text: #!/usr/bin/env python
  from cereal import car, log
  from common.realtime import sec_since_boot
  from selfdrive.config import Conversions as CV
  from selfdrive.controls.lib.drive_helpers import EventTypes as ET, create_event
  from selfdrive.controls.lib.vehicle_model import VehicleModel
  from selfdrive.car.hyundai.carstate import CarState, get_can_parser, get_camera_parser
  from selfdrive.car.hyundai.values import CAMERA_MSGS, CAR, get_hud_alerts
  
  try:
    from selfdrive.car.hyundai.carcontroller import CarController
  except ImportError:
    CarController = None
  
  
  class CarInterface(object):
    def __init__(self, CP, sendcan=None):
      self.CP = CP
      self.VM = VehicleModel(CP)
      self.idx = 0
      self.lanes = 0
      self.lkas_request = 0
  
      self.gas_pressed_prev = False
      self.brake_pressed_prev = False
      self.can_invalid_count = 0
      self.cruise_enabled_prev = False
      self.low_speed_alert = False
  
      # *** init the major players ***
      self.CS = CarState(CP)
      self.cp = get_can_parser(CP)
      self.cp_cam = get_camera_parser(CP)
  
      # sending if read only is False
      if sendcan is not None:
        self.sendcan = sendcan
        self.CC = CarController(self.cp.dbc_name, CP.carFingerprint, CP.enableCamera)
  
    @staticmethod
    def compute_gb(accel, speed):
      return float(accel) / 3.0
  
    @staticmethod
    def calc_accel_override(a_ego, a_target, v_ego, v_target):
      return 1.0
  
    @staticmethod
    def get_params(candidate, fingerprint):
  
      # kg of standard extra cargo to count for drive, gas, etc...
      std_cargo = 136
  
      ret = car.CarParams.new_message()
  
      ret.carName = "hyundai"
      ret.carFingerprint = candidate
      ret.radarOffCan = True
      ret.safetyModel = car.CarParams.SafetyModels.hyundai
      ret.enableCruise = True  # stock acc
  
      # FIXME: hardcoding honda civic 2016 touring params so they can be used to
      # scale unknown params for other cars
      mass_civic = 2923 * CV.LB_TO_KG + std_cargo
      wheelbase_civic = 2.70
      centerToFront_civic = wheelbase_civic * 0.4
      centerToRear_civic = wheelbase_civic - centerToFront_civic
      rotationalInertia_civic = 2500
      tireStiffnessFront_civic = 192150
      tireStiffnessRear_civic = 202500
  
      ret.steerActuatorDelay = 0.1  # Default delay
      tire_stiffness_factor = 1.
  
      if candidate == CAR.SANTA_FE:
        ret.steerKf = 0.00005
        ret.steerRateCost = 0.5
        ret.mass = 3982 * CV.LB_TO_KG + std_cargo
        ret.wheelbase = 2.766
  
        # Values from optimizer
        ret.steerRatio = 16.55  # 13.8 is spec end-to-end
        tire_stiffness_factor = 0.82
  
        ret.steerKiBP, ret.steerKpBP = [[0.], [0.]]
        ret.steerKpV, ret.steerKiV = [[0.37], [0.1]]
        ret.minSteerSpeed = 0.
      elif candidate == CAR.KIA_SORENTO:
        ret.steerKf = 0.00005
        ret.steerRateCost = 0.5
        ret.mass = 1985 + std_cargo
        ret.wheelbase = 2.78
        ret.steerRatio = 14.4 * 1.1   # 10% higher at the center seems reasonable
        ret.steerKiBP, ret.steerKpBP = [[0.], [0.]]
        ret.steerKpV, ret.steerKiV = [[0.25], [0.05]]
        ret.minSteerSpeed = 0.
      elif candidate == CAR.ELANTRA:
        ret.steerKf = 0.00006
        ret.steerRateCost = 0.5
        ret.mass = 1275 + std_cargo
        ret.wheelbase = 2.7
        ret.steerRatio = 13.73   #Spec
        tire_stiffness_factor = 0.385
        ret.steerKiBP, ret.steerKpBP = [[0.], [0.]]
        ret.steerKpV, ret.steerKiV = [[0.25], [0.05]]
        ret.minSteerSpeed = 32 * CV.MPH_TO_MS
      elif candidate == CAR.GENESIS:
        ret.steerKf = 0.00005
        ret.steerRateCost = 0.5
        ret.mass = 2060 + std_cargo
        ret.wheelbase = 3.01
        ret.steerRatio = 16.5
        ret.steerKiBP, ret.steerKpBP = [[0.], [0.]]
        ret.steerKpV, ret.steerKiV = [[0.16], [0.01]]
        ret.minSteerSpeed = 35 * CV.MPH_TO_MS
      elif candidate == CAR.KIA_STINGER:
        ret.steerKf = 0.00005
        ret.steerRateCost = 0.5
        ret.mass = 1825 + std_cargo
        ret.wheelbase = 2.78
        ret.steerRatio = 14.4 * 1.15   # 15% higher at the center seems reasonable
        ret.steerKiBP, ret.steerKpBP = [[0.], [0.]]
        ret.steerKpV, ret.steerKiV = [[0.25], [0.05]]
        ret.minSteerSpeed = 0.
  
      ret.minEnableSpeed = -1.   # enable is done by stock ACC, so ignore this
      ret.longitudinalKpBP = [0.]
      ret.longitudinalKpV = [0.]
      ret.longitudinalKiBP = [0.]
      ret.longitudinalKiV = [0.]
  
      ret.centerToFront = ret.wheelbase * 0.4
  
      centerToRear = ret.wheelbase - ret.centerToFront
  
      # TODO: get actual value, for now starting with reasonable value for
      # civic and scaling by mass and wheelbase
      ret.rotationalInertia = rotationalInertia_civic * \
                              ret.mass * ret.wheelbase**2 / (mass_civic * wheelbase_civic**2)
  
      # TODO: start from empirically derived lateral slip stiffness for the civic and scale by
      # mass and CG position, so all cars will have approximately similar dyn behaviors
      ret.tireStiffnessFront = (tireStiffnessFront_civic * tire_stiffness_factor) * \
                               ret.mass / mass_civic * \
                               (centerToRear / ret.wheelbase) / (centerToRear_civic / wheelbase_civic)
      ret.tireStiffnessRear = (tireStiffnessRear_civic * tire_stiffness_factor) * \
                              ret.mass / mass_civic * \
                              (ret.centerToFront / ret.wheelbase) / (centerToFront_civic / wheelbase_civic)
  
  
      # no rear steering, at least on the listed cars above
      ret.steerRatioRear = 0.
      ret.steerControlType = car.CarParams.SteerControlType.torque
  
      # steer, gas, brake limitations VS speed
      ret.steerMaxBP = [0.]
      ret.steerMaxV = [1.0]
      ret.gasMaxBP = [0.]
      ret.gasMaxV = [1.]
      ret.brakeMaxBP = [0.]
      ret.brakeMaxV = [1.]
      ret.longPidDeadzoneBP = [0.]
      ret.longPidDeadzoneV = [0.]
  
      ret.enableCamera = not any(x for x in CAMERA_MSGS if x in fingerprint)
  
      ret.steerLimitAlert = False
      ret.stoppingControl = False
      ret.startAccel = 0.0
  
      return ret
  
    # returns a car.CarState
    def update(self, c):
      # ******************* do can recv *******************
      canMonoTimes = []
      self.cp.update(int(sec_since_boot() * 1e9), False)
      self.cp_cam.update(int(sec_since_boot() * 1e9), False)
      self.CS.update(self.cp, self.cp_cam)
      # create message
      ret = car.CarState.new_message()
      # speeds
      ret.vEgo = self.CS.v_ego
      ret.vEgoRaw = self.CS.v_ego_raw
      ret.aEgo = self.CS.a_ego
      ret.yawRate = self.CS.yaw_rate
      ret.standstill = self.CS.standstill
      ret.wheelSpeeds.fl = self.CS.v_wheel_fl
      ret.wheelSpeeds.fr = self.CS.v_wheel_fr
      ret.wheelSpeeds.rl = self.CS.v_wheel_rl
      ret.wheelSpeeds.rr = self.CS.v_wheel_rr
  
      # gear shifter
      if self.CP.carFingerprint == CAR.ELANTRA:
        ret.gearShifter = self.CS.gear_shifter_cluster
      else:
        ret.gearShifter = self.CS.gear_shifter
  
      # gas pedal
      ret.gas = self.CS.car_gas
      ret.gasPressed = self.CS.pedal_gas > 1e-3   # tolerance to avoid false press reading
  
      # brake pedal
      ret.brake = self.CS.user_brake
      ret.brakePressed = self.CS.brake_pressed != 0
      ret.brakeLights = self.CS.brake_lights
  
      # steering wheel
      ret.steeringAngle = self.CS.angle_steers
      ret.steeringRate = self.CS.angle_steers_rate  # it's unsigned
  
      ret.steeringTorque = self.CS.steer_torque_driver
      ret.steeringPressed = self.CS.steer_override
  
      # cruise state
      ret.cruiseState.enabled = self.CS.pcm_acc_status != 0
      if self.CS.pcm_acc_status != 0:
        ret.cruiseState.speed = self.CS.cruise_set_speed
      else:
        ret.cruiseState.speed = 0
      ret.cruiseState.available = bool(self.CS.main_on)
      ret.cruiseState.standstill = False
  
      # TODO: button presses
      buttonEvents = []
  
      if self.CS.left_blinker_on != self.CS.prev_left_blinker_on:
        be = car.CarState.ButtonEvent.new_message()
        be.type = 'leftBlinker'
        be.pressed = self.CS.left_blinker_on != 0
        buttonEvents.append(be)
  
      if self.CS.right_blinker_on != self.CS.prev_right_blinker_on:
        be = car.CarState.ButtonEvent.new_message()
        be.type = 'rightBlinker'
        be.pressed = self.CS.right_blinker_on != 0
        buttonEvents.append(be)
  
      ret.buttonEvents = buttonEvents
      ret.leftBlinker = bool(self.CS.left_blinker_on)
      ret.rightBlinker = bool(self.CS.right_blinker_on)
  
      ret.doorOpen = not self.CS.door_all_closed
      ret.seatbeltUnlatched = not self.CS.seatbelt
  
  
      # low speed steer alert hysteresis logic (only for cars with steer cut off above 10 m/s)
      if ret.vEgo < (self.CP.minSteerSpeed + 2.) and self.CP.minSteerSpeed > 10.:
        self.low_speed_alert = True
      if ret.vEgo > (self.CP.minSteerSpeed + 4.):
        self.low_speed_alert = False
  
      # events
      events = []
      if not self.CS.can_valid:
        self.can_invalid_count += 1
        if self.can_invalid_count >= 5:
          events.append(create_event('commIssue', [ET.NO_ENTRY, ET.IMMEDIATE_DISABLE]))
      else:
        self.can_invalid_count = 0
      if not ret.gearShifter == 'drive':
        events.append(create_event('wrongGear', [ET.NO_ENTRY, ET.SOFT_DISABLE]))
      if ret.doorOpen:
        events.append(create_event('doorOpen', [ET.NO_ENTRY, ET.SOFT_DISABLE]))
      if ret.seatbeltUnlatched:
        events.append(create_event('seatbeltNotLatched', [ET.NO_ENTRY, ET.SOFT_DISABLE]))
      if self.CS.esp_disabled:
        events.append(create_event('espDisabled', [ET.NO_ENTRY, ET.SOFT_DISABLE]))
      if not self.CS.main_on:
        events.append(create_event('wrongCarMode', [ET.NO_ENTRY, ET.USER_DISABLE]))
      if ret.gearShifter == 'reverse':
        events.append(create_event('reverseGear', [ET.NO_ENTRY, ET.IMMEDIATE_DISABLE]))
      if self.CS.steer_error:
        events.append(create_event('steerTempUnavailable', [ET.NO_ENTRY, ET.WARNING]))
  
      # enable request in prius is simple, as we activate when Toyota is active (rising edge)
      if ret.cruiseState.enabled and not self.cruise_enabled_prev:
        events.append(create_event('pcmEnable', [ET.ENABLE]))
      elif not ret.cruiseState.enabled:
        events.append(create_event('pcmDisable', [ET.USER_DISABLE]))
  
      # disable on pedals rising edge or when brake is pressed and speed isn't zero
      if (ret.gasPressed and not self.gas_pressed_prev) or \
        (ret.brakePressed and (not self.brake_pressed_prev or ret.vEgoRaw > 0.1)):
        events.append(create_event('pedalPressed', [ET.NO_ENTRY, ET.USER_DISABLE]))
  
      if ret.gasPressed:
        events.append(create_event('pedalPressed', [ET.PRE_ENABLE]))
  
      if self.low_speed_alert:
        events.append(create_event('belowSteerSpeed', [ET.WARNING]))
  
      ret.events = events
      ret.canMonoTimes = canMonoTimes
  
      self.gas_pressed_prev = ret.gasPressed
      self.brake_pressed_prev = ret.brakePressed
      self.cruise_enabled_prev = ret.cruiseState.enabled
  
      return ret.as_reader()
  
    def apply(self, c, perception_state=log.Live20Data.new_message()):
  
      hud_alert = get_hud_alerts(c.hudControl.visualAlert, c.hudControl.audibleAlert)
  
      self.CC.update(self.sendcan, c.enabled, self.CS, c.actuators,
                     c.cruiseControl.cancel, hud_alert)
  
      return False
  