var ursa = require('ursa');
  var fs = require('fs');
  
  var decrypt = {};
  
  decrypt.decrypter = false;
  
  decrypt.whenOk = function (cb) {

      if (this.encrypter) {
          cb();
      } else {
          this.prepare(cb);
      }

  };
  
  decrypt.prepare = function (cb) {

      fs.readFile('config/ci_com.pem', function (err, data) {
          if (err) {
              throw err;
          }
          this.decrypter = ursa.createPrivateKey(data);
          cb();
      });

  };
  

  decrypt.preload = function (cb) {
      this.whenOk(cb);

  };
  
  decrypt.decrypt = function (string, cb) {

      this.whenOk(function () {
          cb(this.decrypter.decrypt(string, 'base64', 'utf8', ursa.RSA_PKCS1_PADDING));
      });

  };
  
  module.exports = decrypt;