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

public static class RSAHelper
{
    private static string publicKey =
        "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";
    private static string privateKey =
        "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";

    // 公钥加密
    public static string Encrypt(string plainText)
    {
        using (RSACryptoServiceProvider rsa = RSAHelper.CreateFromBase64PublicKey(publicKey))
        {
            byte[] data = Encoding.UTF8.GetBytes(plainText);
            byte[] enc = rsa.Encrypt(data, false);
            Debugger.Log(Convert.ToBase64String(rsa.Encrypt(Encoding.UTF8.GetBytes("{\"password\":\"111111\",\"deviceCode\":\"281a228fac1c29d25c1a3e572b15ad47d5f66811\",\"id\":777777}"),false)));
            return Convert.ToBase64String(enc);
        }
    }

    /// <summary>
    /// 将 Base64 公钥（DER 格式）转换成 RSACryptoServiceProvider 可用的 XML 公钥
    /// </summary>
    /// <param name="base64PublicKey">Base64 编码的 DER 公钥</param>
    /// <returns>RSACryptoServiceProvider 实例</returns>
    private static RSACryptoServiceProvider CreateFromBase64PublicKey(string base64PublicKey)
    {
        byte[] keyBytes = Convert.FromBase64String(base64PublicKey);

        // 解析 DER 格式的公钥，获取 Modulus 和 Exponent
        int offset = 0;
        if (keyBytes[offset++] != 0x30) throw new Exception("Invalid public key format");

        ReadLength(keyBytes, ref offset); // 跳过序列长度

        // 跳过算法标识部分
        if (keyBytes[offset++] != 0x30) throw new Exception("Invalid public key format");
        ReadLength(keyBytes, ref offset);
        offset += 13; // rsaEncryption OID + NULL

        if (keyBytes[offset++] != 0x03) throw new Exception("Invalid public key format");
        int bitStringLength = ReadLength(keyBytes, ref offset);
        offset++; // unused bits

        if (keyBytes[offset++] != 0x30) throw new Exception("Invalid public key format");
        ReadLength(keyBytes, ref offset);

        // 读取 Modulus
        if (keyBytes[offset++] != 0x02) throw new Exception("Invalid public key format");
        int modulusLength = ReadLength(keyBytes, ref offset);
        byte[] modulus = new byte[modulusLength];
        Array.Copy(keyBytes, offset, modulus, 0, modulusLength);
        offset += modulusLength;

        // 读取 Exponent
        if (keyBytes[offset++] != 0x02) throw new Exception("Invalid public key format");
        int exponentLength = ReadLength(keyBytes, ref offset);
        byte[] exponent = new byte[exponentLength];
        Array.Copy(keyBytes, offset, exponent, 0, exponentLength);

        // 构造 XML
        string xml = $"<RSAKeyValue><Modulus>{Convert.ToBase64String(modulus)}</Modulus><Exponent>{Convert.ToBase64String(exponent)}</Exponent></RSAKeyValue>";

        RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
        rsa.FromXmlString(xml);
        return rsa;
    }

    private static int ReadLength(byte[] data, ref int offset)
    {
        int length = data[offset++];
        if ((length & 0x80) == 0x80)
        {
            int bytesCount = length & 0x7F;
            length = 0;
            for (int i = 0; i < bytesCount; i++)
            {
                length = (length << 8) | data[offset++];
            }
        }
        return length;
    }

    // 私钥解密
    public static string Decrypt(string cipherText)
    {
        using (RSACryptoServiceProvider rsa = RSAHelper.CreateFromBase64PublicKey(privateKey))
        {
            byte[] data = Convert.FromBase64String(cipherText);
            byte[] dec = rsa.Decrypt(data, false);
            return Encoding.UTF8.GetString(dec);
        }
    }
}