manager-service/ManagerService/Helpers/SlugHelper.cs

using ManagerService.Data;
using System.Linq;
using System.Text.RegularExpressions;

namespace ManagerService.Helpers
{
    public static class SlugHelper
    {
        /// <summary>
        /// Premiers segments d'URL déjà pris par des routes de visitapp-web : un segment
        /// statique l'emporte sur [slug], l'instance serait donc inaccessible.
        /// </summary>
        private static readonly string[] ReservedSlugs = { "download", "demo", "api" };

        public static bool IsTaken(MyInfoMateDbContext db, string slug) =>
            ReservedSlugs.Contains(slug) || db.Instances.Any(i => i.WebSlug == slug);

        /// <summary>
        /// Generate a URL-safe slug from a name, appending "-1", "-2", etc. until unique among Instances.WebSlug.
        /// </summary>
        public static string GenerateUniqueSlug(MyInfoMateDbContext db, string name)
        {
            var slug = name.ToLowerInvariant();
            slug = Regex.Replace(slug, @"[àáâãäå]", "a");
            slug = Regex.Replace(slug, @"[èéêë]", "e");
            slug = Regex.Replace(slug, @"[ìíîï]", "i");
            slug = Regex.Replace(slug, @"[òóôõö]", "o");
            slug = Regex.Replace(slug, @"[ùúûü]", "u");
            slug = Regex.Replace(slug, @"[ç]", "c");
            slug = Regex.Replace(slug, @"[ñ]", "n");
            slug = Regex.Replace(slug, @"[^a-z0-9\s-]", "");
            slug = Regex.Replace(slug, @"[\s-]+", "-").Trim('-');

            var baseSlug = slug;
            var counter = 1;
            while (IsTaken(db, slug))
                slug = $"{baseSlug}-{counter++}";

            return slug;
        }
    }
}