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

public static class CryptoUtil
{
    private static readonly string Key = "7gT9KfL2xQ1bN4pV6sH8jD3zW0cR5mYq"; // 32바이트
    private static readonly string IV = "aB3dE6gH9jK2mP5Q";                // 16바이트

    public static string Encrypt(string plainText)
    {
        using (Aes aes = Aes.Create())
        {
            aes.Key = Encoding.UTF8.GetBytes(Key);
            aes.IV = Encoding.UTF8.GetBytes(IV);

            using (var ms = new MemoryStream())
            using (var cs = new CryptoStream(ms, aes.CreateEncryptor(), CryptoStreamMode.Write))
            using (var sw = new StreamWriter(cs))
            {
                sw.Write(plainText);
                sw.Close();
                return Convert.ToBase64String(ms.ToArray());
            }
        }
    }

    public static string Decrypt(string cipherText)
    {
        byte[] buffer = Convert.FromBase64String(cipherText);

        using (Aes aes = Aes.Create())
        {
            aes.Key = Encoding.UTF8.GetBytes(Key);
            aes.IV = Encoding.UTF8.GetBytes(IV);

            using (var ms = new MemoryStream(buffer))
            using (var cs = new CryptoStream(ms, aes.CreateDecryptor(), CryptoStreamMode.Read))
            using (var sr = new StreamReader(cs))
            {
                return sr.ReadToEnd();
            }
        }
    }

    public static void Save(object data, string filename)
    {
        string json = JsonConvert.SerializeObject(data);

        // 암호화
        string encrypted = Encrypt(json);

        string path = Path.Combine(Application.persistentDataPath, filename);
        File.WriteAllText(path, encrypted);

        //Debug.Log("Saved to: " + path);
    }

    public static T Load<T>(string filename)
    {
        string path = Path.Combine(Application.persistentDataPath, filename);

        if (File.Exists(path) == false)
            return default;

        string encrypted = File.ReadAllText(path);

        string json = Decrypt(encrypted);

        return JsonConvert.DeserializeObject<T>(json, new JsonSerializerSettings
        {
            ObjectCreationHandling = ObjectCreationHandling.Replace
        });
    }

    public static void Del(string filename)
    {
        string path = Path.Combine(Application.persistentDataPath, filename);
        File.Delete(path);
    }
}