import { COSEALG } from './cose.ts';

/**
 * Map X.509 signature algorithm OIDs to COSE algorithm IDs
 *
 * - EC2 OIDs: https://oidref.com/1.2.840.10045.4.3
 * - RSA OIDs: https://oidref.com/1.2.840.113549.1.1
 */
export function mapX509SignatureAlgToCOSEAlg(
  signatureAlgorithm: string,
): COSEALG {
  let alg: COSEALG;

  if (signatureAlgorithm === '1.2.840.10045.4.3.2') {
    alg = COSEALG.ES256;
  } else if (signatureAlgorithm === '1.2.840.10045.4.3.3') {
    alg = COSEALG.ES384;
  } else if (signatureAlgorithm === '1.2.840.10045.4.3.4') {
    alg = COSEALG.ES512;
  } else if (signatureAlgorithm === '1.2.840.113549.1.1.11') {
    alg = COSEALG.RS256;
  } else if (signatureAlgorithm === '1.2.840.113549.1.1.12') {
    alg = COSEALG.RS384;
  } else if (signatureAlgorithm === '1.2.840.113549.1.1.13') {
    alg = COSEALG.RS512;
  } else if (signatureAlgorithm === '1.2.840.113549.1.1.5') {
    alg = COSEALG.RS1;
  } else {
    throw new Error(
      `Unable to map X.509 signature algorithm ${signatureAlgorithm} to a COSE algorithm`,
    );
  }

  return alg;
}