# Copyright 2014 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.

import logging
import os
import Queue
import re
import subprocess
import sys
import threading
import time

from mopy.config import Config
from mopy.paths import Paths

THIS_DIR = os.path.dirname(os.path.abspath(__file__))

sys.path.append(os.path.join(THIS_DIR, '..', '..', '..', 'testing'))
import xvfb

sys.path.append(os.path.join(THIS_DIR, '..', '..', '..', 'tools',
                             'swarming_client', 'utils'))
import subprocess42

# The DISPLAY ID number used for xvfb, incremented with each use.
XVFB_DISPLAY_ID = 9


def run_apptest(config, shell, args, apptest, isolate):
  '''Run the apptest; optionally isolating fixtures across shell invocations.

  Returns the list of test fixtures run and the list of failed test fixtures.
  TODO(msw): Also return the list of DISABLED test fixtures.

  Args:
    config: The mopy.config.Config for the build.
    shell: The mopy.android.AndroidShell, if Android is the target platform.
    args: The arguments for the shell or apptest.
    apptest: The application test URL.
    isolate: True if the test fixtures should be run in isolation.
  '''
  if not isolate:
    return _run_apptest_with_retry(config, shell, args, apptest)

  fixtures = _get_fixtures(config, shell, args, apptest)
  fixtures = [f for f in fixtures if not '.DISABLED_' in f]
  failed = []
  for fixture in fixtures:
    arguments = args + ['--gtest_filter=%s' % fixture]
    failures = _run_apptest_with_retry(config, shell, arguments, apptest)[1]
    failed.extend(failures if failures != [apptest] else [fixture])
    # Abort when 20 fixtures, or a tenth of the apptest fixtures, have failed.
    # base::TestLauncher does this for timeouts and unknown results.
    if len(failed) >= max(20, len(fixtures) / 10):
      print 'Too many failing fixtures (%d), exiting now.' % len(failed)
      return (fixtures, failed + [apptest + ' aborted for excessive failures.'])
  return (fixtures, failed)


# TODO(msw): Determine proper test retry counts; allow configuration.
def _run_apptest_with_retry(config, shell, args, apptest, retry_count=2):
  '''Runs an apptest, retrying on failure; returns the fixtures and failures.'''
  (tests, failed) = _run_apptest(config, shell, args, apptest)
  while failed and retry_count:
    print 'Retrying failed tests (%d attempts remaining)' % retry_count
    arguments = args
    # Retry only the failing fixtures if there is no existing filter specified.
    if (failed and ':'.join(failed) is not apptest and
        not any(a.startswith('--gtest_filter') for a in args)):
      arguments += ['--gtest_filter=%s' % ':'.join(failed)]
    failed = _run_apptest(config, shell, arguments, apptest)[1]
    retry_count -= 1
  return (tests, failed)


def _run_apptest(config, shell, args, apptest):
  '''Runs an apptest; returns the list of fixtures and the list of failures.'''
  command = _build_command_line(config, args, apptest)
  logging.getLogger().debug('Command: %s' % ' '.join(command))
  start_time = time.time()

  try:
    out = _run_test_with_xvfb(config, shell, args, apptest)
  except Exception as e:
    _print_exception(command, e, int(round(1000 * (time.time() - start_time))))
    return ([apptest], [apptest])

  # Find all fixtures begun from gtest's '[ RUN      ] <Suite.Fixture>' output.
  tests = [x for x in out.split('\n') if x.find('[ RUN      ] ') != -1]
  tests = [x.strip(' \t\n\r')[x.find('[ RUN      ] ') + 13:] for x in tests]
  tests = tests or [apptest]

  # Fail on output with gtest's '[  FAILED  ]' or a lack of '[       OK ]'.
  # The latter check ensures failure on broken command lines, hung output, etc.
  # Check output instead of exit codes because mojo shell always exits with 0.
  failed = [x for x in tests if (re.search('\[  FAILED  \].*' + x, out) or
                                 not re.search('\[       OK \].*' + x, out))]

  ms = int(round(1000 * (time.time() - start_time)))
  if failed:
    _print_exception(command, out, ms)
  else:
    logging.getLogger().debug('Passed (in %d ms) with output:\n%s' % (ms, out))
  return (tests, failed)


def _get_fixtures(config, shell, args, apptest):
  '''Returns an apptest's 'Suite.Fixture' list via --gtest_list_tests output.'''
  arguments = args + ['--gtest_list_tests']
  command = _build_command_line(config, arguments, apptest)
  logging.getLogger().debug('Command: %s' % ' '.join(command))
  try:
    tests = _run_test_with_xvfb(config, shell, arguments, apptest)
    # Remove log lines from the output and ensure it matches known formatting.
    # Ignore empty fixture lists when the command line has a gtest filter flag.
    tests = re.sub('^(\[|WARNING: linker:).*\n', '', tests, flags=re.MULTILINE)
    if (not re.match('^(\w*\.\r?\n(  \w*\r?\n)+)+', tests) and
        not [a for a in args if a.startswith('--gtest_filter')]):
      raise Exception('Unrecognized --gtest_list_tests output:\n%s' % tests)
    test_list = []
    for line in tests.split('\n'):
      if not line:
        continue
      if line[0] != ' ':
        suite = line.strip()
        continue
      test_list.append(suite + line.strip())
    logging.getLogger().debug('Tests for %s: %s' % (apptest, test_list))
    return test_list
  except Exception as e:
    _print_exception(command, e)
  return []


def _print_exception(command_line, exception, milliseconds=None):
  '''Print a formatted exception raised from a failed command execution.'''
  details = (' (in %d ms)' % milliseconds) if milliseconds else ''
  if hasattr(exception, 'returncode'):
    details += ' (with exit code %d)' % exception.returncode
  print '\n[  FAILED  ] Command%s: %s' % (details, ' '.join(command_line))
  print 72 * '-'
  if hasattr(exception, 'output'):
    print exception.output
  print str(exception)
  print 72 * '-'


def _build_command_line(config, args, apptest):
  '''Build the apptest command line. This value isn't executed on Android.'''
  not_list_tests = not '--gtest_list_tests' in args
  data_dir = ['--use-temporary-user-data-dir'] if not_list_tests else []
  return Paths(config).mojo_runner + data_dir + args + [apptest]


def _run_test_with_xvfb(config, shell, args, apptest):
  '''Run the test with xvfb; return the output or raise an exception.'''
  env = os.environ.copy()
  # Make sure gtest doesn't try to add color to the output. Color is done via
  # escape sequences which confuses the code that searches the gtest output.
  env['GTEST_COLOR'] = 'no'
  if (config.target_os != Config.OS_LINUX or '--gtest_list_tests' in args
      or not xvfb.should_start_xvfb(env)):
    return _run_test_with_timeout(config, shell, args, apptest, env)

  try:
    # Simply prepending xvfb.py to the command line precludes direct control of
    # test subprocesses, and prevents easily getting output when tests timeout.
    xvfb_proc = None
    openbox_proc = None
    global XVFB_DISPLAY_ID
    display_string = ':' + str(XVFB_DISPLAY_ID)
    (xvfb_proc, openbox_proc) = xvfb.start_xvfb(env, Paths(config).build_dir,
                                                display=display_string)
    XVFB_DISPLAY_ID = (XVFB_DISPLAY_ID + 1) % 50000
    if not xvfb_proc or not xvfb_proc.pid:
      raise Exception('Xvfb failed to start; aborting test run.')
    if not openbox_proc or not openbox_proc.pid:
      raise Exception('Openbox failed to start; aborting test run.')
    logging.getLogger().debug('Running Xvfb %s (pid %d) and Openbox (pid %d).' %
                              (display_string, xvfb_proc.pid, openbox_proc.pid))
    return _run_test_with_timeout(config, shell, args, apptest, env)
  finally:
    xvfb.kill(xvfb_proc)
    xvfb.kill(openbox_proc)


# TODO(msw): Determine proper test timeout durations (starting small).
def _run_test_with_timeout(config, shell, args, apptest, env, seconds=10):
  '''Run the test with a timeout; return the output or raise an exception.'''
  if config.target_os == Config.OS_ANDROID:
    return _run_test_with_timeout_on_android(shell, args, apptest, seconds)

  output = ''
  error = []
  command = _build_command_line(config, args, apptest)
  proc = subprocess42.Popen(command, detached=True, stdout=subprocess42.PIPE,
                            stderr=subprocess42.STDOUT, env=env)
  try:
    output = proc.communicate(timeout=seconds)[0] or ''
    if proc.duration() > seconds:
      error.append('ERROR: Test timeout with duration: %s.' % proc.duration())
      raise subprocess42.TimeoutExpired(proc.args, seconds, output, None)
  except subprocess42.TimeoutExpired as e:
    output = e.output or ''
    logging.getLogger().debug('Terminating the test for timeout.')
    error.append('ERROR: Test timeout after %d seconds.' % proc.duration())
    proc.terminate()
    try:
      output += proc.communicate(timeout=30)[0] or ''
    except subprocess42.TimeoutExpired as e:
      output += e.output or ''
      logging.getLogger().debug('Test termination failed; attempting to kill.')
      proc.kill()
    try:
      output += proc.communicate(timeout=30)[0] or ''
    except subprocess42.TimeoutExpired as e:
      output += e.output or ''
      logging.getLogger().debug('Failed to kill the test process!')

  if proc.returncode:
    error.append('ERROR: Test exited with code: %d.' % proc.returncode)
  elif proc.returncode is None:
    error.append('ERROR: Failed to kill the test process!')

  if not output:
    error.append('ERROR: Test exited with no output.')
  elif output.startswith('This program contains tests'):
    error.append('ERROR: GTest printed help; check the command line.')

  if error:
    raise Exception(output + '\n'.join(error))
  return output


def _run_test_with_timeout_on_android(shell, args, apptest, seconds):
  '''Run the test with a timeout; return the output or raise an exception.'''
  assert shell
  result = Queue.Queue()
  thread = threading.Thread(target=_run_test_on_android,
                            args=(shell, args, apptest, result))
  thread.start()
  thread.join(seconds)
  timeout_exception = ''

  if thread.is_alive():
    timeout_exception = '\nERROR: Test timeout after %d seconds.' % seconds
    logging.getLogger().debug('Killing the Android shell for timeout.')
    shell.kill()
    thread.join(seconds)

  if thread.is_alive():
    raise Exception('ERROR: Failed to kill the test process!')
  if result.empty():
    raise Exception('ERROR: Test exited with no output.')
  (output, exception) = result.get()
  exception += timeout_exception
  if exception:
    raise Exception('%s%s%s' % (output, '\n' if output else '', exception))
  return output


def _run_test_on_android(shell, args, apptest, result):
  '''Run the test on Android; put output and any exception in |result|.'''
  output = ''
  exception = ''
  try:
    (r, w) = os.pipe()
    with os.fdopen(r, 'r') as rf:
      with os.fdopen(w, 'w') as wf:
        arguments = args + [apptest]
        shell.StartActivity('MojoShellActivity', arguments, wf, wf.close)
        output = rf.read()
  except Exception as e:
    output += (e.output + '\n') if hasattr(e, 'output') else ''
    exception += str(e)
  result.put((output, exception))