# Copyright 2016 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Updates Chrome's "lastrun" value for the current user in HKCU."""

import _winreg
import optparse
import sys
import time


def UpdateLastrun(client_state_key_path):
  """ Updates Chrome's "lastrun" value in the registry to the current time.

  Args:
    client_state_key_path: The path to Chrome's ClientState key in the registry.
  """
  # time.time returns seconds since the Unix epoch. Chrome uses microseconds
  # since the Windows epoch. Adjust based on values inspired by
  # https://support.microsoft.com/en-us/kb/167296, which uses 100-nanosecond
  # ticks.
  now_us = str(int(time.time() * 1000000 + 11644473600000000L))
  try:
    with _winreg.OpenKey(_winreg.HKEY_CURRENT_USER, client_state_key_path, 0,
                         _winreg.KEY_SET_VALUE |
                         _winreg.KEY_WOW64_32KEY) as key:
      _winreg.SetValueEx(key, 'lastrun', 0, _winreg.REG_SZ, now_us)
  except WindowsError:
    raise KeyError('Failed opening registry key HKEY_CURRENT_USER\\%s'
                   % client_state_key_path)
  return 0


def main():
  usage = 'usage: %prog client_state_key_path'
  parser = optparse.OptionParser(usage,
    description='Update Chrome\'s "lastrun" value.')
  _, args = parser.parse_args()
  if len(args) != 1:
    parser.error('Incorrect number of arguments.')

  UpdateLastrun(args[0])
  return 0


if __name__ == '__main__':
  sys.exit(main())