LocalizationHelper.cs

using System.Globalization;
using System.Reflection;
using System.Resources;

namespace AIAFBackupTool;

/// <summary>
/// Thin localization accessor.
/// Uses Resources/Strings.resx as English fallback and culture-specific
/// Resources/Strings.xx.resx files when available.
/// </summary>
internal static class L
{
    private static readonly ResourceManager ResourceManager = new(
        "AIAFBackupTool.Resources.Strings",
        Assembly.GetExecutingAssembly());

    public static string CurrentLanguage { get; private set; } = "auto";

    public static void ApplyLanguage(string language)
    {
        CurrentLanguage = string.IsNullOrWhiteSpace(language) ? "auto" : language;

        CultureInfo culture = CurrentLanguage switch
        {
            "de-DE" => new CultureInfo("de-DE"),
            "en-US" => new CultureInfo("en-US"),
            _ => CultureInfo.InstalledUICulture
        };

        CultureInfo.CurrentUICulture = culture;
        CultureInfo.CurrentCulture = culture;
    }

    public static string T(string key)
    {
        return ResourceManager.GetString(key, CultureInfo.CurrentUICulture) ?? $"[{key}]";
    }

    public static string F(string key, params object[] args)
    {
        return string.Format(CultureInfo.CurrentCulture, T(key), args);
    }
}