import * as openpgp from 'openpgp'

/**
 * Generate an OpenPGP RSA key pair.
 *
 * @param name - User name for the key
 * @param email - User email for the key
 * @returns ASCII-armored private and public keys
 */
export const generatePgpKeyPair = async (
  name: string,
  email: string,
): Promise<{ privateKey: string; publicKey: string }> => {
  const { privateKey, publicKey } = await openpgp.generateKey({
    type: 'rsa',
    rsaBits: 2048,
    userIDs: [{ name, email }],
    format: 'armored',
  })

  return { privateKey, publicKey }
}

/**
 * Create a detached OpenPGP signature for the given data.
 *
 * @param data - Raw data to sign (Buffer or Uint8Array)
 * @param armoredPrivateKey - ASCII-armored private key
 * @returns ASCII-armored detached signature (signature.asc content)
 */
export const pgpSignDetached = async (data: Uint8Array, armoredPrivateKey: string): Promise<string> => {
  const privateKey = await openpgp.readPrivateKey({ armoredKey: armoredPrivateKey })
  const message = await openpgp.createMessage({ binary: data })

  const signature = await openpgp.sign({
    message,
    signingKeys: privateKey,
    detached: true,
    format: 'armored',
  })

  return signature as string
}

/**
 * Verify a detached OpenPGP signature.
 *
 * @param data - Original data (Buffer or Uint8Array)
 * @param armoredSignature - ASCII-armored detached signature
 * @param armoredPublicKey - ASCII-armored public key
 * @returns true if signature is valid
 */
export const pgpVerifyDetached = async (
  data: Uint8Array,
  armoredSignature: string,
  armoredPublicKey: string,
): Promise<boolean> => {
  const publicKey = await openpgp.readKey({ armoredKey: armoredPublicKey })
  const signature = await openpgp.readSignature({ armoredSignature })
  const message = await openpgp.createMessage({ binary: data })

  const verificationResult = await openpgp.verify({
    message,
    signature,
    verificationKeys: publicKey,
  })

  const { verified } = verificationResult.signatures[0]!
  try {
    await verified
    return true
  } catch {
    return false
  }
}