Function watchForNextReply

e2e/telegram-api.ts:302–373

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

 * Returns the highest `update_id` consumed (`reachedUpdateId`).
 */
export async function watchForNextReply(args: {
  chatId: string | number;
  sinceUpdateId: number;
  seenCount: 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;
  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;
      if (msg.from?.is_bot) {
        botMessageMap.set(msg.message_id, msg);
      }
    }
    // Collect distinct bot message_ids in insertion order (Map preserves it).
    const distinctMessages = Array.from(botMessageMap.values()).sort(
      (a, b) => a.message_id - b.message_id,
    );
    // Target is the (seenCount+1)-th distinct message, i.e. the first NEW one.
    const target =
      distinctMessages.length > args.seenCount
        ? distinctMessages[args.seenCount]
        : undefined;
    const text = target?.text;
    await args.onSample({
      elapsedMs: Date.now() - start,
      text,
      message: target,
    });
    const len = text?.length ?? 0;
    if (target && len === lastLen && len > 0) {
      stable++;
      if (stable >= 3) break;
    } else {
      stable = 0;