text: from cereal import car
  from common.realtime import DT_CTRL
  from common.numpy_fast import interp, clip
  from selfdrive.config import Conversions as CV
  from selfdrive.car import apply_std_steer_torque_limits, create_gas_command
  from selfdrive.car.gm import gmcan
  from selfdrive.car.gm.values import DBC, SUPERCRUISE_CARS, NO_ASCM_CARS, CanBus
  from opendbc.can.packer import CANPacker
  
  VisualAlert = car.CarControl.HUDControl.VisualAlert
  
  
  class CarControllerParams():
    def __init__(self, car_fingerprint):
      if car_fingerprint in SUPERCRUISE_CARS:
        self.STEER_MAX = 150
        self.STEER_STEP = 1              # how often we update the steer cmd
        self.STEER_DELTA_UP = 2          # 0.75s time to peak torque
        self.STEER_DELTA_DOWN = 5        # 0.3s from peak torque to zero
        self.MIN_STEER_SPEED = -1.       # can steer down to zero
      elif car_fingerprint in NO_ASCM_CARS:
        self.STEER_MAX = 300
        self.STEER_STEP = 1              # how often we update the steer cmd
        self.STEER_DELTA_UP = 3          # ~0.75s time to peak torque (255/50hz/0.75s)
        self.STEER_DELTA_DOWN = 7       # ~0.3s from peak torque to zero
        self.MIN_STEER_SPEED = 3.
      else:
        self.STEER_MAX = 300
        self.STEER_STEP = 2              # how often we update the steer cmd
        self.STEER_DELTA_UP = 7          # ~0.75s time to peak torque (255/50hz/0.75s)
        self.STEER_DELTA_DOWN = 17       # ~0.3s from peak torque to zero
        self.MIN_STEER_SPEED = 3.
  
      self.STEER_DRIVER_ALLOWANCE = 50   # allowed driver torque before start limiting
      self.STEER_DRIVER_MULTIPLIER = 4   # weight driver torque heavily
      self.STEER_DRIVER_FACTOR = 100     # from dbc
      self.NEAR_STOP_BRAKE_PHASE = 0.5 # m/s, more aggressive braking near full stop
  
      # Takes case of "Service Adaptive Cruise" and "Service Front Camera"
      # dashboard messages.
      self.ADAS_KEEPALIVE_STEP = 100
      self.CAMERA_KEEPALIVE_STEP = 100
  
      # pedal lookups, only for Volt
      MAX_GAS = 3072              # Only a safety limit
      ZERO_GAS = 2048
      MAX_BRAKE = 350             # Should be around 3.5m/s^2, including regen
      self.MAX_ACC_REGEN = 1404  # ACC Regen braking is slightly less powerful than max regen paddle
      self.GAS_LOOKUP_BP = [-0.25, 0., 0.5]
      self.GAS_LOOKUP_V = [self.MAX_ACC_REGEN, ZERO_GAS, MAX_GAS]
      self.BRAKE_LOOKUP_BP = [-1., -0.25]
      self.BRAKE_LOOKUP_V = [MAX_BRAKE, 0]
  
  
  def actuator_hystereses(final_pedal, pedal_steady):
    # hyst params... TODO: move these to VehicleParams
    pedal_hyst_gap = 0.01    # don't change pedal command for small oscillations within this value
  
    # for small pedal oscillations within pedal_hyst_gap, don't change the pedal command
    if final_pedal == 0.:
      pedal_steady = 0.
    elif final_pedal > pedal_steady + pedal_hyst_gap:
      pedal_steady = final_pedal - pedal_hyst_gap
    elif final_pedal < pedal_steady - pedal_hyst_gap:
      pedal_steady = final_pedal + pedal_hyst_gap
    final_pedal = pedal_steady
  
    return final_pedal, pedal_steady
  
  def process_hud_alert(hud_alert):
    # initialize to no alert
    steer = 0
    if hud_alert == VisualAlert.steerRequired:
      steer = 1
    return steer
  
  class CarController():
    def __init__(self, dbc_name, CP, VM):
      self.pedal_steady = 0.
      self.start_time = 0.
      self.apply_steer_last = 0
      self.car_fingerprint = CP.carFingerprint
      self.lka_icon_status_last = (False, False)
      self.steer_rate_limited = False
  
      self.params = CarControllerParams(CP.carFingerprint)
  
      self.packer_pt = CANPacker(DBC[CP.carFingerprint]['pt'])
      self.packer_ch = CANPacker(DBC[CP.carFingerprint]['chassis'])
  
    def update(self, enabled, CS, frame, actuators, \
               hud_v_cruise, hud_show_lanes, hud_show_car, hud_alert):
  
      P = self.params
  
      # Send CAN commands.
      can_sends = []
  
      alert_out = process_hud_alert(hud_alert)
      steer = alert_out
  
      ### STEER ###
  
      if (frame % P.STEER_STEP) == 0:
        lkas_enabled = enabled and not CS.steer_not_allowed and CS.out.vEgo > P.MIN_STEER_SPEED
        if lkas_enabled:
          new_steer = actuators.steer * P.STEER_MAX
          apply_steer = apply_std_steer_torque_limits(new_steer, self.apply_steer_last, CS.out.steeringTorque, P)
          self.steer_rate_limited = new_steer != apply_steer
        else:
          apply_steer = 0
  
        self.apply_steer_last = apply_steer
        idx = (frame // P.STEER_STEP) % 4
  
        if self.car_fingerprint in SUPERCRUISE_CARS:
          can_sends += gmcan.create_steering_control_ct6(self.packer_pt,
            CanBus, apply_steer, CS.out.vEgo, idx, lkas_enabled)
        else:
          can_sends.append(gmcan.create_steering_control(self.packer_pt,
            CanBus.POWERTRAIN, apply_steer, idx, lkas_enabled))
  
      ### GAS/BRAKE ###
      if self.car_fingerprint not in SUPERCRUISE_CARS:
        # no output if not enabled, but keep sending keepalive messages
        # treat pedals as one
        final_pedal = actuators.gas - actuators.brake
  
        # *** apply pedal hysteresis ***
        final_brake, self.brake_steady = actuator_hystereses(
          final_pedal, self.pedal_steady)
        
        if not enabled:
          # Stock ECU sends max regen when not enabled.
          apply_gas = P.MAX_ACC_REGEN
          apply_brake = 0
        else:
          apply_gas = int(round(interp(final_pedal, P.GAS_LOOKUP_BP, P.GAS_LOOKUP_V)))
          apply_brake = int(round(interp(final_pedal, P.BRAKE_LOOKUP_BP, P.BRAKE_LOOKUP_V)))
        if not self.car_fingerprint in NO_ASCM_CARS:
          # Gas/regen and brakes - all at 25Hz
          if (frame % 4) == 0:
            idx = (frame // 4) % 4
            at_full_stop = enabled and CS.out.standstill
            near_stop = enabled and (CS.out.vEgo < P.NEAR_STOP_BRAKE_PHASE)
            can_sends.append(gmcan.create_friction_brake_command(self.packer_ch, CanBus.CHASSIS, apply_brake, idx, near_stop, at_full_stop))
            at_full_stop = enabled and CS.out.standstill
            can_sends.append(gmcan.create_gas_regen_command(self.packer_pt, CanBus.POWERTRAIN, apply_gas, idx, enabled, at_full_stop))
        elif CS.CP.enableGasInterceptor:
          #It seems in L mode, accel / decel point is around 1/5
          #0----decel-------0.2-------accel----------1
          new_gas = 0.8 * actuators.gas + 0.2
          new_brake = 0.2 * actuators.brake
          #I am assuming we should not get both a gas and a break value...
          final_pedal2 = new_gas - new_brake
          #TODO: Hysteresis
          #TODO: Use friction brake via AEB for harder braking
  
          #JJS - no adjust yet - scaling needs to be -1 <-> +1
          pedal_gas = clip(final_pedal, 0., 1.)
          #This would be more appropriate
          #pedal_gas = clip(actuators.gas, 0., 1.)
          if (frame % 4) == 0:
            idx = (frame // 4) % 4
            # send exactly zero if apply_gas is zero. Interceptor will send the max between read value and apply_gas.
            # This prevents unexpected pedal range rescaling
            can_sends.append(create_gas_command(self.packer_pt, pedal_gas, idx))
  
        # Send dashboard UI commands (ACC status), 25hz
        if (frame % 4) == 0:
          can_sends.append(gmcan.create_acc_dashboard_command(self.packer_pt, CanBus.POWERTRAIN, enabled, hud_v_cruise * CV.MS_TO_KPH, hud_show_car))
  
        # Radar needs to know current speed and yaw rate (50hz),
        # and that ADAS is alive (10hz)
        time_and_headlights_step = 10
        tt = frame * DT_CTRL
  
        if frame % time_and_headlights_step == 0:
          idx = (frame // time_and_headlights_step) % 4
          can_sends.append(gmcan.create_adas_time_status(CanBus.OBSTACLE, int((tt - self.start_time) * 60), idx))
          can_sends.append(gmcan.create_adas_headlights_status(CanBus.OBSTACLE))
  
        speed_and_accelerometer_step = 2
        if frame % speed_and_accelerometer_step == 0:
          idx = (frame // speed_and_accelerometer_step) % 4
          can_sends.append(gmcan.create_adas_steering_status(CanBus.OBSTACLE, idx))
          can_sends.append(gmcan.create_adas_accelerometer_speed_status(CanBus.OBSTACLE, CS.out.vEgo, idx))
  
        if frame % P.ADAS_KEEPALIVE_STEP == 0:
          can_sends += gmcan.create_adas_keepalive(CanBus.POWERTRAIN)
  
        # Show green icon when LKA torque is applied, and
        # alarming orange icon when approaching torque limit.
        # If not sent again, LKA icon disappears in about 5 seconds.
        # Conveniently, sending camera message periodically also works as a keepalive.
        lka_active = CS.lkas_status == 1
        lka_critical = lka_active and abs(actuators.steer) > 0.9
        lka_icon_status = (lka_active, lka_critical)
        if frame % P.CAMERA_KEEPALIVE_STEP == 0 \
            or lka_icon_status != self.lka_icon_status_last:
          can_sends.append(gmcan.create_lka_icon_command(CanBus.SW_GMLAN, lka_active, lka_critical, steer))
          self.lka_icon_status_last = lka_icon_status
  
      return can_sends
  