kowalski/src/commands/whois.js

module.exports = function(bot, msg) {
  const chatId = msg.chat.id;
  const userName = msg.from.first_name;
  const userId = msg.from.id;
  const userHandle = msg.from.username;
  const isBot = msg.from.is_bot;
  const userPremium = msg.from.is_premium;
  const userLang = msg.from.language_code;
  let haveUsername = "";
  let userPremiumOutput = "";
  
  if (userPremium) {
    userPremiumOutput = "*You have a Telegram Premium subscription.*";
  } else {
    userPremiumOutput = "*You don't have a Telegram Premium subscription.*";
  }

  if (userHandle) {
    haveUsername = `*Your username is:* @${userHandle}`;
  } else {
    haveUsername = "*Your username is:* none";
  }

  const message = `*Your name is:* ${userName}\n${haveUsername}\n*Your ID is:* ${userId}\n*You are a bot:* ${isBot}\n*Your language:* ${userLang}\n\n${userPremiumOutput}`;

  bot.sendMessage(chatId, message, { parse_mode: 'Markdown' })
    .catch(error => console.error('WARN: Message cannot be sent:', error));
}