#!/usr/bin/env python
#
# 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.

'''Prepares the Google Play services split client libraries before usage by
Chrome's build system.

We need to preprocess Google Play services before using it in Chrome
builds for 2 main reasons:

- Getting rid of unused resources: unsupported languages, unused
drawables, etc.

- Merging the differents jars so that it can be proguarded more
easily. This is necessary since debug and test apks get very close
to the dex limit.

The script is supposed to be used with the maven repository that can be
obtained by downloading the "extra-google-m2repository" from the Android SDK
Manager. It also supports importing from already extracted AAR files using the
--is-extracted-repo flag. The expected directory structure in that case would
look like:

    REPOSITORY_DIR
    +-- CLIENT_1
    |   +-- <content of the first AAR file>
    +-- CLIENT_2
    +-- etc.

The json config (see the -c argument) file should provide the following fields:

- lib_version: String. Used when building from the maven repository. It should
  be the package's version (e.g. "7.3.0"). Unused with extracted repositories.

- clients: String array. List of clients to pick. For example, when building
  from the maven repository, it's the artifactId (e.g. "play-services-base") of
  each client. With an extracted repository, it's the name of the
  subdirectories.

- locale_whitelist: String array. Locales that should be allowed in the final
  resources. They are specified the same way they are appended to the `values`
  directory in android resources (e.g. "us-GB", "it", "fil").

The output is a directory with the following structure:

    OUT_DIR
    +-- google-play-services.jar
    +-- res
    |   +-- CLIENT_1
    |   |   +-- color
    |   |   +-- values
    |   |   +-- etc.
    |   +-- CLIENT_2
    |       +-- ...
    +-- stub
        +-- res/[.git-keep-directory]
        +-- src/android/UnusedStub.java

Requires the `jar` utility in the path.

'''

import argparse
import glob
import itertools
import json
import os
import re
import shutil
import stat
import sys

from datetime import datetime
from devil.utils import cmd_helper
from pylib import constants

sys.path.append(
    os.path.join(constants.DIR_SOURCE_ROOT, 'build', 'android', 'gyp'))
from util import build_utils


M2_PKG_PATH = os.path.join('com', 'google', 'android', 'gms')
OUTPUT_FORMAT_VERSION = 1
VERSION_FILE_NAME = 'version_info.json'
VERSION_NUMBER_PATTERN = re.compile(
    '<integer name="google_play_services_version">(\d+)<\/integer>')

def main():
  parser = argparse.ArgumentParser(description=("Prepares the Google Play "
      "services split client libraries before usage by Chrome's build system. "
      "See the script's documentation for more a detailed help."))
  parser.add_argument('-r',
                      '--repository',
                      help='The Google Play services repository location',
                      required=True,
                      metavar='FILE')
  parser.add_argument('-o',
                      '--out-dir',
                      help='The output directory',
                      required=True,
                      metavar='FILE')
  parser.add_argument('-c',
                      '--config-file',
                      help='Config file path',
                      required=True,
                      metavar='FILE')
  parser.add_argument('-x',
                      '--is-extracted-repo',
                      action='store_true',
                      default=False,
                      help='The provided repository is not made of AAR files.')

  args = parser.parse_args()

  ProcessGooglePlayServices(args.repository,
                            args.out_dir,
                            args.config_file,
                            args.is_extracted_repo)


def ProcessGooglePlayServices(repo, out_dir, config_path, is_extracted_repo):
  with open(config_path, 'r') as json_file:
    config = json.load(json_file)

  with build_utils.TempDir() as tmp_root:
    tmp_paths = _SetupTempDir(tmp_root)

    if is_extracted_repo:
      _ImportFromExtractedRepo(config, tmp_paths, repo)
    else:
      _ImportFromAars(config, tmp_paths, repo)

    _GenerateCombinedJar(tmp_paths)
    _ProcessResources(config, tmp_paths)

    if is_extracted_repo:
      printable_repo = repo
    else:
      printable_repo = 'm2repository - ' + config['lib_version']
    _BuildOutput(config, tmp_paths, out_dir, printable_repo)


def _SetupTempDir(tmp_root):
  tmp_paths = {
    'root': tmp_root,
    'imported_clients': os.path.join(tmp_root, 'imported_clients'),
    'extracted_jars': os.path.join(tmp_root, 'jar'),
    'combined_jar': os.path.join(tmp_root, 'google-play-services.jar'),
  }
  os.mkdir(tmp_paths['imported_clients'])
  os.mkdir(tmp_paths['extracted_jars'])

  return tmp_paths


def _SetupOutputDir(out_dir):
  out_paths = {
    'root': out_dir,
    'res': os.path.join(out_dir, 'res'),
    'jar': os.path.join(out_dir, 'google-play-services.jar'),
    'stub': os.path.join(out_dir, 'stub'),
  }

  shutil.rmtree(out_paths['jar'], ignore_errors=True)
  shutil.rmtree(out_paths['res'], ignore_errors=True)
  shutil.rmtree(out_paths['stub'], ignore_errors=True)

  return out_paths


def _MakeWritable(dir_path):
  for root, dirs, files in os.walk(dir_path):
    for path in itertools.chain(dirs, files):
      st = os.stat(os.path.join(root, path))
      os.chmod(os.path.join(root, path), st.st_mode | stat.S_IWUSR)


def _ImportFromAars(config, tmp_paths, repo):
  for client in config['clients']:
    aar_name = '%s-%s.aar' % (client, config['lib_version'])
    aar_path = os.path.join(repo, M2_PKG_PATH, client,
                            config['lib_version'], aar_name)
    aar_out_path = os.path.join(tmp_paths['imported_clients'], client)
    build_utils.ExtractAll(aar_path, aar_out_path)

    client_jar_path = os.path.join(aar_out_path, 'classes.jar')
    build_utils.ExtractAll(client_jar_path, tmp_paths['extracted_jars'],
                           no_clobber=False)


def _ImportFromExtractedRepo(config, tmp_paths, repo):
  # Import the clients
  try:
    for client in config['clients']:
      client_out_dir = os.path.join(tmp_paths['imported_clients'], client)
      shutil.copytree(os.path.join(repo, client), client_out_dir)

      client_jar_path = os.path.join(client_out_dir, 'classes.jar')
      build_utils.ExtractAll(client_jar_path, tmp_paths['extracted_jars'],
                             no_clobber=False)
  finally:
    _MakeWritable(tmp_paths['imported_clients'])


def _GenerateCombinedJar(tmp_paths):
  out_file_name = tmp_paths['combined_jar']
  working_dir = tmp_paths['extracted_jars']
  cmd_helper.Call(['jar', '-cf', out_file_name, '-C', working_dir, '.'])


def _ProcessResources(config, tmp_paths):
  LOCALIZED_VALUES_BASE_NAME = 'values-'
  locale_whitelist = set(config['locale_whitelist'])

  glob_pattern = os.path.join(tmp_paths['imported_clients'], '*', 'res', '*')
  for res_dir in glob.glob(glob_pattern):
    dir_name = os.path.basename(res_dir)

    if dir_name.startswith('drawable'):
      shutil.rmtree(res_dir)
      continue

    if dir_name.startswith(LOCALIZED_VALUES_BASE_NAME):
      dir_locale = dir_name[len(LOCALIZED_VALUES_BASE_NAME):]
      if dir_locale not in locale_whitelist:
        shutil.rmtree(res_dir)


def _GetVersionNumber(config, tmp_paths):
  version_file_path = os.path.join(tmp_paths['imported_clients'],
                                   config['base_client'],
                                   'res',
                                   'values',
                                   'version.xml')

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

  match = VERSION_NUMBER_PATTERN.search(version_file_content)
  if not match:
    raise AttributeError('A value for google_play_services_version was not '
                         'found in ' + version_file_path)

  return match.group(1)


def _BuildOutput(config, tmp_paths, out_dir, printable_repo):
  generation_date = datetime.utcnow()
  play_services_full_version = _GetVersionNumber(config, tmp_paths)

  # Create a version text file to allow quickly checking the version
  gen_info = {
    '@Description@': 'Preprocessed Google Play services clients for chrome',
    'Generator script': os.path.basename(__file__),
    'Repository source': printable_repo,
    'Library version': play_services_full_version,
    'Directory format version': OUTPUT_FORMAT_VERSION,
    'Generation Date (UTC)': str(generation_date)
  }
  tmp_version_file_path = os.path.join(tmp_paths['root'], VERSION_FILE_NAME)
  with open(tmp_version_file_path, 'w') as version_file:
    json.dump(gen_info, version_file, indent=2, sort_keys=True)

  out_paths = _SetupOutputDir(out_dir)

  # Copy the resources to the output dir
  for client in config['clients']:
    res_in_tmp_dir = os.path.join(tmp_paths['imported_clients'], client, 'res')
    if os.path.isdir(res_in_tmp_dir) and os.listdir(res_in_tmp_dir):
      res_in_final_dir = os.path.join(out_paths['res'], client)
      shutil.copytree(res_in_tmp_dir, res_in_final_dir)

  # Copy the jar
  shutil.copyfile(tmp_paths['combined_jar'], out_paths['jar'])

  # Write the java dummy stub. Needed for gyp to create the resource jar
  stub_location = os.path.join(out_paths['stub'], 'src', 'android')
  os.makedirs(stub_location)
  with open(os.path.join(stub_location, 'UnusedStub.java'), 'w') as stub:
    stub.write('package android;'
               'public final class UnusedStub {'
               '    private UnusedStub() {}'
               '}')

  # Create the main res directory. It is needed by gyp
  stub_res_location = os.path.join(out_paths['stub'], 'res')
  os.makedirs(stub_res_location)
  with open(os.path.join(stub_res_location, '.res-stamp'), 'w') as stamp:
    content_str = 'google_play_services_version: %s\nutc_date: %s\n'
    stamp.write(content_str % (play_services_full_version, generation_date))

  shutil.copyfile(tmp_version_file_path,
                  os.path.join(out_paths['root'], VERSION_FILE_NAME))


if __name__ == '__main__':
  sys.exit(main())