import struct
from selfdrive.config import Conversions as CV
from selfdrive.car.honda.values import CAR, HONDA_BOSCH

# *** Honda specific ***
def can_cksum(mm):
  s = 0
  for c in mm:
    c = ord(c)
    s += (c>>4)
    s += c & 0xF
  s = 8-s
  s %= 0x10
  return s


def fix(msg, addr):
  msg2 = msg[0:-1] + chr(ord(msg[-1]) | can_cksum(struct.pack("I", addr)+msg))
  return msg2


def get_pt_bus(car_fingerprint, is_panda_black):
  return 1 if car_fingerprint in HONDA_BOSCH and is_panda_black else 0


def get_lkas_cmd_bus(car_fingerprint, is_panda_black):
  return 2 if car_fingerprint in HONDA_BOSCH and not is_panda_black else 0


def create_brake_command(packer, apply_brake, pump_on, pcm_override, pcm_cancel_cmd, fcw, idx, car_fingerprint, is_panda_black):
  # TODO: do we loose pressure if we keep pump off for long?
  brakelights = apply_brake > 0
  brake_rq = apply_brake > 0
  pcm_fault_cmd = False

  values = {
    "COMPUTER_BRAKE": apply_brake,
    "BRAKE_PUMP_REQUEST": pump_on,
    "CRUISE_OVERRIDE": pcm_override,
    "CRUISE_FAULT_CMD": pcm_fault_cmd,
    "CRUISE_CANCEL_CMD": pcm_cancel_cmd,
    "COMPUTER_BRAKE_REQUEST": brake_rq,
    "SET_ME_1": 1,
    "BRAKE_LIGHTS": brakelights,
    "CHIME": 0,
    # TODO: Why are there two bits for fcw? According to dbc file the first bit should also work
    "FCW": fcw << 1,
    "AEB_REQ_1": 0,
    "AEB_REQ_2": 0,
    "AEB_STATUS": 0,
  }
  bus = get_pt_bus(car_fingerprint, is_panda_black)
  return packer.make_can_msg("BRAKE_COMMAND", bus, values, idx)


def create_steering_control(packer, apply_steer, lkas_active, car_fingerprint, idx, is_panda_black):
  values = {
    "STEER_TORQUE": apply_steer if lkas_active else 0,
    "STEER_TORQUE_REQUEST": lkas_active,
  }
  bus = get_lkas_cmd_bus(car_fingerprint, is_panda_black)
  return packer.make_can_msg("STEERING_CONTROL", bus, values, idx)


def create_ui_commands(packer, pcm_speed, hud, car_fingerprint, is_metric, idx, is_panda_black):
  commands = []
  bus_pt = get_pt_bus(car_fingerprint, is_panda_black)
  bus_lkas = get_lkas_cmd_bus(car_fingerprint, is_panda_black)

  if car_fingerprint not in HONDA_BOSCH:
    acc_hud_values = {
      'PCM_SPEED': pcm_speed * CV.MS_TO_KPH,
      'PCM_GAS': hud.pcm_accel,
      'CRUISE_SPEED': hud.v_cruise,
      'ENABLE_MINI_CAR': hud.mini_car,
      'HUD_LEAD': hud.car,
      'HUD_DISTANCE': 3,    # max distance setting on display
      'IMPERIAL_UNIT': int(not is_metric),
      'SET_ME_X01_2': 1,
      'SET_ME_X01': 1,
    }
    commands.append(packer.make_can_msg("ACC_HUD", bus_pt, acc_hud_values, idx))

  lkas_hud_values = {
    'SET_ME_X41': 0x41,
    'SET_ME_X48': 0x48,
    'STEERING_REQUIRED': hud.steer_required,
    'SOLID_LANES': hud.lanes,
    'BEEP': 0,
  }
  commands.append(packer.make_can_msg('LKAS_HUD', bus_lkas, lkas_hud_values, idx))

  if car_fingerprint in (CAR.CIVIC, CAR.ODYSSEY):
    radar_hud_values = {
      'ACC_ALERTS': hud.acc_alert,
      'LEAD_SPEED': 0x1fe,  # What are these magic values
      'LEAD_STATE': 0x7,
      'LEAD_DISTANCE': 0x1e,
    }
    commands.append(packer.make_can_msg('RADAR_HUD', bus_pt, radar_hud_values, idx))
  return commands


def spam_buttons_command(packer, button_val, idx, car_fingerprint, is_panda_black):
  values = {
    'CRUISE_BUTTONS': button_val,
    'CRUISE_SETTING': 0,
  }
  bus = get_pt_bus(car_fingerprint, is_panda_black)
  return packer.make_can_msg("SCM_BUTTONS", bus, values, idx)