#!/usr/bin/env python
"""This is the GRR client installer module.

GRR allows several installers to be registered as plugins. The
installers are executed when the client is deployed to a target system
in their specified order (according to the registry plugin system).

Installers are usually used to upgrade existing clients and setup
clients in unusual situations.
"""

import logging
import os
import sys

from absl import flags

from grr_response_core import config
from grr_response_core.config import contexts

if sys.platform == "darwin":
  from grr_response_client.osx import installers  # pylint: disable=g-import-not-at-top
elif sys.platform == "win32":
  from grr_response_client.windows import installers  # pylint: disable=g-import-not-at-top
else:
  installers = None


def RunInstaller():
  """Runs installers for the current platform."""

  try:
    os.makedirs(os.path.dirname(config.CONFIG["Installer.logfile"]))
  except OSError:
    pass

  # Always log to the installer logfile at debug level. This way if our
  # installer fails we can send detailed diagnostics.
  handler = logging.FileHandler(config.CONFIG["Installer.logfile"], mode="w")

  handler.setLevel(logging.DEBUG)

  # Add this to the root logger.
  logging.getLogger().addHandler(handler)

  # Ordinarily when the client starts up, the local volatile
  # configuration is read. Howevwer, when running the installer, we
  # need to ensure that only the installer configuration is used so
  # nothing gets overridden by local settings. We there must reload
  # the configuration from the flag and ignore the Config.writeback
  # location.
  config.CONFIG.Initialize(filename=flags.FLAGS.config, reset=True)
  config.CONFIG.AddContext(contexts.INSTALLER_CONTEXT,
                           "Context applied when we run the client installer.")

  if installers is None:
    logging.info("No installers found for %s.", sys.platform)
  else:
    logging.info("Starting installation procedure for GRR client.")
    installers.Run()
