using System;
using System.Collections;
using System.Collections.Generic;
using System.Security.Cryptography;
using System.Text;
using UnityEngine;

namespace WZ
{
    public static class EncryptionUtils
    {
        private static string GetKey(string packageName)
        {
            var keyBytes = Encoding.UTF8.GetBytes(packageName);
            byte[] keyHash;
            using (var md5 = MD5.Create())
            {
                keyHash = md5.ComputeHash(keyBytes);
            }
            return BitConverter.ToString(keyHash).Replace("-", "").ToUpper();
        }
        
        // Aes 加密
        public static string AesEncrypt(string packageName, string content)
        {
            string key = GetKey(packageName);
            var contentBytes = Encoding.UTF8.GetBytes(content);
            var keyBytes = Encoding.UTF8.GetBytes(key);
            byte[] keyHash;
            using (var md5 = MD5.Create())
            {
                keyHash = md5.ComputeHash(keyBytes);
            }
            using var aesAlg = Aes.Create();
            aesAlg.Key = keyHash;
            aesAlg.Mode = CipherMode.ECB;
            aesAlg.Padding = PaddingMode.PKCS7;
            var encryptor = aesAlg.CreateEncryptor();
            var encryptedBytes = encryptor.TransformFinalBlock(contentBytes, 0, contentBytes.Length);
            return BitConverter.ToString(encryptedBytes).Replace("-", "").ToLower();
        }

        // Aes 解密
        public static string AesDecrypt(string packageName, string encrypted)
        {
            string key = GetKey(packageName);
            var keyBytes = Encoding.UTF8.GetBytes(key);
            var encryptedBytes = new byte[encrypted.Length / 2];
            for (var i = 0; i < encryptedBytes.Length; i++)
            {
                encryptedBytes[i] = Convert.ToByte(encrypted.Substring(i * 2, 2), 16);
            }
            // 使用传统的MD5创建方式
            byte[] keyHash;
            using (var md5 = MD5.Create())
            {
                keyHash = md5.ComputeHash(keyBytes);
            }
            using var aesAlg = Aes.Create();
            aesAlg.Key = keyHash;
            aesAlg.Mode = CipherMode.ECB;
            aesAlg.Padding = PaddingMode.PKCS7;
            var decryptor = aesAlg.CreateDecryptor();
            var decryptedBytes = decryptor.TransformFinalBlock(encryptedBytes, 0, encryptedBytes.Length);
            return Encoding.UTF8.GetString(decryptedBytes);
        }
    }
}