#!/usr/bin/env python2
#
# Copyright 2011 Google Inc. All Rights Reserved.
"""Script to image a ChromeOS device.

This script images a remote ChromeOS device with a specific image."
"""

from __future__ import print_function

__author__ = 'asharif@google.com (Ahmad Sharif)'

import argparse
import filecmp
import glob
import os
import re
import shutil
import sys
import tempfile
import time

from cros_utils import command_executer
from cros_utils import locks
from cros_utils import logger
from cros_utils import misc
from cros_utils.file_utils import FileUtils

checksum_file = '/usr/local/osimage_checksum_file'
lock_file = '/tmp/image_chromeos_lock/image_chromeos_lock'


def Usage(parser, message):
  print('ERROR: %s' % message)
  parser.print_help()
  sys.exit(0)


def CheckForCrosFlash(chromeos_root, remote, log_level):
  cmd_executer = command_executer.GetCommandExecuter(log_level=log_level)

  # Check to see if remote machine has cherrypy, ctypes
  command = "python -c 'import cherrypy, ctypes'"
  ret = cmd_executer.CrosRunCommand(
      command, chromeos_root=chromeos_root, machine=remote)
  logger.GetLogger().LogFatalIf(
      ret == 255, 'Failed ssh to %s (for checking cherrypy)' % remote)
  logger.GetLogger().LogFatalIf(
      ret != 0, "Failed to find cherrypy or ctypes on remote '{}', "
      'cros flash cannot work.'.format(remote))


def DoImage(argv):
  """Image ChromeOS."""

  parser = argparse.ArgumentParser()
  parser.add_argument(
      '-c',
      '--chromeos_root',
      dest='chromeos_root',
      help='Target directory for ChromeOS installation.')
  parser.add_argument('-r', '--remote', dest='remote', help='Target device.')
  parser.add_argument('-i', '--image', dest='image', help='Image binary file.')
  parser.add_argument(
      '-b', '--board', dest='board', help='Target board override.')
  parser.add_argument(
      '-f',
      '--force',
      dest='force',
      action='store_true',
      default=False,
      help='Force an image even if it is non-test.')
  parser.add_argument(
      '-n',
      '--no_lock',
      dest='no_lock',
      default=False,
      action='store_true',
      help='Do not attempt to lock remote before imaging.  '
      'This option should only be used in cases where the '
      'exclusive lock has already been acquired (e.g. in '
      'a script that calls this one).')
  parser.add_argument(
      '-l',
      '--logging_level',
      dest='log_level',
      default='verbose',
      help='Amount of logging to be used. Valid levels are '
      "'quiet', 'average', and 'verbose'.")
  parser.add_argument('-a', '--image_args', dest='image_args')

  options = parser.parse_args(argv[1:])

  if not options.log_level in command_executer.LOG_LEVEL:
    Usage(parser, "--logging_level must be 'quiet', 'average' or 'verbose'")
  else:
    log_level = options.log_level

  # Common initializations
  cmd_executer = command_executer.GetCommandExecuter(log_level=log_level)
  l = logger.GetLogger()

  if options.chromeos_root is None:
    Usage(parser, '--chromeos_root must be set')

  if options.remote is None:
    Usage(parser, '--remote must be set')

  options.chromeos_root = os.path.expanduser(options.chromeos_root)

  if options.board is None:
    board = cmd_executer.CrosLearnBoard(options.chromeos_root, options.remote)
  else:
    board = options.board

  if options.image is None:
    images_dir = misc.GetImageDir(options.chromeos_root, board)
    image = os.path.join(images_dir, 'latest', 'chromiumos_test_image.bin')
    if not os.path.exists(image):
      image = os.path.join(images_dir, 'latest', 'chromiumos_image.bin')
    is_xbuddy_image = False
  else:
    image = options.image
    is_xbuddy_image = image.startswith('xbuddy://')
    if not is_xbuddy_image:
      image = os.path.expanduser(image)

  if not is_xbuddy_image:
    image = os.path.realpath(image)

  if not os.path.exists(image) and not is_xbuddy_image:
    Usage(parser, 'Image file: ' + image + ' does not exist!')

  try:
    should_unlock = False
    if not options.no_lock:
      try:
        _ = locks.AcquireLock(
            list(options.remote.split()), options.chromeos_root)
        should_unlock = True
      except Exception as e:
        raise RuntimeError('Error acquiring machine: %s' % str(e))

    reimage = False
    local_image = False
    if not is_xbuddy_image:
      local_image = True
      image_checksum = FileUtils().Md5File(image, log_level=log_level)

      command = 'cat ' + checksum_file
      ret, device_checksum, _ = cmd_executer.CrosRunCommandWOutput(
          command, chromeos_root=options.chromeos_root, machine=options.remote)

      device_checksum = device_checksum.strip()
      image_checksum = str(image_checksum)

      l.LogOutput('Image checksum: ' + image_checksum)
      l.LogOutput('Device checksum: ' + device_checksum)

      if image_checksum != device_checksum:
        [found, located_image] = LocateOrCopyImage(
            options.chromeos_root, image, board=board)

        reimage = True
        l.LogOutput('Checksums do not match. Re-imaging...')

        is_test_image = IsImageModdedForTest(options.chromeos_root,
                                             located_image, log_level)

        if not is_test_image and not options.force:
          logger.GetLogger().LogFatal('Have to pass --force to image a '
                                      'non-test image!')
    else:
      reimage = True
      found = True
      l.LogOutput('Using non-local image; Re-imaging...')

    if reimage:
      # If the device has /tmp mounted as noexec, image_to_live.sh can fail.
      command = 'mount -o remount,rw,exec /tmp'
      cmd_executer.CrosRunCommand(
          command, chromeos_root=options.chromeos_root, machine=options.remote)

      real_src_dir = os.path.join(
          os.path.realpath(options.chromeos_root), 'src')
      real_chroot_dir = os.path.join(
          os.path.realpath(options.chromeos_root), 'chroot')
      if local_image:
        if located_image.find(real_src_dir) != 0:
          if located_image.find(real_chroot_dir) != 0:
            raise RuntimeError('Located image: %s not in chromeos_root: %s' %
                               (located_image, options.chromeos_root))
          else:
            chroot_image = located_image[len(real_chroot_dir):]
        else:
          chroot_image = os.path.join(
              '~/trunk/src', located_image[len(real_src_dir):].lstrip('/'))

      # Check to see if cros flash will work for the remote machine.
      CheckForCrosFlash(options.chromeos_root, options.remote, log_level)

      cros_flash_args = [
          'cros', 'flash', '--board=%s' % board, '--clobber-stateful',
          options.remote
      ]
      if local_image:
        cros_flash_args.append(chroot_image)
      else:
        cros_flash_args.append(image)

      command = ' '.join(cros_flash_args)

      # Workaround for crosbug.com/35684.
      os.chmod(misc.GetChromeOSKeyFile(options.chromeos_root), 0600)

      if log_level == 'average':
        cmd_executer.SetLogLevel('verbose')
      retries = 0
      while True:
        if log_level == 'quiet':
          l.LogOutput('CMD : %s' % command)
        ret = cmd_executer.ChrootRunCommand(
            options.chromeos_root, command, command_timeout=1800)
        if ret == 0 or retries >= 2:
          break
        retries += 1
        if log_level == 'quiet':
          l.LogOutput('Imaging failed. Retry # %d.' % retries)

      if log_level == 'average':
        cmd_executer.SetLogLevel(log_level)

      if found == False:
        temp_dir = os.path.dirname(located_image)
        l.LogOutput('Deleting temp image dir: %s' % temp_dir)
        shutil.rmtree(temp_dir)

      logger.GetLogger().LogFatalIf(ret, 'Image command failed')

      # Unfortunately cros_image_to_target.py sometimes returns early when the
      # machine isn't fully up yet.
      ret = EnsureMachineUp(options.chromeos_root, options.remote, log_level)

      # If this is a non-local image, then the ret returned from
      # EnsureMachineUp is the one that will be returned by this function;
      # in that case, make sure the value in 'ret' is appropriate.
      if not local_image and ret == True:
        ret = 0
      else:
        ret = 1

      if local_image:
        if log_level == 'average':
          l.LogOutput('Verifying image.')
        command = 'echo %s > %s && chmod -w %s' % (image_checksum,
                                                   checksum_file, checksum_file)
        ret = cmd_executer.CrosRunCommand(
            command,
            chromeos_root=options.chromeos_root,
            machine=options.remote)
        logger.GetLogger().LogFatalIf(ret, 'Writing checksum failed.')

        successfully_imaged = VerifyChromeChecksum(options.chromeos_root, image,
                                                   options.remote, log_level)
        logger.GetLogger().LogFatalIf(not successfully_imaged,
                                      'Image verification failed!')
        TryRemountPartitionAsRW(options.chromeos_root, options.remote,
                                log_level)
    else:
      l.LogOutput('Checksums match. Skipping reimage')
    return ret
  finally:
    if should_unlock:
      locks.ReleaseLock(list(options.remote.split()), options.chromeos_root)


def LocateOrCopyImage(chromeos_root, image, board=None):
  l = logger.GetLogger()
  if board is None:
    board_glob = '*'
  else:
    board_glob = board

  chromeos_root_realpath = os.path.realpath(chromeos_root)
  image = os.path.realpath(image)

  if image.startswith('%s/' % chromeos_root_realpath):
    return [True, image]

  # First search within the existing build dirs for any matching files.
  images_glob = ('%s/src/build/images/%s/*/*.bin' % (chromeos_root_realpath,
                                                     board_glob))
  images_list = glob.glob(images_glob)
  for potential_image in images_list:
    if filecmp.cmp(potential_image, image):
      l.LogOutput('Found matching image %s in chromeos_root.' % potential_image)
      return [True, potential_image]
  # We did not find an image. Copy it in the src dir and return the copied
  # file.
  if board is None:
    board = ''
  base_dir = ('%s/src/build/images/%s' % (chromeos_root_realpath, board))
  if not os.path.isdir(base_dir):
    os.makedirs(base_dir)
  temp_dir = tempfile.mkdtemp(prefix='%s/tmp' % base_dir)
  new_image = '%s/%s' % (temp_dir, os.path.basename(image))
  l.LogOutput('No matching image found. Copying %s to %s' % (image, new_image))
  shutil.copyfile(image, new_image)
  return [False, new_image]


def GetImageMountCommand(chromeos_root, image, rootfs_mp, stateful_mp):
  image_dir = os.path.dirname(image)
  image_file = os.path.basename(image)
  mount_command = ('cd %s/src/scripts &&'
                   './mount_gpt_image.sh --from=%s --image=%s'
                   ' --safe --read_only'
                   ' --rootfs_mountpt=%s'
                   ' --stateful_mountpt=%s' %
                   (chromeos_root, image_dir, image_file, rootfs_mp,
                    stateful_mp))
  return mount_command


def MountImage(chromeos_root,
               image,
               rootfs_mp,
               stateful_mp,
               log_level,
               unmount=False):
  cmd_executer = command_executer.GetCommandExecuter(log_level=log_level)
  command = GetImageMountCommand(chromeos_root, image, rootfs_mp, stateful_mp)
  if unmount:
    command = '%s --unmount' % command
  ret = cmd_executer.RunCommand(command)
  logger.GetLogger().LogFatalIf(ret, 'Mount/unmount command failed!')
  return ret


def IsImageModdedForTest(chromeos_root, image, log_level):
  if log_level != 'verbose':
    log_level = 'quiet'
  rootfs_mp = tempfile.mkdtemp()
  stateful_mp = tempfile.mkdtemp()
  MountImage(chromeos_root, image, rootfs_mp, stateful_mp, log_level)
  lsb_release_file = os.path.join(rootfs_mp, 'etc/lsb-release')
  lsb_release_contents = open(lsb_release_file).read()
  is_test_image = re.search('test', lsb_release_contents, re.IGNORECASE)
  MountImage(
      chromeos_root, image, rootfs_mp, stateful_mp, log_level, unmount=True)
  return is_test_image


def VerifyChromeChecksum(chromeos_root, image, remote, log_level):
  cmd_executer = command_executer.GetCommandExecuter(log_level=log_level)
  rootfs_mp = tempfile.mkdtemp()
  stateful_mp = tempfile.mkdtemp()
  MountImage(chromeos_root, image, rootfs_mp, stateful_mp, log_level)
  image_chrome_checksum = FileUtils().Md5File(
      '%s/opt/google/chrome/chrome' % rootfs_mp, log_level=log_level)
  MountImage(
      chromeos_root, image, rootfs_mp, stateful_mp, log_level, unmount=True)

  command = 'md5sum /opt/google/chrome/chrome'
  [_, o, _] = cmd_executer.CrosRunCommandWOutput(
      command, chromeos_root=chromeos_root, machine=remote)
  device_chrome_checksum = o.split()[0]
  if image_chrome_checksum.strip() == device_chrome_checksum.strip():
    return True
  else:
    return False


# Remount partition as writable.
# TODO: auto-detect if an image is built using --noenable_rootfs_verification.
def TryRemountPartitionAsRW(chromeos_root, remote, log_level):
  l = logger.GetLogger()
  cmd_executer = command_executer.GetCommandExecuter(log_level=log_level)
  command = 'sudo mount -o remount,rw /'
  ret = cmd_executer.CrosRunCommand(\
    command, chromeos_root=chromeos_root, machine=remote,
    terminated_timeout=10)
  if ret:
    ## Safely ignore.
    l.LogWarning('Failed to remount partition as rw, '
                 'probably the image was not built with '
                 "\"--noenable_rootfs_verification\", "
                 'you can safely ignore this.')
  else:
    l.LogOutput('Re-mounted partition as writable.')


def EnsureMachineUp(chromeos_root, remote, log_level):
  l = logger.GetLogger()
  cmd_executer = command_executer.GetCommandExecuter(log_level=log_level)
  timeout = 600
  magic = 'abcdefghijklmnopqrstuvwxyz'
  command = 'echo %s' % magic
  start_time = time.time()
  while True:
    current_time = time.time()
    if current_time - start_time > timeout:
      l.LogError(
          'Timeout of %ss reached. Machine still not up. Aborting.' % timeout)
      return False
    ret = cmd_executer.CrosRunCommand(
        command, chromeos_root=chromeos_root, machine=remote)
    if not ret:
      return True


if __name__ == '__main__':
  retval = DoImage(sys.argv)
  sys.exit(retval)