#!/usr/bin/python
#
# Copyright 2011 Google Inc. All Rights Reserved.

"""Script to image a ChromeOS device.

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

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

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

from utils import command_executer
from utils import locks
from utils import logger
from utils import misc
from 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: " + 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'"
  retval = cmd_executer.CrosRunCommand(command,
                                       chromeos_root=chromeos_root,
                                       machine=remote)
  logger.GetLogger().LogFatalIf(
      retval == 255, "Failed ssh to %s (for checking cherrypy)" % remote)
  logger.GetLogger().LogFatalIf(
      retval != 0, "Failed to find cherrypy or ctypes on remote '{}', "
      "cros flash cannot work.".format(remote))


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

  parser = optparse.OptionParser()
  parser.add_option("-c", "--chromeos_root", dest="chromeos_root",
                    help="Target directory for ChromeOS installation.")
  parser.add_option("-r", "--remote", dest="remote",
                    help="Target device.")
  parser.add_option("-i", "--image", dest="image",
                    help="Image binary file.")
  parser.add_option("-b", "--board", dest="board",
                    help="Target board override.")
  parser.add_option("-f", "--force", dest="force",
                    action="store_true",
                    default=False,
                    help="Force an image even if it is non-test.")
  parser.add_option("-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_option("-l", "--logging_level", dest="log_level",
                    default="verbose",
                    help="Amount of logging to be used. Valid levels are "
                    "'quiet', 'average', and 'verbose'.")
  parser.add_option("-a",
                    "--image_args",
                    dest="image_args")


  options = parser.parse_args(argv[1:])[0]

  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")
  else:
    image = options.image
    if image.find("xbuddy://") < 0:
      image = os.path.expanduser(image)

  if image.find("xbuddy://") < 0:
    image = os.path.realpath(image)

  if not os.path.exists(image) and image.find("xbuddy://") < 0:
    Usage(parser, "Image file: " + image + " does not exist!")

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

    reimage = False
    local_image = False
    if image.find("xbuddy://") < 0:
      local_image = True
      image_checksum = FileUtils().Md5File(image, log_level=log_level)

      command = "cat " + checksum_file
      retval, device_checksum, _ = cmd_executer.CrosRunCommand(
          command,
          return_output=True,
          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 Exception("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)

      if local_image:
        cros_flash_args = ["--board=%s" % board,
                           "--clobber-stateful",
                           options.remote,
                           chroot_image]
      else:
        cros_flash_args = ["--board=%s" % board,
                           "--clobber-stateful",
                           options.remote,
                           image]

      command = ("cros flash %s" % " ".join(cros_flash_args))

      # Workaround for crosbug.com/35684.
      os.chmod(misc.GetChromeOSKeyFile(options.chromeos_root), 0600)
      if log_level == "quiet":
        l.LogOutput("CMD : %s" % command)
      elif log_level == "average":
        cmd_executer.SetLogLevel("verbose");
      retval = cmd_executer.ChrootRunCommand(options.chromeos_root,
                                             command, command_timeout=1800)

      retries = 0
      while retval != 0 and retries < 2:
        retries += 1
        if log_level == "quiet":
          l.LogOutput("Imaging failed. Retry # %d." % retries)
          l.LogOutput("CMD : %s" % command)
        retval = cmd_executer.ChrootRunCommand(options.chromeos_root,
                                               command, command_timeout=1800)

      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(retval, "Image command failed")

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

      # If this is a non-local image, then the retval returned from
      # EnsureMachineUp is the one that will be returned by this function;
      # in that case, make sure the value in 'retval' is appropriate.
      if not local_image and retval == True:
        retval = 0
      else:
        retval = 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)
        retval = cmd_executer.CrosRunCommand(command,
                                            chromeos_root=options.chromeos_root,
                                            machine=options.remote)
        logger.GetLogger().LogFatalIf(retval, "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 retval
  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
  retval = cmd_executer.RunCommand(command)
  logger.GetLogger().LogFatalIf(retval, "Mount/unmount command failed!")
  return retval


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.CrosRunCommand(command,
                                          return_output=True,
                                          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 /"
  retval = cmd_executer.CrosRunCommand(\
    command, chromeos_root=chromeos_root, machine=remote, terminated_timeout=10)
  if retval:
    ## 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
    retval = cmd_executer.CrosRunCommand(command,
                                         chromeos_root=chromeos_root,
                                         machine=remote)
    if not retval:
      return True


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