/** Route racine d'une démo (`demo/mail`, `demo/drive`, …). */
export function getDemoRouteRoot(pathname: string): string | null {
  if (!pathname.startsWith("/demo/")) return null
  const segments = pathname.split("/").filter(Boolean)
  if (segments[0] !== "demo" || !segments[1]) return null
  return `demo/${segments[1]}`
}

function isExternalHref(href: string): boolean {
  return (
    href.startsWith("http://") ||
    href.startsWith("https://") ||
    href.startsWith("mailto:") ||
    href.startsWith("tel:") ||
    href.startsWith("javascript:")
  )
}

/** Normalise un href interne vers `pathname + search + hash`, ou `null` si hors scope. */
export function normalizeInternalHref(href: string, origin = window.location.origin): string | null {
  const trimmed = href.trim()
  if (!trimmed || trimmed === "#" || trimmed.startsWith("#")) return null
  if (isExternalHref(trimmed)) return null

  try {
    const url = new URL(trimmed, origin)
    if (url.origin !== origin) return null
    return `${url.pathname}${url.search}${url.hash}`
  } catch {
    return null
  }
}

/** True si la navigation reste dans la démo courante (`/demo/mail/...`, etc.). */
export function isHrefWithinDemoScope(
  href: string,
  demoRouteRoot: string,
  origin = window.location.origin
): boolean {
  const internal = normalizeInternalHref(href, origin)
  if (internal === null) return true

  const prefix = `/${demoRouteRoot}`
  return internal === prefix || internal.startsWith(`${prefix}/`)
}