Explorer-Workbench/src/Explorer.Domain/NameNormalizer.cs

using System.Globalization;
using System.Text;

namespace Explorer.Domain;

public static class NameNormalizer
{
    public static string Normalize(string name)
    {
        if (string.IsNullOrEmpty(name))
        {
            return string.Empty;
        }

        var form = name.Normalize(NormalizationForm.FormC);
        return form.ToLower(CultureInfo.InvariantCulture);
    }

    public static string? Extension(string name)
    {
        if (string.IsNullOrEmpty(name))
        {
            return null;
        }

        var idx = name.LastIndexOf('.');
        if (idx <= 0 || idx == name.Length - 1)
        {
            return null;
        }

        return Normalize(name[(idx + 1)..]);
    }
}