/**
 * Per-account key for the "I've saved my recovery code" flag.
 *
 * It MUST be namespaced by pubkey: a device-global flag let account A's
 * confirmation suppress the backup reminder for account B created later on the
 * same device — leaving B's only key unrecovered.
 */
export function backupConfirmedKey(pubkey: string | undefined): string {
  return `backup-confirmed:${pubkey ?? 'anon'}`;
}

/**
 * Record that this account's key was saved.
 *
 * ⚠️ Call this with the **real** pubkey (e.g. derived from the freshly minted
 * nsec), NOT `useCurrentUser().pubkey` during signup — at that moment `user` is
 * still settling, so the write landed on `backup-confirmed:anon` and the
 * post-signup reminder never learned the key was saved (it nagged every session).
 * Mirrors `useLocalStorage`'s JSON encoding so the hook reads it back.
 */
export function markBackupConfirmed(pubkey: string | undefined): void {
  if (!pubkey) return;
  try {
    localStorage.setItem(backupConfirmedKey(pubkey), JSON.stringify(true));
  } catch {
    // localStorage can throw in strict privacy modes — safe to ignore.
  }
}