// A one-line notice for the site-wide toast (components/DemoToast.jsx), for the
// rare moment a screen has to say something after it has navigated away — the
// account page cannot show "Your account has been deleted." on itself, because
// the account it would be shown on no longer exists.
//
// The same shape as lib/demoNotice.js and drawn by the same toast, so the site
// has one place a passing message appears.

const listeners = new Set()

/** Subscribe to notices. Returns the unsubscribe function. */
export function onNotice(fn) {
  listeners.add(fn)
  return () => listeners.delete(fn)
}

/** Show one notice. */
export function showNotice(message) {
  if (typeof message !== 'string' || !message) return
  for (const fn of listeners) {
    try {
      fn(message)
    } catch {
      // A broken listener must not stop the caller.
    }
  }
}