from selfdrive.car.interfaces import get_interface_attr


FW_VERSIONS = get_interface_attr('FW_VERSIONS', combine_brands=True, ignore_none=True)
_FINGERPRINTS = get_interface_attr('FINGERPRINTS', combine_brands=True, ignore_none=True)

_DEBUG_ADDRESS = {1880: 8}   # reserved for debug purposes


def is_valid_for_fingerprint(msg, car_fingerprint):
  adr = msg.address
  # ignore addresses that are more than 11 bits
  return (adr in car_fingerprint and car_fingerprint[adr] == len(msg.dat)) or adr >= 0x800


def eliminate_incompatible_cars(msg, candidate_cars):
  """Removes cars that could not have sent msg.

     Inputs:
      msg: A cereal/log CanData message from the car.
      candidate_cars: A list of cars to consider.

     Returns:
      A list containing the subset of candidate_cars that could have sent msg.
  """
  compatible_cars = []

  for car_name in candidate_cars:
    car_fingerprints = _FINGERPRINTS[car_name]

    for fingerprint in car_fingerprints:
      fingerprint.update(_DEBUG_ADDRESS)  # add alien debug address

      if is_valid_for_fingerprint(msg, fingerprint):
        compatible_cars.append(car_name)
        break

  return compatible_cars


def all_known_cars():
  """Returns a list of all known car strings."""
  return list({*FW_VERSIONS.keys(), *_FINGERPRINTS.keys()})


def all_legacy_fingerprint_cars():
  """Returns a list of all known car strings, FPv1 only."""
  return list(_FINGERPRINTS.keys())