# Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
#
# Use of this source code is governed by a BSD-style license
# that can be found in the LICENSE file in the root of the source
# tree. An additional intellectual property rights grant can be found
# in the file PATENTS.  All contributing project authors may
# be found in the AUTHORS file in the root of the source tree.

import json
import os
import platform
import re
import subprocess
import sys


# Directories that will be scanned by cpplint by the presubmit script.
CPPLINT_DIRS = [
  'webrtc/audio',
  'webrtc/call',
  'webrtc/common_video',
  'webrtc/examples',
  'webrtc/modules/bitrate_controller',
  'webrtc/modules/congestion_controller',
  'webrtc/modules/pacing',
  'webrtc/modules/remote_bitrate_estimator',
  'webrtc/modules/rtp_rtcp',
  'webrtc/modules/video_coding',
  'webrtc/modules/video_processing',
  'webrtc/sound',
  'webrtc/tools',
  'webrtc/video',
]

# These filters will always be removed, even if the caller specifies a filter
# set, as they are problematic or broken in some way.
#
# Justifications for each filter:
# - build/c++11         : Rvalue ref checks are unreliable (false positives),
#                         include file and feature blacklists are
#                         google3-specific.
BLACKLIST_LINT_FILTERS = [
  '-build/c++11',
]

# List of directories of "supported" native APIs. That means changes to headers
# will be done in a compatible way following this scheme:
# 1. Non-breaking changes are made.
# 2. The old APIs as marked as deprecated (with comments).
# 3. Deprecation is announced to discuss-webrtc@googlegroups.com and
#    webrtc-users@google.com (internal list).
# 4. (later) The deprecated APIs are removed.
# Directories marked as DEPRECATED should not be used. They're only present in
# the list to support legacy downstream code.
NATIVE_API_DIRS = (
  'talk/app/webrtc',
  'webrtc',
  'webrtc/base',  # DEPRECATED.
  'webrtc/common_audio/include',  # DEPRECATED.
  'webrtc/modules/audio_coding/include',
  'webrtc/modules/audio_conference_mixer/include',  # DEPRECATED.
  'webrtc/modules/audio_device/include',
  'webrtc/modules/audio_processing/include',
  'webrtc/modules/bitrate_controller/include',
  'webrtc/modules/congestion_controller/include',
  'webrtc/modules/include',
  'webrtc/modules/remote_bitrate_estimator/include',
  'webrtc/modules/rtp_rtcp/include',
  'webrtc/modules/rtp_rtcp/source',  # DEPRECATED.
  'webrtc/modules/utility/include',
  'webrtc/modules/video_coding/codecs/h264/include',
  'webrtc/modules/video_coding/codecs/i420/include',
  'webrtc/modules/video_coding/codecs/vp8/include',
  'webrtc/modules/video_coding/codecs/vp9/include',
  'webrtc/modules/video_coding/include',
  'webrtc/system_wrappers/include',  # DEPRECATED.
  'webrtc/voice_engine/include',
)


def _VerifyNativeApiHeadersListIsValid(input_api, output_api):
  """Ensures the list of native API header directories is up to date."""
  non_existing_paths = []
  native_api_full_paths = [
      input_api.os_path.join(input_api.PresubmitLocalPath(),
                             *path.split('/')) for path in NATIVE_API_DIRS]
  for path in native_api_full_paths:
    if not os.path.isdir(path):
      non_existing_paths.append(path)
  if non_existing_paths:
    return [output_api.PresubmitError(
        'Directories to native API headers have changed which has made the '
        'list in PRESUBMIT.py outdated.\nPlease update it to the current '
        'location of our native APIs.',
        non_existing_paths)]
  return []


def _CheckNativeApiHeaderChanges(input_api, output_api):
  """Checks to remind proper changing of native APIs."""
  files = []
  for f in input_api.AffectedSourceFiles(input_api.FilterSourceFile):
    if f.LocalPath().endswith('.h'):
      for path in NATIVE_API_DIRS:
        if os.path.dirname(f.LocalPath()) == path:
          files.append(f)

  if files:
    return [output_api.PresubmitNotifyResult(
        'You seem to be changing native API header files. Please make sure '
        'you:\n'
        '  1. Make compatible changes that don\'t break existing clients.\n'
        '  2. Mark the old APIs as deprecated.\n'
        '  3. Create a timeline and plan for when the deprecated method will '
        'be removed (preferably 3 months or so).\n'
        '  4. Update/inform existing downstream code owners to stop using the '
        'deprecated APIs: \n'
        'send announcement to discuss-webrtc@googlegroups.com and '
        'webrtc-users@google.com.\n'
        '  5. (after ~3 months) remove the deprecated API.\n'
        'Related files:',
        files)]
  return []


def _CheckNoIOStreamInHeaders(input_api, output_api):
  """Checks to make sure no .h files include <iostream>."""
  files = []
  pattern = input_api.re.compile(r'^#include\s*<iostream>',
                                 input_api.re.MULTILINE)
  for f in input_api.AffectedSourceFiles(input_api.FilterSourceFile):
    if not f.LocalPath().endswith('.h'):
      continue
    contents = input_api.ReadFile(f)
    if pattern.search(contents):
      files.append(f)

  if len(files):
    return [output_api.PresubmitError(
        'Do not #include <iostream> in header files, since it inserts static ' +
        'initialization into every file including the header. Instead, ' +
        '#include <ostream>. See http://crbug.com/94794',
        files)]
  return []


def _CheckNoFRIEND_TEST(input_api, output_api):
  """Make sure that gtest's FRIEND_TEST() macro is not used, the
  FRIEND_TEST_ALL_PREFIXES() macro from testsupport/gtest_prod_util.h should be
  used instead since that allows for FLAKY_, FAILS_ and DISABLED_ prefixes."""
  problems = []

  file_filter = lambda f: f.LocalPath().endswith(('.cc', '.h'))
  for f in input_api.AffectedFiles(file_filter=file_filter):
    for line_num, line in f.ChangedContents():
      if 'FRIEND_TEST(' in line:
        problems.append('    %s:%d' % (f.LocalPath(), line_num))

  if not problems:
    return []
  return [output_api.PresubmitPromptWarning('WebRTC\'s code should not use '
      'gtest\'s FRIEND_TEST() macro. Include testsupport/gtest_prod_util.h and '
      'use FRIEND_TEST_ALL_PREFIXES() instead.\n' + '\n'.join(problems))]


def _IsLintWhitelisted(whitelist_dirs, file_path):
  """ Checks if a file is whitelisted for lint check."""
  for path in whitelist_dirs:
    if os.path.dirname(file_path).startswith(path):
      return True
  return False


def _CheckApprovedFilesLintClean(input_api, output_api,
                                 source_file_filter=None):
  """Checks that all new or whitelisted .cc and .h files pass cpplint.py.
  This check is based on _CheckChangeLintsClean in
  depot_tools/presubmit_canned_checks.py but has less filters and only checks
  added files."""
  result = []

  # Initialize cpplint.
  import cpplint
  # Access to a protected member _XX of a client class
  # pylint: disable=W0212
  cpplint._cpplint_state.ResetErrorCounts()

  lint_filters = cpplint._Filters()
  lint_filters.extend(BLACKLIST_LINT_FILTERS)
  cpplint._SetFilters(','.join(lint_filters))

  # Create a platform independent whitelist for the CPPLINT_DIRS.
  whitelist_dirs = [input_api.os_path.join(*path.split('/'))
                    for path in CPPLINT_DIRS]

  # Use the strictest verbosity level for cpplint.py (level 1) which is the
  # default when running cpplint.py from command line.
  # To make it possible to work with not-yet-converted code, we're only applying
  # it to new (or moved/renamed) files and files listed in LINT_FOLDERS.
  verbosity_level = 1
  files = []
  for f in input_api.AffectedSourceFiles(source_file_filter):
    # Note that moved/renamed files also count as added.
    if f.Action() == 'A' or _IsLintWhitelisted(whitelist_dirs, f.LocalPath()):
      files.append(f.AbsoluteLocalPath())

  for file_name in files:
    cpplint.ProcessFile(file_name, verbosity_level)

  if cpplint._cpplint_state.error_count > 0:
    if input_api.is_committing:
      # TODO(kjellander): Change back to PresubmitError below when we're
      # confident with the lint settings.
      res_type = output_api.PresubmitPromptWarning
    else:
      res_type = output_api.PresubmitPromptWarning
    result = [res_type('Changelist failed cpplint.py check.')]

  return result

def _CheckNoRtcBaseDeps(input_api, gyp_files, output_api):
  pattern = input_api.re.compile(r"base.gyp:rtc_base\s*'")
  violating_files = []
  for f in gyp_files:
    gyp_exceptions = (
        'base_tests.gyp',
        'desktop_capture.gypi',
        'p2p.gyp',
        'sound.gyp',
        'webrtc_test_common.gyp',
        'webrtc_tests.gypi',
    )
    if f.LocalPath().endswith(gyp_exceptions):
      continue
    contents = input_api.ReadFile(f)
    if pattern.search(contents):
      violating_files.append(f)
  if violating_files:
    return [output_api.PresubmitError(
        'Depending on rtc_base is not allowed. Change your dependency to '
        'rtc_base_approved and possibly sanitize and move the desired source '
        'file(s) to rtc_base_approved.\nChanged GYP files:',
        items=violating_files)]
  return []

def _CheckNoSourcesAboveGyp(input_api, gyp_files, output_api):
  # Disallow referencing source files with paths above the GYP file location.
  source_pattern = input_api.re.compile(r'sources.*?\[(.*?)\]',
                                        re.MULTILINE | re.DOTALL)
  file_pattern = input_api.re.compile(r"'((\.\./.*?)|(<\(webrtc_root\).*?))'")
  violating_gyp_files = set()
  violating_source_entries = []
  for gyp_file in gyp_files:
    if 'supplement.gypi' in gyp_file.LocalPath():
      # Exclude supplement.gypi from this check, as the LSan and TSan
      # suppression files are located in a different location.
      continue
    contents = input_api.ReadFile(gyp_file)
    for source_block_match in source_pattern.finditer(contents):
      # Find all source list entries starting with ../ in the source block
      # (exclude overrides entries).
      for file_list_match in file_pattern.finditer(source_block_match.group(0)):
        source_file = file_list_match.group(0)
        if 'overrides/' not in source_file:
          violating_source_entries.append(source_file)
          violating_gyp_files.add(gyp_file)
  if violating_gyp_files:
    return [output_api.PresubmitError(
        'Referencing source files above the directory of the GYP file is not '
        'allowed. Please introduce new GYP targets and/or GYP files in the '
        'proper location instead.\n'
        'Invalid source entries:\n'
        '%s\n'
        'Violating GYP files:' % '\n'.join(violating_source_entries),
        items=violating_gyp_files)]
  return []

def _CheckGypChanges(input_api, output_api):
  source_file_filter = lambda x: input_api.FilterSourceFile(
      x, white_list=(r'.+\.(gyp|gypi)$',))

  gyp_files = []
  for f in input_api.AffectedSourceFiles(source_file_filter):
    if f.LocalPath().startswith('webrtc'):
      gyp_files.append(f)

  result = []
  if gyp_files:
    result.append(output_api.PresubmitNotifyResult(
        'As you\'re changing GYP files: please make sure corresponding '
        'BUILD.gn files are also updated.\nChanged GYP files:',
        items=gyp_files))
    result.extend(_CheckNoRtcBaseDeps(input_api, gyp_files, output_api))
    result.extend(_CheckNoSourcesAboveGyp(input_api, gyp_files, output_api))
  return result

def _CheckUnwantedDependencies(input_api, output_api):
  """Runs checkdeps on #include statements added in this
  change. Breaking - rules is an error, breaking ! rules is a
  warning.
  """
  # Copied from Chromium's src/PRESUBMIT.py.

  # We need to wait until we have an input_api object and use this
  # roundabout construct to import checkdeps because this file is
  # eval-ed and thus doesn't have __file__.
  original_sys_path = sys.path
  try:
    checkdeps_path = input_api.os_path.join(input_api.PresubmitLocalPath(),
                                            'buildtools', 'checkdeps')
    if not os.path.exists(checkdeps_path):
      return [output_api.PresubmitError(
          'Cannot find checkdeps at %s\nHave you run "gclient sync" to '
          'download Chromium and setup the symlinks?' % checkdeps_path)]
    sys.path.append(checkdeps_path)
    import checkdeps
    from cpp_checker import CppChecker
    from rules import Rule
  finally:
    # Restore sys.path to what it was before.
    sys.path = original_sys_path

  added_includes = []
  for f in input_api.AffectedFiles():
    if not CppChecker.IsCppFile(f.LocalPath()):
      continue

    changed_lines = [line for _, line in f.ChangedContents()]
    added_includes.append([f.LocalPath(), changed_lines])

  deps_checker = checkdeps.DepsChecker(input_api.PresubmitLocalPath())

  error_descriptions = []
  warning_descriptions = []
  for path, rule_type, rule_description in deps_checker.CheckAddedCppIncludes(
      added_includes):
    description_with_path = '%s\n    %s' % (path, rule_description)
    if rule_type == Rule.DISALLOW:
      error_descriptions.append(description_with_path)
    else:
      warning_descriptions.append(description_with_path)

  results = []
  if error_descriptions:
    results.append(output_api.PresubmitError(
        'You added one or more #includes that violate checkdeps rules.',
        error_descriptions))
  if warning_descriptions:
    results.append(output_api.PresubmitPromptOrNotify(
        'You added one or more #includes of files that are temporarily\n'
        'allowed but being removed. Can you avoid introducing the\n'
        '#include? See relevant DEPS file(s) for details and contacts.',
        warning_descriptions))
  return results


def _CheckJSONParseErrors(input_api, output_api):
  """Check that JSON files do not contain syntax errors."""

  def FilterFile(affected_file):
    return input_api.os_path.splitext(affected_file.LocalPath())[1] == '.json'

  def GetJSONParseError(input_api, filename):
    try:
      contents = input_api.ReadFile(filename)
      input_api.json.loads(contents)
    except ValueError as e:
      return e
    return None

  results = []
  for affected_file in input_api.AffectedFiles(
      file_filter=FilterFile, include_deletes=False):
    parse_error = GetJSONParseError(input_api,
                                    affected_file.AbsoluteLocalPath())
    if parse_error:
      results.append(output_api.PresubmitError('%s could not be parsed: %s' %
          (affected_file.LocalPath(), parse_error)))
  return results


def _RunPythonTests(input_api, output_api):
  def join(*args):
    return input_api.os_path.join(input_api.PresubmitLocalPath(), *args)

  test_directories = [
    join('tools', 'autoroller', 'unittests'),
  ]

  tests = []
  for directory in test_directories:
    tests.extend(
      input_api.canned_checks.GetUnitTestsInDirectory(
          input_api,
          output_api,
          directory,
          whitelist=[r'.+_test\.py$']))
  return input_api.RunTests(tests, parallel=True)


def _CommonChecks(input_api, output_api):
  """Checks common to both upload and commit."""
  results = []
  # Filter out files that are in objc or ios dirs from being cpplint-ed since
  # they do not follow C++ lint rules.
  black_list = input_api.DEFAULT_BLACK_LIST + (
    r".*\bobjc[\\\/].*",
  )
  source_file_filter = lambda x: input_api.FilterSourceFile(x, None, black_list)
  results.extend(_CheckApprovedFilesLintClean(
      input_api, output_api, source_file_filter))
  results.extend(input_api.canned_checks.RunPylint(input_api, output_api,
      black_list=(r'^.*gviz_api\.py$',
                  r'^.*gaeunit\.py$',
                  # Embedded shell-script fakes out pylint.
                  r'^build[\\\/].*\.py$',
                  r'^buildtools[\\\/].*\.py$',
                  r'^chromium[\\\/].*\.py$',
                  r'^google_apis[\\\/].*\.py$',
                  r'^net.*[\\\/].*\.py$',
                  r'^out.*[\\\/].*\.py$',
                  r'^testing[\\\/].*\.py$',
                  r'^third_party[\\\/].*\.py$',
                  r'^tools[\\\/]find_depot_tools.py$',
                  r'^tools[\\\/]clang[\\\/].*\.py$',
                  r'^tools[\\\/]generate_library_loader[\\\/].*\.py$',
                  r'^tools[\\\/]gn[\\\/].*\.py$',
                  r'^tools[\\\/]gyp[\\\/].*\.py$',
                  r'^tools[\\\/]isolate_driver.py$',
                  r'^tools[\\\/]protoc_wrapper[\\\/].*\.py$',
                  r'^tools[\\\/]python[\\\/].*\.py$',
                  r'^tools[\\\/]python_charts[\\\/]data[\\\/].*\.py$',
                  r'^tools[\\\/]refactoring[\\\/].*\.py$',
                  r'^tools[\\\/]swarming_client[\\\/].*\.py$',
                  r'^tools[\\\/]vim[\\\/].*\.py$',
                  # TODO(phoglund): should arguably be checked.
                  r'^tools[\\\/]valgrind-webrtc[\\\/].*\.py$',
                  r'^tools[\\\/]valgrind[\\\/].*\.py$',
                  r'^tools[\\\/]win[\\\/].*\.py$',
                  r'^xcodebuild.*[\\\/].*\.py$',),
      disabled_warnings=['F0401',  # Failed to import x
                         'E0611',  # No package y in x
                         'W0232',  # Class has no __init__ method
                        ],
      pylintrc='pylintrc'))

  # WebRTC can't use the presubmit_canned_checks.PanProjectChecks function since
  # we need to have different license checks in talk/ and webrtc/ directories.
  # Instead, hand-picked checks are included below.

  # Skip long-lines check for DEPS, GN and GYP files.
  long_lines_sources = lambda x: input_api.FilterSourceFile(x,
      black_list=(r'.+\.gyp$', r'.+\.gypi$', r'.+\.gn$', r'.+\.gni$', 'DEPS'))
  results.extend(input_api.canned_checks.CheckLongLines(
      input_api, output_api, maxlen=80, source_file_filter=long_lines_sources))
  results.extend(input_api.canned_checks.CheckChangeHasNoTabs(
      input_api, output_api))
  results.extend(input_api.canned_checks.CheckChangeHasNoStrayWhitespace(
      input_api, output_api))
  results.extend(input_api.canned_checks.CheckChangeTodoHasOwner(
      input_api, output_api))
  results.extend(_CheckNativeApiHeaderChanges(input_api, output_api))
  results.extend(_CheckNoIOStreamInHeaders(input_api, output_api))
  results.extend(_CheckNoFRIEND_TEST(input_api, output_api))
  results.extend(_CheckGypChanges(input_api, output_api))
  results.extend(_CheckUnwantedDependencies(input_api, output_api))
  results.extend(_CheckJSONParseErrors(input_api, output_api))
  results.extend(_RunPythonTests(input_api, output_api))
  return results


def CheckChangeOnUpload(input_api, output_api):
  results = []
  results.extend(_CommonChecks(input_api, output_api))
  results.extend(
      input_api.canned_checks.CheckGNFormatted(input_api, output_api))
  return results


def CheckChangeOnCommit(input_api, output_api):
  results = []
  results.extend(_CommonChecks(input_api, output_api))
  results.extend(_VerifyNativeApiHeadersListIsValid(input_api, output_api))
  results.extend(input_api.canned_checks.CheckOwners(input_api, output_api))
  results.extend(input_api.canned_checks.CheckChangeWasUploaded(
      input_api, output_api))
  results.extend(input_api.canned_checks.CheckChangeHasDescription(
      input_api, output_api))
  results.extend(input_api.canned_checks.CheckChangeHasBugField(
      input_api, output_api))
  results.extend(input_api.canned_checks.CheckChangeHasTestField(
      input_api, output_api))
  results.extend(input_api.canned_checks.CheckTreeIsOpen(
      input_api, output_api,
      json_url='http://webrtc-status.appspot.com/current?format=json'))
  return results


# pylint: disable=W0613
def GetPreferredTryMasters(project, change):
  cq_config_path = os.path.join(
      change.RepositoryRoot(), 'infra', 'config', 'cq.cfg')
  # commit_queue.py below is a script in depot_tools directory, which has a
  # 'builders' command to retrieve a list of CQ builders from the CQ config.
  is_win = platform.system() == 'Windows'
  masters = json.loads(subprocess.check_output(
      ['commit_queue', 'builders', cq_config_path], shell=is_win))

  try_config = {}
  for master in masters:
    try_config.setdefault(master, {})
    for builder in masters[master]:
      if 'presubmit' in builder:
        # Do not trigger presubmit builders, since they're likely to fail
        # (e.g. OWNERS checks before finished code review), and we're running
        # local presubmit anyway.
        pass
      else:
        try_config[master][builder] = ['defaulttests']

  return try_config