# Copyright 2014 Google Inc. All Rights Reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Utilities for launching and accessing ChromeOS buildbots."""

from __future__ import print_function

import base64
import json
import os
import time
import urllib2

# pylint: disable=no-name-in-module
from oauth2client.service_account import ServiceAccountCredentials

from cros_utils import command_executer
from cros_utils import logger
from cros_utils import buildbot_json

SLEEP_TIME = 600  # 10 minutes; time between polling of buildbot.
TIME_OUT = 28800  # Decide the build is dead or will never finish
# after this time (8 hours).
OK_STATUS = [  # List of result status values that are 'ok'.
    # This was obtained from:
    #   https://chromium.googlesource.com/chromium/tools/build/+/
    #       master/third_party/buildbot_8_4p1/buildbot/status/results.py
    0,  # "success"
    1,  # "warnings"
    6,  # "retry"
]


class BuildbotTimeout(Exception):
  """Exception to throw when a buildbot operation timesout."""
  pass


def ParseReportLog(url, build):
  """Scrape the trybot image name off the Reports log page.

  This takes the URL for a trybot Reports Stage web page,
  and a trybot build type, such as 'daisy-release'.  It
  opens the web page and parses it looking for the trybot
  artifact name (e.g. something like
  'trybot-daisy-release/R40-6394.0.0-b1389'). It returns the
  artifact name, if found.
  """
  trybot_image = ''
  url += '/text'
  newurl = url.replace('uberchromegw', 'chromegw')
  webpage = urllib2.urlopen(newurl)
  data = webpage.read()
  lines = data.split('\n')
  for l in lines:
    if l.find('Artifacts') > 0 and l.find('trybot') > 0:
      trybot_name = 'trybot-%s' % build
      start_pos = l.find(trybot_name)
      end_pos = l.find('@https://storage')
      trybot_image = l[start_pos:end_pos]

  return trybot_image


def GetBuildData(buildbot_queue, build_id):
  """Find the Reports stage web page for a trybot build.

  This takes the name of a buildbot_queue, such as 'daisy-release'
  and a build id (the build number), and uses the json buildbot api to
  find the Reports stage web page for that build, if it exists.
  """
  builder = buildbot_json.Buildbot(
      'http://chromegw/p/tryserver.chromiumos/').builders[buildbot_queue]
  build_data = builder.builds[build_id].data
  logs = build_data['logs']
  for l in logs:
    fname = l[1]
    if 'steps/Report/' in fname:
      return fname

  return ''


def FindBuildRecordFromLog(description, build_info):
  """Find the right build record in the build logs.

  Get the first build record from build log with a reason field
  that matches 'description'. ('description' is a special tag we
  created when we launched the buildbot, so we could find it at this
  point.)
  """
  for build_log in build_info:
    if description in build_log['reason']:
      return build_log
  return {}


def GetBuildInfo(file_dir, waterfall_builder):
  """Get all the build records for the trybot builds."""

  builder = ''
  if waterfall_builder.endswith('-release'):
    builder = 'release'
  elif waterfall_builder.endswith('-gcc-toolchain'):
    builder = 'gcc_toolchain'
  elif waterfall_builder.endswith('-llvm-toolchain'):
    builder = 'llvm_toolchain'

  sa_file = os.path.expanduser(
      os.path.join(file_dir, 'cros_utils',
                   'chromeos-toolchain-credentials.json'))
  scopes = ['https://www.googleapis.com/auth/userinfo.email']

  credentials = ServiceAccountCredentials.from_json_keyfile_name(
      sa_file, scopes=scopes)
  url = (
      'https://luci-milo.appspot.com/prpc/milo.Buildbot/GetBuildbotBuildsJSON')

  # NOTE: If we want to get build logs for the main waterfall builders, the
  # 'master' field below should be 'chromeos' instead of 'chromiumos.tryserver'.
  # Builder would be 'amd64-gcc-toolchain' or 'arm-llvm-toolchain', etc.

  body = json.dumps({
      'master': 'chromiumos.tryserver',
      'builder': builder,
      'include_current': True,
      'limit': 100
  })
  access_token = credentials.get_access_token()
  headers = {
      'Accept': 'application/json',
      'Content-Type': 'application/json',
      'Authorization': 'Bearer %s' % access_token.access_token
  }
  r = urllib2.Request(url, body, headers)
  u = urllib2.urlopen(r, timeout=60)
  u.read(4)
  o = json.load(u)
  data = [base64.b64decode(item['data']) for item in o['builds']]
  result = []
  for d in data:
    tmp = json.loads(d)
    result.append(tmp)
  return result


def FindArchiveImage(chromeos_root, build, build_id):
  """Returns name of the trybot artifact for board/build_id."""
  ce = command_executer.GetCommandExecuter()
  command = ('gsutil ls gs://chromeos-image-archive/trybot-%s/*b%s'
             '/chromiumos_test_image.tar.xz' % (build, build_id))
  _, out, _ = ce.ChrootRunCommandWOutput(
      chromeos_root, command, print_to_console=False)
  #
  # If build_id is not unique, there may be multiple archive images
  # to choose from; sort them & pick the first (newest).
  #
  # If there are multiple archive images found, out will look something
  # like this:
  #
  # 'gs://.../R35-5692.0.0-b105/chromiumos_test_image.tar.xz
  #  gs://.../R46-7339.0.0-b105/chromiumos_test_image.tar.xz'
  #
  out = out.rstrip('\n')
  tmp_list = out.split('\n')
  # After stripping the final '\n' and splitting on any other '\n', we get
  # something like this:
  #  tmp_list = [ 'gs://.../R35-5692.0.0-b105/chromiumos_test_image.tar.xz' ,
  #               'gs://.../R46-7339.0.0-b105/chromiumos_test_image.tar.xz' ]
  #
  #  If we sort this in descending order, we should end up with the most
  #  recent test image first, so that's what we do here.
  #
  if len(tmp_list) > 1:
    tmp_list = sorted(tmp_list, reverse=True)
  out = tmp_list[0]

  trybot_image = ''
  trybot_name = 'trybot-%s' % build
  if out and out.find(trybot_name) > 0:
    start_pos = out.find(trybot_name)
    end_pos = out.find('/chromiumos_test_image')
    trybot_image = out[start_pos:end_pos]

  return trybot_image


def GetTrybotImage(chromeos_root,
                   buildbot_name,
                   patch_list,
                   build_tag,
                   other_flags=None,
                   build_toolchain=False,
                   async=False):
  """Launch buildbot and get resulting trybot artifact name.

  This function launches a buildbot with the appropriate flags to
  build the test ChromeOS image, with the current ToT mobile compiler.  It
  checks every 10 minutes to see if the trybot has finished.  When the trybot
  has finished, it parses the resulting report logs to find the trybot
  artifact (if one was created), and returns that artifact name.

  chromeos_root is the path to the ChromeOS root, needed for finding chromite
  and launching the buildbot.

  buildbot_name is the name of the buildbot queue, such as lumpy-release or
  daisy-paladin.

  patch_list a python list of the patches, if any, for the buildbot to use.

  build_tag is a (unique) string to be used to look up the buildbot results
  from among all the build records.
  """
  ce = command_executer.GetCommandExecuter()
  cbuildbot_path = os.path.join(chromeos_root, 'chromite/cbuildbot')
  base_dir = os.getcwd()
  patch_arg = ''
  if patch_list:
    for p in patch_list:
      patch_arg = patch_arg + ' -g ' + repr(p)
  toolchain_flags = ''
  if build_toolchain:
    toolchain_flags += '--latest-toolchain'
  os.chdir(cbuildbot_path)
  if other_flags:
    optional_flags = ' '.join(other_flags)
  else:
    optional_flags = ''

  # Launch buildbot with appropriate flags.
  build = buildbot_name
  description = build_tag
  command_prefix = ''
  if not patch_arg:
    command_prefix = 'yes | '
  command = ('%s ./cbuildbot --remote --nochromesdk %s'
             ' --remote-description=%s %s %s %s' % (command_prefix,
                                                    optional_flags, description,
                                                    toolchain_flags, patch_arg,
                                                    build))
  _, out, _ = ce.RunCommandWOutput(command)
  if 'Tryjob submitted!' not in out:
    logger.GetLogger().LogFatal('Error occurred while launching trybot job: '
                                '%s' % command)

  if async:
    # Do not wait for trybot job to finish; return immediately
    return 0

  os.chdir(base_dir)

  build_id = 0
  build_status = None
  # Wait for  buildbot to finish running (check every 10 minutes).  Wait
  # 10 minutes before the first check to give the buildbot time to launch
  # (so we don't start looking for build data before it's out there).
  time.sleep(SLEEP_TIME)
  done = False
  pending = True
  # pending_time is the time between when we submit the job and when the
  # buildbot actually launches the build.  running_time is the time between
  # when the buildbot job launches and when it finishes.  The job is
  # considered 'pending' until we can find an entry for it in the buildbot
  # logs.
  pending_time = SLEEP_TIME
  running_time = 0
  while not done:
    done = True
    build_info = GetBuildInfo(base_dir, build)
    if not build_info:
      if pending_time > TIME_OUT:
        logger.GetLogger().LogFatal('Unable to get build logs for target %s.' %
                                    build)
      else:
        pending_message = 'Unable to find build log; job may be pending.'
        done = False

    if done:
      data_dict = FindBuildRecordFromLog(description, build_info)
      if not data_dict:
        # Trybot job may be pending (not actually launched yet).
        if pending_time > TIME_OUT:
          logger.GetLogger().LogFatal('Unable to find build record for trybot'
                                      ' %s.' % description)
        else:
          pending_message = 'Unable to find build record; job may be pending.'
          done = False

      else:
        # Now that we have actually found the entry for the build
        # job in the build log, we know the job is actually
        # runnning, not pending, so we flip the 'pending' flag.  We
        # still have to wait for the buildbot job to finish running
        # however.
        pending = False
        if True == data_dict['finished']:
          build_id = data_dict['number']
          build_status = data_dict['results']
        else:
          done = False

    if not done:
      if pending:
        logger.GetLogger().LogOutput(pending_message)
        logger.GetLogger().LogOutput('Current pending time: %d minutes.' %
                                     (pending_time / 60))
        pending_time += SLEEP_TIME
      else:
        logger.GetLogger().LogOutput('{0} minutes passed.'.format(running_time /
                                                                  60))
        logger.GetLogger().LogOutput('Sleeping {0} seconds.'.format(SLEEP_TIME))
        running_time += SLEEP_TIME

      time.sleep(SLEEP_TIME)
      if running_time > TIME_OUT:
        done = True

  trybot_image = ''

  if build.endswith('-toolchain'):
    # For rotating testers, we don't care about their build_status
    # result, because if any HWTest failed it will be non-zero.
    trybot_image = FindArchiveImage(chromeos_root, build, build_id)
  else:
    # The nightly performance tests do not run HWTests, so if
    # their build_status is non-zero, we do care.  In this case
    # non-zero means the image itself probably did not build.
    if build_status in OK_STATUS:
      trybot_image = FindArchiveImage(chromeos_root, build, build_id)
  if not trybot_image:
    logger.GetLogger().LogError('Trybot job %s failed with status %d;'
                                ' no trybot image generated.' %
                                (description, build_status))

  logger.GetLogger().LogOutput("trybot_image is '%s'" % trybot_image)
  logger.GetLogger().LogOutput('build_status is %d' % build_status)
  return trybot_image


def DoesImageExist(chromeos_root, build):
  """Check if the image for the given build exists."""

  ce = command_executer.GetCommandExecuter()
  command = ('gsutil ls gs://chromeos-image-archive/%s'
             '/chromiumos_test_image.tar.xz' % (build))
  ret = ce.ChrootRunCommand(chromeos_root, command, print_to_console=False)
  return not ret


def WaitForImage(chromeos_root, build):
  """Wait for an image to be ready."""

  elapsed_time = 0
  while elapsed_time < TIME_OUT:
    if DoesImageExist(chromeos_root, build):
      return
    logger.GetLogger().LogOutput('Image %s not ready, waiting for 10 minutes' %
                                 build)
    time.sleep(SLEEP_TIME)
    elapsed_time += SLEEP_TIME

  logger.GetLogger().LogOutput('Image %s not found, waited for %d hours' %
                               (build, (TIME_OUT / 3600)))
  raise BuildbotTimeout('Timeout while waiting for image %s' % build)