using System.Security.Cryptography;

namespace Common;

/// <summary>
/// 与目标服务器通信将会加密
/// </summary>
public class AESHelper
{
    static readonly byte[] Key =
    [
        0x11,
        0xF2,
        0xAF,
        0xCF,
        0xFF,
        0x8B,
        0x4C,
        0x7D,
        0x23,
        0x96,
        0x1B,
        0x32,
        0x43,
        0xA4,
        0x55,
        0xF6,
        0x29,
        0x1C,
        0x1B,
        0x92,
        0x23,
        0x44,
        0xB5,
        0xF6,
        0x23,
        0x44,
        0xB5,
        0xF6,
        0x44,
        0xB5,
        0xF6,
        0x23,
    ];
    static readonly byte[] IV =
    [
        0xD1,
        0xF7,
        0xAB,
        0xCA,
        0xBC,
        0x7B,
        0x2C,
        0x3D,
        0xFA,
        0xAA,
        0xFC,
        0xA8,
        0x28,
        0x19,
        0x9C,
        0xB6,
    ];

    public static byte[] EncryptStringToBytes_Aes(string plainText)
    {
        // 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("IV");
        byte[] encrypted;

        // Create an Aes object
        // with the specified key and IV.
        using (Aes aesAlg = Aes.Create())
        {
            aesAlg.Key = Key;
            aesAlg.IV = IV;

            // Create an encryptor to perform the stream transform.
            ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);

            // Create the streams used for encryption.
            using (MemoryStream msEncrypt = new MemoryStream())
            {
                using (
                    CryptoStream csEncrypt = new CryptoStream(
                        msEncrypt,
                        encryptor,
                        CryptoStreamMode.Write
                    )
                )
                {
                    using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                    {
                        //Write all data to the stream.
                        swEncrypt.Write(plainText);
                    }
                    encrypted = msEncrypt.ToArray();
                }
            }
        }

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

    public static string DecryptStringFromBytes_Aes(byte[] cipherText)
    {
        // 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("IV");

        // Declare the string used to hold
        // the decrypted text.
        string plaintext = string.Empty;

        // Create an Aes object
        // with the specified key and IV.
        using (Aes aesAlg = Aes.Create())
        {
            aesAlg.Key = Key;
            aesAlg.IV = IV;

            // Create a decryptor to perform the stream transform.
            ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);

            // Create the streams used for decryption.
            using (MemoryStream msDecrypt = new MemoryStream(cipherText))
            {
                using (
                    CryptoStream csDecrypt = new CryptoStream(
                        msDecrypt,
                        decryptor,
                        CryptoStreamMode.Read
                    )
                )
                {
                    using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                    {
                        // Read the decrypted bytes from the decrypting stream
                        // and place them in a string.
                        plaintext = srDecrypt.ReadToEnd();
                    }
                }
            }
        }

        return plaintext;
    }
}