# 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.

"""LayoutTests/ 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 filecmp


def _CheckTestharnessResults(input_api, output_api):
    """Checks for testharness.js test baseline files that contain only PASS lines.

    In general these files are unnecessary because for testharness.js tests, if there is
    no baseline file then the test is considered to pass when the output is all PASS.
    """
    baseline_files = _TestharnessBaselineFilesToCheck(input_api)
    if not baseline_files:
        return []

    checker_path = input_api.os_path.join(input_api.PresubmitLocalPath(),
        '..', 'Tools', 'Scripts', 'check-testharness-expected-pass')

    args = [input_api.python_executable, checker_path]
    args.extend(baseline_files)
    _, errs = input_api.subprocess.Popen(args,
        stdout=input_api.subprocess.PIPE,
        stderr=input_api.subprocess.PIPE).communicate()
    if errs:
        return [output_api.PresubmitError(errs)]
    return []


def _TestharnessBaselineFilesToCheck(input_api):
    """Returns a list of paths of -expected.txt files for testharness.js tests."""
    baseline_files = []
    for f in input_api.AffectedFiles():
        if f.Action() == 'D':
            continue
        path = f.AbsoluteLocalPath()
        if not path.endswith('-expected.txt'):
            continue
        if (input_api.os_path.join('LayoutTests', 'platform') in path or
            input_api.os_path.join('LayoutTests', 'virtual') in path):
            # We want to ignore files in LayoutTests/platform, because some all-PASS
            # platform specific baselines may be necessary to prevent fallback to a
            # more general baseline; we also ignore files in LayoutTests/virtual
            # for a similar reason; some all-pass baselines are necessary to
            # prevent fallback to the corresponding non-virtual test baseline.
            continue
        baseline_files.append(path)
    return baseline_files


def _CheckFilesUsingEventSender(input_api, output_api):
    """Check if any new layout tests still use eventSender. If they do, we encourage replacing them with
       chrome.gpuBenchmarking.pointerActionSequence.
    """
    results = []
    actions = ["eventSender.touch", "eventSender.mouse", "eventSender.gesture"]
    for f in input_api.AffectedFiles():
        if f.Action() == 'A':
            for line_num, line in f.ChangedContents():
                if any(action in line for action in actions):
                    results.append(output_api.PresubmitPromptWarning(
                        'eventSender is deprecated, please use chrome.gpuBenchmarking.pointerActionSequence instead ' +
                        '(see https://crbug.com/711340 and http://goo.gl/BND75q).\n' +
                        'Files: %s:%d %s ' % (f.LocalPath(), line_num, line)))
    return results


def CheckChangeOnUpload(input_api, output_api):
    results = []
    results.extend(_CheckTestharnessResults(input_api, output_api))
    results.extend(_CheckFilesUsingEventSender(input_api, output_api))
    return results


def CheckChangeOnCommit(input_api, output_api):
    results = []
    results.extend(_CheckTestharnessResults(input_api, output_api))
    results.extend(_CheckFilesUsingEventSender(input_api, output_api))
    return results