function secretChat(input) {
  let message = input.shift();
  let line = input.shift();

  while (line !== 'Reveal') {
    const [command, ...params] = line.split(':|:');

    switch (command) {
      case 'InsertSpace':
        const index = Number(params.shift());
        message = message.slice(0, index) + ' ' + message.slice(index);
        console.log(message);
        break;
      case 'Reverse':
        let [substring] = params;

        if (!message.includes(substring)) {
            console.log('error');
            line = input.shift();
            continue;
        }

        message = message.replace(substring, '');
        substring = substring.split('').reverse().join('');
        message += substring;
        console.log(message);
        break;
      case 'ChangeAll':
        const [substr, replacement] = params;

        while (message.includes(substr)){
            message = message.replace(substr, replacement);
        }
        console.log(message);
        break;
    }

    line = input.shift();
  }
  console.log(`You have a new text message: ${message}`);
}