import itertools
import uuid

def convert_secret_key(config_secret_key):
  """ Converts the secret key from the app config into a secret key that is usable by AES
      Cipher. """
  secret_key = None

  # First try parsing the key as an int.
  try:
    big_int = int(config_secret_key)
    secret_key = str(bytearray.fromhex('{:02x}'.format(big_int)))
  except ValueError:
    pass

  # Next try parsing it as an UUID.
  if secret_key is None:
    try:
      secret_key = uuid.UUID(config_secret_key).bytes
    except ValueError:
      pass

  if secret_key is None:
    secret_key = str(bytearray(map(ord, config_secret_key)))

  # Otherwise, use the bytes directly.
  assert len(secret_key)
  return ''.join(itertools.islice(itertools.cycle(secret_key), 32))