using System;
using System.IO;
using System.Text;
using YooAsset;

/// <summary>
/// 文件偏移加密方式
/// </summary>
public class FileOffsetEncryption : IEncryptionServices
{
    public EncryptResult Encrypt(EncryptFileInfo fileInfo)
    {
        // 注意：只对音频资源包加密
        if (fileInfo.BundleName.Contains("_gameres_audio"))
        {
            int offset = 32;
            byte[] fileData = File.ReadAllBytes(fileInfo.FileLoadPath);
            var encryptedData = new byte[fileData.Length + offset];
            Buffer.BlockCopy(fileData, 0, encryptedData, offset, fileData.Length);

            EncryptResult result = new EncryptResult();
            result.Encrypted = true;
            result.EncryptedData = encryptedData;
            return result;
        }
        else
        {
            EncryptResult result = new EncryptResult();
            result.Encrypted = false;
            return result;
        }
    }
}

/// <summary>
/// 文件流加密方式
/// </summary>
public class FileStreamEncryption : IEncryptionServices
{
    public EncryptResult Encrypt(EncryptFileInfo fileInfo)
    {
        if (fileInfo.BundleName.Contains("_gameres_audio"))
        {
            var fileData = File.ReadAllBytes(fileInfo.FileLoadPath);
            for (int i = 0; i < fileData.Length; i++)
            {
                fileData[i] ^= BundleStream.KEY;
            }

            EncryptResult result = new EncryptResult();
            result.Encrypted = true;
            result.EncryptedData = fileData;
            return result;
        }
        else
        {
            EncryptResult result = new EncryptResult();
            result.Encrypted = false;
            return result;
        }
    }
}