[Unity] 세이브 로드 마이그레이션

using System.Collections.Generic;
using UnityEngine;

public abstract class SaveData
{
    public int Version { get; set; }
    public abstract SaveData VersionUp();
}

public class SaveDataV1 : SaveData
{
    public int CurrentDay { get; set; } = 1;
    public int HungerEmptyCount { get; set; } = 0;
    public int CurrentHp { get; set; } = 100;

    public SaveDataV1()
    {
        Version = 1;
    }

    public override SaveData VersionUp()
    {
        return new SaveDataV2
        {
            Version = 2,
            CurrentDay = CurrentDay,
            HungerEmptyCount = HungerEmptyCount,
            CurrentHp = CurrentHp,
            Inventory = new(),
            Storage = new(),
        };
    }
}

public class SaveDataV2 : SaveDataV1
{
    public List<SaveSlotData> Inventory { get; set; } = new();
    public List<SaveSlotData> Storage { get; set; } = new();

    public SaveDataV2()
    {
        Version = 2;
    }

    public override SaveData VersionUp()
    {
        return new SaveDataV3
        {
            Version = 3,
            CurrentDay = CurrentDay,
            HungerEmptyCount = HungerEmptyCount,
            CurrentHp = CurrentHp,
            Inventory = Inventory,
            Storage = Storage,
            TributeLevel = 0,
            CurrentTributeLevel = 0,
            TributeRequirementID = "",
            TributeSubmitted = new(),
        };
    }
}

public class SaveDataV3 : SaveDataV2
{
    public int TributeLevel { get; set; } = 0;
    public int CurrentTributeLevel { get; set; } = 0;
    public string TributeRequirementID { get; set; } = "";
    public List<int> TributeSubmitted { get; set; } = new();

    public SaveDataV3()
    {
        Version = 3;
    }

    public override SaveData VersionUp()
    {
        return this;
    }
}

using System.IO;
using Newtonsoft.Json;
using UnityEngine;
using SaveDataVC = SaveDataV5;

public static class SaveLoadManager
{
    public enum SaveMode
    {
        Text, // .json
        Encrypted, // .dat
    }

    public static SaveMode Mode { get; set; } = SaveMode.Text; // 여기서 모드 전환

    private static readonly int SaveDataVersion = 5;
    private static readonly string SaveDirectory = Path.Combine(
        Application.persistentDataPath,
        "Save"
    );

    private static readonly JsonSerializerSettings Settings = new JsonSerializerSettings
    {
        Formatting = Formatting.Indented,
        TypeNameHandling = TypeNameHandling.All,
    };

    public static SaveDataVC Data { get; set; } = new SaveDataVC();

    private static string SaveFilePath =>
        Mode == SaveMode.Text
            ? Path.Combine(SaveDirectory, "SaveAuto.json")
            : Path.Combine(SaveDirectory, "SaveAuto.dat");

    public static void Init()
    {
        Load();
    }

    public static bool Save()
    {
        if (Data == null)
            return false;

        try
        {
            if (!Directory.Exists(SaveDirectory))
                Directory.CreateDirectory(SaveDirectory);

            string json = JsonConvert.SerializeObject(Data, Settings);

            if (Mode == SaveMode.Text)
                File.WriteAllText(SaveFilePath, json);
            else
                File.WriteAllBytes(SaveFilePath, CryptoUtil.Encrypt(json));

            return true;
        }
        catch
        {
            Debug.LogError("[SaveLoadManager] Save 실패");
            return false;
        }
    }

    public static bool Load()
    {
        if (!File.Exists(SaveFilePath))
            return false;

        try
        {
            string json;

            if (Mode == SaveMode.Text)
                json = File.ReadAllText(SaveFilePath);
            else
                json = CryptoUtil.Decrypt(File.ReadAllBytes(SaveFilePath));

            SaveData saveData = JsonConvert.DeserializeObject<SaveData>(json, Settings);

            while (saveData.Version < SaveDataVersion)
                saveData = saveData.VersionUp();

            Data = saveData as SaveDataVC;
            return true;
        }
        catch
        {
            Debug.LogError("[SaveLoadManager] Load 실패");
            return false;
        }
    }

    public static bool HasSaveData()
    {
        return File.Exists(SaveFilePath);
    }

    public static void DeleteSave()
    {
        if (File.Exists(SaveFilePath))
            File.Delete(SaveFilePath);
        Data = new SaveDataVC();
    }
}