# 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 Skia.

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

import os
import sys


def _CheckChangeHasEol(input_api, output_api, source_file_filter=None):
  """Checks that files end with atleast one \n (LF)."""
  eof_files = []
  for f in input_api.AffectedSourceFiles(source_file_filter):
    contents = input_api.ReadFile(f, 'rb')
    # Check that the file ends in atleast one newline character.
    if len(contents) > 1 and contents[-1:] != '\n':
      eof_files.append(f.LocalPath())

  if eof_files:
    return [output_api.PresubmitPromptWarning(
      'These files should end in a newline character:',
      items=eof_files)]
  return []


def _CommonChecks(input_api, output_api):
  """Presubmit checks common to upload and commit."""
  results = []
  sources = lambda x: (x.LocalPath().endswith('.h') or
                       x.LocalPath().endswith('.gypi') or
                       x.LocalPath().endswith('.gyp') or
                       x.LocalPath().endswith('.py') or
                       x.LocalPath().endswith('.sh') or
                       x.LocalPath().endswith('.cpp'))
  results.extend(
      _CheckChangeHasEol(
          input_api, output_api, source_file_filter=sources))
  return results


def CheckChangeOnUpload(input_api, output_api):
  """Presubmit checks for the change on upload.

  The following are the presubmit checks:
  * Check change has one and only one EOL.
  """
  results = []
  results.extend(_CommonChecks(input_api, output_api))
  return results


def _CheckTreeStatus(input_api, output_api, json_url):
  """Check whether to allow commit.

  Args:
    input_api: input related apis.
    output_api: output related apis.
    json_url: url to download json style status.
  """
  tree_status_results = input_api.canned_checks.CheckTreeIsOpen(
      input_api, output_api, json_url=json_url)
  if not tree_status_results:
    # Check for caution state only if tree is not closed.
    connection = input_api.urllib2.urlopen(json_url)
    status = input_api.json.loads(connection.read())
    connection.close()
    if ('caution' in status['message'].lower() and
        os.isatty(sys.stdout.fileno())):
      # Display a prompt only if we are in an interactive shell. Without this
      # check the commit queue behaves incorrectly because it considers
      # prompts to be failures.
      short_text = 'Tree state is: ' + status['general_state']
      long_text = status['message'] + '\n' + json_url
      tree_status_results.append(
          output_api.PresubmitPromptWarning(
              message=short_text, long_text=long_text))
  return tree_status_results


def CheckChangeOnCommit(input_api, output_api):
  """Presubmit checks for the change on commit.

  The following are the presubmit checks:
  * Check change has one and only one EOL.
  * Ensures that the Skia tree is open in
    http://skia-tree-status.appspot.com/. Shows a warning if it is in 'Caution'
    state and an error if it is in 'Closed' state.
  """
  results = []
  results.extend(_CommonChecks(input_api, output_api))
  results.extend(
      _CheckTreeStatus(input_api, output_api, json_url=(
          'http://skia-tree-status.appspot.com/banner-status?format=json')))
  return results