Argus/Infrastructure/SlugUtility.cs

using System.Text;

namespace Argus.Infrastructure;

public static class SlugUtility
{
    public static string Normalize(string? value)
    {
        if (string.IsNullOrWhiteSpace(value))
        {
            return string.Empty;
        }

        var builder = new StringBuilder(value.Length);
        var lastWasHyphen = false;

        foreach (var character in value.Trim().ToLowerInvariant())
        {
            if (char.IsLetterOrDigit(character))
            {
                builder.Append(character);
                lastWasHyphen = false;
                continue;
            }

            if (!lastWasHyphen)
            {
                builder.Append('-');
                lastWasHyphen = true;
            }
        }

        return builder.ToString().Trim('-');
    }

    public static bool IsValid(string? value) =>
        !string.IsNullOrWhiteSpace(value) &&
        value.Length <= 100 &&
        string.Equals(value, Normalize(value), StringComparison.Ordinal);
}