//encrypt/decrypt functions
const crypto = require('crypto');
var algorithm = 'aes-256-ctr';
var key_phrase = 'a secret key';// 16 symbols should be 16 symbols

function encrypt_cookie(text){
  key = new Buffer.alloc(32, key_phrase);
  iv = new Buffer.alloc(16, key_phrase);
  const cipher = crypto.createCipheriv(algorithm, key, iv);
  var encrypted = cipher.update(text, 'utf8', 'hex');
  encrypted += cipher.final('hex');
  return encrypted;
}

function decrypt_cookie(text){
  key = new Buffer.alloc(32, key_phrase);
  iv = new Buffer.alloc(16, key_phrase);
  const decipher = crypto.createDecipheriv(algorithm, key, iv);
  var dec = decipher.update(text, 'hex', 'utf8');
  dec += decipher.final('utf8');
  return dec;
}

// var encrypted = encrypt_cookie('Hello world!');
// console.log(encrypted);
// console.log(decrypt_cookie(encrypted));

// get/set/delete cookie npm
function get_cookie(req, str){
  console.log(req.headers.cookie);
  var result = req.headers.cookie.match(new RegExp(str+'=([^;]*)', 'i'));
  if(result != null){
    return decrypt_cookie(result[1]);
  }
  return result;
}
function set_cookie(res, cookie_name, cookie_value){
  res.cookie(cookie_name , encrypt_cookie(cookie_value) );
}
function dellete_cookie(res, cookie_name){
  res.clearCookie(cookie_name);
}


var app = express()
// app.use(cookieParser())
app.use(function(req, res, next){

  console.log(req.headers.cookie);

  // set cookie
  set_cookie(res, 'cookie1', 'value1');
  set_cookie(res, 'cookie2', 'value2');
  set_cookie(res, 'cookie3', 'value3');

  // remove cookies
  // dellete_cookie(res, 'cookie1');
  // dellete_cookie(res, 'cookie2');
  // dellete_cookie(res, 'cookie3');

  // set cookies
  var cookie1 = get_cookie(req, 'cookie1');
  var cookie2 = get_cookie(req, 'cookie2');
  var cookie3 = get_cookie(req, 'cookie3');

  console.log(cookie1);
  console.log(cookie2);
  console.log(cookie3);

  // next();
})