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

public class DecryptFileReader
{
    private static byte[] key = Encoding.UTF8.GetBytes("Sixteen byte key"); // 加密密钥，需与加密时一致
    private static byte[] iv = Encoding.UTF8.GetBytes("InitializationVe");  // 确保IV长度为16字节

    public static string ReadAndDecryptData(string filePath)
    {
        string fullPath = Path.Combine(Application.streamingAssetsPath, filePath);
        if (File.Exists(filePath)) return "";
        // 读取加密文件
        byte[] encryptedData = File.ReadAllBytes(fullPath);
        return ReadAndDecryptData(encryptedData);
    }


    public static string ReadAndDecryptData(byte[] encryptedData)
    {

        // 创建AES解密器
        using (Aes aesAlg = Aes.Create())
        {
            aesAlg.Key = key;
            aesAlg.IV = iv;

            ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);

            // 创建内存流和加密流
            using (MemoryStream msDecrypt = new MemoryStream(encryptedData))
            {
                using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                {
                    byte[] decryptedBytes = new byte[encryptedData.Length];
                    int decryptedByteCount = csDecrypt.Read(decryptedBytes, 0, decryptedBytes.Length);

                    // 将解密后的数据转换为字符串
                    string decryptedData = Encoding.UTF8.GetString(decryptedBytes, 0, decryptedByteCount);
                    return decryptedData;
                }
            }
        }
    }
}