text: /**
   * `password` type prompt
   */
  
  var util = require('util');
  var chalk = require('chalk');
  var Base = require('./base');
  var observe = require('../utils/events');
  
  function mask(input) {
    input = String(input);
    if (input.length === 0) {
      return '';
    }
  
    return new Array(input.length + 1).join('*');
  }
  
  /**
   * Module exports
   */
  
  module.exports = Prompt;
  
  /**
   * Constructor
   */
  
  function Prompt() {
    return Base.apply(this, arguments);
  }
  util.inherits(Prompt, Base);
  
  /**
   * Start the Inquiry session
   * @param  {Function} cb      Callback when prompt is done
   * @return {this}
   */
  
  Prompt.prototype._run = function (cb) {
    this.done = cb;
  
    var events = observe(this.rl, this);
  
    // Once user confirm (enter key)
    var submit = events.line.map(this.filterInput.bind(this));
  
    var validation = this.handleSubmitEvents(submit);
    validation.success.forEach(this.onEnd.bind(this));
    validation.error.forEach(this.onError.bind(this));
  
    events.keypress.takeUntil(validation.success).forEach(this.onKeypress.bind(this));
  
    // Init
    this.render();
  
    return this;
  };
  
  /**
   * Render the prompt to screen
   * @return {Prompt} self
   */
  
  Prompt.prototype.render = function (error) {
    var message = this.getQuestion();
    var bottomContent = '';
  
    if (this.status === 'answered') {
      message += chalk.cyan(mask(this.answer));
    } else {
      message += mask(this.rl.line || '');
    }
  
    if (error) {
      bottomContent = '\n' + chalk.red('>> ') + error;
    }
  
    this.screen.render(message, bottomContent);
  };
  
  /**
   * When user press `enter` key
   */
  
  Prompt.prototype.filterInput = function (input) {
    if (!input) {
      return this.opt.default == null ? '' : this.opt.default;
    }
    return input;
  };
  
  Prompt.prototype.onEnd = function (state) {
    this.status = 'answered';
    this.answer = state.value;
  
    // Re-render prompt
    this.render();
  
    this.screen.done();
    this.done(state.value);
  };
  
  Prompt.prototype.onError = function (state) {
    this.render(state.isValid);
    this.rl.output.unmute();
  };
  
  /**
   * When user type
   */
  
  Prompt.prototype.onKeypress = function () {
    this.render();
  };
  