text: import os
  import math
  
  from common.numpy_fast import interp
  from common.realtime import sec_since_boot, DT_MDL
  from selfdrive.swaglog import cloudlog
  from selfdrive.controls.lib.lateral_mpc import libmpc_py
  from selfdrive.controls.lib.drive_helpers import MPC_COST_LAT
  from selfdrive.controls.lib.lane_planner import LanePlanner
  from selfdrive.config import Conversions as CV
  from common.params import Params
  import cereal.messaging as messaging
  from cereal import log
  import common.log as trace1
  
  LaneChangeState = log.PathPlan.LaneChangeState
  LaneChangeDirection = log.PathPlan.LaneChangeDirection
  
  LOG_MPC = os.environ.get('LOG_MPC', True)
  
  LANE_CHANGE_SPEED_MIN = 59 * CV.KPH_TO_MS
  LANE_CHANGE_TIME_MAX = 10.
  
  DESIRES = {
    LaneChangeDirection.none: {
      LaneChangeState.off: log.PathPlan.Desire.none,
      LaneChangeState.preLaneChange: log.PathPlan.Desire.none,
      LaneChangeState.laneChangeStarting: log.PathPlan.Desire.none,
      LaneChangeState.laneChangeFinishing: log.PathPlan.Desire.none,
      LaneChangeState.laneChangeDone: log.PathPlan.Desire.none,
    },
    LaneChangeDirection.left: {
      LaneChangeState.off: log.PathPlan.Desire.none,
      LaneChangeState.preLaneChange: log.PathPlan.Desire.none,
      LaneChangeState.laneChangeStarting: log.PathPlan.Desire.laneChangeLeft,
      LaneChangeState.laneChangeFinishing: log.PathPlan.Desire.laneChangeLeft,
      LaneChangeState.laneChangeDone: log.PathPlan.Desire.laneChangeLeft,
    },
    LaneChangeDirection.right: {
      LaneChangeState.off: log.PathPlan.Desire.none,
      LaneChangeState.preLaneChange: log.PathPlan.Desire.none,
      LaneChangeState.laneChangeStarting: log.PathPlan.Desire.laneChangeRight,
      LaneChangeState.laneChangeFinishing: log.PathPlan.Desire.laneChangeRight,
      LaneChangeState.laneChangeDone: log.PathPlan.Desire.laneChangeRight,
    },
  }
  
  
  def calc_states_after_delay(states, v_ego, steer_angle, curvature_factor, steer_ratio, delay):
    states[0].x = v_ego * delay
    states[0].psi = v_ego * curvature_factor * math.radians(steer_angle) / steer_ratio * delay
    return states
  
  
  class PathPlanner():
    def __init__(self, CP):
      self.LP = LanePlanner()
  
      self.last_cloudlog_t = 0
      self.steer_rate_cost = CP.steerRateCost
  
      self.setup_mpc()
      self.solution_invalid_cnt = 0
      self.lane_change_enabled = Params().get('LaneChangeEnabled') == b'1'
  
      self.lane_change_wait_timer = 0.0
      self.lane_change_state = LaneChangeState.off
      self.lane_change_direction = LaneChangeDirection.none
      self.lane_change_timer = 0.0
      self.lane_change_ll_prob = 1.0
      self.prev_one_blinker = False
  
      self.lane_change_adjust = [0.7, 1.4]
      self.lane_change_adjust_vel = [16, 27]
      self.lane_change_adjust_new = 0.0
  
    def setup_mpc(self):
      self.libmpc = libmpc_py.libmpc
      self.libmpc.init(MPC_COST_LAT.PATH, MPC_COST_LAT.LANE, MPC_COST_LAT.HEADING, self.steer_rate_cost)
  
      self.mpc_solution = libmpc_py.ffi.new("log_t *")
      self.cur_state = libmpc_py.ffi.new("state_t *")
      self.cur_state[0].x = 0.0
      self.cur_state[0].y = 0.0
      self.cur_state[0].psi = 0.0
      self.cur_state[0].delta = 0.0
  
      self.angle_steers_des = 0.0
      self.angle_steers_des_mpc = 0.0
      self.angle_steers_des_prev = 0.0
      self.angle_steers_des_time = 0.0
  
    def update(self, sm, pm, CP, VM):
      v_ego = sm['carState'].vEgo
      angle_steers = sm['carState'].steeringAngle
      active = sm['controlsState'].active
  
      angle_offset = sm['liveParameters'].angleOffset
  
      # Run MPC
      self.angle_steers_des_prev = self.angle_steers_des_mpc
  
      # Update vehicle model
      x = max(sm['liveParameters'].stiffnessFactor, 0.1)
      sr = max(sm['liveParameters'].steerRatio, 0.1)
      VM.update_params(x, sr)
  
      curvature_factor = VM.curvature_factor(v_ego)
  
      self.LP.parse_model(sm['model'])
  
      # Lane change logic
      one_blinker = sm['carState'].leftBlinker != sm['carState'].rightBlinker
      below_lane_change_speed = v_ego < LANE_CHANGE_SPEED_MIN
  
      if sm['carState'].leftBlinker:
        self.lane_change_direction = LaneChangeDirection.left
      elif sm['carState'].rightBlinker:
        self.lane_change_direction = LaneChangeDirection.right
  
      if (not active) or (self.lane_change_timer > LANE_CHANGE_TIME_MAX) or (not one_blinker) or (not self.lane_change_enabled):
        self.lane_change_state = LaneChangeState.off
        self.lane_change_direction = LaneChangeDirection.none
      else:
        torque_applied = sm['carState'].steeringPressed and \
                         ((sm['carState'].steeringTorque > 0 and self.lane_change_direction == LaneChangeDirection.left) or
                          (sm['carState'].steeringTorque < 0 and self.lane_change_direction == LaneChangeDirection.right))
  
        blindspot_detected = ((sm['carState'].leftBlindspot and self.lane_change_direction == LaneChangeDirection.left) or
                              (sm['carState'].rightBlindspot and self.lane_change_direction == LaneChangeDirection.right))
  
        lane_change_prob = self.LP.l_lane_change_prob + self.LP.r_lane_change_prob
  
        # State transitions
        # off
        if self.lane_change_state == LaneChangeState.off and one_blinker and not self.prev_one_blinker and not below_lane_change_speed:
          self.lane_change_state = LaneChangeState.preLaneChange
          self.lane_change_ll_prob = 1.0
          self.lane_change_wait_timer = 0
  
        # pre
        elif self.lane_change_state == LaneChangeState.preLaneChange:
          self.lane_change_wait_timer += DT_MDL
  
          if not one_blinker or below_lane_change_speed:
            self.lane_change_state = LaneChangeState.off
          elif not blindspot_detected and (torque_applied or (self.lane_change_wait_timer > 0.5)):
            self.lane_change_state = LaneChangeState.laneChangeStarting
  
        # starting
        elif self.lane_change_state == LaneChangeState.laneChangeStarting:
          # fade out over .5s
          self.lane_change_adjust_new = interp(v_ego, self.lane_change_adjust_vel, self.lane_change_adjust)
          self.lane_change_ll_prob = max(self.lane_change_ll_prob - self.lane_change_adjust_new*DT_MDL, 0.0)
          # 98% certainty
          if lane_change_prob < 0.02 and self.lane_change_ll_prob < 0.01:
            self.lane_change_state = LaneChangeState.laneChangeFinishing
  
        # finishing
        elif self.lane_change_state == LaneChangeState.laneChangeFinishing:
          # fade in laneline over 1s
          self.lane_change_ll_prob = min(self.lane_change_ll_prob + DT_MDL, 1.0)
          if one_blinker and self.lane_change_ll_prob > 0.99:
            self.lane_change_state = LaneChangeState.laneChangeDone
  
        # done
        elif self.lane_change_state == LaneChangeState.laneChangeDone:
          if not one_blinker:
            self.lane_change_state = LaneChangeState.off
  
      if self.lane_change_state in [LaneChangeState.off, LaneChangeState.preLaneChange]:
        self.lane_change_timer = 0.0
      else:
        self.lane_change_timer += DT_MDL
  
      self.prev_one_blinker = one_blinker
  
      desire = DESIRES[self.lane_change_direction][self.lane_change_state]
  
      # Turn off lanes during lane change
      if desire == log.PathPlan.Desire.laneChangeRight or desire == log.PathPlan.Desire.laneChangeLeft:
        self.LP.l_prob *= self.lane_change_ll_prob
        self.LP.r_prob *= self.lane_change_ll_prob
        
      self.LP.update_d_poly(v_ego)
  
      # account for actuation delay
      self.cur_state = calc_states_after_delay(self.cur_state, v_ego, angle_steers - angle_offset, curvature_factor, VM.sR, CP.steerActuatorDelay)
  
      v_ego_mpc = max(v_ego, 5.0)  # avoid mpc roughness due to low speed
      self.libmpc.run_mpc(self.cur_state, self.mpc_solution,
                          list(self.LP.l_poly), list(self.LP.r_poly), list(self.LP.d_poly),
                          self.LP.l_prob, self.LP.r_prob, curvature_factor, v_ego_mpc, self.LP.lane_width)
  
      # reset to current steer angle if not active or overriding
      if active:
        delta_desired = self.mpc_solution[0].delta[1]
        rate_desired = math.degrees(self.mpc_solution[0].rate[0] * VM.sR)
      else:
        delta_desired = math.radians(angle_steers - angle_offset) / VM.sR
        rate_desired = 0.0
  
      self.cur_state[0].delta = delta_desired
  
      self.angle_steers_des_mpc = float(math.degrees(delta_desired * VM.sR) + angle_offset)
  
      #  Check for infeasable MPC solution
      mpc_nans = any(math.isnan(x) for x in self.mpc_solution[0].delta)
      t = sec_since_boot()
      if mpc_nans:
        self.libmpc.init(MPC_COST_LAT.PATH, MPC_COST_LAT.LANE, MPC_COST_LAT.HEADING, CP.steerRateCost)
        self.cur_state[0].delta = math.radians(angle_steers - angle_offset) / VM.sR
  
        if t > self.last_cloudlog_t + 5.0:
          self.last_cloudlog_t = t
          cloudlog.warning("Lateral mpc - nan: True")
  
      if self.mpc_solution[0].cost > 20000. or mpc_nans:   # TODO: find a better way to detect when MPC did not converge
        self.solution_invalid_cnt += 1
      else:
        self.solution_invalid_cnt = 0
      plan_solution_valid = self.solution_invalid_cnt < 3
  
      plan_send = messaging.new_message('pathPlan')
      plan_send.valid = sm.all_alive_and_valid(service_list=['carState', 'controlsState', 'liveParameters', 'model'])
      plan_send.pathPlan.laneWidth = float(self.LP.lane_width)
      plan_send.pathPlan.dPoly = [float(x) for x in self.LP.d_poly]
      plan_send.pathPlan.lPoly = [float(x) for x in self.LP.l_poly]
      plan_send.pathPlan.lProb = float(self.LP.l_prob)
      plan_send.pathPlan.rPoly = [float(x) for x in self.LP.r_poly]
      plan_send.pathPlan.rProb = float(self.LP.r_prob)
  
      plan_send.pathPlan.angleSteers = float(self.angle_steers_des_mpc)
      plan_send.pathPlan.rateSteers = float(rate_desired)
      #plan_send.pathPlan.angleOffset = float(sm['liveParameters'].angleOffsetAverage)
      plan_send.pathPlan.angleOffset = float(sm['liveParameters'].angleOffset)
      plan_send.pathPlan.mpcSolutionValid = bool(plan_solution_valid)
      plan_send.pathPlan.paramsValid = bool(sm['liveParameters'].valid)
  
      plan_send.pathPlan.desire = desire
      plan_send.pathPlan.laneChangeState = self.lane_change_state
      plan_send.pathPlan.laneChangeDirection = self.lane_change_direction
  
      pm.send('pathPlan', plan_send)
  
      if LOG_MPC:
        dat = messaging.new_message('liveMpc')
        dat.liveMpc.x = list(self.mpc_solution[0].x)
        dat.liveMpc.y = list(self.mpc_solution[0].y)
        dat.liveMpc.psi = list(self.mpc_solution[0].psi)
        dat.liveMpc.delta = list(self.mpc_solution[0].delta)
        dat.liveMpc.cost = self.mpc_solution[0].cost
        pm.send('liveMpc', dat)
  