# Copyright 2013 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.

"""Uninstalls Chrome.

This script reads the uninstall command from registry, calls it, and verifies
the output status code.
"""

import _winreg
import optparse
import subprocess
import sys


def main():
  parser = optparse.OptionParser(description='Uninstall Chrome.')
  parser.add_option('--system-level', action='store_true', dest='system_level',
                    default=False, help='Uninstall Chrome at system level.')
  parser.add_option('--chrome-long-name', default='Google Chrome',
                    help='Google Chrome or Chromium)')
  parser.add_option('--interactive', action='store_true', dest='interactive',
                    default=False, help='Ask before uninstalling Chrome.')
  parser.add_option('--no-error-if-absent', action='store_true',
                    dest='no_error_if_absent', default=False,
                    help='No error if the registry key for uninstalling Chrome '
                         'is absent.')
  options, _ = parser.parse_args()

  # TODO(sukolsak): Add support for uninstalling MSI-based Chrome installs when
  # we support testing MSIs.
  if options.system_level:
    root_key = _winreg.HKEY_LOCAL_MACHINE
  else:
    root_key = _winreg.HKEY_CURRENT_USER
  sub_key = ('SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall\\%s' %
             options.chrome_long_name)
  # Query the key. It will throw a WindowsError if the key doesn't exist.
  try:
    key = _winreg.OpenKey(root_key, sub_key, 0, _winreg.KEY_QUERY_VALUE)
  except WindowsError:
    if options.no_error_if_absent:
      return 0
    raise KeyError('Registry key %s\\%s is missing' % (
        'HKEY_LOCAL_MACHINE' if options.system_level else 'HKEY_CURRENT_USER',
        sub_key))
  if options.interactive:
    prompt = ('Warning: This will uninstall %s at %s. Do you want to continue? '
              '(y/N) ' % (options.chrome_long_name,
                          'system-level' if
                              options.system_level else 'user-level'))
    if raw_input(prompt).strip() != 'y':
      print >> sys.stderr, 'User aborted'
      return 1
  uninstall_string, _ = _winreg.QueryValueEx(key, 'UninstallString')
  exit_status = subprocess.call(uninstall_string + ' --force-uninstall',
                                shell=True)
  # The exit status for successful uninstallation of Chrome is 19 (see
  # chrome/installer/util/util_constants.h).
  if exit_status != 19:
    raise Exception('Could not uninstall Chrome. The installer exited with '
                    'status %d.' % exit_status)
  return 0


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