Лимиты Telegram bot API и работа с ними на Go

/**
 * Used to send messages to all users
 *
 * @module sendout
 * @license MIT
 */

/** Dependencies */

const db = require('./db');

/**
 * Used to send messages to all chats
 * @param {Telegram:Bot} bot Bot that should send messages
 * @param {String} text Text to be sent
 */
function sendAll(bot, text) {
  db.getChats()
    .then((chats) => {
      sendMessage(text, chats, bot, {});
    })
    .catch(/** todo: handle error */);
}

/**
 * Recursive function to send text to an array of chats; please don't use this
 *    function twice at any given point of time. Sends at most 30 messages/sec
 *
 * @param {String} text - Text to be sent
 * @param {[Mongoose:Chat]} chats - Chats to get this message
 * @param  {Telegram:Bot} bot - Bot that should respond
 */
function sendMessage(text, chats, bot, results) {
  if (chats.length <= 0) {
    const keys = Object.keys(results);
    const successKeyIndex = keys.indexOf('success');
    if (successKeyIndex > -1) {
      keys.splice(successKeyIndex, 1);
    }
    let message = `All messages were sent, here are the results:\n\nSuccess: ${results.success || 0}`;

    keys.forEach((key) => {
      message = `${message}\n${key}: ${results[key]}`;
    });

    bot.sendMessage('ваш id', message);
    return;
  }

  /** Get current users and users for the next loop */
  const nextUsers = Object.create(chats);
  const currentUsers = nextUsers.splice(0, 30);
  const resultsCopy = Object.create(results);

  const promises = [];
  currentUsers.forEach((user) => {
    promises.push(new Promise((resolve) => {
      bot.sendMessage(user.id, text, {
        disable_web_page_preview: 'true',
      })
        .then(() => resolve('success'))
        .catch((err) => {
          resolve(String(err.message));
        });
    }));
  });
  Promise.all(promises)
    .then((values) => {
      values.forEach((value) => {
        if (resultsCopy[value]) {
          resultsCopy[value] += 1;
        } else {
          resultsCopy[value] = 1;
        }
      });
      setTimeout(() => {
        sendMessage(text, nextUsers, bot, resultsCopy);
      }, 1500);
    })
    .catch(err => bot.sendMessage('ваш id', err.message));
}

module.exports = {
  sendAll,
};