/**
 * Shared per-navigation state for the language-switch button in the layout.
 * Each page sets this on setup: `available` is false when there is no
 * equivalent page in the other language for the current content (e.g. an
 * untranslated article, or the Italian-only corralito page) — in that case
 * `fallback` is where the switch should go instead (typically the other
 * language's blog index).
 */
interface LangSwitchState {
  available: boolean
  fallback: string
}

export function useLangSwitchState() {
  return useState<LangSwitchState>('lang-switch', () => ({ available: true, fallback: '/en' }))
}