from cereal import car
from opendbc.can.packer import CANPacker
from selfdrive.car.mazda import mazdacan
from selfdrive.car.mazda.values import CarControllerParams, Buttons
from selfdrive.car import apply_std_steer_torque_limits

VisualAlert = car.CarControl.HUDControl.VisualAlert

class CarController():
  def __init__(self, dbc_name, CP, VM):
    self.CP = CP
    self.apply_steer_last = 0
    self.packer = CANPacker(dbc_name)
    self.steer_rate_limited = False
    self.brake_counter = 0

  def update(self, c, CS, frame):
    can_sends = []

    apply_steer = 0
    self.steer_rate_limited = False

    if c.latActive:
      # calculate steer and also set limits due to driver torque
      new_steer = int(round(c.actuators.steer * CarControllerParams.STEER_MAX))
      apply_steer = apply_std_steer_torque_limits(new_steer, self.apply_steer_last,
                                                  CS.out.steeringTorque, CarControllerParams)
      self.steer_rate_limited = new_steer != apply_steer

      if CS.out.standstill and frame % 5 == 0:
        # Mazda Stop and Go requires a RES button (or gas) press if the car stops more than 3 seconds
        # Send Resume button at 20hz if we're engaged at standstill to support full stop and go!
        # TODO: improve the resume trigger logic by looking at actual radar data
        can_sends.append(mazdacan.create_button_cmd(self.packer, self.CP.carFingerprint, CS.crz_btns_counter, Buttons.RESUME))

    if c.cruiseControl.cancel:
      # If brake is pressed, let us wait >70ms before trying to disable crz to avoid
      # a race condition with the stock system, where the second cancel from openpilot
      # will disable the crz 'main on'. crz ctrl msg runs at 50hz. 70ms allows us to
      # read 3 messages and most likely sync state before we attempt cancel.
      self.brake_counter = self.brake_counter + 1
      if frame % 10 == 0 and not (CS.out.brakePressed and self.brake_counter < 7):
        # Cancel Stock ACC if it's enabled while OP is disengaged
        # Send at a rate of 10hz until we sync with stock ACC state
        can_sends.append(mazdacan.create_button_cmd(self.packer, self.CP.carFingerprint, CS.crz_btns_counter, Buttons.CANCEL))
    else:
      self.brake_counter = 0

    self.apply_steer_last = apply_steer

    # send HUD alerts
    if frame % 50 == 0:
      ldw = c.hudControl.visualAlert == VisualAlert.ldw
      steer_required = c.hudControl.visualAlert == VisualAlert.steerRequired
      # TODO: find a way to silence audible warnings so we can add more hud alerts
      steer_required = steer_required and CS.lkas_allowed_speed
      can_sends.append(mazdacan.create_alert_command(self.packer, CS.cam_laneinfo, ldw, steer_required))

    # send steering command
    can_sends.append(mazdacan.create_steering_control(self.packer, self.CP.carFingerprint,
                                                      frame, apply_steer, CS.cam_lkas))

    new_actuators = c.actuators.copy()
    new_actuators.steer = apply_steer / CarControllerParams.STEER_MAX

    return new_actuators, can_sends