helper.js

'use strict';
var Responses = require('./responses/model');

(function (helper) {
  helper.choose = function (array) {
    var index = Math.floor((Math.random() * array.length));
    return array[index];
  };

  helper.shorten = function (string) {
    return string.substring(0, 475);
  };

  helper.response = function (key, callback) {
    Responses.findOne({ key: key }).exec(function (err, result) {
      callback(err, helper.choose(result.response));
    });
  };

  if (!String.format) {
    String.format = function (format) {
      var args = Array.prototype.slice.call(arguments, 1);
      return format.replace(/{(\d+)}/g, function (match, number) {
        return typeof args[number] != 'undefined'
        ? args[number]
        : match;
      });
    };
  }

})(module.exports);