ConfigManager.cs

using System.IO;
using System;
using System.Text.Json;
using System.Windows.Forms;
using System.Diagnostics;

public static class ConfigManager
{
    private static readonly string ConfigFilePath = Path.Combine( // set the expected config filepath
        AppDomain.CurrentDomain.BaseDirectory, "config.json");

    private static AppConfig? _config;

    // Lazily loads config on first access
    public static AppConfig Config => _config ??= Load();

    public static AppConfig Load() // load and deserialise config file
    {
        if (File.Exists(ConfigFilePath))
        {
            try
            {
                string json = File.ReadAllText(ConfigFilePath);
                return JsonSerializer.Deserialize<AppConfig>(json) ?? new AppConfig();
            }
            catch
            {
                return new AppConfig();
            }
        }
        return new AppConfig();
    }

    public static void Save() // serialise and write config to file
    {
        try
        {
            string json = JsonSerializer.Serialize(Config, new JsonSerializerOptions
            {
                WriteIndented = true
            });
            File.WriteAllText(ConfigFilePath, json);
        }
        catch (Exception ex)
        {
            MessageBox.Show($"Failed to save settings: {ex.Message}");
        }
    }

    public static void Reload()
    {
        _config = Load(); // Reload config from disk
        // Debug.WriteLine(JsonSerializer.Serialize(Config));
    }
}