namehash.ts

import sha256 from '../utils/sha256';

export const namehash = (
  name = '',
  { parent, prefix }: { parent?: string; prefix?: boolean } = { prefix: true },
) => {
  parent =
    parent ||
    '0000000000000000000000000000000000000000000000000000000000000000';
  const address = [parent]
    .concat(
      name
        .split('.')
        .reverse()
        .filter(label => label),
    )
    .reduce((parent, label) => childhash(parent, label, { prefix: false }));
  return prefix ? '0x' + address : address;
};

export const childhash = (
  parent: string,
  child: string,
  options: { prefix: boolean } = { prefix: true },
) => {
  parent = parent.replace(/^0x/, '');
  return sha256(parent + sha256(child, { hexPrefix: false }), {
    hexPrefix: options.prefix,
    inputEnc: 'hex',
  });
};

export default namehash;