using Alchemy.Core.Extensions;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using System.Text;
namespace Alchemy.Core.Services
{
    public class CryptoService
    {
        /// <summary>
        /// 将一条十六进制字符串转换为ASCII
        /// </summary>
        /// <param name="hexstring">一条十六进制字符串</param>
        /// <returns>返回一条ASCII码</returns>
        public static string HexStringToASCII(string hexstring)
        {
            byte[] bt = HexStringToBinary(hexstring);
            string lin = "";
            for (int i = 0; i < bt.Length; i++)
            {
                lin = lin + bt[i] + " ";
            }
            string[] ss = lin.Trim().Split(new char[] { ' ' });
            char[] c = new char[ss.Length];
            int a;
            for (int i = 0; i < c.Length; i++)
            {
                a = Convert.ToInt32(ss[i]);
                c[i] = Convert.ToChar(a);
            }
            string b = new string(c);
            return b;
        }
        /**/
        /// <summary>
        /// 16进制字符串转换为二进制数组
        /// </summary>
        /// <param name="hexstring">字符串每个字节之间都应该有空格，大多数的串口通讯资料上面的16进制都是字节之间都是用空格来分割的。</param>
        /// <returns>返回一个二进制字符串</returns>
        public static byte[] HexStringToBinary(string hexstring)
        {
            string[] tmpary = hexstring.Trim().Split(' ');
            byte[] buff = new byte[tmpary.Length];
            for (int i = 0; i < buff.Length; i++)
            {
                buff[i] = Convert.ToByte(tmpary[i], 16);
            }
            return buff;
        }
        /// <summary>
        /// AES 解密
        /// </summary>
        /// <param name="strEncoded"></param>
        /// <param name="strKey"></param>
        /// <returns></returns>
        public static string DecodeAes(string strEncoded, string strKey)
        {
            string strResult = string.Empty;
            byte[] encryptedBytes = Convert.FromBase64String(strEncoded);
            byte[] keyBytes = Encoding.UTF8.GetBytes(strKey);
            using (Aes aes = Aes.Create())
            {
                aes.Key = keyBytes;
                aes.IV = new byte[aes.BlockSize / 8];
                using (MemoryStream memStream = new MemoryStream())
                {
                    using (CryptoStream cryptoStream = new CryptoStream(memStream, aes.CreateDecryptor(), CryptoStreamMode.Write))
                    {
                        cryptoStream.Write(encryptedBytes, 0, encryptedBytes.Length);
                        cryptoStream.FlushFinalBlock();
                        byte[] decryptedBytes = memStream.ToArray();
                        strResult = Encoding.UTF8.GetString(decryptedBytes);
                    }
                }
            }
            return strResult;
        }
        /// <summary>
        /// 唯一识别ID加密算法
        /// </summary>
        /// <param name="numID"></param>
        /// <param name="strString"></param>
        /// <returns></returns>
        public static string EncodeUniqId(int numID, string strString)
        {
            string strUserIDHashed = EncodeMD5(numID.ToString());
            string strUserNameHashed = EncodeMD5(strString);
            string strDatetimeHashed = EncodeMD5(DateTimeService.Now());
            string value = EncodeMD5(EncodeBase64(strUserIDHashed + strUserNameHashed + strDatetimeHashed));
            return value;
        }
        /// <summary>
        /// 用户密码加密算法，使用基础加密算法
        /// </summary>
        /// <param name="strPwd">输入未加密的密码</param>
        /// <returns></returns>
        public static string EncodeUserPwd(string strPwd)
        {
            //string value = EncodeMD5(EncodeBase64(EncodeMD5(strPwd)));
            return EncodeMD5(strPwd);
        }
        /// <summary>
        /// 基础加密算法，先MD5再Base64再MD5
        /// </summary>
        /// <param name="strData">输入未加密的数据</param>
        /// <returns></returns>
        public static string EncodeBasicCrypto(string strData)
        {
            string value = EncodeMD5(EncodeBase64(EncodeMD5(strData)));
            return value;
        }
        /// <summary>
        /// 不安全加密算法，3次Base64
        /// </summary>
        /// <param name="strData"></param>
        /// <returns></returns>
        public static string EncodeUnsafeCrypto(string strData)
        {
            string value = EncodeBase64(EncodeBase64(EncodeBase64(strData)));
            return value;
        }
        public static string DecodeUnsafeCrypto(string strData)
        {
            string value = DecodeBase64(DecodeBase64(DecodeBase64(strData)));
            return value;
        }
        /// <summary>
        /// MD5加密，输出32位小写
        /// </summary>
        /// <param name="strData">输入字符串</param>
        /// <returns></returns>
        public static string EncodeMD5(string strData)
        {
            MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
            byte[] bytValue, bytHash;
            bytValue = Encoding.UTF8.GetBytes(strData);
            bytHash = md5.ComputeHash(bytValue);
            md5.Clear();
            string sTemp = "";
            for (int i = 0; i < bytHash.Length; i++)
            {
                sTemp += bytHash[i].ToString("X").PadLeft(2, '0');
            }
            return sTemp.ToLower();
        }
        /// <summary>
        /// Base64加密
        /// </summary>
        /// <param name="strData">输入字符串</param>
        /// <returns></returns>
        public static string EncodeBase64(string strData)
        {
            byte[] arrData = Encoding.UTF8.GetBytes(strData);
            string strBase64 = Convert.ToBase64String(arrData);
            return strBase64;
        }
        /// <summary>
        /// Base64解密
        /// </summary>
        /// <param name="strData">输入字符串</param>
        /// <returns></returns>
        public static string DecodeBase64(string strData)
        {
            string strRaw = string.Empty;
            try
            {
                byte[] bytes = Convert.FromBase64String(strData);
                strRaw = Encoding.UTF8.GetString(bytes);
            }
            catch (Exception ex)
            {
                //throw new Exception(ex.Message);
                strRaw = strData;
            }
            return strRaw;
        }
        /// <summary>
        /// HMACSHA256加密算法
        /// </summary>
        /// <param name="strData"></param>
        /// <param name="strSecret"></param>
        /// <returns></returns>
        public static string EncodeHMACSHA256forWx(string strSecret)
        {
            return EncodeHMACSHA256("", strSecret);
        }
        /// <summary>
        /// 
        /// </summary>
        /// <param name="strData"></param>
        /// <param name="strSecret"></param>
        /// <returns></returns>
        public static string EncodeHMACSHA256(string strData, string strSecret)
        {
            // 1. 将密钥字符串转换为UTF-8字节数组（不进行Base64解码）
            byte[] keyBytes = Encoding.UTF8.GetBytes(strSecret);

            // 2. 处理空字符串：使用空字节数组
            byte[] dataBytes = string.IsNullOrEmpty(strData)
                ? new byte[0]
                : Encoding.UTF8.GetBytes(strData);

            // 3. 计算HMAC-SHA256
            using var hmac = new HMACSHA256(keyBytes);
            byte[] hashBytes = hmac.ComputeHash(dataBytes);

            // 4. 转换为小写十六进制字符串
            return Convert.ToHexString(hashBytes).ToLowerInvariant();
        }
        /// <summary>
        /// 生成短链接
        /// </summary>
        /// <param name="strKey"></param>
        /// <param name="len"></param>
        /// <returns></returns>
        public static string EncodeShortUrl(string strKey, int len = 6)
        {
            string value = string.Empty;
            List<string> listFilter = new List<string>();
            listFilter.Add("o");
            listFilter.Add("0");
            listFilter.Add("O");
            listFilter.Add("I");
            listFilter.Add("l");
            listFilter.Add("i");
            listFilter.Add("1");
            for (int i = 0; i < len; i++)
            {
                string strChar = EncodeMD5(strKey + Guid.NewGuid().ToString()).ToUpper().Substring(i, 1);
                while (!listFilter.Contains(strChar))
                {
                    strChar = EncodeMD5(strKey + Guid.NewGuid().ToString()).ToUpper().Substring(i, 1);
                }
                value += strChar;
            }
            return value;
        }
        /// <summary>
        /// 生成外部订单号
        /// </summary>
        /// <param name="strPrefix"></param>
        /// <returns></returns>
        public static string EncodeOutTradeNo(string strPrefix)
        {
            return strPrefix + EncodeUniqId(9999, Guid.NewGuid().ToString()).ToUpper();
        }
        /// <summary>
        /// RSA加密
        /// </summary>
        /// <param name="text"></param>
        /// <param name="publicKey"></param>
        /// <returns></returns>
        public static string EncodeRSA(string text, byte[] publicKey)
        {
            using (var x509 = new X509Certificate2(publicKey))
            {
                using (var rsa = (RSACryptoServiceProvider)x509.PublicKey.Key)
                {
                    var buff = rsa.Encrypt(Encoding.UTF8.GetBytes(text), true);
                    return Convert.ToBase64String(buff);
                }
            }
        }
        /// <summary>
        /// 计算文件的 MD5 值
        /// </summary>
        /// <param name="fileName">要计算 MD5 值的文件名和路径</param>
        /// <returns>MD5 值16进制字符串</returns>
        //public static string EncodeMd5FileHash(string fileName)
        //{
        //    return HashFile(fileName, "md5");
        //}
        /// <summary>
        /// 计算文件的哈希值
        /// </summary>
        /// <param name="fileName">要计算哈希值的文件名和路径</param>
        /// <param name="algName">算法:sha1,md5</param>
        /// <returns>哈希值16进制字符串</returns>
        //private static string HashFile(string fileName, string algName)
        //{
        //    if (!File.Exists(fileName))
        //        return string.Empty;
        //    FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);
        //    byte[] hashBytes = HashData(fs, algName);
        //    fs.Close();
        //    return ConvertService.ByteArrayToHexString(hashBytes);
        //}
        /// <summary>
        /// 计算哈希值
        /// </summary>
        /// <param name="stream">要计算哈希值的 Stream</param>
        /// <param name="algName">算法:sha1,md5</param>
        /// <returns>哈希值字节数组</returns>
        private static byte[] HashData(Stream stream, string algName)
        {
            HashAlgorithm algorithm;
            if (algName.IsNull())
            {
                throw new ArgumentNullException("algName 不能为 null");
            }
            if (string.Compare(algName, "sha1", true) == 0)
            {
                algorithm = SHA1.Create();
            }
            else
            {
                if (string.Compare(algName, "md5", true) != 0)
                {
                    throw new Exception("algName 只能使用 sha1 或 md5");
                }
                algorithm = MD5.Create();
            }
            return algorithm.ComputeHash(stream);
        }
    }
}