// Top-level path segments that already have meaning in the SPA router
// (see src/App.tsx) plus a few reserved for infrastructure. Category slugs
// live at the URL root (e.g. /music), so they must never collide with these.
export const RESERVED_SLUGS: readonly string[] = [
  "~",
  "dumps",
  "users",
  "playlists",
  "search",
  "login",
  "register",
  "notifications",
  "reset-password",
  "manage",
  "api",
  "assets",
];

// Lowercase alphanumerics, hyphen-separated, no leading/trailing/double hyphen.
export const CATEGORY_SLUG_RE = /^[a-z0-9]+(?:-[a-z0-9]+)*$/;

export function isValidSlugFormat(slug: string): boolean {
  return CATEGORY_SLUG_RE.test(slug);
}

export function isReservedSlug(slug: string): boolean {
  return RESERVED_SLUGS.includes(slug);
}

/** A slug is available when it is well-formed and not reserved. */
export function isSlugAvailable(slug: string): boolean {
  return isValidSlugFormat(slug) && !isReservedSlug(slug);
}