using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

namespace LauncherUpdater.Function
{
    public static class EncryptionHelper
    {
        public static string Encrypt(string clearText)
        {
            string password = "N1PEUPQX";
            byte[] bytes = Encoding.Unicode.GetBytes(clearText);
            using (Aes aes = Aes.Create())
            {
                Rfc2898DeriveBytes rfc2898DeriveBytes = new Rfc2898DeriveBytes(password, new byte[13]
                {
                    (byte) 73,
                    (byte) 118,
                    (byte) 97,
                    (byte) 110,
                    (byte) 32,
                    (byte) 77,
                    (byte) 101,
                    (byte) 100,
                    (byte) 118,
                    (byte) 101,
                    (byte) 100,
                    (byte) 101,
                    (byte) 118
                });
                aes.Key = rfc2898DeriveBytes.GetBytes(32);
                aes.IV = rfc2898DeriveBytes.GetBytes(16);
                using (MemoryStream memoryStream = new MemoryStream())
                {
                    using (CryptoStream cryptoStream = new CryptoStream((Stream) memoryStream, aes.CreateEncryptor(),
                               CryptoStreamMode.Write))
                    {
                        cryptoStream.Write(bytes, 0, bytes.Length);
                        cryptoStream.Close();
                    }

                    clearText = Convert.ToBase64String(memoryStream.ToArray());
                }
            }

            return clearText;
        }

        public static string Decrypt(string cipherText)
        {
            string password = "N1PEUPQX";
            cipherText = cipherText.Replace(" ", "+");
            byte[] buffer = Convert.FromBase64String(cipherText);
            using (Aes aes = Aes.Create())
            {
                Rfc2898DeriveBytes rfc2898DeriveBytes = new Rfc2898DeriveBytes(password, new byte[13]
                {
                    (byte) 73,
                    (byte) 118,
                    (byte) 97,
                    (byte) 110,
                    (byte) 32,
                    (byte) 77,
                    (byte) 101,
                    (byte) 100,
                    (byte) 118,
                    (byte) 101,
                    (byte) 100,
                    (byte) 101,
                    (byte) 118
                });
                aes.Key = rfc2898DeriveBytes.GetBytes(32);
                aes.IV = rfc2898DeriveBytes.GetBytes(16);
                using (MemoryStream memoryStream = new MemoryStream())
                {
                    using (CryptoStream cryptoStream = new CryptoStream((Stream) memoryStream, aes.CreateDecryptor(),
                               CryptoStreamMode.Write))
                    {
                        cryptoStream.Write(buffer, 0, buffer.Length);
                        cryptoStream.Close();
                    }

                    cipherText = Encoding.Unicode.GetString(memoryStream.ToArray());
                }
            }

            return cipherText;
        }
    }
}