from cereal import car
from common.realtime import DT_CTRL
from common.numpy_fast import interp
from selfdrive.config import Conversions as CV
from selfdrive.car import apply_std_steer_torque_limits
from selfdrive.car.gm import gmcan
from selfdrive.car.gm.values import DBC, CanBus, CarControllerParams
from opendbc.can.packer import CANPacker

VisualAlert = car.CarControl.HUDControl.VisualAlert


class CarController():
  def __init__(self, dbc_name, CP, VM):
    self.start_time = 0.
    self.apply_steer_last = 0
    self.apply_gas = 0
    self.apply_brake = 0

    self.lka_steering_cmd_counter_last = -1
    self.lka_icon_status_last = (False, False)
    self.steer_rate_limited = False

    self.params = CarControllerParams()

    self.packer_pt = CANPacker(DBC[CP.carFingerprint]['pt'])
    self.packer_obj = CANPacker(DBC[CP.carFingerprint]['radar'])
    self.packer_ch = CANPacker(DBC[CP.carFingerprint]['chassis'])

  def update(self, c, CS, frame, actuators, hud_v_cruise, hud_show_lanes, hud_show_car, hud_alert):

    P = self.params

    # Send CAN commands.
    can_sends = []

    # Steering (50Hz)
    # Avoid GM EPS faults when transmitting messages too close together: skip this transmit if we just received the
    # next Panda loopback confirmation in the current CS frame.
    if CS.lka_steering_cmd_counter != self.lka_steering_cmd_counter_last:
      self.lka_steering_cmd_counter_last = CS.lka_steering_cmd_counter
    elif (frame % P.STEER_STEP) == 0:
      lkas_enabled = c.latActive and CS.out.vEgo > P.MIN_STEER_SPEED
      if lkas_enabled:
        new_steer = int(round(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
      # GM EPS faults on any gap in received message counters. To handle transient OP/Panda safety sync issues at the
      # moment of disengaging, increment the counter based on the last message known to pass Panda safety checks.
      idx = (CS.lka_steering_cmd_counter + 1) % 4

      can_sends.append(gmcan.create_steering_control(self.packer_pt, CanBus.POWERTRAIN, apply_steer, idx, lkas_enabled))

    # Gas/regen and brakes - all at 25Hz
    if (frame % 4) == 0:
      if not c.longActive:
        # Stock ECU sends max regen when not enabled.
        self.apply_gas = P.MAX_ACC_REGEN
        self.apply_brake = 0
      else:
        self.apply_gas = int(round(interp(actuators.accel, P.GAS_LOOKUP_BP, P.GAS_LOOKUP_V)))
        self.apply_brake = int(round(interp(actuators.accel, P.BRAKE_LOOKUP_BP, P.BRAKE_LOOKUP_V)))

      idx = (frame // 4) % 4

      at_full_stop = c.longActive and CS.out.standstill
      near_stop = c.longActive and (CS.out.vEgo < P.NEAR_STOP_BRAKE_PHASE)
      can_sends.append(gmcan.create_friction_brake_command(self.packer_ch, CanBus.CHASSIS, self.apply_brake, idx, near_stop, at_full_stop))
      can_sends.append(gmcan.create_gas_regen_command(self.packer_pt, CanBus.POWERTRAIN, self.apply_gas, idx, c.longActive, at_full_stop))

    # Send dashboard UI commands (ACC status), 25hz
    if (frame % 4) == 0:
      send_fcw = hud_alert == VisualAlert.fcw
      can_sends.append(gmcan.create_acc_dashboard_command(self.packer_pt, CanBus.POWERTRAIN, c.longActive, hud_v_cruise * CV.MS_TO_KPH, hud_show_car, send_fcw))

    # 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(self.packer_obj, 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:
      steer_alert = hud_alert in (VisualAlert.steerRequired, VisualAlert.ldw)
      can_sends.append(gmcan.create_lka_icon_command(CanBus.SW_GMLAN, lka_active, lka_critical, steer_alert))
      self.lka_icon_status_last = lka_icon_status

    new_actuators = actuators.copy()
    new_actuators.steer = self.apply_steer_last / P.STEER_MAX
    new_actuators.gas = self.apply_gas
    new_actuators.brake = self.apply_brake

    return new_actuators, can_sends