/* eslint-disable camelcase */
const assert = require('nanoassert')
const Poly1305 = require('./internal/poly1305')
const { crypto_verify_16 } = require('./crypto_verify')

const crypto_onetimeauth_BYTES = 16
const crypto_onetimeauth_KEYBYTES = 32
const crypto_onetimeauth_PRIMITIVE = 'poly1305'

module.exports = {
  crypto_onetimeauth,
  crypto_onetimeauth_verify,
  crypto_onetimeauth_BYTES,
  crypto_onetimeauth_KEYBYTES,
  crypto_onetimeauth_PRIMITIVE
}

function crypto_onetimeauth (mac, msg, key) {
  assert(mac.byteLength === crypto_onetimeauth_BYTES, "mac must be 'crypto_onetimeauth_BYTES' bytes")
  assert(msg.byteLength != null, 'msg must be buffer')
  assert(key.byteLength === crypto_onetimeauth_KEYBYTES, "key must be 'crypto_onetimeauth_KEYBYTES' bytes")

  var s = new Poly1305(key)
  s.update(msg, 0, msg.byteLength)
  s.finish(mac, 0)
}

function crypto_onetimeauth_verify (mac, msg, key) {
  assert(mac.byteLength === crypto_onetimeauth_BYTES, "mac must be 'crypto_onetimeauth_BYTES' bytes")
  assert(msg.byteLength != null, 'msg must be buffer')
  assert(key.byteLength === crypto_onetimeauth_KEYBYTES, "key must be 'crypto_onetimeauth_KEYBYTES' bytes")

  var tmp = new Uint8Array(16)
  crypto_onetimeauth(tmp, msg, key)
  return crypto_verify_16(mac, 0, tmp, 0)
}