# Copyright (c) 2013 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.

"""Top-level presubmit script for Blink.

See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
for more details about the presubmit API built into gcl.
"""

import sys


_EXCLUDED_PATHS = ()


def _CheckForVersionControlConflictsInFile(input_api, f):
    pattern = input_api.re.compile('^(?:<<<<<<<|>>>>>>>) |^=======$')
    errors = []
    for line_num, line in f.ChangedContents():
        if pattern.match(line):
            errors.append('    %s:%d %s' % (f.LocalPath(), line_num, line))
    return errors


def _CheckForVersionControlConflicts(input_api, output_api):
    """Usually this is not intentional and will cause a compile failure."""
    errors = []
    for f in input_api.AffectedFiles():
        errors.extend(_CheckForVersionControlConflictsInFile(input_api, f))

    results = []
    if errors:
        results.append(output_api.PresubmitError(
            'Version control conflict markers found, please resolve.', errors))
    return results


def _CheckWatchlist(input_api, output_api):
    """Check that the WATCHLIST file parses correctly."""
    errors = []
    for f in input_api.AffectedFiles():
        if f.LocalPath() != 'WATCHLISTS':
            continue
        import StringIO
        import logging
        import watchlists

        log_buffer = StringIO.StringIO()
        log_handler = logging.StreamHandler(log_buffer)
        log_handler.setFormatter(
            logging.Formatter('%(levelname)s: %(message)s'))
        logger = logging.getLogger()
        logger.addHandler(log_handler)

        wl = watchlists.Watchlists(input_api.change.RepositoryRoot())

        logger.removeHandler(log_handler)
        log_handler.flush()
        log_buffer.flush()

        if log_buffer.getvalue():
            errors.append(output_api.PresubmitError(
                'Cannot parse WATCHLISTS file, please resolve.',
                log_buffer.getvalue().splitlines()))
    return errors


def _CommonChecks(input_api, output_api):
    """Checks common to both upload and commit."""
    # We should figure out what license checks we actually want to use.
    license_header = r'.*'

    results = []
    results.extend(input_api.canned_checks.PanProjectChecks(
        input_api, output_api, excluded_paths=_EXCLUDED_PATHS,
        maxlen=800, license_header=license_header))
    results.extend(_CheckForVersionControlConflicts(input_api, output_api))
    results.extend(_CheckPatchFiles(input_api, output_api))
    results.extend(_CheckTestExpectations(input_api, output_api))
    results.extend(_CheckUnwantedDependencies(input_api, output_api))
    results.extend(_CheckChromiumPlatformMacros(input_api, output_api))
    results.extend(_CheckWatchlist(input_api, output_api))
    results.extend(_CheckFilePermissions(input_api, output_api))
    return results


def _CheckSubversionConfig(input_api, output_api):
  """Verifies the subversion config file is correctly setup.

  Checks that autoprops are enabled, returns an error otherwise.
  """
  join = input_api.os_path.join
  if input_api.platform == 'win32':
    appdata = input_api.environ.get('APPDATA', '')
    if not appdata:
      return [output_api.PresubmitError('%APPDATA% is not configured.')]
    path = join(appdata, 'Subversion', 'config')
  else:
    home = input_api.environ.get('HOME', '')
    if not home:
      return [output_api.PresubmitError('$HOME is not configured.')]
    path = join(home, '.subversion', 'config')

  error_msg = (
      'Please look at http://dev.chromium.org/developers/coding-style to\n'
      'configure your subversion configuration file. This enables automatic\n'
      'properties to simplify the project maintenance.\n'
      'Pro-tip: just download and install\n'
      'http://src.chromium.org/viewvc/chrome/trunk/tools/build/slave/config\n')

  try:
    lines = open(path, 'r').read().splitlines()
    # Make sure auto-props is enabled and check for 2 Chromium standard
    # auto-prop.
    if (not '*.cc = svn:eol-style=LF' in lines or
        not '*.pdf = svn:mime-type=application/pdf' in lines or
        not 'enable-auto-props = yes' in lines):
      return [
          output_api.PresubmitNotifyResult(
              'It looks like you have not configured your subversion config '
              'file or it is not up-to-date.\n' + error_msg)
      ]
  except (OSError, IOError):
    return [
        output_api.PresubmitNotifyResult(
            'Can\'t find your subversion config file.\n' + error_msg)
    ]
  return []


def _CheckPatchFiles(input_api, output_api):
  problems = [f.LocalPath() for f in input_api.AffectedFiles()
      if f.LocalPath().endswith(('.orig', '.rej'))]
  if problems:
    return [output_api.PresubmitError(
        "Don't commit .rej and .orig files.", problems)]
  else:
    return []


def _CheckTestExpectations(input_api, output_api):
    local_paths = [f.LocalPath() for f in input_api.AffectedFiles()]
    if any(path.startswith('LayoutTests') for path in local_paths):
        lint_path = input_api.os_path.join(input_api.PresubmitLocalPath(),
            'Tools', 'Scripts', 'lint-test-expectations')
        _, errs = input_api.subprocess.Popen(
            [input_api.python_executable, lint_path],
            stdout=input_api.subprocess.PIPE,
            stderr=input_api.subprocess.PIPE).communicate()
        if not errs:
            return [output_api.PresubmitError(
                "lint-test-expectations failed "
                "to produce output; check by hand. ")]
        if errs.strip() != 'Lint succeeded.':
            return [output_api.PresubmitError(errs)]
    return []


def _CheckStyle(input_api, output_api):
    style_checker_path = input_api.os_path.join(input_api.PresubmitLocalPath(),
        'Tools', 'Scripts', 'check-webkit-style')
    args = ([input_api.python_executable, style_checker_path, '--diff-files']
        + [f.LocalPath() for f in input_api.AffectedFiles()])
    results = []

    try:
        child = input_api.subprocess.Popen(args,
                                           stderr=input_api.subprocess.PIPE)
        _, stderrdata = child.communicate()
        if child.returncode != 0:
            results.append(output_api.PresubmitError(
                'check-webkit-style failed', [stderrdata]))
    except Exception as e:
        results.append(output_api.PresubmitNotifyResult(
            'Could not run check-webkit-style', [str(e)]))

    return results


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.
    """
    # 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:
        sys.path = sys.path + [input_api.os_path.realpath(input_api.os_path.join(
                input_api.PresubmitLocalPath(), '..', '..', 'buildtools', 'checkdeps'))]
        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_num, line in f.ChangedContents()]
        added_includes.append([f.LocalPath(), changed_lines])

    deps_checker = checkdeps.DepsChecker(
        input_api.os_path.join(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 _CheckChromiumPlatformMacros(input_api, output_api, source_file_filter=None):
    """Ensures that Blink code uses WTF's platform macros instead of
    Chromium's. Using the latter has resulted in at least one subtle
    build breakage."""
    os_macro_re = input_api.re.compile(r'^\s*#(el)?if.*\bOS_')
    errors = input_api.canned_checks._FindNewViolationsOfRule(
        lambda _, x: not os_macro_re.search(x),
        input_api, source_file_filter)
    errors = ['Found use of Chromium OS_* macro in %s. '
        'Use WTF platform macros instead.' % violation for violation in errors]
    if errors:
        return [output_api.PresubmitPromptWarning('\n'.join(errors))]
    return []


def _CheckForPrintfDebugging(input_api, output_api):
    """Generally speaking, we'd prefer not to land patches that printf
    debug output."""
    printf_re = input_api.re.compile(r'^\s*printf\(')
    errors = input_api.canned_checks._FindNewViolationsOfRule(
        lambda _, x: not printf_re.search(x),
        input_api, None)
    errors = ['  * %s' % violation for violation in errors]
    if errors:
        return [output_api.PresubmitPromptOrNotify(
                    'printf debugging is best debugging! That said, it might '
                    'be a good idea to drop the following occurances from '
                    'your patch before uploading:\n%s' % '\n'.join(errors))]
    return []


def _CheckForDangerousTestFunctions(input_api, output_api):
    """Tests should not be using serveAsynchronousMockedRequests, since it does
    not guarantee that the threaded HTML parser will have completed."""
    serve_async_requests_re = input_api.re.compile(
        r'serveAsynchronousMockedRequests')
    errors = input_api.canned_checks._FindNewViolationsOfRule(
        lambda _, x: not serve_async_requests_re.search(x),
        input_api, None)
    errors = ['  * %s' % violation for violation in errors]
    if errors:
        return [output_api.PresubmitError(
                    'You should be using FrameTestHelpers::'
                    'pumpPendingRequests() instead of '
                    'serveAsynchronousMockedRequests() in the following '
                    'locations:\n%s' % '\n'.join(errors))]
    return []


def _CheckForFailInFile(input_api, f):
    pattern = input_api.re.compile('^FAIL')
    errors = []
    for line_num, line in f.ChangedContents():
        if pattern.match(line):
            errors.append('    %s:%d %s' % (f.LocalPath(), line_num, line))
    return errors


def _CheckFilePermissions(input_api, output_api):
    """Check that all files have their permissions properly set."""
    if input_api.platform == 'win32':
        return []
    path = input_api.os_path.join(
        '..', '..', 'tools', 'checkperms', 'checkperms.py')
    args = [sys.executable, path, '--root', input_api.change.RepositoryRoot()]
    for f in input_api.AffectedFiles():
        args += ['--file', f.LocalPath()]
    checkperms = input_api.subprocess.Popen(
        args, stdout=input_api.subprocess.PIPE)
    errors = checkperms.communicate()[0].strip()
    if errors:
        return [output_api.PresubmitError(
            'checkperms.py failed.', errors.splitlines())]
    return []


def _CheckForInvalidPreferenceError(input_api, output_api):
    pattern = input_api.re.compile('Invalid name for preference: (.+)')
    results = []

    for f in input_api.AffectedFiles():
        if not f.LocalPath().endswith('-expected.txt'):
            continue
        for line_num, line in f.ChangedContents():
            error = pattern.search(line)
            if error:
                results.append(output_api.PresubmitError('Found an invalid preference %s in expected result %s:%s' % (error.group(1), f, line_num)))
    return results

def CheckChangeOnUpload(input_api, output_api):
    results = []
    results.extend(_CommonChecks(input_api, output_api))
    results.extend(_CheckStyle(input_api, output_api))
    results.extend(_CheckForPrintfDebugging(input_api, output_api))
    results.extend(_CheckForDangerousTestFunctions(input_api, output_api))
    results.extend(_CheckForInvalidPreferenceError(input_api, output_api))
    return results


def CheckChangeOnCommit(input_api, output_api):
    results = []
    results.extend(_CommonChecks(input_api, output_api))
    results.extend(input_api.canned_checks.CheckTreeIsOpen(
        input_api, output_api,
        json_url='http://blink-status.appspot.com/current?format=json'))
    results.extend(input_api.canned_checks.CheckChangeHasDescription(
        input_api, output_api))
    results.extend(_CheckSubversionConfig(input_api, output_api))
    return results


def GetPreferredTryMasters(project, change):
    import json
    import os.path
    import platform
    import subprocess

    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]:
            # 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.
            if 'presubmit' not in builder:
                try_config[master][builder] = ['defaulttests']

    return try_config