using System.Globalization;
using System.Resources;

namespace SharepointToolbox.Web.Localization;

/// <summary>
/// Singleton string lookup backed by Strings.resx / Strings.fr.resx.
/// Web version: no INotifyPropertyChanged — culture switching is per-request.
/// </summary>
public class TranslationSource
{
    public static readonly TranslationSource Instance = new();

    private ResourceManager _resourceManager = Strings.ResourceManager;
    private CultureInfo _currentCulture = CultureInfo.CurrentUICulture;

    private TranslationSource() { }

    public string this[string key] =>
        _resourceManager.GetString(key, _currentCulture) ?? $"[{key}]";

    public CultureInfo CurrentCulture
    {
        get => _currentCulture;
        set
        {
            if (Equals(_currentCulture, value)) return;
            _currentCulture = value;
        }
    }

    public void SetCulture(string lang)
    {
        CurrentCulture = lang switch
        {
            "fr" => new CultureInfo("fr"),
            _    => CultureInfo.InvariantCulture
        };
    }
}