#!/usr/bin/env python
import os
import struct

import zmq
import numpy as np

from dbcs import DBC_PATH

from common.realtime import Ratekeeper
from common.services import service_list

import selfdrive.messaging as messaging
from selfdrive.config import CruiseButtons
from selfdrive.car.honda.hondacan import fix
from selfdrive.car.honda.carstate import get_can_parser
from selfdrive.boardd.boardd import can_capnp_to_can_list_old, can_capnp_to_can_list, can_list_to_can_capnp

from selfdrive.car.honda.can_parser import CANParser


from common.dbc import dbc
acura = dbc(os.path.join(DBC_PATH, "acura_ilx_2016_can.dbc"))

def car_plant(pos, speed, grade, gas, brake):
  # vehicle parameters
  mass = 1700
  aero_cd = 0.3
  force_peak = mass*3.
  force_brake_peak = -mass*10.     #1g
  power_peak = 100000   # 100kW
  speed_base = power_peak/force_peak
  rolling_res = 0.01
  g = 9.81
  wheel_r = 0.31
  frontal_area = 2.2
  air_density = 1.225
  gas_to_peak_linear_slope = 3.33
  brake_to_peak_linear_slope = 0.2
  creep_accel_v = [1., 0.]
  creep_accel_bp = [0., 1.5]

  #*** longitudinal model ***
  # find speed where peak torque meets peak power
  force_brake = brake * force_brake_peak * brake_to_peak_linear_slope
  if speed < speed_base: # torque control
    force_gas = gas * force_peak * gas_to_peak_linear_slope
  else: # power control
    force_gas = gas * power_peak / speed * gas_to_peak_linear_slope

  force_grade = - grade * mass  # positive grade means uphill

  creep_accel = np.interp(speed, creep_accel_bp, creep_accel_v)
  force_creep = creep_accel * mass

  force_resistance = -(rolling_res * mass * g + 0.5 * speed**2 * aero_cd * air_density)
  force = force_gas + force_brake + force_resistance + force_grade + force_creep
  acceleration = force / mass

  # TODO: lateral model
  return speed, acceleration

def get_car_can_parser():
  dbc_f = 'acura_ilx_2016_can.dbc'
  signals = [
    ("STEER_TORQUE", 0xe4, 0),
    ("STEER_TORQUE_REQUEST", 0xe4, 0),
    ("COMPUTER_BRAKE", 0x1fa, 0),
    ("COMPUTER_BRAKE_REQUEST", 0x1fa, 0),
    ("GAS_COMMAND", 0x200, 0),
  ]
  checks = [
    (0xe4, 100),
    (0x1fa, 50),
    (0x200, 50),
  ]
  return CANParser(dbc_f, signals, checks)


class Plant(object):
  messaging_initialized = False

  def __init__(self, lead_relevancy=False, rate=100, speed=0.0, distance_lead=2.0):
    self.rate = rate
    self.civic = False
    self.brake_only = False

    if not Plant.messaging_initialized:
      context = zmq.Context()
      Plant.logcan = messaging.pub_sock(context, service_list['can'].port)
      Plant.sendcan = messaging.sub_sock(context, service_list['sendcan'].port)
      Plant.model = messaging.pub_sock(context, service_list['model'].port)
      Plant.live100 = messaging.sub_sock(context, service_list['live100'].port)
      Plant.messaging_initialized = True

    self.angle_steer = 0.
    self.gear_choice = 0
    self.speed, self.speed_prev = 0., 0.

    self.esp_disabled = 0
    self.main_on = 1
    self.user_gas = 0
    self.computer_brake,self.user_brake = 0,0
    self.brake_pressed = 0
    self.distance, self.distance_prev = 0., 0.
    self.speed, self.speed_prev = speed, speed
    self.steer_error, self.brake_error, self.steer_not_allowed = 0, 0, 0
    self.gear_shifter = 4   # D gear
    self.pedal_gas = 0
    self.cruise_setting = 0

    self.seatbelt, self.door_all_closed = True, True
    self.steer_torque, self.v_cruise, self.acc_status = 0, 0, 0  # v_cruise is reported from can, not the one used for controls

    self.lead_relevancy = lead_relevancy

    # lead car
    self.distance_lead, self.distance_lead_prev = distance_lead , distance_lead

    self.rk = Ratekeeper(rate, print_delay_threshold=100)
    self.ts = 1./rate

    self.cp = get_car_can_parser()

  def speed_sensor(self, speed):
    if speed<0.3:
      return 0
    else:
      return speed

  def current_time(self):
    return float(self.rk.frame) / self.rate

  def step(self, v_lead=0.0, cruise_buttons=None, grade=0.0):
    # dbc_f, sgs, ivs, msgs, cks_msgs, frqs = initialize_can_struct(self.civic, self.brake_only)
    cp2 = get_can_parser(self.civic, self.brake_only)
    sgs = cp2._sgs
    msgs = cp2._msgs
    cks_msgs = cp2.msgs_ck

    # ******** get messages sent to the car ********
    can_msgs = []
    for a in messaging.drain_sock(Plant.sendcan):
      can_msgs += can_capnp_to_can_list_old(a.sendcan, [0,2])
    #print can_msgs
    self.cp.update_can(can_msgs)

    # ******** get live100 messages for plotting ***
    live_msgs = []
    for a in messaging.drain_sock(Plant.live100):
      live_msgs.append(a.live100)


    if self.cp.vl[0x1fa]['COMPUTER_BRAKE_REQUEST']:
      brake = self.cp.vl[0x1fa]['COMPUTER_BRAKE']
    else:
      brake = 0.0

    if self.cp.vl[0x200]['GAS_COMMAND'] > 0:
      gas = self.cp.vl[0x200]['GAS_COMMAND'] / 256.0
    else:
      gas = 0.0

    if self.cp.vl[0xe4]['STEER_TORQUE_REQUEST']:
      steer_torque = self.cp.vl[0xe4]['STEER_TORQUE']*1.0/0xf00
    else:
      steer_torque = 0.0

    distance_lead = self.distance_lead_prev + v_lead * self.ts

    # ******** run the car ********
    speed, acceleration = car_plant(self.distance_prev, self.speed_prev, grade, gas, brake)
    standstill = (speed == 0)
    distance = self.distance_prev + speed * self.ts
    speed = self.speed_prev + self.ts * acceleration
    if speed <= 0:
      speed = 0
      acceleration = 0

    # ******** lateral ********
    self.angle_steer -= steer_torque

    # *** radar model ***
    if self.lead_relevancy:
      d_rel = np.maximum(0., self.distance_lead - distance)
      v_rel = v_lead - speed
    else:
      d_rel = 200.
      v_rel = 0.
      a_rel = 0
    lateral_pos_rel = 0.

    # print at 5hz
    if (self.rk.frame%(self.rate/5)) == 0:
      print "%6.2f m  %6.2f m/s  %6.2f m/s2   %.2f ang   gas: %.2f  brake: %.2f  steer: %5.2f     lead_rel: %6.2f m  %6.2f m/s" % (distance, speed, acceleration, self.angle_steer, gas, brake, steer_torque, d_rel, v_rel)

    # ******** publish the car ********
    vls = [self.speed_sensor(speed), self.speed_sensor(speed), self.speed_sensor(speed), self.speed_sensor(speed),
           self.angle_steer, 0, self.gear_choice, speed!=0,
           0, 0, 0, 0,
           self.v_cruise, not self.seatbelt, self.seatbelt, self.brake_pressed,
           self.user_gas, cruise_buttons, self.esp_disabled, 0,
           self.user_brake, self.steer_error, self.speed_sensor(speed), self.brake_error,
           self.brake_error, self.gear_shifter, self.main_on, self.acc_status,
           self.pedal_gas, self.cruise_setting,
           # left_blinker, right_blinker, counter
           0,0,0,
           # interceptor_gas
           0,0]


    # TODO: publish each message at proper frequency
    can_msgs = []
    for msg in set(msgs):
      msg_struct = {}
      indxs = [i for i, x in enumerate(msgs) if msg == msgs[i]]
      for i in indxs:
        msg_struct[sgs[i]] = vls[i]
      if msg in cks_msgs:
        msg_struct["COUNTER"] = self.rk.frame % 4

      msg_data = acura.encode(msg, msg_struct)

      if msg in cks_msgs:
        msg_data = fix(msg_data, msg)

      can_msgs.append([msg, 0, msg_data, 0])

    # add the radar message
    # TODO: use the DBC
    def to_3_byte(x):
      return struct.pack("!H", int(x)).encode("hex")[1:]

    def to_3s_byte(x):
      return struct.pack("!h", int(x)).encode("hex")[1:]
    radar_msg = to_3_byte(d_rel*16.0) + \
                to_3_byte(int(lateral_pos_rel*16.0)&0x3ff) + \
                to_3s_byte(int(v_rel*32.0)) + \
                "0f00000"
    can_msgs.append([0x445, 0, radar_msg.decode("hex"), 1])
    Plant.logcan.send(can_list_to_can_capnp(can_msgs).to_bytes())

    # ******** publish a fake model going straight ********
    md = messaging.new_message()
    md.init('model')
    md.model.frameId = 0
    for x in [md.model.path, md.model.leftLane, md.model.rightLane]:
      x.points = [0.0]*50
      x.prob = 1.0
      x.std = 1.0
    # fake values?
    Plant.model.send(md.to_bytes())


    # ******** update prevs ********
    self.speed_prev = speed
    self.distance_prev = distance
    self.distance_lead_prev = distance_lead

    self.rk.keep_time()
    return (distance, speed, acceleration, distance_lead, brake, gas, steer_torque, live_msgs)

# simple engage in standalone mode
def plant_thread(rate=100):
  plant = Plant(rate)
  while 1:
    if plant.rk.frame%100 >= 20 and plant.rk.frame%100 <= 25:
      cruise_buttons = CruiseButtons.RES_ACCEL
    else:
      cruise_buttons = 0
    plant.step()

if __name__ == "__main__":
  plant_thread()