import { getCryptoBackend } from './backend';

export const RECOVERY_ALPHABET = 'ABCDEFGHJKLMNPQRSTUVWXYZ23456789';
export const RECOVERY_CODE_LEN = 24;

export async function generateRecoveryCode(): Promise<string> {
  const raw = getCryptoBackend().randomBytes(RECOVERY_CODE_LEN);
  let out = '';
  for (let i = 0; i < raw.length; i++) {
    out += RECOVERY_ALPHABET[raw[i]! % RECOVERY_ALPHABET.length];
    if ((i + 1) % 6 === 0 && i !== raw.length - 1) out += '-';
  }
  return out;
}

export function normalizeRecoveryCode(input: string): string {
  return input
    .toUpperCase()
    .split('')
    .filter((c) => RECOVERY_ALPHABET.includes(c))
    .join('');
}