#!/usr/bin/env python3
from cereal import car
from selfdrive.config import Conversions as CV
from selfdrive.controls.lib.drive_helpers import EventTypes as ET, create_event
from selfdrive.car.hyundai.values import Ecu, ECU_FINGERPRINT, CAR, get_hud_alerts, FINGERPRINTS
from selfdrive.car import STD_CARGO_KG, scale_rot_inertia, scale_tire_stiffness, is_ecu_disconnected, gen_empty_fingerprint
from selfdrive.car.interfaces import CarInterfaceBase

class CarInterface(CarInterfaceBase):

  @staticmethod
  def compute_gb(accel, speed):
    return float(accel) / 3.0

  @staticmethod
  def get_params(candidate, fingerprint=gen_empty_fingerprint(), has_relay=False, car_fw=[]):
    ret = CarInterfaceBase.get_std_params(candidate, fingerprint, has_relay)

    ret.carName = "hyundai"
    ret.safetyModel = car.CarParams.SafetyModel.hyundai
    ret.radarOffCan = True

    ret.steerActuatorDelay = 0.1  # Default delay
    ret.steerRateCost = 0.5
    ret.steerLimitTimer = 0.4
    tire_stiffness_factor = 1.

    if candidate == CAR.SANTA_FE:
      ret.lateralTuning.pid.kf = 0.00005
      ret.mass = 3982. * CV.LB_TO_KG + STD_CARGO_KG
      ret.wheelbase = 2.766

      # Values from optimizer
      ret.steerRatio = 16.55  # 13.8 is spec end-to-end
      tire_stiffness_factor = 0.82

      ret.lateralTuning.pid.kiBP, ret.lateralTuning.pid.kpBP = [[9., 22.], [9., 22.]]
      ret.lateralTuning.pid.kpV, ret.lateralTuning.pid.kiV = [[0.2, 0.35], [0.05, 0.09]]
      ret.minSteerSpeed = 0.
    elif candidate == CAR.KIA_SORENTO:
      ret.lateralTuning.pid.kf = 0.00005
      ret.mass = 1985. + STD_CARGO_KG
      ret.wheelbase = 2.78
      ret.steerRatio = 14.4 * 1.1   # 10% higher at the center seems reasonable
      ret.lateralTuning.pid.kiBP, ret.lateralTuning.pid.kpBP = [[0.], [0.]]
      ret.lateralTuning.pid.kpV, ret.lateralTuning.pid.kiV = [[0.25], [0.05]]
      ret.minSteerSpeed = 0.
    elif candidate == CAR.ELANTRA:
      ret.lateralTuning.pid.kf = 0.00006
      ret.mass = 1275. + STD_CARGO_KG
      ret.wheelbase = 2.7
      ret.steerRatio = 13.73   #Spec
      tire_stiffness_factor = 0.385
      ret.lateralTuning.pid.kiBP, ret.lateralTuning.pid.kpBP = [[0.], [0.]]
      ret.lateralTuning.pid.kpV, ret.lateralTuning.pid.kiV = [[0.25], [0.05]]
      ret.minSteerSpeed = 32 * CV.MPH_TO_MS
    elif candidate == CAR.GENESIS:
      ret.lateralTuning.pid.kf = 0.00005
      ret.mass = 2060. + STD_CARGO_KG
      ret.wheelbase = 3.01
      ret.steerRatio = 16.5
      ret.lateralTuning.pid.kiBP, ret.lateralTuning.pid.kpBP = [[0.], [0.]]
      ret.lateralTuning.pid.kpV, ret.lateralTuning.pid.kiV = [[0.16], [0.01]]
      ret.minSteerSpeed = 35 * CV.MPH_TO_MS
    elif candidate == CAR.KIA_OPTIMA:
      ret.lateralTuning.pid.kf = 0.00005
      ret.mass = 3558. * CV.LB_TO_KG
      ret.wheelbase = 2.80
      ret.steerRatio = 13.75
      tire_stiffness_factor = 0.5
      ret.lateralTuning.pid.kiBP, ret.lateralTuning.pid.kpBP = [[0.], [0.]]
      ret.lateralTuning.pid.kpV, ret.lateralTuning.pid.kiV = [[0.25], [0.05]]
    elif candidate == CAR.KIA_STINGER:
      ret.lateralTuning.pid.kf = 0.00005
      ret.mass = 1825. + STD_CARGO_KG
      ret.wheelbase = 2.78
      ret.steerRatio = 14.4 * 1.15   # 15% higher at the center seems reasonable
      ret.lateralTuning.pid.kiBP, ret.lateralTuning.pid.kpBP = [[0.], [0.]]
      ret.lateralTuning.pid.kpV, ret.lateralTuning.pid.kiV = [[0.25], [0.05]]
      ret.minSteerSpeed = 0.

    ret.centerToFront = ret.wheelbase * 0.4

    # TODO: get actual value, for now starting with reasonable value for
    # civic and scaling by mass and wheelbase
    ret.rotationalInertia = scale_rot_inertia(ret.mass, ret.wheelbase)

    # 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, ret.tireStiffnessRear = scale_tire_stiffness(ret.mass, ret.wheelbase, ret.centerToFront,
                                                                         tire_stiffness_factor=tire_stiffness_factor)

    ret.enableCamera = is_ecu_disconnected(fingerprint[0], FINGERPRINTS, ECU_FINGERPRINT, candidate, Ecu.fwdCamera) or has_relay

    return ret

  def update(self, c, can_strings):
    self.cp.update_strings(can_strings)
    self.cp_cam.update_strings(can_strings)

    ret = self.CS.update(self.cp, self.cp_cam)
    ret.canValid = self.cp.can_valid and self.cp_cam.can_valid

    # TODO: button presses
    ret.buttonEvents = []

    events = self.create_common_events(ret)

    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]))

    # 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
    if self.low_speed_alert:
      events.append(create_event('belowSteerSpeed', [ET.WARNING]))

    ret.events = events

    self.gas_pressed_prev = ret.gasPressed
    self.brake_pressed_prev = ret.brakePressed
    self.cruise_enabled_prev = ret.cruiseState.enabled

    self.CS.out = ret.as_reader()
    return self.CS.out

  def apply(self, c):

    hud_alert = get_hud_alerts(c.hudControl.visualAlert)

    can_sends = self.CC.update(c.enabled, self.CS, c.actuators,
                               c.cruiseControl.cancel, hud_alert)

    return can_sends
