Save Load System for Unity

SaveLoadManager.cs

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using UnityEditor;
using UnityEngine;

/*
 * Using - https://docs.unity3d.com/2019.4/Documentation/Manual/com.unity.nuget.newtonsoft-json.html for reading and writing json
*/

/// <summary>
/// Save Load System.
/// Similar to PlayerPref/
/// supported datatypes - string,char,float,bool,int
/// </summary>
public class SaveAndLoadManager : MonoBehaviour
{
    public static SaveLoadManager SaveLoad;
     
    private static string _dataPath = Application.dataPath + "/gameData.json";
    private JsonSerializerSettings jsonSettings;

    void Awake()
    {
        DontDestroyOnLoad(gameObject);
        if (SaveLoad == null)
        {
            SaveLoad = this;
        }
        else
        {
            Destroy(gameObject);
        }
        
#if UNITY_EDITOR
        _dataPath = Application.dataPath + "/gameData.json";
#else
        _dataPath = Application.persistentDataPath + "/gameData.fallen";
#endif
        jsonSettings = new()
        {
            Formatting = Formatting.Indented
        };
    }

    /// <summary>
    /// Save user Data as Key Value Pair
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="key">key of data by which it can be accessed - MUST BE UNIQUE</param>
    /// <param name="data">data you want to save since it generic it can take any data</param>
    public void SaveData(string key, object data)
    {
        Dictionary<string, object> dictData = new();
        if (File.Exists(_dataPath))
        {
            string jsonData = File.ReadAllText(_dataPath, System.Text.Encoding.UTF8);
            dictData = JsonConvert.DeserializeObject<Dictionary<string, object>>(jsonData, jsonSettings);
        }
        dictData[key] = data;
        string newData = JsonConvert.SerializeObject(dictData, jsonSettings);
        File.WriteAllText(_dataPath, newData, System.Text.Encoding.UTF8);
    }

    /// <summary>
    /// Load Data by its Key
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="key">key of data</param>
    /// <param name="defaultValue">specify the value that it can return when data is not found</param>
    /// <returns>return your saved Data</returns>
    public T LoadData<T>(string key, T defaultValue = default)
    {
        if (File.Exists(_dataPath))
        {
            Dictionary<string, object> gameData = new();
            string jsonData = File.ReadAllText(_dataPath, System.Text.Encoding.UTF8);
            gameData = JsonConvert.DeserializeObject<Dictionary<string, object>>(jsonData, jsonSettings);
            if (gameData.TryGetValue(key, out object data))
            {
                return FixedType<T>(data);
            }
            else
            {
                return defaultValue;
            }
        }

        return defaultValue;
    }

#if UNITY_EDITOR

    /// <summary>
    /// Delete the game data file
    /// </summary>
    [MenuItem("Save Data/Delete All")]
    public static void DeleteAllSaveData()
    {
        if (File.Exists(_dataPath))
        {
            File.Delete(_dataPath);
        }
    }

#endif

    /// <summary>
    /// Delete the specify saved data by its key
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="key">key of dat You want to delete</param>
    public void DeleteSaveData<T>(string key)
    {
        Dictionary<string, object> dictData = new();
        if (File.Exists(_dataPath))
        {
            string jsonData = File.ReadAllText(_dataPath, System.Text.Encoding.UTF8);
            dictData = JsonConvert.DeserializeObject<Dictionary<string, object>>(jsonData, jsonSettings);
            dictData.Remove(key);
            string newData = JsonConvert.SerializeObject(dictData, jsonSettings);
            File.WriteAllText(_dataPath, newData, System.Text.Encoding.UTF8);
        }
    }

    private T FixedType<T>(object data)
    {
        if (typeof(T) == typeof(int) && data is long)
        {
            // Convert long to int
            return (T)(object)Convert.ToInt32(data);
        }
        else if (typeof(T) == typeof(float) && data is double)
        {
            return (T)((object)Convert.ToSingle(data));
        }
        // No need to cast for other types
        return (T)data;
    }
}