Method doDs

fbi/fbi.ts:397–446

(msg: Api.Message, args: string[])

      targetName: target.name,
      triggerPeer: String(msg.chatId),
      triggerMsgId: msg.id,
    });
    await this.persistDb();
  }

  /* ====== listen — update cache + check surveillance ====== */

  private async onMsg(msg: Api.Message) {
    // 1) update cache — only public groups, auto-vivify on first sighting
    if (msg.chatId) {
      const peer = String(msg.chatId);
      let chat = this.chatCache.get(peer);
      if (!chat) {
        // first sighting → check if public, cache only public groups
        const cl = await getGlobalClient();
        if (cl) {
          try {
            const entity = entityFields(await cl.getEntity(msg.chatId));
            if (entity.username && (entity.className === 'Channel' || entity.className === 'Chat')) {
              chat = { username: entity.username, title: entity.title, msgs: [] };
              this.chatCache.set(peer, chat);
            }
          } catch { /* getEntity failed → skip */ }
        }
      }
      if (chat) {
        chat.msgs.unshift(stripMsg(msg));
        this.pruneExpired(chat);
        if (chat.msgs.length > CACHE_MSG_LIMIT) chat.msgs.length = CACHE_MSG_LIMIT;
        this.schedulePersistCache();
      }
    }

    // 2) sv surveillance
    if (this.sv.size === 0) return;
    const sid = msg.senderId ? String(msg.senderId) : "";
    if (!sid || !this.sv.has(sid)) return;
    const entry = this.sv.get(sid)!;

    // prevent self-trigger
    if (String(msg.chatId) === entry.triggerPeer && msg.id === entry.triggerMsgId) return;

    // mon scope — only trigger if message is in the target group
    if (entry.scopePeer && String(msg.chatId) !== entry.scopePeer) return;

    // check group is public (has username) before consuming the sv entry
    const cl = await getGlobalClient();
    if (!cl) return;
    const chatEntity = entityFields(await cl.getEntity(msg.peerId));
    if (!chatEntity.username) return; // private group — skip silently, keep sv alive

    this.sv.delete(sid);
    this.persistDb().catch((e) => console.error("[fbi] persistDb error", e));