// Slug normalization for app slugs, mirrored against the backend's
// validate_slug rules in crates/manager-core/src/apps_api.rs:
//   - regex: ^[a-z0-9][a-z0-9-]{0,62}$
//   - 1..=63 chars, lowercase ascii alphanumerics + `-`
//   - must start with [a-z0-9]
//   - reserved words are enforced server-side only
//
// Normalization rules are GitLab-style (close to `Babosa::Latin#to_slug`):
//   1. NFKD-decompose Unicode and drop combining marks (é → e, ñ → n,
//      ü → u, etc.).
//   2. ß → ss (a single common case the strip-marks pass misses).
//   3. Lowercase.
//   4. Replace any run of non-[a-z0-9] with a single `-`.
//   5. Trim leading/trailing `-`.
//   6. Truncate to 63 chars.

export const SLUG_MAX = 63;

export function slugify(input: string): string {
	if (!input) return '';
	let s = input.normalize('NFKD').replace(/[\u0300-\u036f]/g, '');
	s = s.toLowerCase().replace(/ß/g, 'ss');
	s = s.replace(/[^a-z0-9]+/g, '-');
	s = s.replace(/^-+|-+$/g, '');
	if (s.length > SLUG_MAX) {
		// Truncate, then re-trim in case the cut landed on a `-`.
		s = s.slice(0, SLUG_MAX).replace(/-+$/g, '');
	}
	return s;
}