# Copyright 2015 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.

'''
Utility functions for all things related to manipulating google play services
related files.
'''

import argparse
import filecmp
import json
import logging
import os
import re
import sys

sys.path.append(os.path.join(os.path.dirname(__file__), os.pardir))
from devil.utils import cmd_helper


_XML_VERSION_NUMBER_PATTERN = re.compile(
    r'<integer name="google_play_services_version">(\d+)<\/integer>')


class DefaultsRawHelpFormatter(argparse.ArgumentDefaultsHelpFormatter,
                               argparse.RawDescriptionHelpFormatter):
  '''
  Combines the features of RawDescriptionHelpFormatter and
  ArgumentDefaultsHelpFormatter, providing defaults for the arguments and raw
  text for the description.
  '''
  pass


class ConfigParser(object):
  '''Reads and writes the configuration files for play services related scripts

  The configuration files are JSON files. Here is the data they are expected
  to contain:

   -  version_number
      Number. Mirrors @integer/google_play_services_version from the library.
      Example: 815000

  '''
  _VERSION_NUMBER_KEY = 'version_number'

  def __init__(self, path):
    self.path = path
    self.data = {}

    with open(path, 'r') as stream:
      self.data = json.load(stream)

  @property
  def version_number(self):
    return self.data[self._VERSION_NUMBER_KEY]

  def UpdateVersionNumber(self, new_version_number):
    '''Updates the version number and saves it in the configuration file. '''

    with open(self.path, 'w') as stream:
      self.data[self._VERSION_NUMBER_KEY] = new_version_number
      json.dump(self.data, stream, sort_keys=True, indent=2)
      stream.write(os.linesep)


def FileEquals(expected_file, actual_file):
  '''
  Returns whether the two files are equal. Returns False if any of the files
  doesn't exist.
  '''

  if not os.path.isfile(actual_file) or not os.path.isfile(expected_file):
    return False
  return filecmp.cmp(expected_file, actual_file)


def IsRepoDirty(repo_root):
  '''Returns True if there are no staged or modified files, False otherwise.'''

  # diff-index returns 1 if there are staged changes or modified files,
  # 0 otherwise
  cmd = ['git', 'diff-index', '--quiet', 'HEAD']
  return cmd_helper.Call(cmd, cwd=repo_root) == 1


def GetVersionNumberFromLibraryResources(version_xml):
  '''
  Extracts a Google Play services version number from its version.xml file.
  '''

  with open(version_xml, 'r') as version_file:
    version_file_content = version_file.read()

  match = _XML_VERSION_NUMBER_PATTERN.search(version_file_content)
  if not match:
    raise AttributeError('A value for google_play_services_version was not '
                         'found in ' + version_xml)
  return int(match.group(1))


def MakeLocalCommit(repo_root, files_to_commit, message):
  '''Makes a local git commit.'''

  logging.debug('Staging files (%s) for commit.', files_to_commit)
  if cmd_helper.Call(['git', 'add'] + files_to_commit, cwd=repo_root) != 0:
    raise Exception('The local commit failed.')

  logging.debug('Committing.')
  if cmd_helper.Call(['git', 'commit', '-m', message], cwd=repo_root) != 0:
    raise Exception('The local commit failed.')