using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Parameters;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;
using WX.CRM.Common;

namespace WX.CRM.BLL.Util
{
    public class MSecurityHelper
    {
        public MSecurityHelper()
        {
        }

        /// <summary>
        /// 内容根据公钥加密
        /// </summary>
        /// <param name="plainText"></param>
        /// <returns></returns>
        public string content(string plainText, string publicKeyXml)
        {
            //string publicKeyXml = PemToXml(publicKey, false);

            // 创建 RSA 实例
            using (var rsa = new RSACryptoServiceProvider())
            {
                rsa.FromXmlString(publicKeyXml);
                // 将明文转换为字节数组
                var plainBytes = Encoding.UTF8.GetBytes(plainText);

                // 使用公钥加密
                var encryptedBytes = rsa.Encrypt(plainBytes, false);

                // 将加密后的字节数组转换为 Base64 字符串
                var encryptedText = Convert.ToBase64String(encryptedBytes);
                return encryptedText;
            }
        }

        /// <summary>
        /// 根据加密内容 私钥 生成签名
        /// </summary>
        /// <param name="content"></param>
        /// <returns></returns>
        public string sign(string content, string privateKeyXml)
        {
            //string privateKeyXml = PemToXml(privateKey, true);

            var rsa = new RSACryptoServiceProvider();
            rsa.FromXmlString(privateKeyXml);
            //签名返回
            using (var sha256 = new SHA256CryptoServiceProvider())
            {
                var signData = rsa.SignData(Encoding.UTF8.GetBytes(content), sha256);
                return Convert.ToBase64String(signData);
            }
        }

        /// <summary>
        /// 根据私钥解密出key
        /// </summary>
        /// <param name="plainText"></param>
        /// <returns></returns>
        public string decyptContent(string plainText, string privateKeyXml)
        {
            //string privateKeyXml = PemToXml(privateKey, true);

            // 创建 RSA 实例
            using (var rsa = new RSACryptoServiceProvider())
            {
                rsa.FromXmlString(privateKeyXml);
                // 将明文转换为字节数组
                var plainBytes = Convert.FromBase64String(plainText);

                // 使用公钥加密
                var encryptedBytes = rsa.Decrypt(plainBytes, false);
                Encoding encoding = Encoding.UTF8;  // 使用UTF-8编码方式
                string str = encoding.GetString(encryptedBytes);
                return str.ToString();
            }
        }

        /// <summary>
        /// 根据公钥验证签名
        /// </summary>
        /// <param name="sign"></param>
        /// <param name="content"></param>
        /// <returns></returns>
        public string decyptSign(string sign, string content, string publicKeyXml, string privateKeyXml)
        {
            //string publicKeyXml = PemToXml(publicKey, false);

            var rsa = new RSACryptoServiceProvider();
            rsa.FromXmlString(publicKeyXml);
            //签名返回
            using (var sha256 = new SHA256CryptoServiceProvider())
            {
                var cipherbytes = rsa.VerifyData(Encoding.UTF8.GetBytes(content), sha256, Convert.FromBase64String(sign));
                if (cipherbytes)
                {
                    return decyptContent(content, privateKeyXml);
                }
                throw new Exception("验证参数失败");
            }
        }

        /// <summary>
        /// Pem格式密钥转换成Xml格式密钥
        /// </summary>
        /// <param name="pemKey">Pem格式密钥（公钥或私钥）</param>
        /// <param name="isPrivateKey">是否是私钥</param>
        /// <returns>转换后的Xml格式密钥（公钥或私钥）</returns>
        public string PemToXml(string pemKey, bool isPrivateKey)
        {
            string rsaKey = string.Empty;
            object pemObject = null;
            RSAParameters rsaPara = new RSAParameters();
            using (StringReader sReader = new StringReader(pemKey))
            {
                var pemReader = new Org.BouncyCastle.OpenSsl.PemReader(sReader);
                pemObject = pemReader.ReadObject();
            }
            //私钥
            if (isPrivateKey)
            {
                RsaPrivateCrtKeyParameters key = (RsaPrivateCrtKeyParameters)((AsymmetricCipherKeyPair)pemObject).Private;
                rsaPara = new RSAParameters
                {
                    Modulus = key.Modulus.ToByteArrayUnsigned(),
                    Exponent = key.PublicExponent.ToByteArrayUnsigned(),
                    D = key.Exponent.ToByteArrayUnsigned(),
                    P = key.P.ToByteArrayUnsigned(),
                    Q = key.Q.ToByteArrayUnsigned(),
                    DP = key.DP.ToByteArrayUnsigned(),
                    DQ = key.DQ.ToByteArrayUnsigned(),
                    InverseQ = key.QInv.ToByteArrayUnsigned(),
                };
            }
            //公钥
            else
            {
                RsaKeyParameters key = (RsaKeyParameters)pemObject;
                rsaPara = new RSAParameters
                {
                    Modulus = key.Modulus.ToByteArrayUnsigned(),
                    Exponent = key.Exponent.ToByteArrayUnsigned(),
                };
            }
            RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
            rsa.ImportParameters(rsaPara);
            using (StringWriter sw = new StringWriter())
            {
                sw.Write(rsa.ToXmlString(isPrivateKey ? true : false));
                rsaKey = sw.ToString();
            }
            return rsaKey;
        }
    }

    public class SignReturnData
    {
        public string content { get; set; }
        public string sign { get; set; }
    }

    public class MidData
    {
        public int? code { get; set; }
        public string data { get; set; }
        public string message { get; set; }
    }
}