#!/usr/bin/env python3
import time
import struct
import argparse
import signal
from panda import Panda

class CanHandle(object):
  def __init__(self, p):
    self.p = p

  def transact(self, dat):
    self.p.isotp_send(1, dat, 0, recvaddr=2)

    def _handle_timeout(signum, frame):
      # will happen on reset
      raise Exception("timeout")

    signal.signal(signal.SIGALRM, _handle_timeout)
    signal.alarm(1)
    try:
      ret = self.p.isotp_recv(2, 0, sendaddr=1)
    finally:
      signal.alarm(0)

    return ret

  def controlWrite(self, request_type, request, value, index, data, timeout=0):
    # ignore data in reply, panda doesn't use it
    return self.controlRead(request_type, request, value, index, 0, timeout)

  def controlRead(self, request_type, request, value, index, length, timeout=0):
    dat = struct.pack("HHBBHHH", 0, 0, request_type, request, value, index, length)
    return self.transact(dat)

  def bulkWrite(self, endpoint, data, timeout=0):
    if len(data) > 0x10:
      raise ValueError("Data must not be longer than 0x10")
    dat = struct.pack("HH", endpoint, len(data)) + data
    return self.transact(dat)

  def bulkRead(self, endpoint, length, timeout=0):
    dat = struct.pack("HH", endpoint, 0)
    return self.transact(dat)

if __name__ == "__main__":
  parser = argparse.ArgumentParser(description='Flash pedal over can')
  parser.add_argument('--recover', action='store_true')
  parser.add_argument("fn", type=str, nargs='?', help="flash file")
  args = parser.parse_args()

  p = Panda()
  p.set_safety_mode(Panda.SAFETY_ALLOUTPUT)

  while 1:
    if len(p.can_recv()) == 0:
      break

  if args.recover:
    p.can_send(0x200, b"\xce\xfa\xad\xde\x1e\x0b\xb0\x02", 0)
    exit(0)
  else:
    p.can_send(0x200, b"\xce\xfa\xad\xde\x1e\x0b\xb0\x0a", 0)

  if args.fn:
    time.sleep(0.1)
    print("flashing", args.fn)
    code = open(args.fn, "rb").read()
    Panda.flash_static(CanHandle(p), code)

  print("can flash done")