using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Web;

namespace Neo.Legitimate.NLTISWebService.Data
{
    public class CryptoProvider
    {
        public static byte[] Decrypt(byte[] key, byte[] iv, byte[] encryptedData)
        {
            SymmetricAlgorithm csp = new RijndaelManaged();
            ICryptoTransform decryptor = csp.CreateDecryptor(key, iv);
            byte[] result;
            using (MemoryStream ms = new MemoryStream())
            {
                using (CryptoStream cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Write))
                {
                    cs.Write(encryptedData, 0, encryptedData.Length);
                    cs.FlushFinalBlock();
                    byte[] data = ms.ToArray();
                    cs.Clear();
                    result = data;
                }
            }
            return result;
        }

        public static string Decrypt(string key, string iv, string cipher)
        {
	        byte[] keyBuffer = Convert.FromBase64String(key);
	        byte[] ivBuffer = Convert.FromBase64String(iv);
	        byte[] encryptedData = Convert.FromBase64String(cipher);
	        byte[] decryptedData = CryptoProvider.Decrypt(keyBuffer, ivBuffer, encryptedData);
	        return (decryptedData == null) ? null : Encoding.UTF8.GetString(decryptedData);
        }

        public static byte[] Encrypt(byte[] key, byte[] iv, byte[] data)
        {
            SymmetricAlgorithm csp = new RijndaelManaged();
            ICryptoTransform encryptor = csp.CreateEncryptor(key, iv);
            byte[] result;
            using (MemoryStream ms = new MemoryStream())
            {
                using (CryptoStream cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write))
                {
                    cs.Write(data, 0, data.Length);
                    cs.FlushFinalBlock();
                    byte[] encryptedData = ms.ToArray();
                    cs.Clear();
                    result = encryptedData;
                }
            }
            return result;
        }

        public static string Encrypt(string key, string iv, string plainText)
        {
            byte[] keyBuffer = Convert.FromBase64String(key);
            byte[] ivBuffer = Convert.FromBase64String(iv);
            byte[] data = Encoding.UTF8.GetBytes(plainText);
            byte[] encryptedData = CryptoProvider.Encrypt(keyBuffer, ivBuffer, data);
            return Convert.ToBase64String(encryptedData);
        }

    }
}