Function watchForReply

e2e/telegram-api.ts:211–285

(args: {
  chatId: string | number;
  sinceUpdateId: number;
  intervalMs: number;
  timeoutMs: number;
  onSample: (sample: {
    elapsedMs: number;
    text: string | undefined;
    message: TelegramMessage | undefined;
  }) => Promise<void> | void;
})

 * pass it as the baseline for a follow-up `watchForNextReply` call.
 */
export async function watchForReply(args: {
  chatId: string | number;
  sinceUpdateId: number;
  intervalMs: number;
  timeoutMs: number;
  onSample: (sample: {
    elapsedMs: number;
    text: string | undefined;
    message: TelegramMessage | undefined;
  }) => Promise<void> | void;
}): Promise<{
  finalText: string | undefined;
  finalMessage: TelegramMessage | undefined;
  reachedUpdateId: number;
}> {
  const start = Date.now();
  let offset = args.sinceUpdateId + 1;
  // Map from message_id → latest known TelegramMessage (tracks edits).
  const botMessageMap = new Map<number, TelegramMessage>();
  let stable = 0;
  let lastLen = -1;
  // Track the highest update_id we have consumed so callers can use it as the
  // next baseline without re-delivering already-confirmed updates.
  let reachedUpdateId = args.sinceUpdateId;

  while (Date.now() - start < args.timeoutMs) {
    const updates = await getUpdates(offset);
    for (const u of updates) {
      if (u.update_id >= offset) offset = u.update_id + 1;
      if (u.update_id > reachedUpdateId) reachedUpdateId = u.update_id;
      // Accept both new messages and edits.
      const msg = u.message ?? u.edited_message;
      if (!msg) continue;
      if (String(msg.chat.id) !== String(args.chatId)) continue;
      // Track the latest text for each bot message_id.
      if (msg.from?.is_bot) {
        botMessageMap.set(msg.message_id, msg);
      }
    }
    // The "last" bot message is the one with the highest message_id.
    let lastMessage: TelegramMessage | undefined;
    for (const msg of botMessageMap.values()) {
      if (!lastMessage || msg.message_id > lastMessage.message_id) {
        lastMessage = msg;
      }
    }
    const text = lastMessage?.text;
    await args.onSample({
      elapsedMs: Date.now() - start,
      text,
      message: lastMessage,
    });
    const len = text?.length ?? 0;
    if (len === lastLen && len > 0) {
      stable++;
      if (stable >= 3) break;
    } else {
      stable = 0;