text: from math import atan2
  
  from cereal import car
  from common.numpy_fast import interp
  from common.realtime import DT_DMON
  from selfdrive.hardware import TICI
  from common.filter_simple import FirstOrderFilter
  from common.stat_live import RunningStatFilter
  
  EventName = car.CarEvent.EventName
  
  # ******************************************************************************************
  #  NOTE: To fork maintainers.
  #  Disabling or nerfing safety features will get you and your users banned from our servers.
  #  We recommend that you do not change these numbers from the defaults.
  # ******************************************************************************************
  
  class DRIVER_MONITOR_SETTINGS():
    def __init__(self, TICI=TICI, DT_DMON=DT_DMON):
      self._DT_DMON = DT_DMON
      self._AWARENESS_TIME = 300. # passive wheeltouch total timeout
      self._AWARENESS_PRE_TIME_TILL_TERMINAL = 12.
      self._AWARENESS_PROMPT_TIME_TILL_TERMINAL = 6.
      self._DISTRACTED_TIME = 11. # active monitoring total timeout
      self._DISTRACTED_PRE_TIME_TILL_TERMINAL = 8.
      self._DISTRACTED_PROMPT_TIME_TILL_TERMINAL = 6.
  
      self._FACE_THRESHOLD = 0.5
      self._PARTIAL_FACE_THRESHOLD = 0.765 if TICI else 0.43
      self._EYE_THRESHOLD = 0.61 if TICI else 0.55
      self._SG_THRESHOLD = 0.89 if TICI else 0.86
      self._BLINK_THRESHOLD = 0.82 if TICI else 0.588
      self._BLINK_THRESHOLD_SLACK = 0.9 if TICI else 0.77
      self._BLINK_THRESHOLD_STRICT = self._BLINK_THRESHOLD
  
      self._POSE_PITCH_THRESHOLD = 0.3237
      self._POSE_PITCH_THRESHOLD_SLACK = 0.3657
      self._POSE_PITCH_THRESHOLD_STRICT = self._POSE_PITCH_THRESHOLD
      self._POSE_YAW_THRESHOLD = 0.3109
      self._POSE_YAW_THRESHOLD_SLACK = 0.4294
      self._POSE_YAW_THRESHOLD_STRICT = self._POSE_YAW_THRESHOLD
      self._PITCH_NATURAL_OFFSET = 0.057 # initial value before offset is learned
      self._YAW_NATURAL_OFFSET = 0.11 # initial value before offset is learned
      self._PITCH_MAX_OFFSET = 0.124
      self._PITCH_MIN_OFFSET = -0.0881
      self._YAW_MAX_OFFSET = 0.289
      self._YAW_MIN_OFFSET = -0.0246
  
      self._POSESTD_THRESHOLD = 0.38 if TICI else 0.3
      self._HI_STD_FALLBACK_TIME = int(10  / self._DT_DMON)  # fall back to wheel touch if model is uncertain for 10s
      self._DISTRACTED_FILTER_TS = 0.25  # 0.6Hz
  
      self._POSE_CALIB_MIN_SPEED = 13  # 30 mph
      self._POSE_OFFSET_MIN_COUNT = int(60 / self._DT_DMON)  # valid data counts before calibration completes, 1min cumulative
      self._POSE_OFFSET_MAX_COUNT = int(360 / self._DT_DMON)  # stop deweighting new data after 6 min, aka "short term memory"
  
      self._RECOVERY_FACTOR_MAX = 5.  # relative to minus step change
      self._RECOVERY_FACTOR_MIN = 1.25  # relative to minus step change
  
      self._MAX_TERMINAL_ALERTS = 3  # not allowed to engage after 3 terminal alerts
      self._MAX_TERMINAL_DURATION = int(30 / self._DT_DMON)  # not allowed to engage after 30s of terminal alerts
  
  
  # model output refers to center of cropped image, so need to apply the x displacement offset
  RESIZED_FOCAL = 320.0
  H, W, FULL_W = 320, 160, 426
  
  class DistractedType:
    NOT_DISTRACTED = 0
    BAD_POSE = 1
    BAD_BLINK = 2
  
  def face_orientation_from_net(angles_desc, pos_desc, rpy_calib, is_rhd):
    # the output of these angles are in device frame
    # so from driver's perspective, pitch is up and yaw is right
  
    pitch_net, yaw_net, roll_net = angles_desc
  
    face_pixel_position = ((pos_desc[0] + .5)*W - W + FULL_W, (pos_desc[1]+.5)*H)
    yaw_focal_angle = atan2(face_pixel_position[0] - FULL_W//2, RESIZED_FOCAL)
    pitch_focal_angle = atan2(face_pixel_position[1] - H//2, RESIZED_FOCAL)
  
    pitch = pitch_net + pitch_focal_angle
    yaw = -yaw_net + yaw_focal_angle
  
    # no calib for roll
    pitch -= rpy_calib[1]
    yaw -= rpy_calib[2] * (1 - 2 * int(is_rhd))  # lhd -> -=, rhd -> +=
    return roll_net, pitch, yaw
  
  class DriverPose():
    def __init__(self, max_trackable):
      self.yaw = 0.
      self.pitch = 0.
      self.roll = 0.
      self.yaw_std = 0.
      self.pitch_std = 0.
      self.roll_std = 0.
      self.pitch_offseter = RunningStatFilter(max_trackable=max_trackable)
      self.yaw_offseter = RunningStatFilter(max_trackable=max_trackable)
      self.low_std = True
      self.cfactor_pitch = 1.
      self.cfactor_yaw = 1.
  
  class DriverBlink():
    def __init__(self):
      self.left_blink = 0.
      self.right_blink = 0.
      self.cfactor = 1.
  
  class DriverStatus():
    def __init__(self, rhd=False, settings=DRIVER_MONITOR_SETTINGS()):
      # init policy settings
      self.settings = settings
  
      # init driver status
      self.is_rhd_region = rhd
      self.pose = DriverPose(self.settings._POSE_OFFSET_MAX_COUNT)
      self.pose_calibrated = False
      self.blink = DriverBlink()
      self.awareness = 1.
      self.awareness_active = 1.
      self.awareness_passive = 1.
      self.driver_distracted = False
      self.driver_distraction_filter = FirstOrderFilter(0., self.settings._DISTRACTED_FILTER_TS, self.settings._DT_DMON)
      self.face_detected = False
      self.face_partial = False
      self.terminal_alert_cnt = 0
      self.terminal_time = 0
      self.step_change = 0.
      self.active_monitoring_mode = True
      self.is_model_uncertain = False
      self.hi_stds = 0
      self.threshold_pre = self.settings._DISTRACTED_PRE_TIME_TILL_TERMINAL / self.settings._DISTRACTED_TIME
      self.threshold_prompt = self.settings._DISTRACTED_PROMPT_TIME_TILL_TERMINAL / self.settings._DISTRACTED_TIME
  
      self._set_timers(active_monitoring=True)
  
    def _set_timers(self, active_monitoring):
      if self.active_monitoring_mode and self.awareness <= self.threshold_prompt:
        if active_monitoring:
          self.step_change = self.settings._DT_DMON / self.settings._DISTRACTED_TIME
        else:
          self.step_change = 0.
        return  # no exploit after orange alert
      elif self.awareness <= 0.:
        return
  
      if active_monitoring:
        # when falling back from passive mode to active mode, reset awareness to avoid false alert
        if not self.active_monitoring_mode:
          self.awareness_passive = self.awareness
          self.awareness = self.awareness_active
  
        self.threshold_pre = self.settings._DISTRACTED_PRE_TIME_TILL_TERMINAL / self.settings._DISTRACTED_TIME
        self.threshold_prompt = self.settings._DISTRACTED_PROMPT_TIME_TILL_TERMINAL / self.settings._DISTRACTED_TIME
        self.step_change = self.settings._DT_DMON / self.settings._DISTRACTED_TIME
        self.active_monitoring_mode = True
      else:
        if self.active_monitoring_mode:
          self.awareness_active = self.awareness
          self.awareness = self.awareness_passive
  
        self.threshold_pre = self.settings._AWARENESS_PRE_TIME_TILL_TERMINAL / self.settings._AWARENESS_TIME
        self.threshold_prompt = self.settings._AWARENESS_PROMPT_TIME_TILL_TERMINAL / self.settings._AWARENESS_TIME
        self.step_change = self.settings._DT_DMON / self.settings._AWARENESS_TIME
        self.active_monitoring_mode = False
  
    def _is_driver_distracted(self, pose, blink):
      if not self.pose_calibrated:
        pitch_error = pose.pitch - self.settings._PITCH_NATURAL_OFFSET
        yaw_error = pose.yaw - self.settings._YAW_NATURAL_OFFSET
      else:
        pitch_error = pose.pitch - min(max(self.pose.pitch_offseter.filtered_stat.mean(),
                                                         self.settings._PITCH_MIN_OFFSET), self.settings._PITCH_MAX_OFFSET)
        yaw_error = pose.yaw - min(max(self.pose.yaw_offseter.filtered_stat.mean(),
                                                      self.settings._YAW_MIN_OFFSET), self.settings._YAW_MAX_OFFSET)
  
      pitch_error = 0 if pitch_error > 0 else abs(pitch_error) # no positive pitch limit
      yaw_error = abs(yaw_error)
  
      if pitch_error > self.settings._POSE_PITCH_THRESHOLD*pose.cfactor_pitch or \
         yaw_error > self.settings._POSE_YAW_THRESHOLD*pose.cfactor_yaw:
        return DistractedType.BAD_POSE
      elif (blink.left_blink + blink.right_blink)*0.5 > self.settings._BLINK_THRESHOLD*blink.cfactor:
        return DistractedType.BAD_BLINK
      else:
        return DistractedType.NOT_DISTRACTED
  
    def set_policy(self, model_data, car_speed):
      ep = min(model_data.meta.engagedProb, 0.8) / 0.8 # engaged prob
      bp = model_data.meta.disengagePredictions.brakeDisengageProbs[0] # brake disengage prob in next 2s
      # TODO: retune adaptive blink
      self.blink.cfactor = interp(ep, [0, 0.5, 1],
                                             [self.settings._BLINK_THRESHOLD_STRICT,
                                              self.settings._BLINK_THRESHOLD,
                                              self.settings._BLINK_THRESHOLD_SLACK]) / self.settings._BLINK_THRESHOLD
      k1 = max(-0.00156*((car_speed-16)**2)+0.6, 0.2)
      bp_normal = max(min(bp / k1, 0.5),0)
      self.pose.cfactor_pitch = interp(bp_normal, [0, 0.5],
                                             [self.settings._POSE_PITCH_THRESHOLD_SLACK,
                                              self.settings._POSE_PITCH_THRESHOLD_STRICT]) / self.settings._POSE_PITCH_THRESHOLD
      self.pose.cfactor_yaw = interp(bp_normal, [0, 0.5],
                                             [self.settings._POSE_YAW_THRESHOLD_SLACK,
                                              self.settings._POSE_YAW_THRESHOLD_STRICT]) / self.settings._POSE_YAW_THRESHOLD
  
    def get_pose(self, driver_state, cal_rpy, car_speed, op_engaged):
      if not all(len(x) > 0 for x in (driver_state.faceOrientation, driver_state.facePosition,
                                      driver_state.faceOrientationStd, driver_state.facePositionStd)):
        return
  
      self.face_partial = driver_state.partialFace > self.settings._PARTIAL_FACE_THRESHOLD
      self.face_detected = driver_state.faceProb > self.settings._FACE_THRESHOLD or self.face_partial
      self.pose.roll, self.pose.pitch, self.pose.yaw = face_orientation_from_net(driver_state.faceOrientation, driver_state.facePosition, cal_rpy, self.is_rhd_region)
      self.pose.pitch_std = driver_state.faceOrientationStd[0]
      self.pose.yaw_std = driver_state.faceOrientationStd[1]
      # self.pose.roll_std = driver_state.faceOrientationStd[2]
      model_std_max = max(self.pose.pitch_std, self.pose.yaw_std)
      self.pose.low_std = model_std_max < self.settings._POSESTD_THRESHOLD and not self.face_partial
      self.blink.left_blink = driver_state.leftBlinkProb * (driver_state.leftEyeProb > self.settings._EYE_THRESHOLD) * (driver_state.sunglassesProb < self.settings._SG_THRESHOLD)
      self.blink.right_blink = driver_state.rightBlinkProb * (driver_state.rightEyeProb > self.settings._EYE_THRESHOLD) * (driver_state.sunglassesProb < self.settings._SG_THRESHOLD)
  
      self.driver_distracted = self._is_driver_distracted(self.pose, self.blink) > 0 and \
                                     driver_state.faceProb > self.settings._FACE_THRESHOLD and self.pose.low_std
      self.driver_distraction_filter.update(self.driver_distracted)
  
      # update offseter
      # only update when driver is actively driving the car above a certain speed
      if self.face_detected and car_speed > self.settings._POSE_CALIB_MIN_SPEED and self.pose.low_std and (not op_engaged or not self.driver_distracted):
        self.pose.pitch_offseter.push_and_update(self.pose.pitch)
        self.pose.yaw_offseter.push_and_update(self.pose.yaw)
  
      self.pose_calibrated = self.pose.pitch_offseter.filtered_stat.n > self.settings._POSE_OFFSET_MIN_COUNT and \
                                         self.pose.yaw_offseter.filtered_stat.n > self.settings._POSE_OFFSET_MIN_COUNT
  
      self.is_model_uncertain = self.hi_stds > self.settings._HI_STD_FALLBACK_TIME
      self._set_timers(self.face_detected and not self.is_model_uncertain)
      if self.face_detected and not self.pose.low_std and not self.driver_distracted:
        self.hi_stds += 1
      elif self.face_detected and self.pose.low_std:
        self.hi_stds = 0
  
    def update(self, events, driver_engaged, ctrl_active, standstill):
      if (driver_engaged and self.awareness > 0) or not ctrl_active:
        # reset only when on disengagement if red reached
        self.awareness = 1.
        self.awareness_active = 1.
        self.awareness_passive = 1.
        return
  
      driver_attentive = self.driver_distraction_filter.x < 0.37
      awareness_prev = self.awareness
  
      if (driver_attentive and self.face_detected and self.pose.low_std and self.awareness > 0):
        # only restore awareness when paying attention and alert is not red
        self.awareness = min(self.awareness + ((self.settings._RECOVERY_FACTOR_MAX-self.settings._RECOVERY_FACTOR_MIN)*(1.-self.awareness)+self.settings._RECOVERY_FACTOR_MIN)*self.step_change, 1.)
        if self.awareness == 1.:
          self.awareness_passive = min(self.awareness_passive + self.step_change, 1.)
        # don't display alert banner when awareness is recovering and has cleared orange
        if self.awareness > self.threshold_prompt:
          return
  
      standstill_exemption = standstill and self.awareness - self.step_change <= self.threshold_prompt
      certainly_distracted = self.driver_distraction_filter.x > 0.63 and self.driver_distracted and self.face_detected
      maybe_distracted = self.hi_stds > self.settings._HI_STD_FALLBACK_TIME or not self.face_detected
      if certainly_distracted or maybe_distracted:
        # should always be counting if distracted unless at standstill and reaching orange
        if not standstill_exemption:
          self.awareness = max(self.awareness - self.step_change, -0.1)
  
      alert = None
      if self.awareness <= 0.:
        # terminal red alert: disengagement required
        alert = EventName.driverDistracted if self.active_monitoring_mode else EventName.driverUnresponsive
        self.terminal_time += 1
        if awareness_prev > 0.:
          self.terminal_alert_cnt += 1
      elif self.awareness <= self.threshold_prompt:
        # prompt orange alert
        alert = EventName.promptDriverDistracted if self.active_monitoring_mode else EventName.promptDriverUnresponsive
      elif self.awareness <= self.threshold_pre:
        # pre green alert
        alert = EventName.preDriverDistracted if self.active_monitoring_mode else EventName.preDriverUnresponsive
  
      if alert is not None:
        events.add(alert)
  