text: import os
  from common.params import Params
  from common.basedir import BASEDIR
  from selfdrive.car.fingerprints import eliminate_incompatible_cars, all_legacy_fingerprint_cars
  from selfdrive.car.vin import get_vin, VIN_UNKNOWN
  from selfdrive.car.fw_versions import get_fw_versions, match_fw_to_car
  from selfdrive.swaglog import cloudlog
  import cereal.messaging as messaging
  from selfdrive.car import gen_empty_fingerprint
  
  from cereal import car
  EventName = car.CarEvent.EventName
  
  
  def get_startup_event(car_recognized, controller_available, fuzzy_fingerprint, fw_seen):
  
    event = EventName.startup
  
    if not car_recognized:
      if fw_seen:
        event = EventName.startupNoCar
      else:
        event = EventName.startupNoFw
    elif car_recognized and not controller_available:
      event = EventName.startupNoControl
    elif car_recognized and fuzzy_fingerprint:
      event = EventName.startupFuzzyFingerprint
    return event
  
  
  def get_one_can(logcan):
    while True:
      can = messaging.recv_one_retry(logcan)
      if len(can.can) > 0:
        return can
  
  
  def load_interfaces(brand_names):
    ret = {}
    for brand_name in brand_names:
      path = ('selfdrive.car.%s' % brand_name)
      CarInterface = __import__(path + '.interface', fromlist=['CarInterface']).CarInterface
  
      if os.path.exists(BASEDIR + '/' + path.replace('.', '/') + '/carstate.py'):
        CarState = __import__(path + '.carstate', fromlist=['CarState']).CarState
      else:
        CarState = None
  
      if os.path.exists(BASEDIR + '/' + path.replace('.', '/') + '/carcontroller.py'):
        CarController = __import__(path + '.carcontroller', fromlist=['CarController']).CarController
      else:
        CarController = None
  
      for model_name in brand_names[brand_name]:
        ret[model_name] = (CarInterface, CarController, CarState)
    return ret
  
  
  def _get_interface_names():
    # read all the folders in selfdrive/car and return a dict where:
    # - keys are all the car names that which we have an interface for
    # - values are lists of spefic car models for a given car
    brand_names = {}
    for car_folder in [x[0] for x in os.walk(BASEDIR + '/selfdrive/car')]:
      try:
        brand_name = car_folder.split('/')[-1]
        model_names = __import__('selfdrive.car.%s.values' % brand_name, fromlist=['CAR']).CAR
        model_names = [getattr(model_names, c) for c in model_names.__dict__.keys() if not c.startswith("__")]
        brand_names[brand_name] = model_names
      except (ImportError, IOError):
        pass
  
    return brand_names
  
  
  # imports from directory selfdrive/car/<name>/
  interface_names = _get_interface_names()
  interfaces = load_interfaces(interface_names)
  
  
  def only_toyota_left(candidate_cars):
    return all(("TOYOTA" in c or "LEXUS" in c) for c in candidate_cars) and len(candidate_cars) > 0
  
  
  # **** for use live only ****
  def fingerprint(logcan, sendcan, has_relay):
    fixed_fingerprint = os.environ.get('FINGERPRINT', "")
    skip_fw_query = os.environ.get('SKIP_FW_QUERY', False)
  
    if has_relay and not fixed_fingerprint and not skip_fw_query:
      # Vin query only reliably works thorugh OBDII
      bus = 1
  
      cached_params = Params().get("CarParamsCache")
      if cached_params is not None:
        cached_params = car.CarParams.from_bytes(cached_params)
        if cached_params.carName == "mock":
          cached_params = None
  
      if cached_params is not None and len(cached_params.carFw) > 0 and cached_params.carVin is not VIN_UNKNOWN:
        cloudlog.warning("Using cached CarParams")
        vin = cached_params.carVin
        car_fw = list(cached_params.carFw)
      else:
        cloudlog.warning("Getting VIN & FW versions")
        _, vin = get_vin(logcan, sendcan, bus)
        car_fw = get_fw_versions(logcan, sendcan, bus)
  
      exact_fw_match, fw_candidates = match_fw_to_car(car_fw)
    else:
      vin = VIN_UNKNOWN
      exact_fw_match, fw_candidates, car_fw = True, set(), []
  
    cloudlog.warning("VIN %s", vin)
    Params().put("CarVin", vin)
  
    finger = gen_empty_fingerprint()
    candidate_cars = {i: all_legacy_fingerprint_cars() for i in [0, 1]}  # attempt fingerprint on both bus 0 and 1
    frame = 0
    frame_fingerprint = 10  # 0.1s
    car_fingerprint = None
    done = False
  
    while not done:
      a = get_one_can(logcan)
  
      for can in a.can:
        # need to independently try to fingerprint both bus 0 and 1 to work
        # for the combo black_panda and honda_bosch. Ignore extended messages
        # and VIN query response.
        # Include bus 2 for toyotas to disambiguate cars using camera messages
        # (ideally should be done for all cars but we can't for Honda Bosch)
        if can.src in range(0, 4):
          finger[can.src][can.address] = len(can.dat)
        for b in candidate_cars:
          if (can.src == b or (only_toyota_left(candidate_cars[b]) and can.src == 2)) and \
             can.address < 0x800 and can.address not in [0x7df, 0x7e0, 0x7e8]:
            candidate_cars[b] = eliminate_incompatible_cars(can, candidate_cars[b])
  
      # if we only have one car choice and the time since we got our first
      # message has elapsed, exit
      for b in candidate_cars:
        # Toyota needs higher time to fingerprint, since DSU does not broadcast immediately
        if only_toyota_left(candidate_cars[b]):
          frame_fingerprint = 100  # 1s
        if len(candidate_cars[b]) == 1 and frame > frame_fingerprint:
            # fingerprint done
            car_fingerprint = candidate_cars[b][0]
  
      # bail if no cars left or we've been waiting for more than 2s
      failed = (all(len(cc) == 0 for cc in candidate_cars.values()) and frame > frame_fingerprint) or frame > 200
      succeeded = car_fingerprint is not None
      done = failed or succeeded
  
      frame += 1
  
    exact_match = True
    source = car.CarParams.FingerprintSource.can
  
    # If FW query returns exactly 1 candidate, use it
    if len(fw_candidates) == 1:
      car_fingerprint = list(fw_candidates)[0]
      source = car.CarParams.FingerprintSource.fw
      exact_match = exact_fw_match
  
    if fixed_fingerprint:
      car_fingerprint = fixed_fingerprint
      source = car.CarParams.FingerprintSource.fixed
  
    cloudlog.event("fingerprinted", car_fingerprint=car_fingerprint,
                   source=source, fuzzy=not exact_match, fw_count=len(car_fw))
    return car_fingerprint, finger, vin, car_fw, source, exact_match
  
  
  def get_car(logcan, sendcan, has_relay=False):
    candidate, fingerprints, vin, car_fw, source, exact_match = fingerprint(logcan, sendcan, has_relay)
  
    if candidate is None:
      cloudlog.warning("car doesn't match any fingerprints: %r", fingerprints)
      candidate = "KIA STINGER GT2 2018"
  
    selected_car = Params().get("SelectedCar")
    if selected_car:
      candidate = selected_car.decode("utf-8")
  
    CarInterface, CarController, CarState = interfaces[candidate]
    car_params = CarInterface.get_params(candidate, fingerprints, car_fw)
    car_params.carVin = vin
    car_params.carFw = car_fw
    car_params.fingerprintSource = source
    car_params.fuzzyFingerprint = not exact_match
  
    return CarInterface(car_params, CarController, CarState), car_params
  