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

namespace Hncore.Infrastructure.Common
{
    public class SecurityHelper
    {
        #region AES加密

        /// <summary>
        /// AES加密
        /// </summary>
        /// <param name="toEncrypt"></param>
        /// <returns></returns>
        public static string AESEncrypt(string toEncrypt, string key)
        {
            if (string.IsNullOrWhiteSpace(toEncrypt))
                return string.Empty;
            // 256-AES key    
            byte[] keyArray = UTF8Encoding.UTF8.GetBytes(key);
            byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);

            RijndaelManaged rDel = new RijndaelManaged();
            rDel.Key = keyArray;
            rDel.Mode = CipherMode.ECB;
            rDel.Padding = PaddingMode.PKCS7;

            ICryptoTransform cTransform = rDel.CreateEncryptor();
            byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);


            return Convert.ToBase64String(resultArray, 0, resultArray.Length);
        }

        #endregion

        #region AES解密

        /// <summary>
        /// AES解密
        /// </summary>
        /// <param name="toDecrypt"></param>
        /// <returns></returns>
        public static string Decrypt(string toDecrypt, string key)
        {
            if (string.IsNullOrWhiteSpace(toDecrypt))
                return string.Empty;
            try
            {
                // 256-AES key    
                byte[] keyArray = UTF8Encoding.UTF8.GetBytes(key);
                byte[] toEncryptArray = Convert.FromBase64String(toDecrypt);

                RijndaelManaged rDel = new RijndaelManaged();
                rDel.Key = keyArray;
                rDel.Mode = CipherMode.ECB;
                rDel.Padding = PaddingMode.PKCS7;

                ICryptoTransform cTransform = rDel.CreateDecryptor();


                byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
                return UTF8Encoding.UTF8.GetString(resultArray);
            }
            catch(Exception ex)
            {
                LogHelper.Error("aes Decrypt", ex.Message);
                return toDecrypt;
            }
        }

        #endregion

        #region MD5加密

        /// <summary>
        /// MD5加密
        /// </summary>
        /// <param name="input"></param>
        /// <returns></returns>
        public static string GetMd5Hash(string input, Encoding encoding = null)
        {
            if (encoding == null)
            {
                encoding = Encoding.UTF8;
            }


            MD5 myMD5 = new MD5CryptoServiceProvider();
            byte[] signed = myMD5.ComputeHash(encoding.GetBytes(input));
            string signResult = byte2mac(signed);
            return signResult.ToUpper();
        }

        //MD5加密方法
        private static string byte2mac(byte[] signed)
        {
            StringBuilder EnText = new StringBuilder();
            foreach (byte Byte in signed)
            {
                EnText.AppendFormat("{0:x2}", Byte);
            }

            return EnText.ToString();
        }

        #endregion

        #region 对字符串进行DES加密

        /// <summary>
        /// 对字符串进行DES加密
        /// </summary>
        /// <param name="sourceString">待加密的字符串</param>
        /// <returns>加密后的BASE64编码的字符串</returns>
        public static string DesEncrypt(string sourceString, string key, string iv)
        {
            byte[] btKey = Encoding.Default.GetBytes(key);
            byte[] btIV = Encoding.Default.GetBytes(iv);
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            using (MemoryStream ms = new MemoryStream())
            {
                byte[] inData = Encoding.Default.GetBytes(sourceString);
                using (CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(btKey, btIV), CryptoStreamMode.Write))
                {
                    cs.Write(inData, 0, inData.Length);
                    cs.FlushFinalBlock();
                }

                return Convert.ToBase64String(ms.ToArray());
            }
        }

        #endregion

        #region 对DES加密后的字符串进行解密

        /// <summary>
        /// 对DES加密后的字符串进行解密
        /// </summary>
        /// <param name="encryptedString">待解密的字符串</param>
        /// <returns>解密后的字符串</returns>
        public static string DesDecrypt(string encryptedString, string key, string iv)
        {
            byte[] btKey = Encoding.Default.GetBytes(key);
            byte[] btIV = Encoding.Default.GetBytes(iv);
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            using (MemoryStream ms = new MemoryStream())
            {
                byte[] inData = Convert.FromBase64String(encryptedString);
                using (CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(btKey, btIV), CryptoStreamMode.Write))
                {
                    cs.Write(inData, 0, inData.Length);
                    cs.FlushFinalBlock();
                }

                return Encoding.Default.GetString(ms.ToArray());
            }
        }

        #endregion


        public static string Sha1(string str)
        {
            SHA1 sha1 = new SHA1CryptoServiceProvider();

            byte[] bytes_in = Encoding.UTF8.GetBytes(str);
            byte[] bytes_out = sha1.ComputeHash(bytes_in);
            sha1.Dispose();

            var sb = new StringBuilder();
            foreach (byte b in bytes_out)
            {
                sb.Append(b.ToString("x2"));
            }

            return sb.ToString();
        }

        public static string HMACSHA1(string text, string key)
        {
            HMACSHA1 myhmacsha1 = new HMACSHA1(Encoding.UTF8.GetBytes(key));
            byte[] byteArray = Encoding.UTF8.GetBytes(text);
            MemoryStream stream = new MemoryStream(byteArray);
            string signature = Convert.ToBase64String(myhmacsha1.ComputeHash(stream));

            return signature;
        }

        #region  JS Aes解密

        /// <summary>
        /// JS Aes解密
        /// </summary>
        /// <param name="toDecrypt"></param>
        /// <param name="key"></param>
        /// <param name="iv"></param>
        /// <returns></returns>
        public static string JsAesDecrypt(string toDecrypt, string key, string iv)
        {
            byte[] keyArray = UTF8Encoding.UTF8.GetBytes(key);
            byte[] ivArray = UTF8Encoding.UTF8.GetBytes(iv);
            byte[] cipherText = HexToByteArray(toDecrypt);
            // Check arguments.
            if (cipherText == null || cipherText.Length <= 0)
            {
                throw new ArgumentNullException("cipherText");
            }

            if (key == null || key.Length <= 0)
            {
                throw new ArgumentNullException("key");
            }

            if (iv == null || iv.Length <= 0)
            {
                throw new ArgumentNullException("key");
            }

            string plaintext = null;
            using (var rijAlg = new RijndaelManaged())
            {
                //Settings
                rijAlg.Mode = CipherMode.CBC;
                rijAlg.Padding = PaddingMode.PKCS7;
                rijAlg.FeedbackSize = 128;

                rijAlg.Key = keyArray;
                rijAlg.IV = ivArray;

                var decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.IV);

                using (var msDecrypt = new MemoryStream(cipherText))
                {
                    using (var csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                    {
                        using (var srDecrypt = new StreamReader(csDecrypt))
                        {
                            plaintext = srDecrypt.ReadToEnd();
                        }
                    }
                }
            }

            return plaintext;
        }

        private static byte[] HexToByteArray(string hex)
        {
            int NumberChars = hex.Length;
            byte[] bytes = new byte[NumberChars / 2];
            for (int i = 0; i < NumberChars; i += 2)
                bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);
            return bytes;
        }

        #endregion

        #region JS Aes 加密

        /// <summary>
        /// JsAesEncrypt
        /// </summary>
        /// <param name="plainText"></param>
        /// <param name="key"></param>
        /// <param name="iv"></param>
        /// <returns></returns>
        public static string JsAesEncrypt(string plainText, string key, string iv)
        {
            byte[] keyArray = UTF8Encoding.UTF8.GetBytes(key);
            byte[] ivArray = UTF8Encoding.UTF8.GetBytes(iv);

            // Check arguments.
            if (plainText == null || plainText.Length <= 0)
            {
                throw new ArgumentNullException("plainText");
            }

            if (key == null || key.Length <= 0)
            {
                throw new ArgumentNullException("key");
            }

            if (iv == null || iv.Length <= 0)
            {
                throw new ArgumentNullException("key");
            }

            byte[] encrypted;
            using (var rijAlg = new RijndaelManaged())
            {
                rijAlg.Mode = CipherMode.CBC;
                rijAlg.Padding = PaddingMode.PKCS7;
                rijAlg.FeedbackSize = 128;

                rijAlg.Key = keyArray;
                rijAlg.IV = ivArray;

                var encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV);
                using (var msEncrypt = new MemoryStream())
                {
                    using (var csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
                    {
                        using (var swEncrypt = new StreamWriter(csEncrypt))
                        {
                            swEncrypt.Write(plainText);
                        }

                        encrypted = msEncrypt.ToArray();
                    }
                }
            }

            // Return the encrypted bytes from the memory stream.
            return ByteArrayToHex(encrypted);
        }

        private static string ByteArrayToHex(byte[] ba)
        {
            string hex = BitConverter.ToString(ba);
            return hex.Replace("-", "");
        }

        #endregion

        #region 加密隐藏信息（将原信息其中一部分数据替换为特殊字符）

        /// <summary>
        /// 加密隐藏信息（将原信息其中一部分数据替换为特殊字符）
        /// </summary>
        /// <param name="param">原参数信息</param>
        /// <param name="key">更换后的特殊字符</param>
        /// <param name="index">下标</param>
        /// <param name="length">位数,-1代表到队尾</param>
        /// <returns></returns>
        public static string Encrypt(string param, string key, int index, int length = -1)
        {
            if (string.IsNullOrEmpty(param))
            {
                return "";
            }

            string str = "";
            if (index > param.Length - 1)
            {
                return param;
            }

            str = param.Substring(0, index);
            if (length == -1)
            {
                length = param.Length - index;
            }

            for (int i = 0; i < length; i++)
            {
                str += key;
            }

            if (index + length < param.Length)
            {
                str += param.Substring(index + length);
            }

            return str;
        }

        #endregion


        /// <summary>
        /// 将密码使用MD5算法求哈希值
        /// </summary>
        /// <param name="password"></param>
        /// <returns></returns>
        public static string HashPassword(string password)
        {
            using (MD5 md5 = MD5.Create())
            {
                byte[] bytes = md5.ComputeHash(Encoding.UTF8.GetBytes(password));
                return Convert.ToBase64String(bytes);
            }
        }
    }
}