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

namespace Quadarax.Foundation.Common.Security
{
    public static class Secure
    {
        static string _passwordHash = "OmMC:7i%+o.MlIeg`kRcv:R3haPyx|#vuM,G,oB1n=IBUG'!M6";
        static string _saltKey = "vo:Y:pWYcS\"*m@^6R\\O#$eSg!,23H\\R8KfIi\\u1IED91TE0J#~";
        static string _vIKey = "@!PYn,b=t4\\%`Am`z!ubwE1H2Ek1?*R&,6cF:f1mZJ1dxB&DZH";


        public static void SetProperties(string passwordHash, string saltKey, string vIKey)
        {
            _passwordHash = passwordHash;
            _saltKey = saltKey;
            _vIKey = vIKey;
        }

        public static string Encrypt(string plainText)
        {
            var plainTextBytes = Encoding.UTF8.GetBytes(plainText);

            var keyBytes = new Rfc2898DeriveBytes(_passwordHash, Encoding.ASCII.GetBytes(_saltKey)).GetBytes(256 / 8);
            var symmetricKey = new RijndaelManaged() { Mode = CipherMode.CBC, Padding = PaddingMode.Zeros };
            var encryptor = symmetricKey.CreateEncryptor(keyBytes, Encoding.ASCII.GetBytes(_vIKey));
			
            byte[] cipherTextBytes;

            using (var memoryStream = new MemoryStream())
            {
                using (var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
                {
                    cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
                    cryptoStream.FlushFinalBlock();
                    cipherTextBytes = memoryStream.ToArray();
                    cryptoStream.Close();
                }
                memoryStream.Close();
            }
            return Convert.ToBase64String(cipherTextBytes);
        }

        public static string Decrypt(string encryptedText)
        {
            var cipherTextBytes = Convert.FromBase64String(encryptedText);
            var keyBytes = new Rfc2898DeriveBytes(_passwordHash, Encoding.ASCII.GetBytes(_saltKey)).GetBytes(256 / 8);
            var symmetricKey = new RijndaelManaged() { Mode = CipherMode.CBC, Padding = PaddingMode.None };

            var decryptor = symmetricKey.CreateDecryptor(keyBytes, Encoding.ASCII.GetBytes(_vIKey));
            var memoryStream = new MemoryStream(cipherTextBytes);
            var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read);
            byte[] plainTextBytes = new byte[cipherTextBytes.Length];

            int decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
            memoryStream.Close();
            cryptoStream.Close();
            return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount).TrimEnd("\0".ToCharArray());
        }
    }
}