'Не удалось обновить реакцию');
      return;
    }
    notifier.value = result.info;
    _applyReactionInfoToMessage(message.id, result.info);
    final appliedReaction = result.info?['yourReaction']?.toString();
    if (!isToggleOff &&
        appliedReaction != null &&
        EmojiKeywordIndex.normalize(appliedReaction) ==
            EmojiKeywordIndex.normalize(emoji)) {
      final event = ReactionAnimationEvent(
        messageId: message.id,
        emoji: appliedReaction,
        token: ++_reactionAnimationToken,
      );
      WidgetsBinding.instance.addPostFrameCallback((_) {
        if (mounted) _reactionAnimation.value = event;
      });
    }
  }

  void _applyReactionInfoToMessage(
    String messageId,
    Map<String, dynamic>? info,
  ) {
    final idx = _messages.indexWhere((m) => m.id == messageId);
    if (idx == -1) return;
    final payload = <String, dynamic>{...?_messages[idx].payload};
    if (info == null) {
      payload.remove('reactionInfo');
    } else {
      payload['reactionInfo'] = info;
    }
    _messages[idx] = _messages[idx].copyWith(payload: payload);
  }

  Map<String, dynamic>? _applyLocalReaction(
    Map<String, dynamic>? current,
    String emoji,
  ) {
    final counters = <String, int>{};
    final order = <String>[];
    final rawCounters = current?['counters'];
    if (rawCounters is List) {
      for (final c in rawCounters) {
        if (c is! Map) continue;
        final r = c['reaction']?.toString();
        if (r == null || r.isEmpty) continue;
        final n = c['count'];
        counters[r] = n is int ? n : 0;
        order.add(r);
      }
    }

    void decrement(String key) {
      final next = (counters[key] ?? 1) - 1;
      if (next <= 0) {
        counters.remove(key);
        order.remove(key);
      } else {
        counters[key] = next;
      }
    }

    final prev = current?['yourReaction']?.toString();
    String? your;
    if (prev != null &&
        EmojiKeywordIndex.normalize(prev) ==
            EmojiKeywordIndex.normalize(emoji)) {
      decrement(prev);
      your = null;
    } else {
      if (prev != null && prev.isNotEmpty) decrement(prev);
      if (!counters.containsKey(emoji)) order.add(emoji);
      counters[emoji] = (counters[emoji] ?? 0) + 1;
      your = emoji;
    }

    if (counters.isEmpty) return null;
    final total = counters.values.fold<int>(0, (a, b) => a + b);
    return {
      'counters': [
        for (final key in order) {'reaction': key, 'count': counters[key]},
      ],
      'yourReaction': ?your,
      'totalCount': total,
    };
  }

  void _pruneReactionNotifiers() {
    final liveIds = _messages.map((m) => m.id).toSet();
    final dead = _reactionNotifiers.keys
        .where((id) => !liveIds.contains(id))
        .toList();
    for (final id in dead) {
      _reactionNotifiers.remove(id)?.dispose();
    }
    _messageKeys.removeWhere((id, _) => !liveIds.contains(id));
  }

  int _otherStatus = 0;
  int? _otherSeenTime;
  int? _participantsCount;

  final ValueNotifier<CachedMessage?> _replyTo = ValueNotifier(null);
  final ValueNotifier<List<CachedMessage>> _pendingForwards = ValueNotifier(
    const [],
  );
  static const bool _crossChatReplySupported = false;
  int? _replySourceChatId;
  ForwardRequest? _forwardRequest;
  bool _forwardSending = false;
  final ValueNotifier<String?> _highlightMessageId = ValueNotifier(null);
  Timer? _highlightTimer;
  final ValueNotifier<double?> _jumpCacheExtent = ValueNotifier<double?>(null);
  Timer? _goToMessageSettleTimer;
  static const double _jumpCacheExtentPx = 800.0;

  late final ChatSearchController _search;
  late final AnimationController _searchAnim;
  final FocusNode _searchFocusNode = FocusNode();

  late final ChatPrankController _prank = ChatPrankController(
    vsync: this,
    contextOf: () => context,
    isMounted: () => mounted,
    onChanged: () {
      if (mounted) setState(() {});
    },
  );
  final ValueNotifier<String> _headerStatusNotifier = ValueNotifier('');
  final ValueNotifier<int> _otherReadTime = ValueNotifier(0);
  int _tempIdCounter = 0;
  late final AnimationController _attachAnim;
  late final CommandPanelController _commandPanel;
  late final MentionPanelController _mentionPanel;

  String _nextTempId() =>
      'temp_${++_tempIdCounter}_${DateTime.now().microsecondsSinceEpoch}';
  late AnimationController _shimmerController;
  Timer? _shimmerStartTimer;
  bool _previewChat = false;
  bool _subscribing = false;
  String? _channelLink;
  final ChatController _chatController = ChatController();

  List<CachedMessage> get _messages => _chatController.messages;
  set _messages(List<CachedMessage> v) => _chatController.messages = v;
  ValueNotifier<int> get _messagesRev => _chatController.messagesRev;
  bool get _historyKickedOff => _chatController.historyKickedOff;
  set _historyKickedOff(bool v) => _chatController.historyKickedOff = v;

  final GlobalKey _messageListKey = GlobalKey();
  _ChatMessageList? _messageListWidget;
  final Set<String> _deletingIds = {};

  static const double _avgMessageHeight = 72.0;
  static const double _historyPrefetchExtent = _avgMessageHeight * 8;
  static const double _scrollDownRevealExtent = _avgMessageHeight * 30;
  static const double _scrollDownRevealFactor = 0.6;
  static const double _scrollDownTeleportFactor = 2.0;
  static const double _glossyHeaderHeight = 76.0;
  static const double _glossySearchHeight = 58.0;
  static const double _pinnedBannerLift = 6.0;

  final BackdropKey _barBackdrop = BackdropKey();
  final BackdropKey _pillBackdrop = BackdropKey();
  bool get _isLoadingMore => _chatController.isLoadingMore;
  set _isLoadingMore(bool v) => _chatController.isLoadingMore = v;
  bool get _hasMoreHistory => _chatController.hasMoreHistory;
  set _hasMoreHistory(bool v) => _chatController.hasMoreHistory = v;
  List<Object>? _combinedItemsCache;
  int? _combinedItemsKey;
  bool _floatingDateScheduled = false;
  int get _myId => _chatController.myId;
  set _myId(int v) => _chatController.myId = v;
  CachedChat? chat;
  bool _peerIsBot = false;
  bool _botStartRequested = false;
  ChatWallpaper? _wallpaper;

  bool get _composerFrosted =>
      AppComposerBackground.current.value != ComposerBackground.standard;

  bool get _composerUnderlap =>
      AppChatChrome.current.value != ChatChromeStyle.color || _composerFrosted;

  bool get _liquidChrome =>
      AppVisualStyle.current.value.glossyChrome &&
      ChatChromeMaterial.isLiquid(AppChatChrome.current.value);

  ChatChromeStyle get _effectiveChrome {
    final chrome = AppChatChrome.current.value;
    if (chrome == ChatChromeStyle.liquidGlass) return ChatChromeStyle.transparent;
    if (_wallpaper != null && chrome == ChatChromeStyle.none) {
      return ChatChromeStyle.blur;
    }
    return chrome;
  }

  final ValueNotifier<double> _composerHeight = ValueNotifier(96);
  final ValueNotifier<double> _pinnedBannerHeight = ValueNotifier(0);

  final ValueNotifier<DateTime?> _floatingDate = ValueNotifier(null);
  Timer? _floatingDateTimer;
  late final AnimationController _floatingDateAnimController;
  late final CurvedAnimation _floatingDateCurved;
  late final AnimationController _scrollDownAnimController;
  late final CurvedAnimation _scrollDownCurved;
  bool _scrollDownVisible = false;
  final ValueNotifier<int> _newMessageCount = ValueNotifier(0);
  bool _clearCountScheduled = false;
  bool _retainOffsetOnce = false;
  late final ScrollPhysics _listPhysics = RetainOffsetScrollPhysics(
    retain: _consumeRetainOffset,
  );
  int _listEpoch = 0;
  final List<({String id, double pixels, double alignment})> _returnStack = [];
  bool _returningToAnchor = false;
  final Map<int, GlobalKey> _separatorKeys = {};
  String? _lastSentId;
  final ValueNotifier<int> _otherUnread = ValueNotifier(0);
  final ValueNotifier<bool> _animojiHold = ValueNotifier(true);

  final ValueNotifier<Set<String>> _selectedIds = ValueNotifier(const {});
  final ValueNotifier<({String id, Offset pos})?> _textSelection =
      ValueNotifier(null);
  late final AnimationController _selectionAnim;

  bool get _selectionMode => _selectedIds.value.isNotEmpty;

  void _prewarmQuickReactions() {
    if (!mounted || !RlottieEngine.instance.available) return;
    final dpr = (MediaQuery.maybeOf(context)?.devicePixelRatio ?? 2.0).clamp(
      1.0,
      2.0,
    );
    final px = ((44.0 * dpr).clamp(96.0, 512.0) / 32).ceil() * 32;
    for (final a in animojiModule.quickAnimojis) {
      for (final url in [a.lottieUrl, a.lottiePlayUrl]) {
        if (url != null && url.isNotEmpty) {
          unawaited(RlottieEngine.instance.prewarm(url, px));
        }
      }
    }
  }

  @override
  void initState() {
    super.initState();
    _previewChat = widget.channelSubscribed == false;
    _chatController.chatId = widget.chatId;
    _chatController.isMounted = () => mounted;
    if (!_commentsMode) ChatScreen._open.add(this);
    unawaited(PushService.clearChatNotification(widget.chatId));
    unawaited(
      animojiModule
          .ensureLoaded()
          .then((_) {
            _prewarmQuickReactions();
            if (mounted) _bumpMessages();
          })
          .catchError((_) {}),
    );
    WidgetsBinding.instance.addObserver(this);
    _mediaSendSub = MediaSendService.instance.events.listen(_onMediaSendEvent);
    chats.chatsChanged.addListener(_onChatsBump);
    _messageController.addListener(_onTextChanged);
    _scrollController.addListener(_onScrollForDate);
    _scrollController.addListener(_maybeLoadMoreHistory);
    _scrollController.addListener(_recordScrollPixels);
    _scrollController.addListener(_scheduleReadMarker);
    _scrollController.addListener(_exitTextSelectionOnScroll);
    _scrollController.addListener(_updateScrollDownVisible);
    AppVisualStyle.current.addListener(_onVisualStyleChanged);
    AppChatChrome.current.addListener(_onVisualStyleChanged);
    AppComposerStyle.current.addListener(_onVisualStyleChanged);
    AppComposerBackground.current.addListener(_onVisualStyleChanged);
    _shimmerController = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 1500),
    );
    _attachAnim = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 320),
      reverseDuration: const Duration(milliseconds: 240),
    );
    _stickers = StickerPanelController(
      vsync: this,
      onSendTyping: () => messagesModule.sendTyping(widget.chatId, 'STICKER'),
    );
    _showAttachmentPanel.addListener(_onAttachPanelToggle);
    _commandPanel = CommandPanelController(
      vsync: this,
      textOf: () => _messageController.text,
      onSelected: _onCommandSelected,
    );
    _mentionPanel = MentionPanelController(
      vsync: this,
      chatId: widget.chatId,
      enabled: _mentionsAvailable,
      selfId: () => _myId,
      valueOf: () => _messageController.value,
      onSelected: _onMentionSelected,
    );
    _selectionAnim = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 260),
      reverseDuration: const Duration(milliseconds: 200),
    );
    _searchAnim = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 280),
      reverseDuration: const Duration(milliseconds: 220),
    );
    _search = ChatSearchController(
      chatId: widget.chatId,
      isMounted: () => mounted,
    );
    final incomingReply = widget.replyRequest;
    if (incomingReply != null) {
      _replyTo.value = incomingReply.message;
      _replySourceChatId = incomingReply.sourceChatId == widget.chatId
          ? null
          : incomingReply.sourceChatId;
    }
    final incomingForward = widget.forwardRequest;
    if (incomingForward != null) {
      _forwardRequest = incomingForward;
      _pendingForwards.value = incomingForward.messages;
    }
    _pushSub = api.pushStream
        .where(
          (p) =>
              p.opcode == Opcode.notifMark ||
              p.opcode == Opcode.notifTyping ||
              p.opcode == Opcode.notifMsgDelayed,
        )
        .listen(_onIncomingPush);
    _messageEventSub = chats.messageEvents
        .where((e) => e.chatId == widget.chatId)
        .listen(_onMessageEvent);
    if (_commentsMode) {
      _commentSub = commentsModule.commentStream
          .where(
            (e) =>
                e.chatId == widget.chatId && e.postId == widget.commentPostId,
          )
          .listen(_onLiveComment);
    } else if (widget.chatType == 'CHANNEL') {
      _commentsInfoSub = commentsModule.infoStream.listen(_onCommentsInfo);
    }
    ChatActivityStore.instance
        .listenable(widget.chatId)
        .addListener(_recomputeHeaderStatus);
    _connSub = api.stateStream.listen((_) {
      if (mounted) _recomputeHeaderStatus();
    });
    debugForceOffline.addListener(_recomputeHeaderStatus);
    PresenceFetch.revision.addListener(_onPresenceChanged);
    ContactsModule.revision.addListener(_onContactsChanged);
    _floatingDateAnimController = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 220),
      reverseDuration: const Duration(milliseconds: 380),
    );
    _floatingDateCurved = CurvedAnimation(
      parent: _floatingDateAnimController,
      curve: Curves.easeOut,
      reverseCurve: Curves.easeIn,
    );
    _scrollDownAnimController = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 220),
      reverseDuration: const Duration(milliseconds: 180),
    );
    _scrollDownCurved = CurvedAnimation(
      parent: _scrollDownAnimController,
      curve: Curves.easeOut,
      reverseCurve: Curves.easeIn,
    );

    unawaited(_fastPreloadCache());
    unawaited(_loadParticipantsCount());
    WidgetsBinding.instance.addPostFrameCallback(_onFirstFrameRendered);
  }

  @override
  void reloadAfterReconnect() {
    if (!_historyKickedOff) return;
    unawaited(_loadHistory());
    unawaited(_loadParticipantsCount());
  }

  Future<void> _loadParticipantsCount() async {
    if (_commentsMode) return;
    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;
      _recomputeHeaderStatus();
    }
  }

  Future<void> _loadPeerKind() async {
    if (widget.chatType != 'DIALOG' || _myId == 0) return;
    final peerId = widget.chatId ^ _myId;
    if (peerId <= 0) return;
    final cached = ContactInfoFetch.peek(peerId);
    if (cached != null) _applyPeerKind(cached.isBot);
    final info = await ContactInfoFetch.get(peerId);
    if (info != null) _applyPeerKind(info.isBot);
    if ((info ?? cached)?.isBot ?? false) {
      unawaited(BotInfoFetch.get(peerId));
    }
  }

  void _applyPeerKind(bool isBot) {
    if (!mounted || _peerIsBot == isBot) return;
    setState(() => _peerIsBot = isBot);
  }

  Future<void> _fastPreloadCache() async {
    final p = await AppDatabase.loadActiveProfile();
    if (!mounted) return;
    _myId = p?.id ?? 0;
    if (p != null && p.id != 0) {
      final myName = [
        p.firstName,
        p.lastName,
      ].whereType<String>().where((s) => s.isNotEmpty).join(' ');
      if (myName.isNotEmpty) ContactCache.put(p.id, myName);
      ContactCache.putAvatar(p.id, p.baseUrl);
    }
    if (_commentsMode) return;
    _restoreDraft();
    unawaited(_loadPeerKind());
    unawaited(_loadWallpaper());
    unawaited(_loadEncryption());
    unawaited(_refreshBadge());

    try {
      final chatRows = await chats.getChat(_myId, widget.chatId);
      if (!mounted) return;
      if (chatRows.isNotEmpty) {
        final channelSubscribed =
            widget.chatType != 'CHANNEL' ||
            await AppDatabase.isChatInList(_myId, widget.chatId);
        if (!mounted) return;
        setState(() {
          chat = chatRows.first;
          if (widget.chatType == 'CHANNEL') {
            _previewChat = !channelSubscribed;
          }
        });
        _bumpMessages();
        _seedPresenceFromChat();
        _recomputeHeaderStatus();
        _syncOtherReadTime();
      }
    } catch (_) {}

    _resolveUnreadAnchor();

    final cached = MessageSessionCache.get(_myId, widget.chatId);
    if (cached != null && cached.messages.isNotEmpty) {
      setState(() {
        _messages = List<CachedMessage>.of(cached.messages);
        _hasMoreHistory = !cached.reachedStart;
        _messagesRev.value++;
      });
      _mergePendingMedia();
      _syncReactionNotifiersFromMessages();
      _requestCommentCounts();
      _revealOrHoldInitial();
      return;
    }

    final firstRows = await AppDatabase.loadMessages(
      _myId,
      widget.chatId,
      limit: 20,
      onlyVisible: !KometSettings.viewDeleted.value,
    );
    if (!mounted) return;
    if (firstRows.isNotEmpty) {
      final first = firstRows.reversed
          .map((r) => CachedMessage.fromDbRow(r))
          .toList();
      setState(() {
        _messages = first;
        _messagesRev.value++;
      });
      _mergePendingMedia();
      _requestCommentCounts();
      _revealOrHoldInitial();
    }
  }

  void _resolveUnreadAnchor() {
    final c = chat;
    _readMarkTime = c?.participants[_myId] ?? 0;
    if (c == null || c.unreadCount <= 0) {
      _unreadAnchorTime = null;
    } else {
      final myMark = c.participants[_myId] ?? 0;
      _unreadAnchorTime = myMark > 0 ? myMark : null;
    }
    _awaitingPosition = c != null && c.unreadCount > 0;
  }

  void _resolveCountBasedAnchor() {
    final c = chat;
    if (c == null || c.unreadCount <= 0 || _messages.isEmpty) return;
    final unread = c.unreadCount;
    if (_messages.length > unread) {
      _unreadAnchorTime = _messages[_messages.length - unread - 1].time;
    } else if (!_hasMoreHistory) {
      _unreadAnchorTime = _messages.first.time - 1;
    }
  }

  void _revealOrHoldInitial() {
    if (_awaitingPosition && !_canPositionNow()) return;
    setState(() {
      _isLoading = false;
      _onLoadingFinished();
    });
  }

  bool _canPositionNow() {
    if (_unreadAnchorTime == null) _resolveCountBasedAnchor();
    final ua = _unreadAnchorTime;
    if (ua == null) return false;
    final firstUnread = _messages.indexWhere((m) => m.time > ua);
    if (firstUnread == -1) return _newestMessageLoaded();
    return firstUnread > 0 || !_hasMoreHistory;
  }

  bool _newestMessageLoaded() {
    if (_messages.isEmpty) return false;
    final serverLast = chat?.lastMsgTime ?? 0;
    return _messages.last.time >= serverLast;
  }

  void _onFirstFrameRendered(Duration _) {
    if (!mounted) return;
    if (widget.embedded) {
      _kickoffHistory();
      return;
    }
    final anim = ModalRoute.of(context)?.animation;
    if (anim == null || anim.status == AnimationStatus.completed) {
      _kickoffHistory();
      return;
    }
    Timer? safety;
    void onStatus(AnimationStatus status) {
      if (status != AnimationStatus.completed) return;
      anim.removeStatusListener(onStatus);
      safety?.cancel();
      if (!mounted) return;
      _kickoffHistory();
    }

    anim.addStatusListener(onStatus);
    safety = Timer(const Duration(milliseconds: 400), () {
      anim.removeStatusListener(onStatus);
      if (!mounted) return;
      _kickoffHistory();
    });
  }

  void _kickoffHistory() {
    _animojiHold.value = false;
    if (_historyKickedOff) return;
    _historyKickedOff = true;
    _shimmerStartTimer = Timer(const Duration(milliseconds: 150), () {
      if (!mounted || !_isLoading) return;
      _shimmerController.repeat();
    });
    unawaited(_loadHistory().then((_) => _sendPendingBotStart()));
  }

  bool get _isRouteCurrent {
    if (!mounted) return false;
    final route = ModalRoute.of(context);
    return route == null || route.isCurrent;
  }

  Future<void> _sendPendingBotStart() async {
    final payload = widget.botStartPayload;
    if (payload == null || _botStartRequested || !mounted) return;
    _botStartRequested = true;
    await _sendBotStart(payload);
  }

  Future<void> _sendBotStart(String startPayload) async {
    if (_myId == 0) {
      final profile = await AppDatabase.loadActiveProfile();
      if (!mounted) return;
      _myId = profile?.id ?? 0;
    }
    try {
      final sent = await messagesModule.sendBotStart(
        widget.chatId,
        startPayload,
      );
      if (!mounted) return;
      if (sent == null) {
        showCustomNotification(context, 'Не удалось запустить бота');
        return;
      }
      await _persistOutgoing(
        CachedMessage.fromPushPayload(_myId, widget.chatId, sent),
      );
    } catch (_) {
      if (mounted) showCustomNotification(context, 'Не удалось запустить бота');
    }
  }

  void _onLoadingFinished() {
    _shimmerStartTimer?.cancel();
    _shimmerStartTimer = null;
    _applyInitialPositioning();
  }

  void _recordScrollPixels() {
    if (!_scrollController.hasClients) return;
    if (_initialPositionDone &&
        _scrollController.position.userScrollDirection !=
            ScrollDirection.idle) {
      _userDidScroll = true;
      _pinnedMessageId = null;
    }
  }

  void _positionToMessage(String messageId, double alignment) {
    _pinnedMessageId = messageId;
    _pinnedAlignment = alignment.clamp(0.0, 1.0);
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (!mounted) return;
      _scrollToLoadedMessage(
        messageId,
        alignment: _pinnedAlignment,
        highlight: false,
        notifyIfMissing: false,
        onSettled: () {
          if (mounted) setState(_markPositioned);
        },
      );
    });
  }

  void _reapplyPinIfNeeded() {
    final id = _pinnedMessageId;
    if (id == null || _userDidScroll || !_scrollController.hasClients) return;
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (!mounted || _pinnedMessageId != id || _userDidScroll) return;
      _alignLoadedMessage(id, _pinnedAlignment, 0);
    });
  }

  void _applyInitialPositioning() {
    if (_initialPositionDone) {
      if (_shimmerController.isAnimating) _shimmerController.stop();
      _scheduleReadMarker();
      return;
    }
    if (_positioningInFlight) return;
    if (_commentsMode) {
      _initialPositionDone = true;
      _markPositioned();
      WidgetsBinding.instance.addPostFrameCallback((_) {
        if (!mounted || !_scrollController.hasClients) return;
        _scrollController.jumpTo(_scrollController.position.maxScrollExtent);
      });
      return;
    }
    if (_messages.isEmpty) {
      if (!_hasMoreHistory) _markPositioned();
      return;
    }

    final c = chat;
    if (c != null && c.unreadCount > 0) {
      if (_unreadAnchorTime == null) _resolveCountBasedAnchor();
      final ua = _unreadAnchorTime;
      if (ua == null) {
        if (_hasMoreHistory) {
          _positioningInFlight = true;
          unawaited(_loadUntilUnreadReady());
        } else {
          _markPositioned();
        }
        return;
      }
      final firstUnread = _messages.indexWhere((m) => m.time > ua);
      if (firstUnread == -1) {
        _markPositioned();
        return;
      }
      if (firstUnread > 0 || !_hasMoreHistory) {
        _initialPositionDone = true;
        _positionToMessage(_messages[firstUnread].id, 0.15);
      } else {
        _positioningInFlight = true;
        unawaited(_loadUntilUnreadReady());
      }
      return;
    }

    _markPositioned();
  }

  void _markPositioned() {
    _positioningInFlight = false;
    _initialPositionDone = true;
    _awaitingPosition = false;
    _isLoading = false;
    if (_shimmerController.isAnimating) _shimmerController.stop();
    _scheduleReadMarker();
    _maybeRunInitialTarget();
  }

  void _maybeRunInitialTarget() {
    if (_initialTargetHandled || widget.initialMessageId == null) return;
    _initialTargetHandled = true;
    _beginTargetNavigation();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (mounted) unawaited(_navigateToInitialMessage());
    });
  }

  void _beginTargetNavigation() {
    _navigatingToTarget = true;
    _jumpCacheExtent.value = _jumpCacheExtentPx;
    _goToMessageSettleTimer?.cancel();
    if (!_shimmerController.isAnimating) _shimmerController.repeat();
  }

  void _finishTargetNavigation() {
    _goToMessageSettleTimer?.cancel();
    if (!mounted) {
      _navigatingToTarget = false;
      return;
    }
    if (_navigatingToTarget) {
      setState(() => _navigatingToTarget = false);
    }
    if (_shimmerController.isAnimating) _shimmerController.stop();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (mounted) _jumpCacheExtent.value = null;
    });
  }

  void _openChatInfo({ChatInfoTab? initialTab}) {
    final navigator = Navigator.of(context);
    final chatRoute = ModalRoute.of(context);
    navigator.push(
      MaterialPageRoute(
        builder: (_) => ChatInfoScreen(
          chatId: widget.chatId,
          name: _headerName(),
          imageUrl: widget.imageUrl,
          chatType: widget.chatType,
          heroTag: _profileHeroTag,
          initialTab: initialTab,
          openedFromChat: true,
          onJumpToMessage: (chatRoute == null || widget.embedded)
              ? null
              : (messageId, time) {
                  navigator.popUntil((r) => r == chatRoute);
                  _requestGoToMessage(messageId, time);
                },
        ),
      ),
    );
  }

  late final PhotoViewerActions _photoActions = PhotoViewerActions(
    goToMessage: _requestGoToMessage,
    forward: _forwardMessageById,
    delete: (messageId, senderId) =>
        _confirmDeleteMessage(messageId, senderId == _myId),
    viewAllMedia: () => _openChatInfo(initialTab: ChatInfoTab.media),
  );

  void _forwardMessageById(String messageId) {
    final message = _messages.where((m) => m.id == messageId).firstOrNull;
    if (message == null) {
      showCustomNotification(context, 'Сообщение не загружено');
      return;
    }
    unawaited(_forwardMessages([message]));
  }

  void _requestGoToMessage(String id, int time) {
    if (!mounted) return;
    setState(_beginTargetNavigation);
    _goToMessageSettleTimer = Timer(const Duration(milliseconds: 340), () {
      if (mounted) unawaited(_runGoToMessage(id, time));
    });
  }

  Future<void> _loadUntilUnreadReady() async {
    await _walkHistoryBack(
      reached: () {
        if (_unreadAnchorTime == null) _resolveCountBasedAnchor();
        final ua = _unreadAnchorTime;
        return ua != null && _messages.indexWhere((m) => m.time > ua) > 0;
      },
      maxPages: 15,
    );
    if (!mounted) return;
    if (_unreadAnchorTime == null) _resolveCountBasedAnchor();
    final ua = _unreadAnchorTime;
    final idx = ua == null ? -1 : _messages.indexWhere((m) => m.time > ua);
    _positioningInFlight = false;
    _initialPositionDone = true;
    if (idx >= 0) {
      _positionToMessage(_messages[idx].id, 0.15);
    } else {
      setState(_markPositioned);
    }
  }

  void _scheduleReadMarker() {
    _readMarkTimer?.cancel();
    _readMarkTimer = Timer(
      const Duration(milliseconds: 350),
      _updateReadMarker,
    );
  }

  void _updateReadMarker() {
    if (_commentsMode) return;
    if (!mounted || _myId == 0 || _messages.isEmpty) return;
    if (_awaitingPosition || !_initialPositionDone) return;
    if (!_scrollController.hasClients) return;
    final listBox = _listKey.currentContext?.findRenderObject();
    if (listBox is! RenderBox) return;
    final viewportBottom = listBox.size.height;
    if (viewportBottom <= 0) return;

    CachedMessage? candidate;
    int topIndex = -1;
    for (int i = _messages.length - 1; i >= 0; i--) {
      final m = _messages[i];
      final ctx = _messageKeys[m.id]?.currentContext;
      if (ctx == null) continue;
      final box = ctx.findRenderObject();
      if (box is! RenderBox || !box.attached) continue;
      final top = box.localToGlobal(Offset.zero, ancestor: listBox).dy;
      final bottom = top + box.size.height;
      if (bottom <= 0 || top >= viewportBottom) continue;
      candidate ??= m;
      topIndex = i;
    }
    if (candidate == null) return;

    final atBottom = candidate.id == _messages.last.id;

    if (_unreadAnchorTime != null &&
        _unreadSeparatorScrolledPast(
          atBottom,
          topIndex,
          listBox,
          viewportBottom,
        )) {
      _unreadAnchorTime = null;
      _bumpMessages();
    }

    if (candidate.time <= _readMarkTime) return;
    _readMarkTime = candidate.time;
    final remaining = _messages
        .where((m) => m.time > _readMarkTime && m.senderId != _myId)
        .length;
    unawaited(
      chats.markReadUpTo(
        api,
        _myId,
        widget.chatId,
        candidate.id,
        candidate.time,
        remaining: remaining,
      ),
    );
  }

  bool _unreadSeparatorScrolledPast(
    bool atBottom,
    int topIndex,
    RenderBox listBox,
    double viewportBottom,
  ) {
    if (atBottom) return true;
    final ua = _unreadAnchorTime;
    if (ua == null) return false;
    final firstUnread = _messages.indexWhere((m) => m.time > ua);
    if (firstUnread == -1) return true;
    if (topIndex >= 0 && topIndex > firstUnread) return true;
    final box = _messageKeys[_messages[firstUnread].id]?.currentContext
        ?.findRenderObject();
    if (box is RenderBox && box.attached) {
      final top = box.localToGlobal(Offset.zero, ancestor: listBox).dy;
      if (top <= 0) return true;
    }
    return false;
  }

  Future<void> _markMessageUnread(CachedMessage message) async {
    final unread = await chats.markUnread(
      api,
      _myId,
      widget.chatId,
      message.time,
    );
    if (!mounted) return;
    if (unread == null) {
      showCustomNotification(context, 'Не удалось пометить непрочитанным');
      return;
    }
    Navigator.of(context).pop();
  }

  bool _canShowReadBy(CachedMessage message) {
    if (message.isControl || message.deleted) return false;
    if (int.tryParse(message.id) == null) return false;
    final type = chat?.type ?? widget.chatType;
    return type == 'CHAT' || type == 'GROUP';
  }

  Future<List<MessageReader>> _loadReadBy(CachedMessage message) async {
    final marks = await chats.getReadMarks(api, _myId, widget.chatId);
    final reactions = await messagesModule.getDetailedReactions(
      widget.chatId,
      message.id,
    );

    final readerIds = <int>{
      ...marks.entries.where((e) => e.value >= message.time).map((e) => e.key),
      ...reactions.keys,
    }..removeAll({_myId, message.senderId});
    if (readerIds.isEmpty || !mounted) return const [];

    await messagesModule.ensureContactNames(readerIds);
    await animojiModule.ensureLoaded();
    if (!mounted) return const [];

    final animojiByEmoji = {
      for (final animoji in animojiModule.animojis)
        EmojiKeywordIndex.normalize(animoji.emoji): animoji,
    };
    final unknownName = AppLocalizations.of(
      context,
    )!.msgActionsReadByUnknownUser;

    final readers = readerIds.map((id) {
      final emoji = reactions[id];
      final animoji = emoji == null
          ? null
          : animojiByEmoji[EmojiKeywordIndex.normalize(emoji)];
      final name = ContactCache.get(id);
      return MessageReader(
        id: id,
        name: name == null || name.isEmpty ? unknownName : name,
        avatarUrl: ContactCache.getAvatar(id),
        reaction: emoji == null
            ? null
            : ReactionEmoji(
                emoji: emoji,
                animationUrl: animoji?.lottieUrl,
                staticUrl: animoji?.iconUrl,
              ),
      );
    }).toList();

    readers.sort((a, b) {
      final aReacted = a.reaction != null;
      final bReacted = b.reaction != null;
      if (aReacted != bReacted) return aReacted ? -1 : 1;
      return (marks[b.id] ?? 0).compareTo(marks[a.id] ?? 0);
    });
    return readers;
  }

  bool _canPinMessage(CachedMessage message) {
    if (message.isControl) return false;
    if (int.tryParse(message.id) == null) return false;
    return chat?.canPinMessages(_myId) ?? false;
  }

  Future<void> _togglePinMessage(CachedMessage message) async {
    final messageId = int.tryParse(message.id);
    if (messageId == null) return;
    final previousChat = chat;
    final willUnpin = chat?.pinnedMsgId == messageId;
    if (willUnpin) {
      _applyPinnedMessageLocally();
    } else {
      final preview = _pinnedPreviewFor(message);
      _applyPinnedMessageLocally(
        messageId: messageId,
        text: preview.text,
        time: message.time,
        isPreview: preview.isPreview,
      );
    }
    final error = await chats.setPinnedMessage(
      api,
      chatId: widget.chatId,
      messageId: willUnpin ? null : messageId,
      notify: !willUnpin,
    );
    if (!mounted) return;
    if (error != null) {
      if (previousChat != null) setState(() => chat = previousChat);
      showCustomNotification(context, error);
      return;
    }
    showCustomNotification(
      context,
      willUnpin ? 'Сообщение откреплено' : 'Сообщение закреплено',
    );
  }

  Future<void> _unpinCurrentMessage() async {
    final previousChat = chat;
    _applyPinnedMessageLocally();
    final error = await chats.setPinnedMessage(
      api,
      chatId: widget.chatId,
      messageId: null,
      notify: false,
    );
    if (!mounted) return;
    if (error != null) {
      if (previousChat != null) setState(() => chat = previousChat);
      showCustomNotification(context, error);
      return;
    }
    showCustomNotification(context, 'Сообщение откреплено');
  }

  ({String? text, bool isPreview}) _pinnedPreviewFor(CachedMessage message) {
    final payload = message.payload;
    if (payload != null) return pinnedMessagePreview(payload);
    return pinnedMessagePreview({
      'text': message.text,
      'attaches':
          message.attachments?.map((a) => a.toMap()).toList() ?? const [],
    });
  }

  void _applyPinnedMessageLocally({
    int? messageId,
    String? text,
    int? time,
    bool isPreview = false,
  }) {
    final current = chat;
    if (current == null) return;
    setState(() {
      chat = current.copyWith(
        pinnedMsgId: messageId,
        pinnedMsgText: text,
        pinnedMsgTime: time,
        pinnedMsgIsPreview: isPreview,
      );
    });
  }

  void _jumpToPinnedMessage() {
    final id = chat?.pinnedMsgId;
    if (id == null) return;
    final messageId = id.toString();
    if (_messages.any((m) => m.id == messageId)) {
      _scrollToLoadedMessage(messageId);
      return;
    }
    setState(_beginTargetNavigation);
    unawaited(_runGoToMessage(messageId, chat?.pinnedMsgTime ?? 0));
  }

  bool _badgeRefreshing = false;
  bool _badgeRefreshQueued = false;

  void _onChatsBump() {
    unawaited(_reloadChatMeta());
    if (_badgeRefreshing) {
      _badgeRefreshQueued = true;
      return;
    }
    unawaited(_runBadgeRefresh());
  }

  Future<void> _reloadChatMeta() async {
    if (_myId == 0) return;
    final rows = await chats.getChat(_myId, widget.chatId);
    if (!mounted || rows.isEmpty) return;
    final fresh = rows.first;
    final current = chat;
    if (current != null &&
        current.pinnedMsgId == fresh.pinnedMsgId &&
        current.pinnedMsgText == fresh.pinnedMsgText &&
        current.pinnedMsgTime == fresh.pinnedMsgTime &&
        current.pinnedMsgIsPreview == fresh.pinnedMsgIsPreview &&
        current.owner == fresh.owner &&
        current.options.length == fresh.options.length &&
        current.options.containsAll(fresh.options) &&
        current.admins.length == fresh.admins.length &&
        current.admins.containsAll(fresh.admins)) {
      return;
    }
    setState(() => chat = fresh);
  }

  Future<void> _runBadgeRefresh() async {
    _badgeRefreshing = true;
    try {
      await _refreshBadge();
    } finally {
      _badgeRefreshing = false;
      if (_badgeRefreshQueued && mounted) {
        _badgeRefreshQueued = false;
        unawaited(_runBadgeRefresh());
      }
    }
  }

  Future<void> _refreshBadge() async {
    if (_myId == 0) return;
    final total = await AppDatabase.sumUnread(
      _myId,
      excludeChatId: widget.chatId,
      excludeChatIds: ArchivedChatsStore.instance.archivedChatIds(_myId),
    );
    if (mounted) _otherUnread.value = total;
  }

  Future<void> _loadHistory() async {
    if (_myId == 0) {
      final activeProfile = await AppDatabase.loadActiveProfile();
      if (!mounted) return;
      _myId = activeProfile?.id ?? 0;
    }
    if (_commentsMode) {
      await _loadCommentsHistory();
      return;
    }
    if (widget.chatType == 'DIALOG') {
      unawaited(_loadOtherPresence());
    }
    unawaited(_refreshScheduledCount());
    await _chatController.loadRemainingHistory(
      onApplyMerged: _applyMergedMessages,
      onLoadingFinished: () {
        setState(() {
          _isLoading = false;
          _onLoadingFinished();
        });
      },
      onPreview: () => _previewChat = true,
      onSenderNames: () {
        _loadForwardedSenderNames();
        _loadGroupSenderNames();
      },
    );
  }

  void _maybeLoadMoreHistory() {
    if (!_scrollController.hasClients) return;
    if (_historyAutoloadSuppressed) return;
    if (_isLoading) return;
    if (_commentsMode) {
      if (_commentsLoadingMore || !_commentsHasMore || _messages.isEmpty) return;
      final pos = _scrollController.position;
      if (pos.pixels - pos.minScrollExtent <= _historyPrefetchExtent) {
        unawaited(_loadMoreComments());
      }
      return;
    }
    _maybeFillGap();
    if (_isLoadingMore || !_hasMoreHistory) return;
    if (_messages.isEmpty) return;
    final pos = _scrollController.position;
    if (pos.maxScrollExtent <= 0) return;
    if (pos.maxScrollExtent - pos.pixels <= _historyPrefetchExtent) {
      unawaited(_loadMoreHistory());
    }
  }

  void _maybeFillGap() {
    final controller = _chatController;
    if (!controller.hasGap || controller.loadingGap) return;
    for (final gap in controller.gaps) {
      final box = _keyForMessage(gap.edgeId).currentContext?.findRenderObject();
      if (box is RenderBox && box.attached) {
        unawaited(_fillGapForward(gap));
        return;
      }
    }
  }

  Future<void> _fillGapForward(HistoryGap gap) async {
    final edgeId = gap.edgeId;
    final beforeDy = _messageOffsetInList(edgeId);
    final added = await _chatController.fillGapForward(gap);
    if (!mounted || added == 0) return;

    _syncReactionNotifiersFromMessages();
    _bumpMessages();
    await WidgetsBinding.instance.endOfFrame;
    if (!mounted || !_scrollController.hasClients) return;

    final afterDy = _messageOffsetInList(edgeId);
    if (beforeDy != null && afterDy != null) {
      final delta = beforeDy - afterDy;
      if (delta.abs() > 0.5) {
        final pos = _scrollController.position;
        _scrollController.jumpTo(
          (pos.pixels + delta).clamp(pos.minScrollExtent, pos.maxScrollExtent),
        );
      }
    }
    _loadForwardedSenderNames();
    _loadGroupSenderNames();
  }

  bool _consumeRetainOffset() {
    if (!_retainOffsetOnce) return false;
    _retainOffsetOnce = false;
    return true;
  }

  void _retainOffsetForNextLayout() {
    _retainOffsetOnce = true;
    WidgetsBinding.instance.addPostFrameCallback((_) {
      _retainOffsetOnce = false;
    });
  }

  String? _viewportAnchorId() {
    final listBox = _listKey.currentContext?.findRenderObject();
    if (listBox is! RenderBox || !listBox.attached) return null;
    final height = listBox.size.height;
    for (final message in _messages) {
      final box = _messageKeys[message.id]?.currentContext?.findRenderObject();
      if (box is! RenderBox || !box.attached) continue;
      final dy = box.localToGlobal(Offset.zero, ancestor: listBox).dy;
      if (dy >= 0 && dy <= height) return message.id;
    }
    return null;
  }

  Future<void> _holdScrollAfterAppend(String? anchorId, double? beforeDy) async {
    if (anchorId == null || beforeDy == null) return;
    await WidgetsBinding.instance.endOfFrame;
    if (!mounted || !_scrollController.hasClients) return;

    final afterDy = _messageOffsetInList(anchorId);
    if (afterDy == null) return;
    final delta = beforeDy - afterDy;
    if (delta.abs() <= 0.5) return;

    final pos = _scrollController.position;
    if (pos.userScrollDirection != ScrollDirection.idle) return;
    final target = (pos.pixels + delta).clamp(
      pos.minScrollExtent,
      pos.maxScrollExtent,
    );
    if ((target - pos.pixels).abs() <= 0.5) return;
    _scrollController.jumpTo(target);
  }

  double? _messageOffsetInList(String messageId) {
    final listBox = _listKey.currentContext?.findRenderObject();
    final box = _keyForMessage(messageId).currentContext?.findRenderObject();
    if (listBox is! RenderBox || box is! RenderBox || !box.attached) {
      return null;
    }
    return box.localToGlobal(Offset.zero, ancestor: listBox).dy;
  }

  Future<void> _loadMessageWindow(String messageId, int targetTime) async {
    if (targetTime <= 0) {
      await _walkHistoryBack(
        reached: () => _messages.any((m) => m.id == messageId),
        maxPages: 10,
      );
      return;
    }

    _historyAutoloadSuppressCount++;
    try {
      await _chatController.loadMessageWindow(
        targetId: messageId,
        targetTime: targetTime,
      );
    } finally {
      _historyAutoloadSuppressCount--;
    }
    if (!mounted) return;
    _syncReactionNotifiersFromMessages();
    _bumpMessages();
    _loadForwardedSenderNames();
    _loadGroupSenderNames();
  }

  Future<void> _walkHistoryBack({
    required bool Function() reached,
    required int maxPages,
    int targetTime = 0,
  }) async {
    if (reached()) return;
    _historyAutoloadSuppressCount++;
    try {
      var page = 0;
      while (mounted &&
          page < maxPages &&
          _hasMoreHistory &&
          !reached() &&
          (_messages.isEmpty || _messages.first.time > targetTime)) {
        page++;
        final before = _messages.isEmpty ? 0 : _messages.first.time;
        await _loadMoreHistory(
          resolveSenderNames: false,
          pageSize: ChatController.historyWalkPageSize,
          persist: false,
        );
        if (!mounted) return;
        final after = _messages.isEmpty ? 0 : _messages.first.time;
        if (after == before) break;
      }
    } finally {
      _historyAutoloadSuppressCount--;
    }
    if (!mounted) return;
    _chatController.persistSessionCache();
    _loadForwardedSenderNames();
    _loadGroupSenderNames();
  }

  Future<void> _loadMoreHistory({
    bool resolveSenderNames = true,
    int? pageSize,
    bool persist = true,
  }) async {
    await _chatController.loadMoreHistory(
      pageSize: pageSize,
      persist: persist,
      onLoadingStarted: _bumpMessages,
      onLoaded: (added) {
        if (added > 0) _syncReactionNotifiersFromMessages();
        _bumpMessages();
        if (resolveSenderNames) {
          _loadForwardedSenderNames();
          _loadGroupSenderNames();
        }
      },
      onError: (_) {
        if (mounted) {
          _isLoadingMore = false;
          _bumpMessages();
        }
      },
    );
  }

  void _applyMergedMessages(
    List<CachedMessage> decodedDesc, {
    bool markLoaded = false,
  }) {
    final changed = _chatController.mergeMessages(decodedDesc);
    _requestCommentCounts();

    if (!changed && !markLoaded) return;

    setState(() {
      if (markLoaded) {
        _isLoading = false;
        _onLoadingFinished();
      }
    });
    if (changed) {
      _syncReactionNotifiersFromMessages();
      _pruneReactionNotifiers();
      _chatController.persistSessionCache();
      _reapplyPinIfNeeded();
    }
  }

  void _requestCommentCounts() {
    if (_commentsMode) return;
    if ((chat?.type ?? widget.chatType) != 'CHANNEL') return;
    final pending = <String>[];
    for (final m in _messages) {
      if (m.isControl) continue;
      if (_commentCountsRequested.contains(m.id)) continue;
      _commentCountsRequested.add(m.id);
      pending.add(m.id);
    }
    if (pending.isEmpty) return;
    unawaited(
      commentsModule.fetchInfo(
        accountId: _myId,
        chatId: widget.chatId,
        postIds: pending,
      ),
    );
  }

  void _onCommentsInfo(Map<String, CommentsInfo> info) {
    if (!mounted) return;
    var changed = false;
    for (final m in _messages) {
      final count = info[m.id]?.totalCount;
      if (count == null) continue;
      if (_commentCounts[m.id] != count) {
        _commentCounts[m.id] = count;
        changed = true;
      }
    }
    if (changed) setState(() {});
  }

  String _commentsLabelFor(String postId) {
    final l10n = AppLocalizations.of(context)!;
    final count = _commentCounts[postId];
    if (count == null || count == 0) return l10n.commentsWrite;
    return l10n.commentsCount(count);
  }

  void _openComments(CachedMessage post) {
    Navigator.of(context)
        .push(
          MaterialPageRoute(
            builder: (_) => ChatScreen(
              chatId: widget.chatId,
              name: widget.name,
              imageUrl: widget.imageUrl,
              chatType: 'CHANNEL',
              commentPostId: post.id,
              postMessage: _stripInlineKeyboard(post),
            ),
          ),
        )
        .then((_) => _refreshCommentCount(post.id));
  }

  void _refreshCommentCount(String postId) {
    if (!mounted) return;
    _commentCountsRequested.remove(postId);
    _requestCommentCounts();
  }

  CachedMessage _stripInlineKeyboard(CachedMessage post) {
    final attaches = post.attachments;
    if (attaches == null || attaches.isEmpty) return post;
    final filtered = attaches
        .where((a) => a.type != AttachmentType.inlineKeyboard)
        .toList();
    if (filtered.length == attaches.length) return post;
    return post.copyWith(attachments: filtered);
  }

  Future<void> _loadCommentsHistory() async {
    final post = widget.postMessage;
    final loaded = await commentsModule.fetchHistory(
      _myId,
      widget.chatId,
      widget.commentPostId!,
      fromTime: post?.time ?? DateTime.now().millisecondsSinceEpoch,
      forward: 30,
      backward: 0,
    );
    if (!mounted) return;
    final comments = [...loaded]..sort((a, b) => a.time.compareTo(b.time));
    _messages = post != null ? [post, ...comments] : comments;
    _commentsHasMore = comments.isNotEmpty;
    _syncReactionNotifiersFromMessages();
    unawaited(_resolveCommentNames(comments));
    _bumpMessages();
    setState(() {
      _isLoading = false;
      _onLoadingFinished();
    });
  }

  Future<void> _loadMoreComments() async {
    if (_commentsLoadingMore || !_commentsHasMore || _messages.isEmpty) return;
    _commentsLoadingMore = true;
    final newest = _messages.last;
    try {
      final more = await commentsModule.fetchHistory(
        _myId,
        widget.chatId,
        widget.commentPostId!,
        fromTime: newest.time,
        forward: 30,
        backward: 0,
      );
      if (!mounted) return;
      final existing = _messages.map((m) => m.id).toSet();
      final fresh = more.where((c) => !existing.contains(c.id)).toList();
      if (fresh.isEmpty) {
        _commentsHasMore = false;
      } else {
        _messages = [..._messages, ...fresh]
          ..sort((a, b) => a.time.compareTo(b.time));
        _syncReactionNotifiersFromMessages();
        unawaited(_resolveCommentNames(fresh));
        _bumpMessages();
      }
    } finally {
      _commentsLoadingMore = false;
    }
  }

  void _onLiveComment(CommentAddedEvent event) {
    if (!mounted) return;
    final comment = event.comment;
    if (comment.senderId == _myId) return;
    if (_messages.any((m) => m.id == comment.id)) return;
    final nearBottom = _isNearListBottom();
    final anchorId = nearBottom ? null : _viewportAnchorId();
    final anchorDy = anchorId == null ? null : _messageOffsetInList(anchorId);
    if (!nearBottom) _retainOffsetForNextLayout();
    _messages.add(comment);
    _syncReactionNotifiersFromMessages();
    _bumpMessages();
    unawaited(_resolveCommentNames([comment]));
    if (nearBottom) {
      _scrollToBottom();
    } else {
      _noteMissedMessage();
      unawaited(_holdScrollAfterAppend(anchorId, anchorDy));
    }
  }

  bool _isNearListBottom() {
    if (!_scrollController.hasClients) return true;
    return _scrollController.position.pixels <= _historyPrefetchExtent;
  }

  Future<void> _resolveCommentNames(List<CachedMessage> list) async {
    final ids = list
        .map((m) => m.senderId)
        .where((id) => id != 0 && ContactCache.get(id) == null)
        .toSet();
    if (ids.isEmpty) return;
    final resolved = await messagesModule.ensureContactNames(ids);
    if (resolved && mounted) _bumpMessages();
  }

  void _syncReactionNotifiersFromMessages() {
    for (final m in _messages) {
      if (_reactionNotifiers.containsKey(m.id)) continue;
      final info = m.payload?['reactionInfo'];
      _reactionNotifiers[m.id] = ValueNotifier(
        info is Map ? Map<String, dynamic>.from(info) : null,
      );
    }
  }

  @override
  void deactivate() {
    _saveDraft();
    super.deactivate();
  }

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    if (state == AppLifecycleState.paused ||
        state == AppLifecycleState.inactive) {
      if (_voiceRec.isRecording.value) {
        unawaited(_voiceRec.stop(cancel: true));
      }
      if (_note.isRecording.value) {
        unawaited(_note.stop(cancel: true));
      }
      _saveDraft();
    }
    super.didChangeAppLifecycleState(state);
  }

  @override
  void didChangeMetrics() {
    super.didChangeMetrics();
    final view = View.of(context);
    final keyboardOpen = view.viewInsets.bottom / view.devicePixelRatio > 100;
    if (_keyboardWasOpen && !keyboardOpen && _messageFocusNode.hasFocus) {
      _messageFocusNode.unfocus();
    }
    _keyboardWasOpen = keyboardOpen;
  }

  @override
  void dispose() {
    ChatScreen._open.remove(this);
    _chatController.persistSessionCache();
    if (_previewChat) {
      unawaited(chats.subscribeChat(api, widget.chatId, subscribe: false));
    }
    WidgetsBinding.instance.removeObserver(this);
    _mediaSendSub?.cancel();
    chats.chatsChanged.removeListener(_onChatsBump);
    _otherUnread.dispose();
    _animojiHold.dispose();
    _saveDraft();
    _messageController.removeListener(_onTextChanged);
    _scrollController.removeListener(_onScrollForDate);
    _scrollController.removeListener(_maybeLoadMoreHistory);
    _scrollController.removeListener(_recordScrollPixels);
    _scrollController.removeListener(_scheduleReadMarker);
    _scrollController.removeListener(_exitTextSelectionOnScroll);
    _scrollController.removeListener(_updateScrollDownVisible);
    _readMarkTimer?.cancel();
    AppVisualStyle.current.removeListener(_onVisualStyleChanged);
    AppChatChrome.current.removeListener(_onVisualStyleChanged);
    AppComposerStyle.current.removeListener(_onVisualStyleChanged);
    AppComposerBackground.current.removeListener(_onVisualStyleChanged);
    _composerHeight.dispose();
    _pinnedBannerHeight.dispose();
    _floatingDateTimer?.cancel();
    _floatingDateCurved.dispose();
    _floatingDateAnimController.dispose();
    _floatingDate.dispose();
    _scrollDownCurved.dispose();
    _scrollDownAnimController.dispose();
    _newMessageCount.dispose();
    _hasText.dispose();
    _scheduledCount.dispose();
    _showAttachmentPanel.removeListener(_onAttachPanelToggle);
    _showAttachmentPanel.dispose();
    _uploadSub?.cancel();
    _pushSub?.cancel();
    _messageEventSub?.cancel();
    _commentsInfoSub?.cancel();
    _commentSub?.cancel();
    _connSub?.cancel();
    _voiceRec.dispose();
    _note.dispose();
    debugForceOffline.removeListener(_recomputeHeaderStatus);
    for (final n in _reactionNotifiers.values) {
      n.dispose();
    }
    _reactionNotifiers.clear();
    _reactionAnimation.dispose();
    for (final n in _photoUploadProgress.values) {
      n.dispose();
    }
    _photoUploadProgress.clear();
    ChatActivityStore.instance
        .listenable(widget.chatId)
        .removeListener(_recomputeHeaderStatus);
    PresenceFetch.revision.removeListener(_onPresenceChanged);
    ContactsModule.revision.removeListener(_onContactsChanged);
    if (_wallpaperListening) {
      ChatWallpaperStore.instance.revision.removeListener(
        _applyEffectiveWallpaper,
      );
    }
    if (_encryptionListening) {
      ChatEncryptionStore.instance.revision.removeListener(_applyEncryption);
    }
    _headerStatusNotifier.dispose();
    _otherReadTime.dispose();
    _chatController.dispose();
    _prank.dispose();
    _uploadStatus.dispose();
    _attachAnim.dispose();
    _commandPanel.dispose();
    _mentionPanel.dispose();
    _selectionAnim.dispose();
    _searchAnim.dispose();
    _searchFocusNode.dispose();
    _search.dispose();
    _selectedIds.dispose();
    _textSelection.dispose();
    _messageController.dispose();
    _messageFocusNode.dispose();
    _stickers.dispose();
    _scrollController.dispose();
    _shimmerStartTimer?.cancel();
    _shimmerController.dispose();
    _replyTo.dispose();
    _pendingForwards.dispose();
    _highlightTimer?.cancel();
    _highlightMessageId.dispose();
    _goToMessageSettleTimer?.cancel();
    _jumpCacheExtent.dispose();
    _messageKeys.clear();
    super.dispose();
  }

  void _onTextChanged() {
    final newHasText = _messageController.text.trim().isNotEmpty;
    if (newHasText != _hasText.value) {
      _hasText.value = newHasText;
    }
    _commandPanel.update();
    _mentionPanel.update();
  }

  bool _mentionsAvailable() =>
      !_commentsMode && (chat?.type ?? widget.chatType) == 'CHAT';

  void _onMentionSelected(MentionCandidate candidate, MentionQuery query) {
    _messageController.insertMention(
      userId: candidate.id,
      name: candidate.name,
      start: query.start,
      end: query.end,
    );
    _mentionPanel.update();
    _messageFocusNode.requestFocus();
  }

  void _onCommandSelected(SlashCommand c) {
    final text = '${c.name} ';
    _messageController.value = TextEditingValue(
      text: text,
      selection: TextSelection.collapsed(offset: text.length),
    );
    _messageFocusNode.requestFocus();
  }

  void _restoreDraft() {
    if (_myId == 0 || _commentsMode || _messageController.text.isNotEmpty) {
      return;
    }
    final shared = widget.initialText?.trim();
    final draft = (shared != null && shared.isNotEmpty)
        ? shared
        : DraftStore.instance.get(_myId, widget.chatId);
    if (draft == null || draft.isEmpty) return;
    _messageController.text = draft;
    _messageController.selection = TextSelection.collapsed(
      offset: draft.length,
    );
  }

  void _saveDraft() {
    if (_myId == 0 || _commentsMode) return;
    unawaited(
      DraftStore.instance.set(
        _myId,
        widget.chatId,
        _messageController.buildContent().text,
      ),
    );
  }

  void _onAttachPanelToggle() {
    if (_showAttachmentPanel.value) {
      _attachAnim.forward();
    } else {
      _attachAnim.reverse();
    }
  }

  int _computeOtherReadTime() {
    final c = chat;
    if (c == null) return 0;
    int otherReadTime = 0;
    for (final entry in c.participants.entries) {
      if (entry.key != _myId && entry.value > otherReadTime) {
        otherReadTime = entry.value;
      }
    }
    return otherReadTime;
  }

  void _syncOtherReadTime() {
    final t = _computeOtherReadTime();
    if (_otherReadTime.value != t) _otherReadTime.value = t;
  }

  String? _effectiveStatus(CachedMessage msg) {
    if (msg.senderId != _myId) return null;
    if (msg.status == 'sending' || msg.status == 'error') return msg.status;
    return 'sent';
  }

  void _onIncomingPush(Packet packet) {
    if (!mounted) return;
    switch (packet.opcode) {
      case Opcode.notifMark:
        _onMessageRead(packet);
      case Opcode.notifTyping:
        _onTyping(packet);
      case Opcode.notifMsgDelayed:
        final p = packet.payload;
        if (p is Map && p['chatId'] == widget.chatId) {
          // lastDelayedUpdateTime — авторитетный признак от сервера:
          // 0 — отложенных в чате не осталось, иначе они есть. Реагируем
          // мгновенно по пушу, не дожидаясь повторного запроса.
          final t = p['lastDelayedUpdateTime'];
          if (t is int && t == 0) {
            _scheduledCount.value = 0;
          } else {
            if (_scheduledCount.value == 0) _scheduledCount.value = 1;
            _refreshScheduledCount();
          }
        }
    }
  }

  void _markHasScheduled() {
    if (_scheduledCount.value == 0) _scheduledCount.value = 1;
  }

  Future<void> _refreshScheduledCount() async {
    if (_myId == 0) return;
    try {
      final list = await messagesModule.fetchDelayedMessages(
        _myId,
        widget.chatId,
      );
      if (mounted) _scheduledCount.value = list.length;
    } catch (_) {}
  }

  void _bumpMessages() {
    _combinedItemsCache = null;
    _messagesRev.value++;
  }

  void _enterSelection(CachedMessage message) {
    if (message.isControl) return;
    Haptics.medium();
    if (_selectedIds.value.contains(message.id)) return;
    _selectedIds.value = {..._selectedIds.value, message.id};
    _syncSelectionAnim();
  }

  void _toggleSelection(CachedMessage message) {
    if (message.isControl) return;
    final next = Set<String>.from(_selectedIds.value);
    if (!next.remove(message.id)) next.add(message.id);
    Haptics.selection();
    _selectedIds.value = next;
    if (!next.contains(message.id)) _exitTextSelection(message.id);
    _syncSelectionAnim();
  }

  void _clearSelection() {
    _exitTextSelection();
    if (_selectedIds.value.isEmpty) return;
    _selectedIds.value = const {};
    _syncSelectionAnim();
  }

  void _startTextSelection(CachedMessage message, Offset globalPosition) {
    if (message.isControl || message.selectableText == null) return;
    _textSelection.value = (id: message.id, pos: globalPosition);
  }

  void _exitTextSelection([String? onlyId]) {
    final current = _textSelection.value;
    if (current == null) return;
    if (onlyId != null && current.id != onlyId) return;
    _textSelection.value = null;
  }

  void _exitTextSelectionOnScroll() {
    if (_textSelection.value == null) return;
    if (!_scrollController.hasClients) return;
    if (_scrollController.position.userScrollDirection !=
        ScrollDirection.idle) {
      _exitTextSelection();
    }
  }

  void _syncSelectionAnim() {
    if (_selectedIds.value.isEmpty) {
      _selectionAnim.reverse();
    } else if (_selectionAnim.status != AnimationStatus.forward &&
        _selectionAnim.value < 1) {
      _selectionAnim.forward();
    }
  }

  List<CachedMessage> _selectedMessages(Set<String> ids) =>
      _messages.where((m) => ids.contains(m.id)).toList();

  CachedMessage? _singleCopyableText(Set<String> ids) {
    CachedMessage? found;
    var textCount = 0;
    for (final m in _messages) {
      if (!ids.contains(m.id)) continue;
      if ((m.text ?? '').isEmpty) continue;
      if (++textCount > 1) return null;
      found = m;
    }
    return found;
  }

  CachedMessage? _singleEditable(Set<String> ids) {
    if (ids.length != 1) return null;
    final list = _selectedMessages(ids);
    if (list.isEmpty) return null;
    return _canEditMessage(list.first) ? list.first : null;
  }

  void _copySelected(CachedMessage message) {
    final text = message.text;
    if (text == null || text.isEmpty) return;
    Clipboard.setData(ClipboardData(text: text));
    Haptics.tap();
    showCustomNotification(context, 'Скопировано');
    _clearSelection();
  }

  void _editSelected(CachedMessage message) {
    _clearSelection();
    _startEditMessage(message);
  }

  Future<void> _deleteSelected() async {
    final msgs = _selectedMessages(_selectedIds.value);
    if (msgs.isEmpty) return;

    final serverMsgs = msgs.where((m) => !m.id.startsWith('temp_')).toList();
    if (serverMsgs.isEmpty) {
      for (final m in msgs) {
        _startDeleteAnimation(m.id);
      }
      _clearSelection();
      return;
    }

    final canForEveryone = serverMsgs.every((m) => m.senderId == _myId);
    final forEveryone = await _showDeleteMessageDialog(canForEveryone);
    if (forEveryone == null || !mounted) return;

    final ok = await messagesModule.deleteMessages(
      widget.chatId,
      serverMsgs.map((m) => m.id).toList(),
      forEveryone: forEveryone,
    );
    if (!mounted) return;
    if (!ok) {
      Haptics.error();
      showCustomNotification(context, 'Не удалось удалить сообщения');
      return;
    }
    for (final m in msgs) {
      _startDeleteAnimation(m.id);
    }
    _clearSelection();
  }

  void _replySelected() {
    final msgs = _selectedMessages(_selectedIds.value);
    if (msgs.isEmpty) return;
    final message = msgs.first;
    _clearSelection();
    _startReply(message);
  }

  void _forwardSelected() {
    final msgs = _selectedMessages(_selectedIds.value);
    _clearSelection();
    unawaited(_forwardMessages(msgs));
  }

  Future<void> _forwardMessages(List<CachedMessage> msgs) async {
    final forwardable = msgs
        .where((message) => int.tryParse(message.id) != null)
        .toList();
    if (forwardable.isEmpty) {
      showCustomNotification(context, 'Нечего пересылать');
      return;
    }

    final target = await openForwardScreen(
      context: context,
      messageCount: forwardable.length,
    );
    if (target == null || !mounted) return;

    final ordered = [...forwardable]..sort((a, b) => a.time.compareTo(b.time));
    final request = ForwardRequest(
      sourceChatId: widget.chatId,
      sourceChatName: widget.name,
      sourceChatIconUrl: widget.imageUrl,
      sourceChatType: widget.chatType,
      messages: ordered,
    );

    if (target.chatId == widget.chatId) {
      _setForwardRequest(request);
      return;
    }

    pushSwipeable(
      context,
      (_) => ChatScreen(
        chatId: target.chatId,
        name: target.name,
        imageUrl: target.imageUrl,
        chatType: target.chatType,
        forwardRequest: request,
      ),
    );
  }

  void _setForwardRequest(ForwardRequest request) {
    _cancelReply();
    _forwardRequest = request;
    _pendingForwards.value = request.messages;
  }

  void _cancelForward() {
    _forwardRequest = null;
    _pendingForwards.value = const [];
  }

  Future<bool> _sendForwardRequest() async {
    var request = _forwardRequest;
    if (request == null) return true;
    if (api.state != SessionState.online) {
      showCustomNotification(context, 'Нет соединения');
      return false;
    }
    Haptics.send();
    while (request != null && request.messages.isNotEmpty) {
      if (!identical(_forwardRequest, request)) return false;
      final source = request.messages.first;
      final optimistic = MessagesModule.buildForwardMessage(
        myId: _myId,
        targetChatId: widget.chatId,
        sourceChatId: request.sourceChatId,
        source: source,
        tempId: _nextTempId(),
        time: DateTime.now().millisecondsSinceEpoch,
        status: 'sending',
        sourceChatName: request.sourceChatName,
        sourceChatIconUrl: request.sourceChatIconUrl,
        sourceChatType: request.sourceChatType,
      );
      _messages.add(optimistic);
      _bumpMessages();
      _scrollToBottom();
      await _syncForwardOutgoing(optimistic);
      final sent = await _sendOneForward(optimistic, request.sourceChatId);
      if (!sent || !mounted) return false;
      if (!identical(_forwardRequest, request)) return false;
      final remaining = request.messages.skip(1).toList(growable: false);
      if (remaining.isEmpty) {
        _cancelForward();
        return true;
      }
      request = request.withMessages(remaining);
      _forwardRequest = request;
      _pendingForwards.value = request.messages;
    }
    _cancelForward();
    return true;
  }

  Future<bool> _sendOneForward(
    CachedMessage optimistic,
    int sourceChatId,
  ) async {
    final link = optimistic.payload?['link'];
    final rawWireId = link is Map ? link['messageId'] : null;
    final wireId = rawWireId is int ? rawWireId : null;
    if (wireId == null) return false;
    try {
      final realId = await messagesModule.forwardMessage(
        widget.chatId,
        sourceChatId,
        wireId,
      );
      final sent = MessagesModule.reidentifyMessage(
        optimistic,
        realId.isNotEmpty ? realId : optimistic.id,
        status: 'sent',
      );
      if (mounted) {
        final index = _messages.indexWhere((m) => m.id == optimistic.id);
        if (index != -1) {
          _messages[index] = sent;
          _bumpMessages();
        }
      }
      await _syncForwardOutgoing(sent, removeId: optimistic.id);
      return true;
    } catch (_) {
      final index = _messages.indexWhere((m) => m.id == optimistic.id);
      if (index != -1 && mounted) {
        _messages.removeAt(index);
        _bumpMessages();
      }
      try {
        await AppDatabase.deleteMessage(_myId, widget.chatId, optimistic.id);
      } catch (_) {}
      if (mounted) {
        Haptics.error();
        showCustomNotification(context, 'Не удалось переслать');
      }
      return false;
    }
  }

  Future<void> _syncForwardOutgoing(
    CachedMessage message, {
    String? removeId,
  }) async {
    await _persistOutgoing(message, removeId: removeId);
    try {
      await chats.applyOutgoing(
        _myId,
        widget.chatId,
        messageId: message.id,
        time: message.time,
        text: MessagesModule.forwardPreviewText(message),
        status: message.status ?? 'sending',
      );
    } catch (_) {}
  }

  Widget _buildComposerArea(BuildContext context) {
    final cs = Theme.of(context).colorScheme;
    final content = Column(
      mainAxisSize: MainAxisSize.min,
      children: [
        AnimatedBuilder(
          animation: _selectionAnim,
          builder: (context, child) {
            final t = Curves.easeOut.transform(
              _selectionAnim.value.clamp(0.0, 1.0),
            );
            if (t == 0) return child!;
            if (t == 1) return const SizedBox.shrink();
            return ClipRect(
              child: Align(
                alignment: Alignment.topCenter,
                heightFactor: 1 - t,
                child: Transform.translate(
                  offset: Offset(0, 48 * t),
                  child: Opacity(opacity: 1 - t, child: child),
                ),
              ),
            );
          },
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              AnimatedBuilder(
                animation: _attachAnim,
                builder: (context, _) {
                  if (_attachAnim.value == 0) {
                    return const SizedBox.shrink();
                  }
                  final curve = _attachAnim.status == AnimationStatus.reverse
                      ? Curves.easeIn
                      : Curves.easeOut;
                  final t = curve.transform(_attachAnim.value);
                  return Padding(
                    padding: const EdgeInsets.fromLTRB(12, 0, 12, 8),
                    child: ClipRect(
                      child: Align(
                        alignment: Alignment.bottomCenter,
                        heightFactor: t,
                        child: Opacity(
                          opacity: t,
                          child: AttachmentPanel(
                            onClose: () => _showAttachmentPanel.value = false,
                            onPickFile: _pickAndUploadFile,
                            onSendById: _sendFileById,
                          ),
                        ),
                      ),
                    ),
                  );
                },
              ),
              AnimatedBuilder(
                animation: _stickers.anim,
                builder: (context, _) => ComposerInputBar(
                  bottomSafe: _stickers.anim.value == 0,
                  chatType: _commentsMode ? 'CHAT' : widget.chatType,
                  chrome: _effectiveChrome,
                  style: AppComposerStyle.current.value,
                  background: AppComposerBackground.current.value,
                  backdropKey: _pillBackdrop,
                  attachAnim: _attachAnim,
                  replyTo: _replyTo,
                  forwardMessages: _pendingForwards,
                  myId: _myId,
                  hasText: _hasText,
                  uploadStatus: _uploadStatus,
                  messageController: _messageController,
                  messageFocusNode: _messageFocusNode,
                  voiceRec: _voiceRec,
                  note: _note,
                  onToggleStickerPanel: _toggleStickerPanel,
                  onSendText: _sendMessage,
                  onScheduleMessage: _scheduleMessage,
                  onOpenAttach: _openAttachmentSheet,
                  onOpenAttachScheduled: _openAttachmentSheetScheduled,
                  onSendHistory: _sendHistoryFile,
                  onCancelReply: _cancelReply,
                  onCancelForward: _cancelForward,
                  onPickReplyChat: _commentsMode || !_crossChatReplySupported
                      ? null
                      : () => unawaited(_pickReplyChat()),
                  formatElapsed: formatVoiceElapsed,
                  contextMenuBuilder: (ctx, state) =>
                      _formatContextMenu(_messageController, ctx, state),
                  isMuted: chat?.isMuted ?? false,
                  onToggleMute: _toggleChatMute,
                  channelSubscribed: !_previewChat,
                  channelSubscribing: _subscribing,
                  onSubscribe: _subscribeChannel,
                  showStickerButton: !_commentsMode,
                  showAttachButton: !_commentsMode,
                  forceSend: _commentsMode,
                  hintText: _commentsMode ? 'Комментарий' : 'Message',
                ),
              ),
              StickerPanelView(
                stickers: _stickers,
                onStickerTap: _sendSticker,
                onEmojiTap: _insertAnimoji,
              ),
            ],
          ),
        ),
        AnimatedBuilder(
          animation: _selectionAnim,
          builder: (context, child) {
            final t = Curves.easeOut.transform(
              _selectionAnim.value.clamp(0.0, 1.0),
            );
            if (t == 0) return const SizedBox.shrink();
            return ClipRect(
              child: Align(
                alignment: Alignment.bottomCenter,
                heightFactor: t,
                child: Opacity(opacity: t, child: child),
              ),
            );
          },
          child: ValueListenableBuilder<Set<String>>(
            valueListenable: _selectedIds,
            builder: (context, selected, _) => SelectionBottomBar(
              cs: cs,
              selected: selected,
              onReply: _replySelected,
              onForward: _forwardSelected,
            ),
          ),
        ),
      ],
    );
    Widget wrapChrome(Widget child) {
      if (_composerFrosted) {
        if (AppComposerStyle.current.value != ComposerStyle.materialYou) {
          return child;
        }
        return _FrostedPanel(
          sigma: AppFrost.sigma,
          tint: AppFrost.panelTint(cs),
          border: Border(top: AppFrost.hairline(cs)),
          backdropKey: _barBackdrop,
          child: child,
        );
      }
      if (_effectiveChrome != ChatChromeStyle.blur) return child;
      return _FrostedPanel(
        tint: AppFrost.blurPanelTint(cs),
        border: Border(top: AppFrost.hairline(cs)),
        backdropKey: _barBackdrop,
        child: child,
      );
    }

    final base = wrapChrome(content);
    return AnimatedBuilder(
      animation: _searchAnim,
      builder: (context, _) {
        final s = Curves.easeOut.transform(_searchAnim.value.clamp(0.0, 1.0));
        if (s == 0) return base;
        if (s >= 1) return const SizedBox.shrink();
        return ClipRect(
          child: Align(
            alignment: Alignment.topCenter,
            heightFactor: 1 - s,
            child: Opacity(
              opacity: 1 - s,
              child: IgnorePointer(child: base),
            ),
          ),
        );
      },
    );
  }

  bool _canEditMessage(CachedMessage message) {
    if (message.senderId != _myId) return false;
    if (message.id.startsWith('temp_')) return false;
    if (message.isControl) return false;
    final status = message.status;
    if (status == 'sending' || status == 'error') return false;
    return true;
  }

  Future<void> _startEditMessage(CachedMessage message) async {
    final cs = Theme.of(context).colorScheme;
    final controller = RichMessageController(text: message.text ?? '')
      ..setFormatRanges(message.formatRanges);

    final saved = await showModalBottomSheet<bool>(
      context: context,
      isScrollControlled: true,
      backgroundColor: cs.surfaceContainerHigh,
      shape: const RoundedRectangleBorder(
        borderRadius: BorderRadius.vertical(top: Radius.circular(24)),
      ),
      builder: (sheetContext) => Padding(
        padding: EdgeInsets.only(
          left: 20,
          right: 20,
          top: 20,
          bottom: MediaQuery.viewInsetsOf(sheetContext).bottom + 20,
        ),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Text(
              'Изменить сообщение',
              style: TextStyle(
                color: cs.onSurface,
                fontSize: 18,
                fontWeight: FontWeight.w600,
                fontFamily: 'Outfit',
              ),
            ),
            const SizedBox(height: 16),
            TextField(
              controller: controller,
              autofocus: true,
              minLines: 1,
              maxLines: 6,
              style: TextStyle(color: cs.onSurface),
              contextMenuBuilder: (ctx, state) =>
                  _formatContextMenu(controller, ctx, state),
              decoration: InputDecoration(
                hintText: 'Текст сообщения',
                filled: true,
                fillColor: cs.surfaceContainerHighest,
                border: OutlineInputBorder(
                  borderRadius: BorderRadius.circular(14),
                  borderSide: BorderSide.none,
                ),
              ),
            ),
            const SizedBox(height: 20),
            FilledButton(
              onPressed: () => Navigator.of(sheetContext).pop(true),
              child: const Text('Сохранить'),
            ),
          ],
        ),
      ),
    );

    if (saved != true || !mounted) {
      controller.dispose();
      return;
    }

    final content = controller.buildContent();
    final rawText = content.text;
    final newText = rawText.trim();
    final elements = _trimmedElements(content.elements, rawText, newText);
    controller.dispose();

    final oldElements = serializeFormatElements(
      message.formatRanges.where((r) => composerFormats.contains(r.format)),
    );
    if (newText == (message.text ?? '') &&
        _sameElements(elements, oldElements)) {
      return;
    }

    final ok = await messagesModule.editMessage(
      widget.chatId,
      message.id,
      text: newText,
      elements: elements,
    );
    if (!mounted) return;
    if (!ok) {
      Haptics.error();
      showCustomNotification(context, 'Не удалось изменить сообщение');
      return;
    }

    final idx = _messages.indexWhere((m) => m.id == message.id);
    if (idx != -1) {
      final old = _messages[idx];
      final newHistory = KometSettings.viewRedacted.value
          ? CachedMessage.appendEditHistory(
              old.editHistory,
              old.text,
              DateTime.now().millisecondsSinceEpoch,
            )
          : old.editHistory;
      final edited = CachedMessage(
        id: old.id,
        accountId: old.accountId,
        chatId: old.chatId,
        senderId: old.senderId,
        text: newText.isEmpty ? null : newText,
        time: old.time,
        status: 'EDITED',
        payload: {...?old.payload, 'elements': elements},
        attachments: old.attachments,
        isControl: old.isControl,
        editHistory: newHistory,
      );
      _messages[idx] = edited;
      _bumpMessages();
      unawaited(_persistOutgoing(edited));
    }
    Haptics.send();
  }

  Future<void> _confirmDeleteMessage(String messageId, bool isMe) async {
    final isLocalOnly = messageId.startsWith('temp_');
    final canForEveryone = isMe && !isLocalOnly;

    if (isLocalOnly) {
      _startDeleteAnimation(messageId);
      return;
    }

    final forEveryone = await _showDeleteMessageDialog(canForEveryone);
    if (forEveryone == null || !mounted) return;

    final ok = await messagesModule.deleteMessages(widget.chatId, [
      messageId,
    ], forEveryone: forEveryone);
    if (!mounted) return;
    if (!ok) {
      Haptics.error();
      showCustomNotification(context, 'Не удалось удалить сообщение');
      return;
    }
    _startDeleteAnimation(messageId);
  }

  void _startDeleteAnimation(String messageId) {
    if (!_deletingIds.add(messageId)) return;
    Haptics.tap();
    _bumpMessages();
  }

  Future<void> _finalizeDelete(String messageId) async {
    if (!mounted) return;
    _deletingIds.remove(messageId);
    final idx = _messages.indexWhere((m) => m.id == messageId);
    if (idx != -1) {
      _messages.removeAt(idx);
      _reactionNotifiers.remove(messageId)?.dispose();
    }
    _bumpMessages();
    try {
      await AppDatabase.deleteMessage(_myId, widget.chatId, messageId);
      await chats.reconcileLastMessage(_myId, widget.chatId);
    } catch (_) {}
  }

  Future<bool?> _showDeleteMessageDialog(bool canForEveryone) {
    final cs = Theme.of(context).colorScheme;
    var alsoForEveryone = canForEveryone;
    return showDialog<bool>(
      context: context,
      builder: (ctx) {
        return StatefulBuilder(
          builder: (ctx, setLocalState) {
            return AlertDialog(
              backgroundColor: cs.surfaceContainerHigh,
              title: const Text('Удалить сообщение'),
              content: Column(
                mainAxisSize: MainAxisSize.min,
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    'Вы точно хотите удалить это сообщение?',
                    style: TextStyle(color: cs.onSurfaceVariant, fontSize: 15),
                  ),
                  if (canForEveryone) ...[
                    const SizedBox(height: 16),
                    InkWell(
                      onTap: () => setLocalState(
                        () => alsoForEveryone = !alsoForEveryone,
                      ),
                      borderRadius: BorderRadius.circular(8),
                      child: Row(
                        children: [
                          Checkbox(
                            value: alsoForEveryone,
                            onChanged: (v) => setLocalState(
                              () => alsoForEveryone = v ?? false,
                            ),
                          ),
                          Expanded(
                            child: Text(
                              'Также удалить для ${widget.name}',
                              maxLines: 1,
                              overflow: TextOverflow.ellipsis,
                              style: TextStyle(
                                color: cs.onSurface,
                                fontSize: 15,
                              ),
                            ),
                          ),
                        ],
                      ),
                    ),
                  ],
                ],
              ),
              actions: [
                TextButton(
                  onPressed: () => Navigator.pop(ctx),
                  child: const Text('Отмена'),
                ),
                TextButton(
                  onPressed: () =>
                      Navigator.pop(ctx, canForEveryone && alsoForEveryone),
                  child: Text('Удалить', style: TextStyle(color: cs.error)),
                ),
              ],
            );
          },
        );
      },
    );
  }

  void _onMessageEvent(MessageEvent event) {
    if (!mounted) return;
    if (_commentsMode) return;
    switch (event) {
      case MessageAddedEvent(:final message):
        if (message.senderId == _myId) return;
        if (_messages.any((m) => m.id == message.id)) return;
        final nearBottom = _isNearBottom();
        final anchorId = nearBottom ? null : _viewportAnchorId();
        final anchorDy = anchorId == null
            ? null
            : _messageOffsetInList(anchorId);
        if (!nearBottom) _retainOffsetForNextLayout();
        _lastSentId = message.id;
        _messages.add(message);
        _bumpMessages();
        _clearTyping(message.senderId);
        Haptics.tap();
        if (nearBottom) {
          _scrollToBottom();
          _scheduleReadMarker();
        } else {
          _noteMissedMessage();
          unawaited(_holdScrollAfterAppend(anchorId, anchorDy));
          _reapplyPinIfNeeded();
        }
        _prank.checkTrigger(message);
      case MessageEditedEvent(:final message):
        final idx = _messages.indexWhere((m) => m.id == message.id);
        if (idx == -1) return;
        _messages[idx] = message;
        _bumpMessages();
      case MessageSentEvent(:final tempId, :final message):
        final idx = _messages.indexWhere((m) => m.id == tempId);
        if (idx == -1) return;
        _lastSentId = message.id;
        _messages[idx] = message;
        _bumpMessages();
      case MessageRemovedEvent(:final messageId):
        final idx = _messages.indexWhere((m) => m.id == messageId);
        if (idx == -1) return;
        _messages.removeAt(idx);
        _bumpMessages();
        _reactionNotifiers.remove(messageId)?.dispose();
      case MessageMarkedDeletedEvent(:final messageId):
        final idx = _messages.indexWhere((m) => m.id == messageId);
        if (idx == -1) return;
        if (_messages[idx].deleted) return;
        _messages[idx] = _messages[idx].copyWith(deleted: true);
        _bumpMessages();
      case MessageReactionsChangedEvent(:final messageId, :final reactionInfo):
        _reactionNotifiers[messageId]?.value = reactionInfo;
    }
  }

  Future<void> _loadOtherPresence() async {
    if (_myId == 0) return;
    final otherId = widget.chatId ^ _myId;
    if (otherId <= 0) return;
    if (PresenceFetch.live(otherId) != null) return;
    try {
      final entry = await PresenceFetch.get(otherId);
      if (!mounted || entry == null) return;
      PresenceFetch.apply(otherId, entry);
    } catch (_) {}
  }

  void _onPresenceChanged() {
    if (!mounted) return;
    final otherId = _resolveOtherId();
    if (otherId == null) return;
    final p = PresenceFetch.live(otherId);
    if (p == null) return;
    _otherStatus = (p['status'] as int?) ?? 0;
    _otherSeenTime = p['seen'] as int?;
    _recomputeHeaderStatus();
  }

  void _onVisualStyleChanged() {
    if (mounted) {
      setState(() {});
      _bumpMessages();
    }
  }

  void _onContactsChanged() {
    if (mounted) setState(() {});
  }

  String _headerName() {
    if (_commentsMode) return AppLocalizations.of(context)!.commentsTitle;
    if (widget.chatType == 'DIALOG') {
      final otherId = _resolveOtherId();
      if (otherId != null) {
        final cached = ContactCache.get(otherId);
        if (cached != null && cached.isNotEmpty) return cached;
      }
    }
    return widget.name;
  }

  PreferredSizeWidget _buildAppBar(ColorScheme cs) {
    final glossy = AppVisualStyle.current.value.glossyChrome;
    final searchT = Curves.easeOut.transform(_searchAnim.value.clamp(0.0, 1.0));
    final height = glossy
        ? ui.lerpDouble(_glossyHeaderHeight, _glossySearchHeight, searchT)!
        : kToolbarHeight;
    final chrome = _effectiveChrome;
    return AppBar(
      backgroundColor: chrome == ChatChromeStyle.color
          ? (glossy ? Colors.transparent : cs.surfaceContainerHigh)
          : Colors.transparent,
      flexibleSpace: chrome == ChatChromeStyle.blur
          ? _FrostedPanel(
              tint: AppFrost.blurPanelTint(cs),
              border: Border(bottom: AppFrost.hairline(cs)),
              backdropKey: _barBackdrop,
              child: const SizedBox.expand(),
            )
          : (chrome == ChatChromeStyle.none && !glossy)
          ? IgnorePointer(
              child: DecoratedBox(
                decoration: BoxDecoration(
                  gradient: LinearGradient(
                    begin: Alignment.topCenter,
                    end: Alignment.bottomCenter,
                    colors: [
                      cs.surface,
                      cs.surface,
                      cs.surface.withValues(alpha: 0.0),
                    ],
                    stops: const [0.0, 0.72, 1.0],
                  ),
                ),
                child: const SizedBox.expand(),
              ),
            )
          : (chrome == ChatChromeStyle.transparent && !glossy)
          ? _FrostedPanel(
              sigma: AppFrost.sigma,
              tint: AppFrost.panelTint(cs),
              border: Border(bottom: AppFrost.hairline(cs)),
              backdropKey: _barBackdrop,
              child: const SizedBox.expand(),
            )
          : null,
      foregroundColor: cs.onSurface,
      surfaceTintColor: Colors.transparent,
      iconTheme: IconThemeData(color: cs.onSurface),
      elevation: 0,
      toolbarHeight: height,
      automaticallyImplyLeading: false,
      titleSpacing: 0,
      centerTitle: false,
      title: SizedBox(
        height: height,
        child: AnimatedBuilder(
          animation: Listenable.merge([_selectionAnim, _searchAnim]),
          builder: (context, _) {
            final t = Curves.easeOut.transform(
              _selectionAnim.value.clamp(0.0, 1.0),
            );
            final s = Curves.easeOut.transform(
              _searchAnim.value.clamp(0.0, 1.0),
            );
            return ValueListenableBuilder<Set<String>>(
              valueListenable: _selectedIds,
              builder: (context, selected, _) => Stack(
                fit: StackFit.expand,
                children: [
                  if (t < 1 && s < 1)
                    IgnorePointer(
                      ignoring: t > 0.5 || s > 0.5,
                      child: Opacity(
                        opacity: (1 - t) * (1 - s),
                        child: Transform.translate(
                          offset: Offset(0, -height * 0.4 * t),
                          child: ChatHeaderRow(
                            glossy: glossy,
                            frosted:
                                glossy && chrome == ChatChromeStyle.transparent,
                            liquid: _liquidChrome,
                            backdropKey: _pillBackdrop,
                            cs: cs,
                            embedded: widget.embedded,
                            chatId: widget.chatId,
                            heroTag: _profileHeroTag,
                            name: _headerName(),
                            imageUrl: widget.imageUrl,
                            chatType: widget.chatType,
                            isOfficial: chat?.isOfficial ?? false,
                            encrypted: _encryptionEnabled,
                            myId: _myId,
                            headerStatus: _headerStatusNotifier,
                            scheduledCount: _scheduledCount,
                            otherUnread: _otherUnread,
                            showCall: !_commentsMode &&
                                widget.chatType == 'DIALOG' &&
                                !_peerIsBot,
                            onClose: widget.onClose,
                            onOpenInfo: _commentsMode ? () {} : _openChatInfo,
                            onOpenScheduled: _openScheduledMessages,
                            onCall: _startCall,
                            onMenu: _commentsMode ? (_) {} : _openChatMenu,
                          ),
                        ),
                      ),
                    ),
                  if (t > 0)
                    IgnorePointer(
                      ignoring: t < 0.5,
                      child: Opacity(
                        opacity: t,
                        child: Transform.translate(
                          offset: Offset(0, height * 0.4 * (1 - t)),
                          child: SelectionTopBar(
                            cs: cs,
                            selected: selected,
                            glossy: glossy,
                            copyMsg: _singleCopyableText(selected),
                            editMsg: _singleEditable(selected),
                            onClear: _clearSelection,
                            onCopy: _copySelected,
                            onEdit: _editSelected,
                            onDelete: _deleteSelected,
                          ),
                        ),
                      ),
                    ),
                  if (s > 0)
                    IgnorePointer(
                      ignoring: s < 0.5,
                      child: Opacity(
                        opacity: s,
                        child: SearchTopBar(
                          cs: cs,
                          glossy: glossy,
                          search: _search,
                          focusNode: _searchFocusNode,
                          onClose: _closeSearch,
                        ),
                      ),
                    ),
                ],
              ),
            );
          },
        ),
      ),
    );
  }

  bool get _hasMiniApp {
    if (widget.chatType != 'DIALOG' || _commentsMode) return false;
    final peerId = _resolveOtherId();
    if (peerId == null) return false;
    if (hasMiniAppOption(ContactCache.getOptions(peerId))) return true;
    return hasMiniAppOption(chat?.options);
  }

  Future<void> _openMiniApp() async {
    final peerId = _resolveOtherId();
    if (peerId == null) return;
    await openMiniApp(
      context,
      botId: peerId,
      chatId: widget.chatId,
      title: _headerName(),
    );
  }

  void _openChatMenu(BuildContext btnContext) {
    final box = btnContext.findRenderObject() as RenderBox?;
    if (box == null || !box.hasSize) return;
    final anchorRect = box.localToGlobal(Offset.zero) & box.size;
    showChatMenu(
      context: context,
      anchorRect: anchorRect,
      items: [
        if (_hasMiniApp)
          ChatMenuItem(
            icon: Symbols.apps,
            label: AppLocalizations.of(context)!.miniAppOpen,
            dividerAfter: true,
            onTap: () => unawaited(_openMiniApp()),
          ),
        ChatMenuItem(
          icon: (chat?.isMuted ?? false)
              ? Symbols.volume_off
              : Symbols.volume_up,
          label: (chat?.isMuted ?? false)
              ? 'Включить уведомления'
              : 'Отключить уведомления',
          dividerAfter: true,
          onTap: _toggleChatMute,
        ),
        ChatMenuItem(icon: Symbols.search, label: 'Поиск', onTap: _openSearch),
        ChatMenuItem(
          icon: Symbols.wallpaper,
          label: 'Изменить обои',
          onTap: _openWallpaperSheet,
        ),
        ChatMenuItem(
          icon: Symbols.mop,
          label: 'Очистить историю',
          onTap: _clearHistory,
        ),
        ChatMenuItem(
          icon: _encryptionEnabled ? Symbols.lock : Symbols.lock_open,
          label: 'Шифрование сообщений',
          onTap: _openEncryptionSettings,
        ),
        ChatMenuItem(
          icon: Symbols.delete,
          label: 'Удалить чат',
          onTap: _deleteChat,
        ),
      ],
    );
  }

  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;
    final muted = current.isMuted;
    final target = muted ? ChatsModule.muteOff : ChatsModule.muteForever;
    final error = await chats.setChatMute(
      api,
      chatId: widget.chatId,
      dontDisturbUntil: target,
    );
    if (!mounted) return;
    if (error != null) {
      showCustomNotification(context, error);
      return;
    }
    setState(() => chat = current.copyWith(dontDisturbUntil: target));
    showCustomNotification(
      context,
      muted ? 'Уведомления включены' : 'Уведомления отключены',
    );
  }

  bool _encryptionListening = false;

  Future<void> _loadEncryption() async {
    await ChatEncryptionStore.instance.load();
    if (!mounted) return;
    if (!_encryptionListening) {
      _encryptionListening = true;
      ChatEncryptionStore.instance.revision.addListener(_applyEncryption);
    }
    _applyEncryption();
  }

  void _applyEncryption() {
    if (!mounted) return;
    final enabled = ChatEncryptionStore.instance.isEnabled(
      _myId,
      widget.chatId,
    );
    if (enabled != _encryptionEnabled) {
      setState(() => _encryptionEnabled = enabled);
    }
    if (enabled && _myId != 0) {
      unawaited(ChatCryptoService.instance.warmKey(_myId, widget.chatId));
    }
  }

  Future<void> _openEncryptionSettings() async {
    if (_myId == 0) return;
    await pushSwipeable(
      context,
      (context) =>
          ChatEncryptionScreen(accountId: _myId, chatId: widget.chatId),
    );
    if (!mounted) return;
    _applyEncryption();
  }

  bool _wallpaperListening = false;

  Future<void> _loadWallpaper() async {
    await ChatWallpaperStore.instance.load();
    if (!mounted) return;
    if (!_wallpaperListening) {
      _wallpaperListening = true;
      ChatWallpaperStore.instance.revision.addListener(
        _applyEffectiveWallpaper,
      );
    }
    _applyEffectiveWallpaper();
  }

  void _applyEffectiveWallpaper() {
    if (!mounted) return;
    final store = ChatWallpaperStore.instance;
    final wp =
        store.get(_myId, widget.chatId) ??
        store.get(_myId, kGlobalWallpaperChatId);
    if (!identical(wp, _wallpaper)) setState(() => _wallpaper = wp);
  }

  Future<void> _openWallpaperSheet() async {
    if (_myId == 0) return;
    final pick = await showChatWallpaperSheet(context, current: _wallpaper);
    if (pick == null || !mounted) return;
    final store = ChatWallpaperStore.instance;
    switch (pick.type) {
      case WallpaperPickType.none:
        await store.clear(_myId, widget.chatId);
        _applyEffectiveWallpaper();
        break;
      case WallpaperPickType.theme:
        final theme = pick.theme;
        if (theme == null) break;
        await store.setTheme(_myId, widget.chatId, theme.id);
        _applyEffectiveWallpaper();
        break;
      case WallpaperPickType.gallery:
        await _pickWallpaperFromGallery();
        break;
    }
  }

  Future<void> _pickWallpaperFromGallery() async {
    final result = await FilePicker.platform.pickFiles(
      type: FileType.image,
      withData: true,
    );
    if (result == null || result.files.isEmpty) return;
    final bytes = result.files.first.bytes;
    if (bytes == null) {
      if (mounted) showCustomNotification(context, 'Не удалось прочитать файл');
      return;
    }
    if (!mounted) return;
    final settings = await Navigator.of(context).push<WallpaperImageSettings>(
      MaterialPageRoute(
        builder: (_) => ChatWallpaperPreviewScreen(imageBytes: bytes),
      ),
    );
    if (settings == null || !mounted) return;
    final wp = await ChatWallpaperStore.instance.setImage(
      _myId,
      widget.chatId,
      bytes,
      settings: settings,
    );
    if (!mounted) return;
    if (wp == null) {
      showCustomNotification(context, 'Не удалось сохранить обои');
      return;
    }
    _applyEffectiveWallpaper();
  }

  Future<void> _clearHistory() async {
    final current = chat;
    final canClearForAll =
        (widget.chatType == 'CHAT' || widget.chatType == 'CHANNEL') &&
        (current?.iAmAdmin(_myId) ?? false);
    final choice = await showBlurredConfirm(
      context,
      title: 'Очистить историю',
      message:
          'Все сообщения в этом чате будут удалены без возможности '
          'восстановления.',
      confirmLabel: 'Очистить',
      cancelLabel: 'Отмена',
      destructive: true,
      checkboxLabel: canClearForAll ? 'Для всех' : null,
    );
    if (!mounted || !choice.confirmed) return;
    final err = await chats.clearHistory(
      api,
      chatId: widget.chatId,
      lastEventTime: current?.lastEventTime ?? 0,
      forAll: canClearForAll && choice.checked,
    );
    if (!mounted) return;
    if (err != null) {
      showCustomNotification(context, err);
      return;
    }
    setState(() {
      _messages = [];
      _hasMoreHistory = false;
      _combinedItemsCache = null;
    });
    _messagesRev.value++;
  }

  Future<void> _deleteChat() async {
    final confirmed = await showConfirmDialog(
      context,
      title: 'Удалить чат',
      message: 'Чат будет удалён вместе со всей перепиской.',
      confirmLabel: 'Удалить',
      destructive: true,
    );
    if (!mounted || !confirmed) return;
    final err = await chats.deleteChat(
      api,
      chatId: widget.chatId,
      lastEventTime: chat?.lastEventTime ?? 0,
      forAll: false,
    );
    if (!mounted) return;
    if (err != null) {
      showCustomNotification(context, err);
      return;
    }
    Navigator.of(context).pop();
  }

  Future<void> _startCall() async {
    if (widget.chatType != 'DIALOG' || _peerIsBot) {
      showCustomNotification(context, 'Звонки доступны только в диалогах');
      return;
    }
    // Звонок уже идёт (возможно, свёрнут) — просто открываем его экран снова.
    final navigator = Navigator.of(context);
    final active = CallController.instance.activeSession;
    if (active != null) {
      await navigator.push(
        MaterialPageRoute(
          builder: (_) => CallScreen(
            name: widget.name,
            avatarUrl: widget.imageUrl.isNotEmpty ? widget.imageUrl : null,
            session: active,
          ),
        ),
      );
      _onCallScreenClosed();
      return;
    }
    final peerId = widget.chatId ^ _myId;
    if (peerId <= 0) return;
    try {
      final session = await CallController.instance.startOutgoing(peerId);
      if (!mounted) return;
      await navigator.push(
        MaterialPageRoute(
          builder: (_) => CallScreen(
            name: widget.name,
            avatarUrl: widget.imageUrl.isNotEmpty ? widget.imageUrl : null,
            session: session,
          ),
        ),
      );
      _onCallScreenClosed();
    } catch (_) {
      if (!mounted) return;
      showCustomNotification(context, 'Не удалось начать звонок');
    }
  }

  void _onCallScreenClosed() {
    if (!mounted) return;
    if (CallController.instance.activeSession != null) return;
    unawaited(_refreshAfterCall());
  }

  Future<void> _refreshAfterCall() async {
    await Future.delayed(const Duration(milliseconds: 700));
    if (!mounted || _myId == 0) return;
    try {
      final serverMessages = await messagesModule.fetchHistory(
        _myId,
        widget.chatId,
      );
      if (KometSettings.viewDeleted.value) {
        await chats.reconcileDeletedFromFetch(
          _myId,
          widget.chatId,
          serverMessages,
        );
      }
      final rows = await AppDatabase.loadMessages(
        _myId,
        widget.chatId,
        limit: 100,
        onlyVisible: !KometSettings.viewDeleted.value,
      );
      final decoded = await CachedMessage.fromDbRowsAsync(rows);
      if (mounted) _applyMergedMessages(decoded);
    } catch (e) {
      logger.w('Обновление после звонка не удалось: $e');
    }
  }

  void _seedPresenceFromChat() {
    if (_otherStatus != 0 || _otherSeenTime != null) return;
    final otherId = _resolveOtherId();
    if (otherId == null) return;
    final p = PresenceFetch.live(otherId);
    if (p == null) return;
    _otherStatus = (p['status'] as int?) ?? 0;
    _otherSeenTime = p['seen'] as int?;
  }

  void _recomputeHeaderStatus() {
    if (_commentsMode) {
      _headerStatusNotifier.value = '';
      return;
    }
    _headerStatusNotifier.value = _headerStatus();
  }

  String _headerStatus() {
    final conn = connectionStatusLabel(api.state);
    if (conn != null) return conn;
    final activity = ChatActivityStore.instance.activity(widget.chatId);
    if (activity != null) return activity.label;
    if (widget.chatType == 'CHAT') {
      final count = _participantsCount ?? chat?.participants.length ?? 0;
      return '$count участников';
    }
    if (widget.chatType == 'CHANNEL') {
      final count = _participantsCount ?? chat?.participants.length ?? 0;
      return '$count подписчиков';
    }
    if (_otherStatus == 1) return 'В сети';
    if (_otherStatus == 2 || _otherStatus == 3) return 'Был(-а) недавно';
    final s = _otherSeenTime;
    if (s != null && s > 0) return formatLastSeen(s);
    return '';
  }

  void _onTyping(Packet packet) {
    final payload = packet.payload;
    if (payload is! Map) return;
    if (payload['chatId'] != widget.chatId) return;
    final userId = payload['userId'];
    if (userId is! int || userId == _myId) return;
    ChatActivityStore.instance.mark(
      widget.chatId,
      userId,
      chatActivityFromType(payload['type']),
    );
  }

  void _clearTyping(int userId) {
    ChatActivityStore.instance.clearUser(widget.chatId, userId);
  }

  void _onMessageRead(Packet packet) {
    final payload = packet.payload;
    if (payload is! Map) return;
    if (payload['chatId'] != widget.chatId) return;
    final userId = payload['userId'];
    if (userId is! int || userId == _myId) return;
    final mark = payload['mark'];
    if (mark is! int) return;
    if (payload['setAsUnread'] == true) return;
    final c = chat;
    if (c == null) return;
    if (c.participants[userId] == mark) return;
    c.participants[userId] = mark;
    _syncOtherReadTime();
  }

  static String _formatLabel(TextFormat format) {
    switch (format) {
      case TextFormat.heading:
        return 'Заголовок';
      case TextFormat.strong:
        return 'Жирный';
      case TextFormat.emphasized:
        return 'Курсив';
      case TextFormat.underline:
        return 'Подчёркнутый';
      case TextFormat.strikethrough:
        return 'Зачёркнутый';
      case TextFormat.monospaced:
        return 'Моноширинный';
      case TextFormat.quote:
        return 'Цитата';
      case TextFormat.link:
        return 'Ссылка';
      case TextFormat.animoji:
        return 'Animoji';
      case TextFormat.userMention:
        return 'Упоминание';
    }
  }

  Widget _formatContextMenu(
    RichMessageController controller,
    BuildContext context,
    EditableTextState editableState,
  ) {
    final selection = controller.selection;
    final buttonItems = <ContextMenuButtonItem>[];
    if (selection.isValid && !selection.isCollapsed) {
      for (final format in composerFormats) {
        final active = controller.isFormatActive(format);
        buttonItems.add(
          ContextMenuButtonItem(
            label: '${active ? '✓ ' : ''}${_formatLabel(format)}',
            onPressed: () {
              controller.toggleFormat(format);
              editableState.hideToolbar();
            },
          ),
        );
      }
    }
    buttonItems.addAll(editableState.contextMenuButtonItems);
    return AdaptiveTextSelectionToolbar.buttonItems(
      anchors: editableState.contextMenuAnchors,
      buttonItems: buttonItems,
    );
  }

  static bool _sameElements(
    List<Map<String, dynamic>> a,
    List<Map<String, dynamic>> b,
  ) {
    if (a.length != b.length) return false;
    String canon(List<Map<String, dynamic>> els) {
      final copy = [...els]
        ..sort((x, y) {
          final t = (x['type'] as String).compareTo(y['type'] as String);
          return t != 0 ? t : (x['from'] as int).compareTo(y['from'] as int);
        });
      return copy
          .map((e) => '${e['type']}:${e['from']}:${e['length']}')
          .join(',');
    }

    return canon(a) == canon(b);
  }

  List<Map<String, dynamic>> _trimmedElements(
    List<Map<String, dynamic>> raw,
    String rawText,
    String text,
  ) {
    if (raw.isEmpty) return const [];
    final leading = rawText.length - rawText.trimLeft().length;
    final result = <Map<String, dynamic>>[];
    for (final element in raw) {
      var from = (element['from'] as int) - leading;
      var length = element['length'] as int;
      if (from < 0) {
        length += from;
        from = 0;
      }
      if (from >= text.length || length <= 0) continue;
      if (from + length > text.length) length = text.length - from;
      if (length <= 0) continue;
      result.add({...element, 'from': from, 'length': length});
    }
    return result;
  }

  Future<String?> _encryptOutgoing(String text) async {
    if (!_encryptionEnabled || _myId == 0) return text;
    final result = await ChatCryptoService.instance.encrypt(
      _myId,
      widget.chatId,
      text,
    );
    if (result.isOk) {
      if (result.text!.length > kMaxEncryptedMessageLength) {
        if (mounted) {
          showCustomNotification(
            context,
            'Слишком длинное сообщение. Разделите на несколько',
          );
        }
        return null;
      }
      return result.text;
    }
    if (mounted) {
      showCustomNotification(
        context,
        result.failure == CryptoFailure.noKey
            ? 'Не задан ключ шифрования'
            : 'Не удалось зашифровать сообщение',
      );
    }
    return null;
  }

  Future<void> _sendMessage() async {
    if (_forwardRequest == null) {
      await _sendTextMessage();
      return;
    }
    if (_forwardSending || _myId == 0) return;
    _forwardSending = true;
    try {
      final forwarded = await _sendForwardRequest();
      if (!forwarded || !mounted) return;
      if (_messageController.text.trim().isEmpty) return;
      await _sendTextMessage();
    } finally {
      _forwardSending = false;
    }
  }

  Future<void> _sendTextMessage() async {
    final content = _messageController.buildContent();
    final rawText = content.text;
    final text = rawText.trim();
    if (text.isEmpty || _myId == 0) return;

    if (AppCommands.current.value && text.startsWith('/')) {
      final command = findSlashCommand(text);
      if (command == null) {
        _messageController.clear();
        _hasText.value = false;
        showCustomNotification(context, 'ТАКОЙ КОМАНДЫ НЕТУ🚨🚨🚨');
        return;
      }
      if (command.run != null) {
        final args = commandArgs(text);
        _messageController.clear();
        _hasText.value = false;
        unawaited(command.run!(_commandContext(args)));
        return;
      }
    }

    final wireText = await _encryptOutgoing(text);
    if (wireText == null || !mounted) return;
    final encrypted = wireText != text;

    final tempId = _nextTempId();
    final now = DateTime.now().millisecondsSinceEpoch;
    final online = api.state == SessionState.online;

    final reply = _replyTo.value;
    final int? replyId = reply == null ? null : int.tryParse(reply.id);
    final int? replySourceChatId = replyId == null ? null : _replySourceChatId;
    Map<String, dynamic>? replyPayload;
    if (reply != null && replyId != null) {
      replyPayload = {
        'link': {
          'type': 'REPLY',
          'chatId': replySourceChatId ?? widget.chatId,
          'message': {
            'id': replyId,
            'sender': reply.senderId,
            'text': reply.text,
            'time': reply.time,
            'attaches': reply.payload?['attaches'] ?? const [],
          },
        },
      };
    }
    _replyTo.value = null;
    _replySourceChatId = null;

    final elements = encrypted
        ? const <Map<String, dynamic>>[]
        : _trimmedElements(content.elements, rawText, text);
    final Map<String, dynamic>? composedPayload =
        (replyPayload == null && elements.isEmpty)
        ? null
        : {...?replyPayload, if (elements.isNotEmpty) 'elements': elements};

    final composed = CachedMessage(
      id: tempId,
      accountId: _myId,
      chatId: widget.chatId,
      senderId: _myId,
      text: wireText,
      time: now,
      status: online ? 'sending' : 'pending',
      payload: composedPayload,
    );
    if (encrypted) MessageDecryptionCache.instance.seed(tempId, text);

    _hasText.value = false;
    _lastSentId = tempId;
    _messages.add(composed);
    _messageController.clear();
    if (!_commentsMode &&
        DraftStore.instance.get(_myId, widget.chatId) != null) {
      unawaited(DraftStore.instance.clear(_myId, widget.chatId));
    }
    _bumpMessages();
    if (!_commentsMode) {
      unawaited(_persistOutgoing(composed));
      unawaited(
        chats.applyOutgoing(
          _myId,
          widget.chatId,
          messageId: tempId,
          time: now,
          text: wireText,
          status: composed.status ?? 'sending',
          elements: elements,
        ),
      );
    }

    // Instant tactile "whoosh" the moment the message leaves the composer,
    // not after the network round-trip — feedback must feel immediate.
    Haptics.send();

    _scrollToBottom();
    _prank.checkTrigger(composed);

    if (!online) return;

    try {
      final actualId = _commentsMode
          ? await commentsModule.sendComment(
              _myId,
              widget.chatId,
              widget.commentPostId!,
              wireText,
              replyToMessageId: replyId,
              elements: elements,
            )
          : await messagesModule.sendMessage(
              _myId,
              widget.chatId,
              wireText,
              replyToMessageId: replyId,
              replySourceChatId: replySourceChatId,
              elements: elements,
            );

      final index = _messages.indexWhere((m) => m.id == tempId);
      if (index != -1 && mounted) {
        final sent = CachedMessage(
          id: actualId.isNotEmpty ? actualId : tempId,
          accountId: _myId,
          chatId: widget.chatId,
          senderId: _myId,
          text: wireText,
          time: now,
          status: 'sent',
          payload: composedPayload,
        );
        if (encrypted) {
          MessageDecryptionCache.instance.adopt(tempId, sent.id);
        }
        _messages[index] = sent;
        _bumpMessages();
        if (!_commentsMode) {
          unawaited(_persistOutgoing(sent, removeId: tempId));
          unawaited(
            chats.applyOutgoing(
              _myId,
              widget.chatId,
              messageId: sent.id,
              time: now,
              text: wireText,
              status: 'sent',
              elements: elements,
            ),
          );
        }
      }

      if (!_commentsMode && chat == null) {
        unawaited(
          chats.refreshChats(api, [widget.chatId]).then((list) {
            if (!mounted || list.isEmpty) return;
            setState(() => chat = list.first);
            _bumpMessages();
            _syncOtherReadTime();
          }),
        );
      }
    } catch (e) {
      if (replySourceChatId != null) {
        logger.w('Cross-chat reply rejected: $e');
        final index = _messages.indexWhere((m) => m.id == tempId);
        if (index != -1 && mounted) {
          _messages.removeAt(index);
          _bumpMessages();
        }
        unawaited(AppDatabase.deleteMessage(_myId, widget.chatId, tempId));
        if (mounted) {
          Haptics.error();
          showCustomNotification(context, e.toString());
        }
        return;
      }
      final index = _messages.indexWhere((m) => m.id == tempId);
      if (index != -1 && mounted) {
        final queued = CachedMessage(
          id: tempId,
          accountId: _myId,
          chatId: widget.chatId,
          senderId: _myId,
          text: text,
          time: now,
          status: 'pending',
          payload: composedPayload,
        );
        _messages[index] = queued;
        _bumpMessages();
        if (!_commentsMode) {
          unawaited(_persistOutgoing(queued));
          unawaited(
            chats.applyOutgoing(
              _myId,
              widget.chatId,
              messageId: tempId,
              time: now,
              text: text,
              status: 'pending',
              elements: elements,
            ),
          );
        }
      }
    }
  }

  int? _resolveOtherId() {
    if (widget.chatType != 'DIALOG' || _myId == 0) return null;
    final id = widget.chatId ^ _myId;
    return id > 0 ? id : null;
  }

  int _complaintTypeId(String type) {
    switch (type) {
      case 'CHANNEL':
        return 5;
      case 'CHAT':
        return 4;
      default:
        return 3;
    }
  }

  Future<List<({int id, String title})>> _loadReportReasons(int typeId) async {
    final reasons = await ComplaintsModule.reasonsFor(api, typeId);
    return reasons.map((r) => (id: r.reasonId, title: r.reasonTitle)).toList();
  }

  Future<bool> _reportMessage(
    CachedMessage message,
    int typeId,
    int reasonId,
  ) async {
    final messageIdNum = int.tryParse(message.id);
    if (messageIdNum == null) {
      if (mounted) {
        showCustomNotification(context, 'Не удалось отправить жалобу');
      }
      return false;
    }
    final ok = await ComplaintsModule.sendComplaint(
      api,
      reasonId: reasonId,
      typeId: typeId,
      ids: [messageIdNum],
      parentId: widget.chatId,
    );
    if (!mounted) return ok;
    showCustomNotification(
      context,
      ok ? 'Жалоба отправлена' : 'Не удалось отправить жалобу',
    );
    return ok;
  }

  CachedMessage _replaceMessage(
    int index, {
    String? id,
    String? text,
    String? status,
  }) {
    final old = _messages[index];
    final updated = CachedMessage(
      id: id ?? old.id,
      accountId: old.accountId,
      chatId: old.chatId,
      senderId: old.senderId,
      text: text ?? old.text,
      time: old.time,
      status: status ?? old.status,
      payload: old.payload,
      attachments: old.attachments,
      isControl: old.isControl,
      editHistory: old.editHistory,
    );
    _messages[index] = updated;
    _bumpMessages();
    return updated;
  }

  Future<String> _postCommandMessage(String text) async {
    if (!mounted || _myId == 0) return '';
    final tempId = _nextTempId();
    final now = DateTime.now().millisecondsSinceEpoch;
    final online = api.state == SessionState.online;
    final composed = CachedMessage(
      id: tempId,
      accountId: _myId,
      chatId: widget.chatId,
      senderId: _myId,
      text: text,
      time: now,
      status: online ? 'sending' : 'pending',
    );
    _messages.add(composed);
    _bumpMessages();
    _scrollToBottom();
    unawaited(_persistOutgoing(composed));
    unawaited(
      chats.applyOutgoing(
        _myId,
        widget.chatId,
        messageId: tempId,
        time: now,
        text: text,
        status: composed.status ?? 'sending',
      ),
    );
    if (!online) return tempId;
    try {
      final actualId = await messagesModule.sendMessage(
        _myId,
        widget.chatId,
        text,
      );
      final realId = actualId.isNotEmpty ? actualId : tempId;
      final i = _messages.indexWhere((m) => m.id == tempId);
      if (i != -1) {
        final sent = _replaceMessage(i, id: realId, status: 'sent');
        unawaited(_persistOutgoing(sent, removeId: tempId));
        unawaited(
          chats.applyOutgoing(
            _myId,
            widget.chatId,
            messageId: realId,
            time: now,
            text: text,
            status: 'sent',
          ),
        );
      }
      return realId;
    } catch (_) {
      return tempId;
    }
  }

  Future<void> _updateCommandMessage(String id, String text) async {
    if (id.isEmpty) return;
    final i = _messages.indexWhere((m) => m.id == id);
    if (i != -1) {
      final edited = _replaceMessage(i, text: text, status: 'EDITED');
      unawaited(_persistOutgoing(edited));
    }
    if (!id.startsWith('temp_')) {
      await messagesModule.editMessage(widget.chatId, id, text: text);
    }
  }

  CommandContext _commandContext(String args) => CommandContext(
    accountId: _myId,
    chatId: widget.chatId,
    otherUserId: _resolveOtherId(),
    args: args,
    messages: messagesModule,
    isOnline: () => api.state == SessionState.online,
    isActive: () => mounted,
    notify: (message, {duration}) {
      if (mounted) showCustomNotification(context, message, duration: duration);
    },
    postMessage: _postCommandMessage,
    updateMessage: _updateCommandMessage,
    sendPhotos: _sendPhotos,
    sendVideoNote: _sendVideoNote,
  );

  Future<void> _scheduleMessage() async {
    final text = _messageController.text.trim();
    if (text.isEmpty || _myId == 0) return;

    final when = await _pickScheduleTime();
    if (when == null || !mounted) return;

    try {
      await messagesModule.sendMessage(
        _myId,
        widget.chatId,
        text,
        scheduledTime: when.millisecondsSinceEpoch,
      );
      if (!mounted) return;
      _hasText.value = false;
      _messageController.clear();
      Haptics.send();
      _markHasScheduled();
      showCustomNotification(
        context,
        'Запланировано на ${formatDateTimeWords(when)}',
      );
    } catch (_) {
      if (!mounted) return;
      Haptics.error();
      showCustomNotification(context, 'Не удалось запланировать сообщение');
    }
  }

  Future<DateTime?> _pickScheduleTime() => showScheduleTimePicker(context);

  void _openScheduledMessages() {
    Navigator.of(context)
        .push(
          MaterialPageRoute(
            builder: (_) => ScheduledMessagesScreen(
              chatId: widget.chatId,
              accountId: _myId,
              chatName: widget.name,
            ),
          ),
        )
        .then((_) {
          if (mounted) _refreshScheduledCount();
        });
  }

  Future<void> _persistOutgoing(CachedMessage msg, {String? removeId}) async {
    try {
      if (removeId != null && removeId != msg.id) {
        await AppDatabase.deleteMessage(_myId, widget.chatId, removeId);
      }
      await AppDatabase.saveMessages([msg.toDbRow()]);
    } catch (_) {}
  }

  Future<void> _loadGroupSenderNames() async {
    if (widget.chatType != 'CHAT' && widget.chatType != 'CHANNEL') return;

    final unknownIds = <int>{};
    for (final msg in _messages) {
      if (msg.isControl) continue;
      final id = msg.senderId;
      if (id == 0 || id == _myId) continue;
      if (ContactCache.get(id) == null) unknownIds.add(id);
    }
    if (unknownIds.isEmpty) return;

    final resolved = await messagesModule.ensureContactNames(unknownIds);
    if (resolved && mounted) _bumpMessages();
  }

  Future<void> _loadForwardedSenderNames() async {
    final forwardIds = <int>{};
    for (final msg in _messages) {
      if (msg.attachments != null) {
        for (final a in msg.attachments!) {
          if (a is ForwardedMessageAttachment) {
            if (a.originalSenderId != 0 &&
                a.originalSenderName == null &&
                ContactCache.get(a.originalSenderId) == null) {
              forwardIds.add(a.originalSenderId);
            }
          }
        }
      }
    }
    if (forwardIds.isEmpty) return;

    final resolved = <int, ({String name, String? avatar})>{};
    for (final id in forwardIds) {
      final name = await messagesModule.searchContactById(id);
      if (name != null) {
        resolved[id] = (name: name, avatar: ContactCache.getAvatar(id));
      }
    }
    if (resolved.isEmpty || !mounted) return;

    var anyChanged = false;
    for (var i = 0; i < _messages.length; i++) {
      final msg = _messages[i];
      final attaches = msg.attachments;
      if (attaches == null) continue;

      var msgChanged = false;
      final newAttaches = attaches.map((a) {
        if (a is ForwardedMessageAttachment &&
            a.originalSenderName == null &&
            resolved.containsKey(a.originalSenderId)) {
          final r = resolved[a.originalSenderId]!;
          msgChanged = true;
          return ForwardedMessageAttachment(
            originalSenderId: a.originalSenderId,
            originalSenderName: r.name,
            originalSenderAvatar: r.avatar,
            originalType: a.originalType,
            originalMessageId: a.originalMessageId,
            originalTime: a.originalTime,
            originalText: a.originalText,
            originalChatId: a.originalChatId,
            originalFormatRanges: a.originalFormatRanges,
            originalAttachments: a.originalAttachments,
            originalContact: a.originalContact,
          );
        }
        return a;
      }).toList();

      if (!msgChanged) continue;
      anyChanged = true;
      _messages[i] = msg.copyWith(attachments: newAttaches);
    }

    if (anyChanged) {
      _bumpMessages();
    }
  }

  void _scrollToBottom() {
    _returnStack.clear();
    _newMessageCount.value = 0;
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (!_scrollController.hasClients) return;
      final pos = _scrollController.position;
      final runway = pos.viewportDimension;
      final teleport = pos.pixels > runway * _scrollDownTeleportFactor;
      if (teleport) {
        _pinnedMessageId = null;
        _listEpoch++;
        _jumpCacheExtent.value = _jumpCacheExtentPx;
        _bumpMessages();
        _scrollController.jumpTo(runway);
      }
      unawaited(
        _scrollController
            .animateTo(
              pos.minScrollExtent,
              duration: const Duration(milliseconds: 300),
              curve: Curves.easeOut,
            )
            .whenComplete(() {
              if (!teleport) return;
              WidgetsBinding.instance.addPostFrameCallback((_) {
                if (mounted) _jumpCacheExtent.value = null;
              });
            }),
      );
    });
  }

  void _updateScrollDownVisible() {
    if (!_scrollController.hasClients) {
      _setScrollDownVisible(_newMessageCount.value > 0);
      return;
    }
    final pos = _scrollController.position;
    final atBottom = _isNearBottom();
    if (_returnStack.isNotEmpty &&
        atBottom &&
        pos.userScrollDirection != ScrollDirection.idle) {
      _returnStack.clear();
    }
    if (atBottom && _newMessageCount.value > 0) _clearNewMessageCountSoon();
    final reveal = math.min(
      _scrollDownRevealExtent,
      pos.viewportDimension * _scrollDownRevealFactor,
    );
    _setScrollDownVisible(
      pos.pixels >= reveal ||
          _returnStack.isNotEmpty ||
          _newMessageCount.value > 0,
    );
  }

  void _setScrollDownVisible(bool show) {
    if (show == _scrollDownVisible) return;
    _scrollDownVisible = show;
    if (show) {
      _scrollDownAnimController.forward();
    } else {
      _scrollDownAnimController.reverse();
    }
  }

  void _noteMissedMessage() {
    _newMessageCount.value++;
    _updateScrollDownVisible();
  }

  void _clearNewMessageCountSoon() {
    if (_clearCountScheduled) return;
    _clearCountScheduled = true;
    WidgetsBinding.instance.addPostFrameCallback((_) {
      _clearCountScheduled = false;
      if (!mounted || !_isNearBottom()) return;
      _newMessageCount.value = 0;
      _updateScrollDownVisible();
    });
  }

  void _pushReturnAnchor(String messageId) {
    if (!_scrollController.hasClients) return;
    final listBox = _listKey.currentContext?.findRenderObject();
    final dy = _messageOffsetInList(messageId);
    final viewportH = listBox is RenderBox ? listBox.size.height : 0.0;
    final alignment = viewportH > 0 && dy != null
        ? (dy / viewportH).clamp(0.0, 1.0)
        : 0.5;
    _returnStack.add((
      id: messageId,
      pixels: _scrollController.position.pixels,
      alignment: alignment.toDouble(),
    ));
    if (!_scrollDownVisible) {
      _scrollDownVisible = true;
      _scrollDownAnimController.forward();
    }
  }

  void _onScrollDownTap() {
    if (_returningToAnchor || _navigatingToTarget) return;
    if (!_scrollController.hasClients) {
      _scrollToBottom();
      return;
    }
    final pixels = _scrollController.position.pixels;
    while (_returnStack.isNotEmpty) {
      final anchor = _returnStack.removeLast();
      if (anchor.pixels < pixels && _messages.any((m) => m.id == anchor.id)) {
        _returningToAnchor = true;
        unawaited(
          _returnToAnchor(
            anchor,
          ).whenComplete(() => _returningToAnchor = false),
        );
        return;
      }
    }
    _scrollToBottom();
  }

  Future<void> _returnToAnchor(
    ({String id, double pixels, double alignment}) anchor,
  ) async {
    final pos = _scrollController.position;
    final runway = pos.viewportDimension;
    final target = anchor.pixels.clamp(
      pos.minScrollExtent,
      pos.maxScrollExtent,
    );
    final distance = (pos.pixels - target).abs();
    final far = distance > runway * _scrollDownTeleportFactor;

    if (!far) {
      await _scrollController.animateTo(
        target,
        duration: const Duration(milliseconds: 300),
        curve: Curves.easeOut,
      );
      if (!mounted) return;
      await _scrollToMessagePrecise(anchor.id, alignment: anchor.alignment);
      return;
    }

    _jumpCacheExtent.value = _jumpCacheExtentPx;
    if (target + runway < distance) {
      _listEpoch++;
      _bumpMessages();
      _scrollController.jumpTo(target + runway);
      await _scrollController.animateTo(
        target,
        duration: const Duration(milliseconds: 300),
        curve: Curves.easeOut,
      );
      if (!mounted) return;
    }
    await _scrollToMessagePrecise(anchor.id, alignment: anchor.alignment);
    if (!mounted) return;
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (mounted) _jumpCacheExtent.value = null;
    });
  }

  bool _isNearBottom() {
    if (!_scrollController.hasClients) return true;
    return _scrollController.position.pixels <= 120;
  }

  void _startReply(CachedMessage message) {
    _cancelForward();
    _replyTo.value = message;
    _replySourceChatId = null;
    _messageFocusNode.requestFocus();
  }

  void _cancelReply() {
    _replyTo.value = null;
    _replySourceChatId = null;
  }

  Future<void> _pickReplyChat() async {
    final reply = _replyTo.value;
    if (reply == null) return;
    if (reply.id.startsWith('temp_')) {
      showCustomNotification(context, 'Сообщение ещё не отправлено');
      return;
    }

    final sourceChatId = _replySourceChatId ?? widget.chatId;
    final target = await openForwardScreen(context: context);
    if (target == null || !mounted) return;

    if (target.chatId == widget.chatId) {
      _replySourceChatId = sourceChatId == widget.chatId ? null : sourceChatId;
      _messageFocusNode.requestFocus();
      return;
    }

    await chats.ensureChatCached(api, _myId, target.chatId);
    if (!mounted) return;
    pushSwipeable(
      context,
      (_) => ChatScreen(
        chatId: target.chatId,
        name: target.name,
        imageUrl: target.imageUrl,
        chatType: target.chatType,
        replyRequest: ReplyRequest(sourceChatId: sourceChatId, message: reply),
      ),
    );
  }

  void _openSenderProfile(int senderId) {
    if (senderId == 0 || senderId == _myId) return;
    unawaited(
      openContactDialogProfile(
        context,
        contactId: senderId,
        name: ContactCache.get(senderId) ?? 'User #$senderId',
        avatarUrl: ContactCache.getAvatar(senderId),
      ),
    );
  }

  void _openForwardedSource(ForwardedMessageAttachment forwarded) {
    if (forwarded.isChannel) {
      unawaited(_openForwardedChannel(forwarded));
      return;
    }
    final senderId = forwarded.originalSenderId;
    if (senderId == 0 || senderId == _myId) return;
    unawaited(
      openContactDialogProfile(
        context,
        contactId: senderId,
        name:
            forwarded.originalSenderName ??
            ContactCache.get(senderId) ??
            'User #$senderId',
        avatarUrl:
            forwarded.originalSenderAvatar ?? ContactCache.getAvatar(senderId),
      ),
    );
  }

  Future<void> _openForwardedChannel(
    ForwardedMessageAttachment forwarded,
  ) async {
    final sourceChatId = forwarded.originalChatId;
    if (sourceChatId == null) {
      showCustomNotification(context, 'Канал недоступен');
      return;
    }
    final sourceMessageId = forwarded.originalMessageId;
    if (sourceChatId == widget.chatId) {
      if (sourceMessageId == null) return;
      _beginTargetNavigation();
      await _runGoToMessage(sourceMessageId, forwarded.originalTime ?? 0);
      return;
    }

    await chats.ensureChatCached(api, _myId, sourceChatId);
    if (!mounted) return;
    final cached = await chats.getChat(_myId, sourceChatId);
    if (!mounted) return;
    final channel = cached.isEmpty ? null : cached.first;
    pushSwipeable(
      context,
      (_) => ChatScreen(
        chatId: sourceChatId,
        name: channel?.title ?? forwarded.originalSenderName ?? 'Канал',
        imageUrl: channel?.iconUrl ?? forwarded.originalSenderAvatar ?? '',
        chatType: channel?.type ?? 'CHANNEL',
        initialMessageId: sourceMessageId,
        initialMessageTime: forwarded.originalTime,
      ),
    );
  }

  void _openStickerPack(StickerAttachment sticker) {
    final stickerId = int.tryParse(sticker.stickerId ?? '');
    if (stickerId == null) {
      showCustomNotification(context, 'Стикерпак недоступен');
      return;
    }
    showStickerPackSheet(
      context,
      stickerId: stickerId,
      knownSetId: int.tryParse(sticker.stickerPackId ?? ''),
    );
  }

  void _jumpToMessage(String messageId, {String? fromId}) {
    final index = _messages.indexWhere((m) => m.id == messageId);
    if (index == -1) {
      showCustomNotification(context, 'Сообщение не загружено');
      return;
    }

    if (fromId != null) _pushReturnAnchor(fromId);

    final key = _keyForMessage(messageId);
    final ctx = key.currentContext;
    if (ctx != null) {
      Scrollable.ensureVisible(
        ctx,
        duration: const Duration(milliseconds: 300),
        curve: Curves.easeOut,
        alignment: 0.4,
      );
    } else {
      unawaited(_scrollToMessagePrecise(messageId, alignment: 0.4));
    }

    _highlightTimer?.cancel();
    _highlightMessageId.value = messageId;
    _highlightTimer = Timer(const Duration(milliseconds: 1400), () {
      if (!mounted) return;
      if (_highlightMessageId.value == messageId) {
        _highlightMessageId.value = null;
      }
    });
  }

  final Map<String, GlobalKey> _messageKeys = {};

  GlobalKey _keyForMessage(String messageId) =>
      _messageKeys.putIfAbsent(messageId, () => GlobalKey());

  void _openSearch() {
    if (_search.searchMode.value || _selectionMode) return;
    _search.searchMode.value = true;
    _searchAnim.forward();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (mounted && _search.searchMode.value) _searchFocusNode.requestFocus();
    });
  }

  void _closeSearch() {
    if (!_search.searchMode.value) return;
    _searchFocusNode.unfocus();
    _searchAnim.reverse();
    _search.reset();
  }

  Future<void> _navigateToInitialMessage() async {
    final id = widget.initialMessageId;
    if (id == null) {
      _finishTargetNavigation();
      return;
    }
    await _runGoToMessage(id, widget.initialMessageTime ?? 0);
  }

  Future<void> _runGoToMessage(String id, int targetTime) async {
    await WidgetsBinding.instance.endOfFrame;
    if (!mounted) return;

    if (!_messages.any((m) => m.id == id)) {
      await _loadMessageWindow(id, targetTime);
      if (!mounted) return;
      await WidgetsBinding.instance.endOfFrame;
      if (!mounted) return;
    }

    if (!_messages.any((m) => m.id == id)) {
      if (mounted) showCustomNotification(context, 'Сообщение не загружено');
      _finishTargetNavigation();
      return;
    }

    _highlightTimer?.cancel();
    _highlightMessageId.value = id;
    _highlightTimer = Timer(const Duration(milliseconds: 2200), () {
      if (!mounted) return;
      if (_highlightMessageId.value == id) _highlightMessageId.value = null;
    });

    await _scrollToMessagePrecise(id);
    _finishTargetNavigation();
  }

  ({int min, int max})? _laidOutMessageRange(List<Object> items) {
    int? lo;
    int? hi;
    for (var i = 0; i < items.length; i++) {
      final it = items[i];
      if (it is! _MessageItem) continue;
      final ro = _keyForMessage(
        it.message.id,
      ).currentContext?.findRenderObject();
      if (ro is RenderBox && ro.attached) {
        lo ??= i;
        hi = i;
      }
    }
    if (lo == null) return null;
    return (min: lo, max: hi!);
  }

  Future<void> _scrollToMessagePrecise(
    String id, {
    double alignment = 0.32,
  }) async {
    if (!mounted || !_scrollController.hasClients) return;
    if (_messages.indexWhere((m) => m.id == id) == -1) return;

    _historyAutoloadSuppressCount++;
    try {
      var stable = 0;
      for (var iter = 0; iter < 120; iter++) {
        if (!mounted || !_scrollController.hasClients) return;
        final listObj = _listKey.currentContext?.findRenderObject();
        final boxObj = _keyForMessage(id).currentContext?.findRenderObject();
        final p = _scrollController.position;

        if (listObj is RenderBox && boxObj is RenderBox && boxObj.attached) {
          final viewportH = listObj.size.height;
          final actualTop = boxObj
              .localToGlobal(Offset.zero, ancestor: listObj)
              .dy;
          final desiredTop = alignment * viewportH;
          final delta = desiredTop - actualTop;
          final target = (p.pixels + delta).clamp(
            p.minScrollExtent,
            p.maxScrollExtent,
          );

          if (delta.abs() <= 2.0 || (target - p.pixels).abs() <= 1.0) {
            stable++;
            if (stable >= 4) return;
            await Future.delayed(const Duration(milliseconds: 60));
            continue;
          }
          stable = 0;
          _scrollController.jumpTo(target);
          await WidgetsBinding.instance.endOfFrame;
          continue;
        }

        stable = 0;
        final items = _buildCombinedItems();
        final pos = items.indexWhere(
          (it) => it is _MessageItem && it.message.id == id,
        );
        if (pos == -1) return;

        final viewportH = listObj is RenderBox ? listObj.size.height : 600.0;
        var stepMag = viewportH * 0.8;
        if (stepMag > 700) stepMag = 700;

        final range = _laidOutMessageRange(items);
        final step = (range != null && pos > range.max) ? -stepMag : stepMag;

        final target = (p.pixels + step).clamp(
          p.minScrollExtent,
          p.maxScrollExtent,
        );
        if ((target - p.pixels).abs() < 1.0) return;
        _scrollController.jumpTo(target);
        await WidgetsBinding.instance.endOfFrame;
      }
    } finally {
      _historyAutoloadSuppressCount--;
    }
  }

  Future<void> _openSearchResult(MessageSearchResult result) async {
    _closeSearch();
    if (_messages.any((m) => m.id == result.id)) {
      await WidgetsBinding.instance.endOfFrame;
      if (!mounted) return;
      _scrollToLoadedMessage(result.id);
      return;
    }
    setState(_beginTargetNavigation);
    await _runGoToMessage(result.id, result.time);
  }

  void _scrollToLoadedMessage(
    String messageId, {
    double alignment = 0.4,
    bool highlight = true,
    bool notifyIfMissing = true,
    VoidCallback? onSettled,
  }) {
    if (!_scrollController.hasClients) {
      onSettled?.call();
      return;
    }
    final items = _buildCombinedItems();
    final pos = items.indexWhere(
      (it) => it is _MessageItem && it.message.id == messageId,
    );
    if (pos == -1) {
      if (notifyIfMissing) {
        showCustomNotification(context, 'Сообщение не загружено');
      }
      onSettled?.call();
      return;
    }

    final laidOut = _keyForMessage(
      messageId,
    ).currentContext?.findRenderObject();
    if (laidOut is! RenderBox || !laidOut.attached) {
      var below = 0.0;
      for (var i = pos + 1; i < items.length; i++) {
        below += items[i] is _MessageItem ? _avgMessageHeight : 44.0;
      }
      final maxExtent = _scrollController.position.maxScrollExtent;
      _scrollController.jumpTo(below.clamp(0.0, maxExtent).toDouble());
    }

    if (highlight) {
      _highlightTimer?.cancel();
      _highlightMessageId.value = messageId;
      _highlightTimer = Timer(const Duration(milliseconds: 1600), () {
        if (!mounted) return;
        if (_highlightMessageId.value == messageId) {
          _highlightMessageId.value = null;
        }
      });
    }
    WidgetsBinding.instance.addPostFrameCallback(
      (_) => _alignLoadedMessage(messageId, alignment, 0, onSettled: onSettled),
    );
  }

  void _alignLoadedMessage(
    String messageId,
    double alignment,
    int attempt, {
    VoidCallback? onSettled,
  }) {
    if (!mounted || !_scrollController.hasClients) {
      onSettled?.call();
      return;
    }
    final listBox = _listKey.currentContext?.findRenderObject();
    final box = _keyForMessage(messageId).currentContext?.findRenderObject();
    if (listBox is! RenderBox || box is! RenderBox || !box.attached) {
      if (attempt >= 8) {
        onSettled?.call();
        return;
      }
      WidgetsBinding.instance.addPostFrameCallback(
        (_) => _alignLoadedMessage(
          messageId,
          alignment,
          attempt + 1,
          onSettled: onSettled,
        ),
      );
      return;
    }

    final viewportHeight = listBox.size.height;
    final actualTop = box.localToGlobal(Offset.zero, ancestor: listBox).dy;
    final desiredTop = alignment.clamp(0.0, 1.0) * viewportHeight;
    final delta = desiredTop - actualTop;
    final pos = _scrollController.position;
    final target = (pos.pixels + delta).clamp(
      pos.minScrollExtent,
      pos.maxScrollExtent,
    );

    if (viewportHeight <= 0 ||
        delta.abs() <= 0.5 ||
        (target - pos.pixels).abs() <= 0.5 ||
        attempt >= 8) {
      onSettled?.call();
      return;
    }

    _scrollController.jumpTo(target);
    WidgetsBinding.instance.addPostFrameCallback(
      (_) => _alignLoadedMessage(
        messageId,
        alignment,
        attempt + 1,
        onSettled: onSettled,
      ),
    );
  }

  String _searchSenderName(int senderId) {
    if (senderId == _myId) return 'Вы';
    final cached = ContactCache.get(senderId);
    if (cached != null && cached.isNotEmpty) return cached;
    if (widget.chatType == 'DIALOG') return widget.name;
    return 'Пользователь';
  }

  String? _searchSenderAvatar(int senderId) {
    final cached = ContactCache.getAvatar(senderId);
    if (cached != null && cached.isNotEmpty) return cached;
    if (senderId != _myId &&
        widget.chatType == 'DIALOG' &&
        widget.imageUrl.isNotEmpty) {
      return widget.imageUrl;
    }
    return null;
  }

  int _firstUnreadIndex() {
    final anchor = _unreadAnchorTime;
    if (anchor == null) return -1;
    return _messages.indexWhere((m) => m.time > anchor);
  }

  List<Object> _buildCombinedItems() {
    final key = Object.hash(
      _messagesRev.value,
      _messages.length,
      _unreadAnchorTime,
    );
    final cached = _combinedItemsCache;
    if (cached != null && _combinedItemsKey == key) return cached;

    final unreadIndex = _firstUnreadIndex();

    final List<Object> items = [];
    final Set<int> usedDates = {};

    for (int i = 0; i < _messages.length; i++) {
      final msg = _messages[i];
      final msgDate = DateTime.fromMillisecondsSinceEpoch(msg.time);
      final dayMillis = DateTime(
        msgDate.year,
        msgDate.month,
        msgDate.day,
      ).millisecondsSinceEpoch;

      bool needSeparator = i == 0;
      if (!needSeparator) {
        final prevDate = DateTime.fromMillisecondsSinceEpoch(
          _messages[i - 1].time,
        );
        final prevDayMillis = DateTime(
          prevDate.year,
          prevDate.month,
          prevDate.day,
        ).millisecondsSinceEpoch;
        needSeparator = dayMillis != prevDayMillis;
      }

      if (needSeparator) {
        _separatorKeys.putIfAbsent(dayMillis, () => GlobalKey());
        usedDates.add(dayMillis);
        items.add(
          _DateSeparatorItem(
            DateTime.fromMillisecondsSinceEpoch(dayMillis),
            _separatorKeys[dayMillis]!,
          ),
        );
      }

      if (i == unreadIndex) {
        items.add(const _UnreadSeparatorItem());
      }

      items.add(_MessageItem(msg, i));
    }

    _separatorKeys.removeWhere((k, _) => !usedDates.contains(k));
    _combinedItemsCache = items;
    _combinedItemsKey = key;
    return items;
  }

  void _onScrollForDate() {
    if (!_scrollController.hasClients) return;

    _floatingDateTimer?.cancel();
    _floatingDateTimer = Timer(const Duration(seconds: 1), () {
      if (mounted) _floatingDateAnimController.reverse();
    });

    if (_floatingDateScheduled) return;
    _floatingDateScheduled = true;
    WidgetsBinding.instance.addPostFrameCallback((_) {
      _floatingDateScheduled = false;
      _updateFloatingDate();
    });
  }

  void _updateFloatingDate() {
    if (!mounted || _separatorKeys.isEmpty) return;
    DateTime? result;

    final listRenderBox = _listKey.currentContext?.findRenderObject();
    if (listRenderBox is! RenderBox) return;

    _separatorKeys.forEach((dayMillis, gkey) {
      final ctx = gkey.currentContext;
      if (ctx == null) return;
      final box = ctx.findRenderObject();
      if (box is! RenderBox) return;
      final pos = box.localToGlobal(Offset.zero, ancestor: listRenderBox);
      if (pos.dy + box.size.height < 4) {
        final date = DateTime.fromMillisecondsSinceEpoch(dayMillis);
        if (result == null || date.isAfter(result!)) {
          result = date;
        }
      }
    });

    if (result == null) return;

    final bool dateChanged = result != _floatingDate.value;
    _floatingDate.value = result;

    if (dateChanged) {
      _floatingDateAnimController.forward(from: 0);
    } else {
      _floatingDateAnimController.forward();
    }
  }

  String _formatDateLabel(DateTime date) {
    final now = DateTime.now();
    final today = DateTime(now.year, now.month, now.day);
    final yesterday = today.subtract(const Duration(days: 1));
    final d = DateTime(date.year, date.month, date.day);

    if (d == today) return 'Сегодня';
    if (d == yesterday) return 'Вчера';

    const months = [
      'января',
      'февраля',
      'марта',
      'апреля',
      'мая',
      'июня',
      'июля',
      'августа',
      'сентября',
      'октября',
      'ноября',
      'декабря',
    ];
    if (date.year == now.year) {
      return '${date.day} ${months[date.month - 1]}';
    }
    return '${date.day} ${months[date.month - 1]} ${date.year}';
  }

  Widget _buildDateSeparatorWidget(
    BuildContext context,
    DateTime date, {
    Key? key,
    bool floating = false,
  }) {
    final cs = Theme.of(context).colorScheme;
    return Padding(
      key: key,
      padding: EdgeInsets.symmetric(vertical: floating ? 2 : 8),
      child: Center(
        child: Container(
          padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 4),
          decoration: BoxDecoration(
            color: cs.surfaceContainerHighest,
            borderRadius: BorderRadius.circular(12),
          ),
          child: Text(
            _formatDateLabel(date),
            style: TextStyle(
              color: cs.onSurfaceVariant,
              fontSize: 12,
              fontStyle: floating ? FontStyle.normal : FontStyle.italic,
            ),
          ),
        ),
      ),
    );
  }

  Widget _buildUnreadSeparatorWidget(BuildContext context) {
    final cs = Theme.of(context).colorScheme;
    final accent = cs.primary;
    return Padding(
      padding: const EdgeInsets.fromLTRB(8, 8, 8, 6),
      child: Row(
        children: [
          Expanded(
            child: Container(
              height: 1.5,
              decoration: BoxDecoration(
                color: accent.withValues(alpha: 0.45),
                borderRadius: BorderRadius.circular(1),
              ),
            ),
          ),
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: 10),
            child: Text(
              'Непрочитанные сообщения',
              style: TextStyle(
                color: accent,
                fontSize: 12,
                fontWeight: FontWeight.w600,
                letterSpacing: 0.2,
              ),
            ),
          ),
          Expanded(
            child: Container(
              height: 1.5,
              decoration: BoxDecoration(
                color: accent.withValues(alpha: 0.45),
                borderRadius: BorderRadius.circular(1),
              ),
            ),
          ),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    final theme = _prank.active
        ? _prank.pinkTheme(Theme.of(context))
        : Theme.of(context);
    final cs = theme.colorScheme;
    final underlap = _effectiveChrome != ChatChromeStyle.color;

    // TODO: Локализация
    // TODO: Cклонения
    final mq = MediaQuery.of(context);
    final bottomInset = _keyboardReserve > 0
        ? math.max(mq.viewInsets.bottom, _keyboardReserve)
        : mq.viewInsets.bottom;
    return ListenableBuilder(
      listenable: Listenable.merge([
        _selectedIds,
        _search.searchMode,
        _textSelection,
      ]),
      builder: (context, child) => PopScope(
        canPop:
            _selectedIds.value.isEmpty &&
            !_search.searchMode.value &&
            _textSelection.value == null,
        onPopInvokedWithResult: (didPop, _) {
          if (didPop) return;
          if (_search.searchMode.value) {
            _closeSearch();
          } else if (_textSelection.value != null) {
            _exitTextSelection();
          } else {
            _clearSelection();
          }
        },
        child: child!,
      ),
      child: MediaQuery(
        data: mq.copyWith(
          viewInsets: mq.viewInsets.copyWith(bottom: bottomInset),
        ),
        child: Theme(
          data: theme,
          child: RepaintBoundary(
            key: _prank.captureKey,
            child: ValueListenableBuilder<bool>(
              valueListenable: AppSwipeBackDesktop.current,
              builder: (context, desktopSwipe, child) => SwipeToPop(
                enabled: widget.embedded && desktopSwipe,
                onPop: widget.onClose,
                child: child!,
              ),
              child: AnimatedBuilder(
                animation: _searchAnim,
                child: LottieHoldScope(
                  isHeld: _animojiHold,
                  child: underlap ? _buildUnderlapBody() : _buildColorBody(),
                ),
                builder: (context, body) => Scaffold(
                  backgroundColor: cs.surface,
                  extendBodyBehindAppBar: underlap,
                  appBar: _buildAppBar(cs),
                  body: body,
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }

  Widget? _buildPinnedBanner({required bool floating}) {
    final pinned = chat;
    if (pinned == null || !pinned.hasPinnedMessage) return null;
    return _PinnedMessageBanner(
      text: pinned.pinnedMsgText,
      isPreview: pinned.pinnedMsgIsPreview,
      floating: floating,
      frosted: _effectiveChrome == ChatChromeStyle.transparent,
      liquid: _liquidChrome,
      backdropKey: _pillBackdrop,
      onTap: _jumpToPinnedMessage,
      onUnpin: pinned.canPinMessages(_myId)
          ? () => unawaited(_unpinCurrentMessage())
          : null,
    );
  }

  Widget _buildColorBody() {
    final cs = Theme.of(context).colorScheme;
    final banner = _buildPinnedBanner(floating: false);
    final frosted = _composerFrosted;
    final composer = _MeasureSize(
      onHeight: (value) => _composerHeight.value = value,
      child: _buildComposerArea(context),
    );
    return Column(
      children: [
        ?banner,
        Expanded(
          child: Stack(
            fit: StackFit.expand,
            children: [
              if (_wallpaper != null)
                Positioned.fill(
                  child: ChatWallpaperView(wallpaper: _wallpaper!),
                ),
              Positioned.fill(child: _buildMessagesArea()),
              ValueListenableBuilder<double>(
                valueListenable: _composerHeight,
                builder: (context, height, _) => Positioned(
                  left: 0,
                  right: 0,
                  bottom: frosted ? height : 0,
                  child: Column(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      MentionPanelView(mentionPanel: _mentionPanel),
                      CommandPanelView(commandPanel: _commandPanel),
                    ],
                  ),
                ),
              ),
              if (frosted)
                Positioned(left: 0, right: 0, bottom: 0, child: composer),
              SearchOverlay(
                cs: cs,
                searchAnim: _searchAnim,
                search: _search,
                onOpenResult: _openSearchResult,
                senderName: _searchSenderName,
                senderAvatar: _searchSenderAvatar,
              ),
            ],
          ),
        ),
        if (!frosted) composer,
      ],
    );
  }

  double _pinnedBannerTop() {
    final glossy = AppVisualStyle.current.value.glossyChrome;
    return MediaQuery.paddingOf(context).top +
        (glossy ? _glossyHeaderHeight : kToolbarHeight) -
        _pinnedBannerLift;
  }

  void _resetPinnedBannerHeight() {
    if (_pinnedBannerHeight.value == 0) return;
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (mounted && chat?.hasPinnedMessage != true) {
        _pinnedBannerHeight.value = 0;
      }
    });
  }

  Widget _buildUnderlapBody() {
    final cs = Theme.of(context).colorScheme;
    final vignette = _effectiveChrome == ChatChromeStyle.none;
    final bannerTop = _pinnedBannerTop();
    final banner = _buildPinnedBanner(floating: true);
    if (banner == null) _resetPinnedBannerHeight();
    return Stack(
      fit: StackFit.expand,
      children: [
        if (_wallpaper != null)
          Positioned.fill(child: ChatWallpaperView(wallpaper: _wallpaper!)),
        Positioned.fill(child: _buildMessagesArea()),
        SearchOverlay(
          cs: cs,
          searchAnim: _searchAnim,
          search: _search,
          onOpenResult: _openSearchResult,
          senderName: _searchSenderName,
          senderAvatar: _searchSenderAvatar,
        ),
        if (vignette) ...[
          Positioned(
            top: 0,
            left: 0,
            right: 0,
            child: _buildEdgeVignette(cs, top: true),
          ),
          ValueListenableBuilder<double>(
            valueListenable: _composerHeight,
            builder: (context, height, _) => Positioned(
              left: 0,
              right: 0,
              bottom: 0,
              child: _buildEdgeVignette(cs, top: false, height: height),
            ),
          ),
        ],
        if (banner != null)
          Positioned(
            top: bannerTop,
            left: 8,
            right: 8,
            child: _MeasureSize(
              onHeight: (value) => _pinnedBannerHeight.value = value,
              child: banner,
            ),
          ),
        ValueListenableBuilder<double>(
          valueListenable: _composerHeight,
          builder: (context, height, _) => Positioned(
            left: 0,
            right: 0,
            bottom: height,
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                MentionPanelView(mentionPanel: _mentionPanel),
                CommandPanelView(commandPanel: _commandPanel),
              ],
            ),
          ),
        ),
        Positioned(
          left: 0,
          right: 0,
          bottom: 0,
          child: Builder(
            builder: (context) => MediaQuery.removePadding(
              context: context,
              removeTop: true,
              child: _MeasureSize(
                onHeight: (value) => _composerHeight.value = value,
                child: _buildComposerArea(context),
              ),
            ),
          ),
        ),
      ],
    );
  }

  Widget _buildEdgeVignette(
    ColorScheme cs, {
    required bool top,
    double? height,
  }) {
    final double resolved;
    if (height != null) {
      resolved = height;
    } else {
      final glossy = AppVisualStyle.current.value.glossyChrome;
      resolved =
          MediaQuery.paddingOf(context).top +
          (glossy ? _glossyHeaderHeight : kToolbarHeight);
    }
    return IgnorePointer(
      child: Container(
        height: resolved,
        decoration: BoxDecoration(
          gradient: LinearGradient(
            begin: top ? Alignment.topCenter : Alignment.bottomCenter,
            end: top ? Alignment.bottomCenter : Alignment.topCenter,
            colors: [cs.surface, cs.surface.withValues(alpha: 0.0)],
          ),
        ),
      ),
    );
  }

  Widget _buildMessagesArea() {
    final showShimmer = _messages.isEmpty
        ? _isLoading
        : (_awaitingPosition || _navigatingToTarget);
    return Stack(
      fit: StackFit.expand,
      children: [
        Opacity(
          opacity: showShimmer ? 0.0 : 1.0,
          child: NotificationListener<ScrollEndNotification>(
            onNotification: (_) {
              _updateReadMarker();
              return false;
            },
            child: _buildMessagesList(),
          ),
        ),
        if (showShimmer)
          Positioned.fill(child: ShimmerLoading(shimmer: _shimmerController)),
      ],
    );
  }

  Widget _buildMessagesList() =>
      _messageListWidget ??= _ChatMessageList(this, key: _messageListKey);

  EdgeInsets _messagesListPadding(BuildContext context) {
    if (AppChatChrome.current.value == ChatChromeStyle.color) {
      return const EdgeInsets.symmetric(vertical: 8);
    }
    final topInset = MediaQuery.paddingOf(context).top;
    return EdgeInsets.only(top: topInset + 8, bottom: 8);
  }

  double _floatingDateTop(double pinnedHeight) {
    if (AppChatChrome.current.value == ChatChromeStyle.color) {
      final glossy = AppVisualStyle.current.value.glossyChrome;
      return glossy ? 2 : 4;
    }
    if (chat?.hasPinnedMessage == true && pinnedHeight > 0) {
      return _pinnedBannerTop() + pinnedHeight + 2;
    }
    return _pinnedBannerTop() + 2;
  }

  Widget _buildLoadMoreIndicator() {
    final cs = Theme.of(context).colorScheme;
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 12),
      child: Center(
        child: SmallSpinner(size: 22, color: cs.onSurfaceVariant),
      ),
    );
  }

  Widget _buildMessagesListContent() {
    if (_messages.isEmpty) {
      return Center(
        child: Text(
          'No messages yet',
          style: TextStyle(
            color: Theme.of(context).colorScheme.onSurfaceVariant,
          ),
        ),
      );
    }

    final items = _buildCombinedItems();

    return Stack(
      key: _listKey,
      children: [
        ValueListenableBuilder<double>(
          valueListenable: AppCacheExtent.current,
          builder: (context, userCacheExtent, _) =>
              ValueListenableBuilder<double?>(
                valueListenable: _jumpCacheExtent,
                builder: (context, jumpExtent, _) {
                  final cacheExtent =
                      jumpExtent != null && jumpExtent < userCacheExtent
                      ? jumpExtent
                      : userCacheExtent;
                  return CustomScrollView(
                    controller: _scrollController,
                    reverse: true,
                    physics: _listPhysics,
                    cacheExtent: cacheExtent,
                    slivers: [
                      SliverPadding(
                        padding: _messagesListPadding(context),
                        sliver: SliverList(
                          key: ValueKey(_listEpoch),
                          delegate: SliverChildBuilderDelegate(
                            (context, index) {
                              if (index == 0) {
                                return ValueListenableBuilder<double>(
                                  valueListenable: _composerHeight,
                                  builder: (context, height, _) => SizedBox(
                                    height: _composerUnderlap ? height : 0,
                                  ),
                                );
                              }
                              if (index > items.length) {
                                return _buildLoadMoreIndicator();
                              }
                              final item = items[items.length - index];

                              if (item is _DateSeparatorItem) {
                                return _buildDateSeparatorWidget(
                                  context,
                                  item.date,
                                  key: item.key,
                                );
                              }

                              if (item is _UnreadSeparatorItem) {
                                return _buildUnreadSeparatorWidget(context);
                              }

                              final msgItem = item as _MessageItem;
                              final message = msgItem.message;
                              final msgIndex = msgItem.index;
                              final isMe = message.senderId == _myId;
                              final prevMessage = msgIndex > 0
                                  ? _messages[msgIndex - 1]
                                  : null;
                              final nextMessage =
                                  msgIndex < _messages.length - 1
                                  ? _messages[msgIndex + 1]
                                  : null;

                              final bool isChannelPost =
                                  !_commentsMode &&
                                  (chat?.type ?? widget.chatType) == 'CHANNEL' &&
                                  !message.isControl;
                              final bool isCommentedPost =
                                  _commentsMode &&
                                  message.id == widget.commentPostId;

                              final bubble = MessageBubble(
                                message: message,
                                isMe: isMe,
                                myId: _myId,
                                prevMessage: prevMessage,
                                nextMessage: nextMessage,
                                chatType: _commentsMode
                                    ? 'CHAT'
                                    : (chat?.type ?? 'CHAT'),
                                chatId: widget.chatId,
                                photoActions: _photoActions,
                                overrideStatus: _effectiveStatus(message),
                                otherReadTime: _otherReadTime,
                                reactionsListenable: _reactionNotifierFor(
                                  message,
                                ),
                                reactionAnimation: _reactionAnimation,
                                uploadProgress: _photoProgressFor(message),
                                onReplyTap: (id) =>
                                    _jumpToMessage(id, fromId: message.id),
                                onAvatarTap: _openSenderProfile,
                                onForwardedSourceTap: _openForwardedSource,
                                onStickerTap: _openStickerPack,
                                onReactionTap: message.isControl
                                    ? null
                                    : (emoji) =>
                                          _reactToMessage(message, emoji),
                                peerName: widget.name,
                                peerAvatarUrl: widget.imageUrl,
                                senderNameOverride: isCommentedPost
                                    ? widget.name
                                    : null,
                                senderAvatarOverride: isCommentedPost
                                    ? widget.imageUrl
                                    : null,
                                textSelection: _textSelection,
                                onExitTextSelection: _exitTextSelection,
                                commentsLabel: isChannelPost
                                    ? _commentsLabelFor(message.id)
                                    : null,
                                onCommentsTap: isChannelPost
                                    ? () => _openComments(message)
                                    : null,
                              );

                              final canReport = !isMe && !message.isControl;
                              final reportTypeId = _complaintTypeId(
                                chat?.type ?? widget.chatType,
                              );

                              final pressable = _SelectableMessageRow(
                                message: message,
                                isMe: isMe,
                                selectedIds: _selectedIds,
                                selectionAnim: _selectionAnim,
                                isSelectionActive: () => _selectionMode,
                                onToggleSelection: () =>
                                    _toggleSelection(message),
                                onEnterSelection: () =>
                                    _enterSelection(message),
                                onStartTextSelection: (pos) =>
                                    _startTextSelection(message, pos),
                                onDelete: () =>
                                    _confirmDeleteMessage(message.id, isMe),
                                onEdit: _canEditMessage(message)
                                    ? () => _startEditMessage(message)
                                    : null,
                                onReply: message.isControl
                                    ? null
                                    : () => _startReply(message),
                                onForward: message.isControl
                                    ? null
                                    : () => _forwardMessages([message]),
                                onMarkUnread: message.isControl
                                    ? null
                                    : () => _markMessageUnread(message),
                                onPin: _canPinMessage(message)
                                    ? () => _togglePinMessage(message)
                                    : null,
                                isPinned: () =>
                                    chat?.pinnedMsgId ==
                                    int.tryParse(message.id),
                                loadReadBy: _canShowReadBy(message)
                                    ? () => _loadReadBy(message)
                                    : null,
                                onReaderTap: _openSenderProfile,
                                loadReportReasons: canReport
                                    ? () => _loadReportReasons(reportTypeId)
                                    : null,
                                onReport: canReport
                                    ? (reasonId) => _reportMessage(
                                        message,
                                        reportTypeId,
                                        reasonId,
                                      )
                                    : null,
                                onReact: message.isControl
                                    ? null
                                    : (emoji) =>
                                          _reactToMessage(message, emoji),
                                reactions: _reactionNotifierFor(message),
                                child: bubble,
                              );

                              final isChannel =
                                  (chat?.type ?? widget.chatType) == 'CHANNEL';
                              final swipeable = (message.isControl || isChannel)
                                  ? pressable
                                  : _SwipeToReply(
                                      isMe: isMe,
                                      onReply: () => _startReply(message),
                                      child: pressable,
                                    );

                              final Widget child;
                              if (_deletingIds.contains(message.id)) {
                                child = _DeletingMessageAnimation(
                                  key: ValueKey('del_${message.id}'),
                                  onComplete: () => _finalizeDelete(message.id),
                                  child: IgnorePointer(child: swipeable),
                                );
                              } else if (message.id == _lastSentId) {
                                child = _SentMessageAnimation(
                                  key: ValueKey('anim_${message.id}'),
                                  onComplete: () {
                                    if (mounted) {
                                      _lastSentId = null;
                                      _bumpMessages();
                                    }
                                  },
                                  child: swipeable,
                                );
                              } else {
                                child = swipeable;
                              }

                              final highlightable =
                                  ValueListenableBuilder<String?>(
                                    valueListenable: _highlightMessageId,
                                    builder: (context, hl, c) =>
                                        AnimatedContainer(
                                          duration: const Duration(
                                            milliseconds: 250,
                                          ),
                                          color: hl == message.id
                                              ? Theme.of(context)
                                                    .colorScheme
                                                    .primary
                                                    .withValues(alpha: 0.12)
                                              : Colors.transparent,
                                          child: c,
                                        ),
                                    child: child,
                                  );

                              final builtItem = RepaintBoundary(
                                key: ValueKey('msg_${message.id}'),
                                child: KeyedSubtree(
                                  key: _keyForMessage(message.id),
                                  child: highlightable,
                                ),
                              );
                              return message.id == _prank.bubbleId
                                  ? KeyedSubtree(
                                      key: _prank.bubbleKey,
                                      child: builtItem,
                                    )
                                  : builtItem;
                            },
                            childCount:
                                items.length + 1 + (_isLoadingMore ? 1 : 0),
                          ),
                        ),
                      ),
                    ],
                  );
                },
              ),
        ),
        ValueListenableBuilder<double>(
          valueListenable: _pinnedBannerHeight,
          builder: (context, pinnedHeight, child) => Positioned(
            top: _floatingDateTop(pinnedHeight),
            left: 0,
            right: 0,
            child: child!,
          ),
          child: IgnorePointer(
            child: ValueListenableBuilder<DateTime?>(
              valueListenable: _floatingDate,
              builder: (context, date, _) {
                if (date == null) return const SizedBox.shrink();
                return AnimatedBuilder(
                  animation: _floatingDateCurved,
                  builder: (context, child) {
                    final t = _floatingDateCurved.value;
                    return Opacity(
                      opacity: t,
                      child: Transform.scale(
                        scale: 0.82 + 0.18 * t,
                        child: child,
                      ),
                    );
                  },
                  child: _buildDateSeparatorWidget(
                    context,
                    date,
                    floating: true,
                  ),
                );
              },
            ),
          ),
        ),
        _buildScrollDownButton(),
      ],
    );
  }

  Widget _buildScrollDownButton() {
    final cs = Theme.of(context).colorScheme;
    final frosted = _effectiveChrome == ChatChromeStyle.transparent;
    return ValueListenableBuilder<double>(
      valueListenable: _composerHeight,
      builder: (context, height, child) => Positioned(
        right: 16,
        bottom: (_composerUnderlap ? height : 0) + 12,
        child: child!,
      ),
      child: AnimatedBuilder(
        animation: _scrollDownCurved,
        builder: (context, child) {
          final t = _scrollDownCurved.value;
          if (t == 0) return const SizedBox.shrink();
          return Opacity(
            opacity: t,
            child: Transform.scale(scale: 0.82 + 0.18 * t, child: child),
          );
        },
        child: SizedBox(
          width: 46,
          height: 46,
          child: Stack(
            clipBehavior: Clip.none,
            children: [
              Positioned.fill(
                child: GlossyPill(
                  color: frosted || _liquidChrome
                      ? AppFrost.pillTint(cs)
                      : null,
                  blurSigma: frosted && !_liquidChrome ? AppFrost.sigma : null,
                  liquid: _liquidChrome,
                  backdropKey: _pillBackdrop,
                  elevated: true,
                  onTap: _onScrollDownTap,
                  child: Center(
                    child: Icon(
                      Symbols.keyboard_arrow_down,
                      color: cs.onSurface,
                      weight: 500,
                      size: 26,
                    ),
                  ),
                ),
              ),
              Positioned(
                top: -5,
                right: -3,
                child: ValueListenableBuilder<int>(
                  valueListenable: _newMessageCount,
                  builder: (context, count, _) =>
                      count <= 0 ? const SizedBox.shrink() : _unreadBadge(cs, count),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }

  Widget _unreadBadge(ColorScheme cs, int count) {
    return Container(
      constraints: const BoxConstraints(minWidth: 21),
      height: 21,
      padding: const EdgeInsets.symmetric(horizontal: 6),
      alignment: Alignment.center,
      decoration: BoxDecoration(
        color: cs.primary,
        borderRadius: BorderRadius.circular(11),
      ),
      child: Text(
        count > 99 ? '99+' : '$count',
        style: TextStyle(
          color: cs.onPrimary,
          fontSize: 12,
          height: 1,
          fontWeight: FontWeight.w700,
        ),
      ),
    );
  }

  Uint8List _buildWave(List<double> amps, {int bars = 80}) {
    final out = Uint8List(bars);
    if (amps.isEmpty) return out;
    for (var i = 0; i < bars; i++) {
      final start = (i * amps.length / bars).floor();
      final end = (((i + 1) * amps.length / bars).ceil()).clamp(
        start + 1,
        amps.length,
      );
      var peak = 0.0;
      for (var j = start; j < end; j++) {
        if (amps[j] > peak) peak = amps[j];
      }
      out[i] = (peak * 120).round().clamp(0, 120);
    }
    return out;
  }

  Future<void> _sendVoice(File file, int durationMs, List<double> amps) async {
    if (_myId == 0) {
      try {
        await file.delete();
      } catch (_) {}
      return;
    }
    final wave = _buildWave(amps);
    final tempId = _nextTempId();
    final progress = ValueNotifier<List<double>>(const [0]);
    _photoUploadProgress[tempId] = progress;
    _messages.add(
      CachedMessage(
        id: tempId,
        accountId: _myId,
        chatId: widget.chatId,
        senderId: _myId,
        time: DateTime.now().millisecondsSinceEpoch,
        status: 'sending',
        attachments: [AudioAttachment(duration: durationMs)],
      ),
    );
    _lastSentId = tempId;
    _bumpMessages();
    Haptics.send();
    _scrollToBottom();

    try {
      final info = await messagesModule.requestAudioUploadUrl();
      if (info == null || info.url.isEmpty) throw Exception('no_url');

      final ok = await fileUploader.uploadMediaFile(
        Uri.parse(info.url),
        file,
        onProgress: (sent, total) {
          if (total > 0) progress.value = [(sent / total).clamp(0.0, 1.0)];
        },
      );
      if (!ok) throw Exception('upload_failed');
      if (!mounted) {
        _disposePhotoProgress(tempId);
        return;
      }

      final serverMsg = await messagesModule.sendAudioMessage(
        widget.chatId,
        info.token,
        duration: durationMs,
        wave: wave,
      );
      if (!mounted) {
        _disposePhotoProgress(tempId);
        return;
      }
      if (serverMsg == null) throw Exception('send_failed');

      final real = CachedMessage.fromPushPayload(
        _myId,
        widget.chatId,
        serverMsg,
      );
      final idx = _messages.indexWhere((m) => m.id == tempId);
      if (idx != -1) {
        _messages[idx] = real;
        _bumpMessages();
        unawaited(_persistOutgoing(real, removeId: tempId));
      }
      _disposePhotoProgress(tempId);
    } catch (_) {
      if (mounted) {
        _failPhotoMessage(tempId);
      } else {
        _disposePhotoProgress(tempId);
      }
    } finally {
      try {
        await file.delete();
      } catch (_) {}
    }
  }

  Future<void> _sendVideoNote(File file, int durationMs) async {
    if (_myId == 0) {
      try {
        await file.delete();
      } catch (_) {}
      return;
    }
    final tempId = _nextTempId();
    final progress = ValueNotifier<List<double>>(const [0]);
    _photoUploadProgress[tempId] = progress;
    _messages.add(
      CachedMessage(
        id: tempId,
        accountId: _myId,
        chatId: widget.chatId,
        senderId: _myId,
        time: DateTime.now().millisecondsSinceEpoch,
        status: 'sending',
        attachments: [VideoAttachment(duration: durationMs, videoType: 1)],
      ),
    );
    _lastSentId = tempId;
    _bumpMessages();
    Haptics.send();
    _scrollToBottom();

    try {
      final info = await messagesModule.requestVideoNoteUploadUrl();
      if (info == null || info.url.isEmpty) throw Exception('no_url');
      final ok = await fileUploader.uploadMediaFile(
        Uri.parse(info.url),
        file,
        onProgress: (sent, total) {
          if (total > 0) progress.value = [(sent / total).clamp(0.0, 1.0)];
        },
      );
      if (!ok) throw Exception('upload_failed');
      if (!mounted) {
        _disposePhotoProgress(tempId);
        return;
      }
      final serverMsg = await messagesModule.sendVideoNoteMessage(
        widget.chatId,
        info.token,
        duration: durationMs,
      );
      if (!mounted) {
        _disposePhotoProgress(tempId);
        return;
      }
      if (serverMsg == null) throw Exception('send_failed');
      final real = CachedMessage.fromPushPayload(
        _myId,
        widget.chatId,
        serverMsg,
      );
      final idx = _messages.indexWhere((m) => m.id == tempId);
      if (idx != -1) {
        _messages[idx] = real;
        _bumpMessages();
        unawaited(_persistOutgoing(real, removeId: tempId));
      }
      _disposePhotoProgress(tempId);
    } catch (e) {
      logger.w('sendVideoNote failed: $e');
      if (mounted) {
        _failPhotoMessage(tempId);
        final reason = e is PacketError
            ? '${e.errorKey ?? ''} ${e.message}'.trim()
            : e is Exception && e.toString().contains('send_failed')
            ? 'сервер не обработал видео'
            : e is Exception && e.toString().contains('upload_failed')
            ? 'загрузка отклонена'
            : e.toString();
        showCustomNotification(context, 'Кружок не отправлен: $reason');
      } else {
        _disposePhotoProgress(tempId);
      }
    } finally {
      try {
        await file.delete();
      } catch (_) {}
    }
  }

  String _addOptimisticFileMessage(FileAttachment attachment) {
    final now = DateTime.now().millisecondsSinceEpoch;
    final tempId = _nextTempId();
    final msg = CachedMessage(
      id: tempId,
      accountId: _myId,
      chatId: widget.chatId,
      senderId: _myId,
      time: now,
      status: 'sending',
      attachments: [attachment],
    );
    _lastSentId = tempId;
    _messages.add(msg);
    _bumpMessages();
    Haptics.send();
    _scrollToBottom();
    return tempId;
  }

  void _updateFileMessageStatus(
    String tempId,
    String status, {
    FileAttachment? attachment,
    String? realId,
  }) {
    if (!mounted) return;
    final idx = _messages.indexWhere((m) => m.id == tempId);
    if (idx == -1) return;
    final old = _messages[idx];
    _messages[idx] = CachedMessage(
      id: realId != null && realId.isNotEmpty ? realId : tempId,
      accountId: old.accountId,
      chatId: old.chatId,
      senderId: old.senderId,
      text: old.text,
      time: old.time,
      status: status,
      payload: old.payload,
      attachments: attachment != null ? [attachment] : old.attachments,
    );
    _bumpMessages();
  }

  Future<void> _sendHistoryFile(FileHistoryEntry entry) async {
    final tempId = _addOptimisticFileMessage(
      FileAttachment(
        fileId: entry.fileId,
        fileToken: entry.token,
        name: entry.filename,
        size: entry.size,
      ),
    );
    _showAttachmentPanel.value = false;
    try {
      final realId = await messagesModule.sendFileMessage(
        widget.chatId,
        entry.fileId,
        token: entry.token,
      );
      _updateFileMessageStatus(
        tempId,
        realId != null ? 'sent' : 'error',
        realId: realId,
      );
    } catch (_) {
      _updateFileMessageStatus(tempId, 'error');
    }
  }

  Future<bool> _sendFileById(int fileId) async {
    final tempId = _addOptimisticFileMessage(FileAttachment(fileId: fileId));
    try {
      final realId = await messagesModule.sendFileMessage(widget.chatId, fileId);
      final ok = realId != null;
      if (!mounted) return ok;
      if (ok) {
        FileHistoryCache.add(
          FileHistoryEntry(fileId: fileId, sentAt: DateTime.now()),
        );
        _updateFileMessageStatus(tempId, 'sent', realId: realId);
        _showAttachmentPanel.value = false;
      } else {
        _updateFileMessageStatus(tempId, 'error');
        showCustomNotification(context, 'Ошибка отправки');
      }
      return ok;
    } catch (e) {
      _updateFileMessageStatus(tempId, 'error');
      if (mounted) showCustomNotification(context, 'Ошибка: $e');
      return false;
    }
  }

  Future<void> _openAttachmentSheetScheduled() async {
    final when = await _pickScheduleTime();
    if (when == null || !mounted) return;
    await _openAttachmentSheet(scheduledTime: when.millisecondsSinceEpoch);
  }

  Future<void> _openAttachmentSheet({int? scheduledTime}) async {
    final keyboard = MediaQuery.viewInsetsOf(context).bottom;
    final hadKeyboard = keyboard > 0;
    if (hadKeyboard) {
      setState(() => _keyboardReserve = keyboard);
    }
    FocusManager.instance.primaryFocus?.unfocus();
    await showAttachmentSheet(
      context,
      title: widget.name,
      onSend: scheduledTime == null
          ? _sendPhotos
          : (picked, caption) =>
                _sendScheduledPhotos(picked, caption, scheduledTime),
      onPickFile: _encryptionEnabled
          ? () => _refuseUnencrypted('Файлы')
          : (scheduledTime == null
                ? _pickAndUploadFile
                : () => _pickAndUploadFile(scheduledTime: scheduledTime)),
      onShareLocation: _encryptionEnabled
          ? () => _refuseUnencrypted('Геолокацию')
          : _shareLocation,
      onCreatePoll: _encryptionEnabled
          ? () => _refuseUnencrypted('Опросы')
          : _createPoll,
      onSendContact: _encryptionEnabled
          ? (_) => _refuseUnencrypted('Контакты')
          : _sendContact,
    );
    if (!mounted || !hadKeyboard) return;
    _messageFocusNode.requestFocus();
    await Future.delayed(const Duration(milliseconds: 350));
    if (mounted) setState(() => _keyboardReserve = 0);
  }

  Future<void> _sendPhotos(List<PickedPhoto> picked, String caption) async {
    if (_myId == 0) return;
    if (_encryptionEnabled) return _sendEncryptedPhotos(picked, caption);
    final videos = picked.where((ph) => ph.item.isVideo).toList();
    final photos = picked.where((ph) => !ph.item.isVideo).toList();
    if (photos.isEmpty && videos.isEmpty) return;

    for (var i = 0; i < videos.length; i++) {
      final cap = (photos.isEmpty && i == 0) ? caption : '';
      await _sendVideo(videos[i], cap);
    }
    if (photos.isEmpty) return;

    final jobs = <({File file, GalleryItem? item})>[];
    final attachments = <PhotoAttachment>[];
    for (final photo in photos) {
      final edited = photo.editedFile;
      final file =
          edited ?? photo.item.localFile ?? await photo.item.originFile();
      if (file == null) continue;
      final dim = edited != null
          ? await imageFileDimensions(edited)
          : await photo.item.dimensions();
      jobs.add((file: file, item: edited == null ? photo.item : null));
      attachments.add(
        PhotoAttachment(localPath: file.path, width: dim?.$1, height: dim?.$2),
      );
    }
    if (jobs.isEmpty || !mounted) return;

    final tempId = _nextTempId();
    final placeholder = CachedMessage(
      id: tempId,
      accountId: _myId,
      chatId: widget.chatId,
      senderId: _myId,
      text: caption.isEmpty ? null : caption,
      time: DateTime.now().millisecondsSinceEpoch,
      status: 'sending',
      attachments: attachments,
    );

    _messages.add(placeholder);
    _lastSentId = tempId;
    _bumpMessages();
    Haptics.send();
    _scrollToBottom();

    unawaited(
      MediaSendService.instance.sendPhotos(
        accountId: _myId,
        chatId: widget.chatId,
        tempId: tempId,
        jobs: jobs,
        caption: caption,
        placeholder: placeholder,
      ),
    );
  }

  Future<void> _sendVideo(
    PickedPhoto video,
    String caption, {
    int? scheduledTime,
  }) async {
    if (_myId == 0) return;
    final file =
        video.editedFile ??
        video.item.localFile ??
        await video.item.originFile();
    if (file == null || !mounted) return;

    var durationMs = video.item.duration?.inMilliseconds;
    if (durationMs == null && DesktopVideoProbe.supported) {
      durationMs = (await DesktopVideoProbe.duration(file.path))?.inMilliseconds;
    }
    final dims = await video.item.dimensions();
    Uint8List? thumbBytes;
    try {
      thumbBytes = await video.item.thumbnail(512);
    } catch (_) {}
    if (!mounted) return;
    final thumbData = thumbBytes == null || thumbBytes.isEmpty
        ? null
        : 'data:image/jpeg;base64,${base64Encode(thumbBytes)}';

    final tempId = _nextTempId();
    CachedMessage? placeholder;

    if (scheduledTime != null) {
      showCustomNotification(context, 'Загрузка…');
    } else {
      placeholder = CachedMessage(
        id: tempId,
        accountId: _myId,
        chatId: widget.chatId,
        senderId: _myId,
        text: caption.isEmpty ? null : caption,
        time: DateTime.now().millisecondsSinceEpoch,
        status: 'sending',
        attachments: [
          VideoAttachment(
            duration: durationMs,
            localPath: file.path,
            previewData: thumbData,
            width: dims?.$1,
            height: dims?.$2,
          ),
        ],
      );
      _messages.add(placeholder);
      _lastSentId = tempId;
      _bumpMessages();
      Haptics.send();
      _scrollToBottom();
    }

    unawaited(
      MediaSendService.instance.sendVideo(
        accountId: _myId,
        chatId: widget.chatId,
        tempId: tempId,
        file: file,
        caption: caption,
        placeholder: placeholder,
        scheduledTime: scheduledTime,
      ),
    );
  }

  void _onMediaSendEvent(MediaSendEvent event) {
    if (!mounted || event.chatId != widget.chatId) return;
    if (event is MediaSendDone) {
      if (event.scheduled) {
        Haptics.send();
        _markHasScheduled();
        final at = event.scheduledTime;
        showCustomNotification(
          context,
          at == null
              ? 'Запланировано'
              : 'Запланировано на '
                    '${formatDateTimeWords(DateTime.fromMillisecondsSinceEpoch(at))}',
        );
        return;
      }
      final real = event.message;
      if (real == null) return;
      final idx = _messages.indexWhere((m) => m.id == event.tempId);
      if (idx != -1) {
        _messages[idx] = real;
        _bumpMessages();
      }
    } else if (event is MediaSendFailed) {
      if (event.scheduled) {
        Haptics.error();
        showCustomNotification(context, 'Не удалось запланировать');
        return;
      }
      _failPhotoMessage(event.tempId);
    }
  }

  void _mergePendingMedia() {
    final service = MediaSendService.instance;
    var changed = false;

    for (var i = _messages.length - 1; i >= 0; i--) {
      final msg = _messages[i];
      if (!isSendingStatus(msg.status)) continue;
      final done = service.completedFor(msg.id);
      if (done != null) {
        if (done.id != msg.id && _messages.any((m) => m.id == done.id)) {
          _messages.removeAt(i);
        } else {
          _messages[i] = done;
        }
        changed = true;
        continue;
      }
      if (service.didFail(msg.id)) {
        _messages[i] = msg.copyWith(status: 'error');
        changed = true;
      }
    }

    for (final msg in service.pendingFor(widget.chatId)) {
      if (_messages.any((m) => m.id == msg.id)) continue;
      _messages.add(msg);
      changed = true;
    }

    if (changed) _bumpMessages();
  }

  Future<void> _sendScheduledPhotos(
    List<PickedPhoto> picked,
    String caption,
    int scheduledTime,
  ) async {
    if (_myId == 0) return;
    final videos = picked.where((ph) => ph.item.isVideo).toList();
    final photos = picked.where((ph) => !ph.item.isVideo).toList();
    if (photos.isEmpty && videos.isEmpty) return;

    for (var i = 0; i < videos.length; i++) {
      final cap = (photos.isEmpty && i == 0) ? caption : '';
      await _sendVideo(videos[i], cap, scheduledTime: scheduledTime);
    }
    if (photos.isEmpty) return;

    final jobs = <({File file, GalleryItem? item})>[];
    for (final photo in photos) {
      final edited = photo.editedFile;
      final file =
          edited ?? photo.item.localFile ?? await photo.item.originFile();
      if (file != null) {
        jobs.add((file: file, item: edited == null ? photo.item : null));
      }
    }
    if (jobs.isEmpty || !mounted) return;

    showCustomNotification(context, 'Загрузка…');
    unawaited(
      MediaSendService.instance.sendPhotos(
        accountId: _myId,
        chatId: widget.chatId,
        tempId: _nextTempId(),
        jobs: jobs,
        caption: caption,
        scheduledTime: scheduledTime,
      ),
    );
  }

  Future<void> _sendAttachMessage(
    List<MessageAttachment> optimistic,
    Future<Map<String, dynamic>?> Function() send,
  ) async {
    if (_myId == 0) return;
    final tempId = _nextTempId();
    final now = DateTime.now().millisecondsSinceEpoch;

    final tempMessage = CachedMessage(
      id: tempId,
      accountId: _myId,
      chatId: widget.chatId,
      senderId: _myId,
      time: now,
      status: 'sending',
      attachments: optimistic,
    );
    _messages.add(tempMessage);
    _lastSentId = tempId;
    _bumpMessages();
    Haptics.send();
    _scrollToBottom();

    try {
      final serverMsg = await send();
      if (!mounted) return;
      final idx = _messages.indexWhere((m) => m.id == tempId);
      if (idx == -1) return;
      if (serverMsg == null) {
        _updateFileMessageStatus(tempId, 'error');
        showCustomNotification(context, 'Ошибка отправки');
        return;
      }
      final real = CachedMessage.fromPushPayload(
        _myId,
        widget.chatId,
        serverMsg,
      );
      _messages[idx] = real;
      _bumpMessages();
      unawaited(_persistOutgoing(real, removeId: tempId));
    } catch (e) {
      if (!mounted) return;
      _updateFileMessageStatus(tempId, 'error');
      showCustomNotification(context, 'Ошибка: $e');
    }
  }

  void _toggleStickerPanel() {
    if (_stickers.showPanel.value) {
      _stickers.hide();
      if (_keyboardBeforeStickers) _messageFocusNode.requestFocus();
      return;
    }
    final keyboard = MediaQuery.viewInsetsOf(context).bottom;
    _keyboardBeforeStickers = keyboard > 120 || _messageFocusNode.hasFocus;
    if (keyboard > 120) _stickers.setBaseHeight(keyboard);
    FocusManager.instance.primaryFocus?.unfocus();
    _stickers.showPanel.value = true;
  }

  Future<void> _sendSticker(StickerItem sticker) async {
    await _sendAttachMessage([
      StickerAttachment(
        stickerId: sticker.id.toString(),
        baseUrl: sticker.url,
        lottieUrl: sticker.lottieUrl,
        width: sticker.width,
        height: sticker.height,
      ),
    ], () => messagesModule.sendStickerMessage(widget.chatId, sticker.id));
  }

  void _insertAnimoji(Animoji animoji) {
    _messageController.insertAnimoji(animoji);
    unawaited(animojiModule.noteUsed(animoji));
    Haptics.selection();
  }

  Future<void> _shareLocation() async {
    final position = await _resolveCurrentPosition();
    if (position == null || !mounted) return;
    final lat = position.latitude;
    final lon = position.longitude;
    await _sendAttachMessage([
      LocationAttachment(latitude: lat, longitude: lon, zoom: 15),
    ], () => messagesModule.sendLocationMessage(widget.chatId, lat, lon));
  }

  Future<Position?> _resolveCurrentPosition() async {
    try {
      if (!await Geolocator.isLocationServiceEnabled()) {
        if (mounted) showCustomNotification(context, 'Включите геолокацию');
        return null;
      }
      var permission = await Geolocator.checkPermission();
      if (permission == LocationPermission.denied) {
        permission = await Geolocator.requestPermission();
      }
      if (permission == LocationPermission.denied ||
          permission == LocationPermission.deniedForever) {
        if (mounted)
          showCustomNotification(context, 'Нет доступа к геолокации');
        return null;
      }
      return await Geolocator.getCurrentPosition(
        locationSettings: const LocationSettings(
          accuracy: LocationAccuracy.high,
        ),
      );
    } catch (e) {
      if (mounted)
        showCustomNotification(context, 'Не удалось получить геопозицию');
      return null;
    }
  }

  Future<void> _sendContact(CachedContact contact) async {
    final last = contact.lastName;
    final fullName = (last != null && last.isNotEmpty)
        ? '${contact.firstName} $last'
        : contact.firstName;
    await _sendAttachMessage([
      ContactAttachment(
        contactId: contact.id,
        firstName: contact.firstName,
        lastName: last,
        name: fullName,
        photoUrl: contact.baseUrl,
      ),
    ], () => messagesModule.sendContactMessage(widget.chatId, contact.id));
  }

  Future<void> _createPoll() async {
    final draft = await showCreatePollSheet(context);
    if (draft == null || !mounted) return;
    await _sendAttachMessage(
      [PollAttachment(pollId: 0, title: draft.title)],
      () => messagesModule.sendPollMessage(
        widget.chatId,
        draft.title,
        draft.answers,
        multiple: draft.multiple,
        anonymous: draft.anonymous,
      ),
    );
  }


  void _failPhotoMessage(String tempId) {
    final idx = _messages.indexWhere((m) => m.id == tempId);
    if (idx != -1) {
      _messages[idx] = _messages[idx].copyWith(status: 'error');
      _bumpMessages();
    }
    _disposePhotoProgress(tempId);
    Haptics.error();
  }

  void _disposePhotoProgress(String tempId) {
    _photoUploadProgress.remove(tempId)?.dispose();
  }

  void _refuseUnencrypted(String what) {
    if (!mounted) return;
    _showAttachmentPanel.value = false;
    showCustomNotification(context, '$what пока нельзя зашифровать');
  }

  Future<void> _sendEncryptedPhotos(
    List<PickedPhoto> picked,
    String caption,
  ) async {
    final photos = picked.where((ph) => !ph.item.isVideo).toList();
    if (photos.length != picked.length && mounted) {
      showCustomNotification(context, 'Видео пока нельзя зашифровать');
    }
    if (photos.isEmpty) return;

    for (final photo in photos) {
      final source =
          photo.editedFile ??
          photo.item.localFile ??
          await photo.item.originFile();
      if (source == null || !mounted) continue;

      _showAttachmentPanel.value = false;
      _uploadStatus.value = const UploadStatus(active: true);
      final stamp = DateTime.now().microsecondsSinceEpoch.toString();
      final prepared = await prepareEncryptedPhoto(
        accountId: _myId,
        chatId: widget.chatId,
        source: source,
        stamp: stamp,
      );
      if (!mounted) return;
      if (!prepared.isOk) {
        _uploadStatus.value = const UploadStatus();
        showCustomNotification(
          context,
          prepared.failure == CryptoFailure.noKey
              ? 'Не задан ключ шифрования'
              : 'Не удалось зашифровать фото',
        );
        return;
      }

      final encrypted = prepared.file!;
      await _uploadAsFile(
        source: encrypted,
        filename: 'photo_$stamp$kEncryptedPhotoExtension',
        size: await encrypted.length(),
      );
      if (!mounted) return;
    }

    if (caption.isNotEmpty) {
      final wire = await _encryptOutgoing(caption);
      if (wire != null && mounted) {
        await messagesModule.sendMessage(_myId, widget.chatId, wire);
      }
    }
  }

  Future<void> _pickAndUploadFile({int? scheduledTime}) async {
    final result = await FilePicker.platform.pickFiles();
    if (result == null || result.files.isEmpty) return;
    final picked = result.files.first;
    if (picked.path == null) return;
    await _uploadAsFile(
      source: File(picked.path!),
      filename: picked.name,
      size: picked.size,
      scheduledTime: scheduledTime,
    );
  }

  Future<void> _uploadAsFile({
    required File source,
    required String filename,
    required int size,
    int? scheduledTime,
  }) async {
    final file = (name: filename, size: size);
    final done = Completer<void>();

    _showAttachmentPanel.value = false;
    _uploadStatus.value = UploadStatus(active: true, total: file.size);

    final scheduled = scheduledTime != null;
    final tempId = scheduled
        ? null
        : _addOptimisticFileMessage(
            FileAttachment(name: file.name, size: file.size),
          );
    ValueNotifier<List<double>>? fileProgress;
    if (tempId != null) {
      fileProgress = ValueNotifier<List<double>>(const [0]);
      _photoUploadProgress[tempId] = fileProgress;
    }

    UploadNotificationService.start(file.name);

    var notifLastSent = 0;
    var notifLastMs = DateTime.now().millisecondsSinceEpoch;
    var notifSpeedBps = 0;
    var notifLastPercent = -1;

    void stopNotif() => UploadNotificationService.stop();

    _uploadSub?.cancel();
    _uploadSub = fileUploader
        .upload(
          chatId: widget.chatId,
          file: source,
          filename: file.name,
          totalSize: file.size,
          scheduledTime: scheduledTime,
        )
        .listen(
          (event) {
            if (!mounted) return;
            switch (event) {
              case UploadProgress(:final sent, :final total):
                _uploadStatus.value = UploadStatus(
                  active: true,
                  sent: sent,
                  total: total,
                );
                if (total > 0) {
                  fileProgress?.value = [(sent / total).clamp(0.0, 1.0)];
                }
                final nowMs = DateTime.now().millisecondsSinceEpoch;
                final elapsed = nowMs - notifLastMs;
                if (elapsed >= 500) {
                  notifSpeedBps = ((sent - notifLastSent) * 1000 / elapsed)
                      .round();
                  notifLastSent = sent;
                  notifLastMs = nowMs;
                }
                final percent = total > 0 ? (sent * 100 ~/ total) : 0;
                if (percent != notifLastPercent) {
                  notifLastPercent = percent;
                  UploadNotificationService.update(
                    filename: file.name,
                    progressPercent: percent,
                    speedBps: notifSpeedBps,
                  );
                }
              case UploadDone(
                :final fileId,
                :final token,
                :final url,
                :final messageId,
              ):
                stopNotif();
                FileHistoryCache.add(
                  FileHistoryEntry(
                    fileId: fileId,
                    url: url,
                    token: token,
                    filename: file.name,
                    size: file.size,
                    sentAt: DateTime.now(),
                  ),
                );
                if (scheduled) {
                  Haptics.send();
                  showCustomNotification(
                    context,
                    'Запланировано на '
                    '${formatDateTimeWords(DateTime.fromMillisecondsSinceEpoch(scheduledTime))}',
                  );
                } else {
                  _disposePhotoProgress(tempId!);
                  _updateFileMessageStatus(
                    tempId,
                    'sent',
                    realId: messageId,
                    attachment: FileAttachment(
                      fileId: fileId,
                      fileToken: token,
                      name: file.name,
                      size: file.size,
                    ),
                  );
                }
              case UploadError(:final message):
                stopNotif();
                showCustomNotification(context, 'Ошибка: $message');
                if (tempId != null) {
                  _disposePhotoProgress(tempId);
                  _updateFileMessageStatus(tempId, 'error');
                }
            }
          },
          onDone: () {
            if (!mounted) return;
            stopNotif();
            if (tempId != null) {
              final inFlight = _messages.firstWhere(
                (m) => m.id == tempId,
                orElse: () => CachedMessage(
                  id: '',
                  accountId: 0,
                  chatId: 0,
                  senderId: 0,
                  time: 0,
                ),
              );
              if (inFlight.id == tempId && inFlight.status == 'sending') {
                _disposePhotoProgress(tempId);
                _updateFileMessageStatus(tempId, 'error');
              }
            }
            _uploadStatus.value = const UploadStatus();
            _uploadSub = null;
            if (!done.isCompleted) done.complete();
          },
          onError: (Object e) {
            if (!mounted) return;
            stopNotif();
            showCustomNotification(context, 'Ошибка: $e');
            if (tempId != null) {
              _disposePhotoProgress(tempId);
              _updateFileMessageStatus(tempId, 'error');
            }
            _uploadStatus.value = const UploadStatus();
            _uploadSub = null;
            if (!done.isCompleted) done.complete();
          },
        );
    return done.future;
  }
}

class _SwipeToReply extends StatefulWidget {
  final Widget child;
  final bool isMe;
  final VoidCallback onReply;

  const _SwipeToReply({
    required this.child,
    required this.isMe,
    required this.onReply,
  });

  @override
  State<_SwipeToReply> createState() => _SwipeToReplyState();
}

class _SwipeToReplyState extends State<_SwipeToReply>
    with SingleTickerProviderStateMixin {
  static const double _maxDrag = 72.0;
  static const double _triggerThreshold = 56.0;

  late final AnimationController _springBack;
  double _dragX = 0.0;
  double _springFrom = 0.0;
  bool _triggered = false;

  @override
  void initState() {
    super.initState();
    _springBack =
        AnimationController(
          vsync: this,
          duration: const Duration(milliseconds: 200),
        )..addListener(() {
          final t = Curves.easeOut.transform(_springBack.value);
          setState(() => _dragX = _springFrom * (1 - t));
        });
  }

  @override
  void dispose() {
    _springBack.dispose();
    super.dispose();
  }

  void _onDragUpdate(DragUpdateDetails d) {
    if (_springBack.isAnimating) _springBack.stop();
    var next = _dragX + d.delta.dx;
    if (next > 0) next = 0;
    if (next < -_maxDrag) next = -_maxDrag;
    final wasTriggered = _triggered;
    _triggered = next <= -_triggerThreshold;
    if (_triggered && !wasTriggered) Haptics.medium();
    setState(() => _dragX = next);
  }

  void _onDragEnd(DragEndDetails d) {
    if (_triggered) widget.onReply();
    _settle();
  }

  void _onDragCancel() => _settle();

  void _settle() {
    _triggered = false;
    _springFrom = _dragX;
    _springBack.forward(from: 0);
  }

  @override
  Widget build(BuildContext context) {
    final cs = Theme.of(context).colorScheme;
    final progress = (-_dragX / _triggerThreshold).clamp(0.0, 1.0);
    return RawGestureDetector(
      behavior: HitTestBehavior.opaque,
      gestures: <Type, GestureRecognizerFactory>{
        LeftwardDragRecognizer:
            GestureRecognizerFactoryWithHandlers<LeftwardDragRecognizer>(
              () => LeftwardDragRecognizer(debugOwner: this),
              (instance) {
                instance
                  ..onUpdate = _onDragUpdate
                  ..onEnd = _onDragEnd
                  ..onCancel = _onDragCancel;
              },
            ),
      },
      child: Stack(
        alignment: Alignment.centerRight,
        children: [
          Positioned(
            right: 16,
            child: Opacity(
              opacity: progress,
              child: Transform.scale(
                scale: 0.6 + 0.4 * progress,
                child: Container(
                  padding: const EdgeInsets.all(6),
                  decoration: BoxDecoration(
                    color: cs.surfaceContainerHighest,
                    shape: BoxShape.circle,
                  ),
                  child: Icon(Symbols.reply, size: 20, color: cs.primary),
                ),
              ),
            ),
          ),
          Transform.translate(offset: Offset(_dragX, 0), child: widget.child),
        ],
      ),
    );
  }
}

class _PinnedMessageBanner extends StatelessWidget {
  final String? text;
  final bool isPreview;
  final VoidCallback onTap;
  final VoidCallback? onUnpin;
  final bool floating;
  final bool frosted;
  final bool liquid;
  final BackdropKey? backdropKey;

  const _PinnedMessageBanner({
    required this.text,
    required this.isPreview,
    required this.onTap,
    this.onUnpin,
    this.floating = false,
    this.frosted = false,
    this.liquid = false,
    this.backdropKey,
  });

  @override
  Widget build(BuildContext context) {
    final cs = Theme.of(context).colorScheme;
    final content = Material(
      color: frosted
          ? AppFrost.panelTint(cs)
          : floating
          ? cs.surfaceContainerHigh.withValues(alpha: 0.92)
          : cs.surfaceContainerHigh,
      borderRadius: floating ? BorderRadius.circular(16) : null,
      clipBehavior: Clip.antiAlias,
      child: InkWell(
        onTap: onTap,
        child: Padding(
          padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
          child: Row(
            children: [
              Container(
                width: 3,
                height: 34,
                decoration: BoxDecoration(
                  color: cs.primary,
                  borderRadius: BorderRadius.circular(2),
                ),
              ),
              const SizedBox(width: 10),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    Text(
                      AppLocalizations.of(context)!.pinnedMessageTitle,
                      style: TextStyle(
                        color: cs.primary,
                        fontWeight: FontWeight.w600,
                        fontSize: 14,
                      ),
                    ),
                    const SizedBox(height: 2),
                    _PinnedMessageText(
                      text: text,
                      isPreview: isPreview,
                      color: cs.onSurfaceVariant,
                    ),
                  ],
                ),
              ),
              if (onUnpin != null) ...[
                const SizedBox(width: 8),
                IconButton(
                  icon: Icon(Symbols.close, color: cs.onSurfaceVariant),
                  iconSize: 20,
                  visualDensity: VisualDensity.compact,
                  onPressed: onUnpin,
                ),
              ],
            ],
          ),
        ),
      ),
    );

    final bottomBorder = Border(bottom: AppFrost.hairline(cs));

    if (frosted) {
      return GlassSurface(
        liquid: liquid,
        borderRadius: floating
            ? BorderRadius.circular(16)
            : BorderRadius.zero,
        frostTint: Colors.transparent,
        border: floating ? null : bottomBorder,
        backdropKey: backdropKey,
        child: content,
      );
    }

    if (!floating) {
      return DecoratedBox(
        decoration: BoxDecoration(border: bottomBorder),
        child: content,
      );
    }
    return content;
  }
}

class _PinnedMessageText extends StatefulWidget {
  final String? text;
  final bool isPreview;
  final Color color;

  const _PinnedMessageText({
    required this.text,
    required this.isPreview,
    required this.color,
  });

  @override
  State<_PinnedMessageText> createState() => _PinnedMessageTextState();
}

class _PinnedMessageTextState extends State<_PinnedMessageText> {
  late String? _primaryText;
  late bool _primaryIsPreview;
  late String? _secondaryText;
  late bool _secondaryIsPreview;
  bool _showSecondary = false;

  @override
  void initState() {
    super.initState();
    _primaryText = widget.text;
    _primaryIsPreview = widget.isPreview;
    _secondaryText = widget.text;
    _secondaryIsPreview = widget.isPreview;
  }

  @override
  void didUpdateWidget(covariant _PinnedMessageText oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (widget.text == oldWidget.text &&
        widget.isPreview == oldWidget.isPreview) {
      return;
    }
    if (_showSecondary) {
      _primaryText = widget.text;
      _primaryIsPreview = widget.isPreview;
    } else {
      _secondaryText = widget.text;
      _secondaryIsPreview = widget.isPreview;
    }
    _showSecondary = !_showSecondary;
  }

  @override
  Widget build(BuildContext context) {
    return ClipRect(
      child: AnimatedTextSwap(
        showAlternate: _showSecondary,
        alternate: _buildText(context, _secondaryText, _secondaryIsPreview),
        child: _buildText(context, _primaryText, _primaryIsPreview),
      ),
    );
  }

  Widget _buildText(BuildContext context, String? text, bool isPreview) {
    final label = text == null || text.isEmpty
        ? AppLocalizations.of(context)!.msgActionsNoText
        : text;
    return Text(
      label,
      maxLines: 1,
      overflow: TextOverflow.ellipsis,
      style: TextStyle(
        color: widget.color,
        fontSize: 14,
        fontStyle: isPreview ? FontStyle.italic : null,
      ),
    );
  }
}

class _SelectableMessageRow extends StatefulWidget {
  final Widget child;
  final CachedMessage message;
  final bool isMe;
  final ValueListenable<Set<String>> selectedIds;
  final Animation<double> selectionAnim;
  final bool Function() isSelectionActive;
  final VoidCallback onToggleSelection;
  final VoidCallback onEnterSelection;
  final void Function(Offset globalPosition) onStartTextSelection;
  final VoidCallback onDelete;
  final VoidCallback? onEdit;
  final VoidCallback? onReply;
  final VoidCallback? onForward;
  final VoidCallback? onMarkUnread;
  final VoidCallback? onPin;
  final bool Function() isPinned;
  final Future<List<MessageReader>> Function()? loadReadBy;
  final void Function(int userId)? onReaderTap;
  final Future<List<({int id, String title})>> Function()? loadReportReasons;
  final Future<bool> Function(int reasonId)? onReport;
  final void Function(String emoji)? onReact;
  final ValueListenable<Map<String, dynamic>?>? reactions;

  const _SelectableMessageRow({
    required this.child,
    required this.message,
    required this.isMe,
    required this.selectedIds,
    required this.selectionAnim,
    required this.isSelectionActive,
    required this.onToggleSelection,
    required this.onEnterSelection,
    required this.onStartTextSelection,
    required this.onDelete,
    this.onEdit,
    this.onReply,
    this.onForward,
    this.onMarkUnread,
    this.onPin,
    required this.isPinned,
    this.loadReadBy,
    this.onReaderTap,
    this.loadReportReasons,
    this.onReport,
    this.onReact,
    this.reactions,
  });

  @override
  State<_SelectableMessageRow> createState() => _SelectableMessageRowState();
}

class _SelectableMessageRowState extends State<_SelectableMessageRow> {
  static const double _gutterWidth = 40;

  final GlobalKey _boundaryKey = GlobalKey();
  Offset? _lastTapDown;
  Timer? _openTimer;

  bool _isPinnedNow() => widget.isPinned();

  @override
  void dispose() {
    _openTimer?.cancel();
    super.dispose();
  }

  void _openMenu() {
    final ctx = _boundaryKey.currentContext;
    if (ctx == null) return;
    final renderObject = ctx.findRenderObject();
    if (renderObject is! RenderRepaintBoundary) return;

    final origin = renderObject.localToGlobal(Offset.zero);
    final rect = origin & renderObject.size;
    final rawDpr = MediaQuery.of(ctx).devicePixelRatio;
    final dpr = rawDpr > 2.0 ? 2.0 : rawDpr;

    final ui.Image snapshot;
    try {
      snapshot = renderObject.toImageSync(pixelRatio: dpr);
    } catch (_) {
      return;
    }

    Haptics.tap();

    final controller = MessageActionsController();
    showMessageActions(
      context: ctx,
      snapshot: snapshot,
      originRect: rect,
      tapPoint: _lastTapDown ?? rect.center,
      isMe: widget.isMe,
      messageText: widget.message.text,
      controller: controller,
      style: AppMessageActionsStyle.current.value,
      interaction: MessageActionsInteraction.tap,
      editHistory: widget.message.editHistory,
      loadReadBy: widget.loadReadBy,
      onReaderTap: widget.onReaderTap,
      loadReportReasons: widget.loadReportReasons,
      onReport: widget.onReport,
      onDelete: widget.onDelete,
      onEdit: widget.onEdit,
      onReply: widget.onReply,
      onForward: widget.onForward,
      onMarkUnread: widget.onMarkUnread,
      onPin: widget.onPin,
      isPinned: _isPinnedNow(),
      onReact: widget.onReact,
      selectedReaction: widget.reactions?.value?['yourReaction']?.toString(),
      quickReactions: _quickReactionEmojis(),
      loadReactionEmojis: () async {
        await animojiModule.ensureLoaded();
        return _animojiReactionEmojis();
      },
      onDispose: controller.dispose,
    );
  }

  List<ReactionEmoji> _quickReactionEmojis() {
    final quick = animojiModule.quickAnimojis;
    if (quick.isEmpty) {
      return AnimojiModule.fallbackReactions
          .map((e) => ReactionEmoji(emoji: e))
          .toList();
    }
    return quick.map(_toReactionEmoji).toList();
  }

  List<ReactionEmoji> _animojiReactionEmojis() {
    final list = animojiModule.animojis;
    if (list.isEmpty) {
      return AnimojiModule.fallbackReactions
          .map((e) => ReactionEmoji(emoji: e))
          .toList();
    }
    return list.map(_toReactionEmoji).toList();
  }

  ReactionEmoji _toReactionEmoji(Animoji a) => ReactionEmoji(
    emoji: a.emoji,
    animationUrl: a.lottieUrl,
    staticUrl: a.iconUrl,
  );

  void _onSecondaryTapDown(TapDownDetails details) {
    final ctx = _boundaryKey.currentContext;
    if (ctx == null) return;
    final renderObject = ctx.findRenderObject();
    if (renderObject is! RenderRepaintBoundary) return;

    final origin = renderObject.localToGlobal(Offset.zero);
    final rect = origin & renderObject.size;

    final controller = MessageActionsController();
    showMessageActions(
      context: ctx,
      originRect: rect,
      tapPoint: details.globalPosition,
      isMe: widget.isMe,
      messageText: widget.message.text,
      controller: controller,
      style: MessageActionsStyle.list,
      interaction: MessageActionsInteraction.click,
      editHistory: widget.message.editHistory,
      loadReadBy: widget.loadReadBy,
      onReaderTap: widget.onReaderTap,
      loadReportReasons: widget.loadReportReasons,
      onReport: widget.onReport,
      onDelete: widget.onDelete,
      onEdit: widget.onEdit,
      onReply: widget.onReply,
      onForward: widget.onForward,
      onMarkUnread: widget.onMarkUnread,
      onPin: widget.onPin,
      isPinned: _isPinnedNow(),
      onDispose: controller.dispose,
    );
  }

  void _handleTap() {
    if (widget.isSelectionActive()) {
      widget.onToggleSelection();
      return;
    }
    final react = widget.onReact;
    if (react != null && (_openTimer?.isActive ?? false)) {
      _openTimer?.cancel();
      _openTimer = null;
      Haptics.tap();
      react('❤️');
      return;
    }
    _openTimer?.cancel();
    _openTimer = Timer(const Duration(milliseconds: 200), () {
      if (mounted && !widget.isSelectionActive()) _openMenu();
    });
  }

  void _handleLongPressStart(Offset globalPosition) {
    if (!widget.isSelectionActive()) {
      widget.onEnterSelection();
      return;
    }
    final selected = widget.selectedIds.value.contains(widget.message.id);
    final hasText = widget.message.selectableText != null;
    if (selected && hasText && !widget.message.isControl) {
      widget.onStartTextSelection(globalPosition);
    } else {
      widget.onToggleSelection();
    }
  }

  Widget _buildCheckCircle(bool selected, ColorScheme cs) {
    return AnimatedContainer(
      duration: const Duration(milliseconds: 160),
      curve: Curves.easeOut,
      width: 24,
      height: 24,
      decoration: BoxDecoration(
        shape: BoxShape.circle,
        color: selected ? cs.primary : Colors.transparent,
        border: Border.all(
          color: selected ? cs.primary : cs.mutedText,
          width: 2,
        ),
      ),
      child: selected
          ? Icon(Symbols.check, size: 16, weight: 700, color: cs.onPrimary)
          : null,
    );
  }

  @override
  Widget build(BuildContext context) {
    if (widget.message.isControl) return widget.child;
    final cs = Theme.of(context).colorScheme;

    return AnimatedBuilder(
      animation: widget.selectionAnim,
      builder: (context, _) {
        final t = Curves.easeOut.transform(
          widget.selectionAnim.value.clamp(0.0, 1.0),
        );
        return ValueListenableBuilder<Set<String>>(
          valueListenable: widget.selectedIds,
          builder: (context, selected, _) {
            final isSelected = selected.contains(widget.message.id);
            final active = selected.isNotEmpty;

            return GestureDetector(
              behavior: HitTestBehavior.opaque,
              onTapDown: (d) => _lastTapDown = d.globalPosition,
              onTap: _handleTap,
              onLongPressStart: (d) => _handleLongPressStart(d.globalPosition),
              onSecondaryTapDown: active ? null : _onSecondaryTapDown,
              child: ColoredBox(
                color: isSelected
                    ? cs.primary.withValues(alpha: 0.10)
                    : Colors.transparent,
                child: Stack(
                  children: [
                    RepaintBoundary(
                      key: _boundaryKey,
                      child: IgnorePointer(
                        ignoring: active,
                        child: Padding(
                          padding: EdgeInsets.only(left: _gutterWidth * t),
                          child: widget.child,
                        ),
                      ),
                    ),
                    if (t > 0)
                      Positioned(
                        left: 8,
                        bottom: 10,
                        child: Opacity(
                          opacity: t,
                          child: _buildCheckCircle(isSelected, cs),
                        ),
                      ),
                  ],
                ),
              ),
            );
          },
        );
      },
    );
  }
}

class _DeletingMessageAnimation extends StatefulWidget {
  final Widget child;
  final VoidCallback onComplete;

  const _DeletingMessageAnimation({
    super.key,
    required this.child,
    required this.onComplete,
  });

  @override
  State<_DeletingMessageAnimation> createState() =>
      _DeletingMessageAnimationState();
}

class _DeletingMessageAnimationState extends State<_DeletingMessageAnimation>
    with SingleTickerProviderStateMixin {
  late final AnimationController _ctrl;
  late final Animation<double> _opacity;
  late final Animation<double> _scale;
  late final Animation<double> _collapse;
  bool _fired = false;

  @override
  void initState() {
    super.initState();
    _ctrl = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 280),
    );
    _opacity = Tween<double>(
      begin: 1,
      end: 0,
    ).animate(CurvedAnimation(parent: _ctrl, curve: const Interval(0.0, 0.6)));
    _scale = Tween<double>(
      begin: 1,
      end: 0.82,
    ).animate(CurvedAnimation(parent: _ctrl, curve: const Interval(0.0, 0.6)));
    _collapse = Tween<double>(begin: 1, end: 0).animate(
      CurvedAnimation(
        parent: _ctrl,
        curve: const Interval(0.35, 1.0, curve: Curves.easeInOut),
      ),
    );
    _ctrl.forward().whenComplete(() {
      if (_fired) return;
      _fired = true;
      widget.onComplete();
    });
  }

  @override
  void dispose() {
    _ctrl.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return SizeTransition(
      sizeFactor: _collapse,
      axisAlignment: 0.0,
      child: FadeTransition(
        opacity: _opacity,
        child: ScaleTransition(
          scale: _scale,
          alignment: Alignment.center,
          child: widget.child,
        ),
      ),
    );
  }
}

class _SentMessageAnimation extends StatefulWidget {
  final Widget child;
  final VoidCallback onComplete;

  const _SentMessageAnimation({
    super.key,
    required this.child,
    required this.onComplete,
  });

  @override
  State<_SentMessageAnimation> createState() => _SentMessageAnimationState();
}

class _SentMessageAnimationState extends State<_SentMessageAnimation>
    with SingleTickerProviderStateMixin {
  late final AnimationController _ctrl;
  late final Animation<double> _opacity;
  late final Animation<double> _slide;

  @override
  void initState() {
    super.initState();
    _ctrl = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 220),
    );
    _opacity = CurvedAnimation(parent: _ctrl, curve: Curves.easeOut);
    _slide = Tween<double>(
      begin: 16,
      end: 0,
    ).animate(CurvedAnimation(parent: _ctrl, curve: Curves.easeOut));
    _ctrl.forward().whenComplete(widget.onComplete);
  }

  @override
  void dispose() {
    _ctrl.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return AnimatedBuilder(
      animation: _ctrl,
      builder: (context, child) => Opacity(
        opacity: _opacity.value,
        child: Transform.translate(
          offset: Offset(0, _slide.value),
          child: child,
        ),
      ),
      child: widget.child,
    );
  }
}

class _ChatMessageList extends StatefulWidget {
  final _ChatScreenState host;
  const _ChatMessageList(this.host, {super.key});

  @override
  State<_ChatMessageList> createState() => _ChatMessageListState();
}

class _ChatMessageListState extends State<_ChatMessageList> {
  @override
  Widget build(BuildContext context) {
    return ValueListenableBuilder<int>(
      valueListenable: widget.host._messagesRev,
      builder: (context, _, _) => widget.host._buildMessagesListContent(),
    );
  }
}
