using System;
using System.Security.Cryptography;
using System.Text;
using WX.Interface.Security;

namespace WX.CRM.Common
{
    public class AESHelper
    {
        public static string Decrypt(string text, string key)
        {
            try
            {
                byte[] encryptedData = strToHexByte(text);
                RijndaelManaged rijndaelCipher = new RijndaelManaged();
                rijndaelCipher.Key = Encoding.UTF8.GetBytes(key);
                rijndaelCipher.Mode = CipherMode.ECB;
                rijndaelCipher.Padding = PaddingMode.None;
                ICryptoTransform transform = rijndaelCipher.CreateDecryptor();
                byte[] plainText = transform.TransformFinalBlock(encryptedData, 0, encryptedData.Length);
                string result = Encoding.Default.GetString(plainText);
                return result;

            }
            catch (Exception ex)
            {
                return null;
            }
        }

        public static string Encrypt(string text, string key)
        {
            try
            {
                byte[] encryptedData = Encoding.UTF8.GetBytes(text);
                encryptedData = padding(encryptedData);
                RijndaelManaged rijndaelCipher = new RijndaelManaged();
                rijndaelCipher.Key = Encoding.UTF8.GetBytes(key);
                rijndaelCipher.Mode = CipherMode.ECB;
                rijndaelCipher.Padding = PaddingMode.None;
                ICryptoTransform transform = rijndaelCipher.CreateEncryptor();
                byte[] plainText = transform.TransformFinalBlock(encryptedData, 0, encryptedData.Length);
                return byteToHexStr(plainText);
            }
            catch (Exception ex)
            {
                return null;
            }
        }
        // 坐席那边的解密函数，拿过来用
        public static string decyptData(string cryptograph, string clientId)
        {
            try
            {
                ClientKey client = ClientKey.GetClientKey(clientId);
                if (client == null)
                    throw new Exception("非法客户端访问");
                var accessKey = client.AccessKey;
                SymmetricAlgorithm des = new DESCryptoServiceProvider();

                Encoding utf = new UTF8Encoding();
                byte[] key = utf.GetBytes(accessKey);
                byte[] iv = { 0x75, 0x70, 0x63, 0x68, 0x69, 0x6e, 0x61, 0x31 };
                ICryptoTransform decryptor = des.CreateDecryptor(key, iv);
                byte[] encData = Convert.FromBase64String(cryptograph);
                byte[] data = decryptor.TransformFinalBlock(encData, 0, encData.Length);
                return utf.GetString(data);
            }
            catch (Exception ex)
            {
                return null;
            }
        }
        // 坐席那边的加密函数，拿过来用
        public static string encyptData(string ciphertext, string clientId)
        {
            ClientKey client = ClientKey.GetClientKey(clientId);
            if (client == null)
                throw new Exception("非法客户端访问");
            var accessKey = client.AccessKey;
            SymmetricAlgorithm des = new DESCryptoServiceProvider();

            Encoding utf = new UTF8Encoding();
            byte[] key = utf.GetBytes(accessKey);
            byte[] iv = { 0x75, 0x70, 0x63, 0x68, 0x69, 0x6e, 0x61, 0x31 };
            ICryptoTransform encryptor = des.CreateEncryptor(key, iv);
            byte[] data = utf.GetBytes(ciphertext);
            byte[] encData = encryptor.TransformFinalBlock(data, 0, data.Length);
            return Convert.ToBase64String(encData);
        }
        private static byte[] strToHexByte(string hexString)
        {
            hexString = hexString.Replace(" ", "");
            if ((hexString.Length % 2) != 0)
                hexString += " ";
            byte[] returnBytes = new byte[hexString.Length / 2];
            for (int i = 0; i < returnBytes.Length; i++)
                returnBytes[i] = Convert.ToByte(hexString.Substring(i * 2, 2), 16);
            return returnBytes;
        }


        private static byte[] padding(byte[] src)
        {
            if (src.Length % 16 == 0)
            {
                return src;
            }
            byte[] buffer = new byte[src.Length / 16 * 16 + 16];
            System.Array.Copy(src, 0, buffer, 0, src.Length);
            return buffer;
        }

        private static string byteToHexStr(byte[] bytes)
        {
            string hexString = string.Empty;
            if (bytes != null)
            {
                StringBuilder strB = new StringBuilder();
                for (int i = 0; i < bytes.Length; i++)
                {
                    strB.Append(bytes[i].ToString("X2"));
                }
                hexString = strB.ToString();
            }
            return hexString.ToLower();
        }
    }
}