#!/usr/bin/env python3
import datetime
import os
import subprocess
import time
from typing import NoReturn

from timezonefinder import TimezoneFinder

import cereal.messaging as messaging
from openpilot.common.params import Params
from openpilot.common.swaglog import cloudlog
from openpilot.system.hardware import AGNOS


def set_timezone(timezone):
  valid_timezones = subprocess.check_output('timedatectl list-timezones', shell=True, encoding='utf8').strip().split('\n')
  if timezone not in valid_timezones:
    cloudlog.error(f"Timezone not supported {timezone}")
    return

  cloudlog.debug(f"Setting timezone to {timezone}")
  try:
    if AGNOS:
      tzpath = os.path.join("/usr/share/zoneinfo/", timezone)
      subprocess.check_call(f'sudo su -c "ln -snf {tzpath} /data/etc/tmptime && \
                              mv /data/etc/tmptime /data/etc/localtime"', shell=True)
      subprocess.check_call(f'sudo su -c "echo \"{timezone}\" > /data/etc/timezone"', shell=True)
    else:
      subprocess.check_call(f'sudo timedatectl set-timezone {timezone}', shell=True)
  except subprocess.CalledProcessError:
    cloudlog.exception(f"Error setting timezone to {timezone}")


def set_time(new_time):
  diff = datetime.datetime.now() - new_time
  if diff < datetime.timedelta(seconds=10):
    cloudlog.debug(f"Time diff too small: {diff}")
    return

  cloudlog.debug(f"Setting time to {new_time}")
  try:
    subprocess.run(f"TZ=UTC date -s '{new_time}'", shell=True, check=True)
  except subprocess.CalledProcessError:
    cloudlog.exception("timed.failed_setting_time")


def main() -> NoReturn:
  """
    timed has two responsibilities:
    - getting the current time
    - getting the current timezone

    GPS directly gives time, and timezone is looked up from GPS position.
    AGNOS will also use NTP to update the time.
  """

  params = Params()
  tf = TimezoneFinder()

  # Restore timezone from param
  tz = params.get("Timezone", encoding='utf8')
  tf = TimezoneFinder()
  if tz is not None:
    cloudlog.debug("Restoring timezone from param")
    set_timezone(tz)

  pm = messaging.PubMaster(['clocks'])
  sm = messaging.SubMaster(['liveLocationKalman'])
  while True:
    sm.update(1000)

    msg = messaging.new_message('clocks', valid=True)
    msg.clocks.wallTimeNanos = time.time_ns()
    pm.send('clocks', msg)

    llk = sm['liveLocationKalman']
    if not llk.gpsOK or (time.monotonic() - sm.logMonoTime['liveLocationKalman']/1e9) > 0.2:
      continue

    # set time
    # TODO: account for unixTimesatmpMillis being a (usually short) time in the past
    gps_time = datetime.datetime.fromtimestamp(llk.unixTimestampMillis / 1000.)
    set_time(gps_time)

    # set timezone
    pos = llk.positionGeodetic.value
    if len(pos) == 3:
      gps_timezone = tf.timezone_at(lat=pos[0], lng=pos[1])
      if gps_timezone is None:
        cloudlog.critical(f"No timezone found based on {pos=}")
      else:
        set_timezone(gps_timezone)
        params.put_nonblocking("Timezone", gps_timezone)

    time.sleep(10)

if __name__ == "__main__":
  main()