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

import argparse
import logging
import os
import re
import shutil
import sys
import tempfile
import zipfile

from util import build_utils
from util import zipalign

sys.path.insert(1, os.path.join(os.path.dirname(__file__), os.path.pardir))

import convert_dex_profile


def _ParseArgs(args):
  args = build_utils.ExpandFileArgs(args)
  parser = argparse.ArgumentParser()

  build_utils.AddDepfileOption(parser)
  parser.add_argument('--output', required=True, help='Dex output path.')
  parser.add_argument('--input-list', help='GN-list of additional input paths.')
  parser.add_argument(
      '--main-dex-list-path',
      help='File containing a list of the classes to include in the main dex.')
  parser.add_argument(
      '--multi-dex',
      action='store_true',
      help='Allow multiple dex files within output.')
  parser.add_argument('--r8-jar-path', required=True, help='Path to R8 jar.')
  parser.add_argument(
      '--release',
      action='store_true',
      help='Run D8 in release mode. Release mode maximises main dex and '
      'deletes non-essential line number information (vs debug which minimizes '
      'main dex and keeps all line number information, and then some.')
  parser.add_argument(
      '--min-api', help='Minimum Android API level compatibility.')
  parser.add_argument('inputs', nargs='*', help='Input .jar files.')

  group = parser.add_argument_group('Dexlayout')
  group.add_argument(
      '--dexlayout-profile',
      help=('Text profile for dexlayout. If present, a dexlayout '
            'pass will happen'))
  group.add_argument(
      '--profman-path',
      help=('Path to ART profman binary. There should be a lib/ directory at '
            'the same path with shared libraries (shared with dexlayout).'))
  group.add_argument(
      '--dexlayout-path',
      help=('Path to ART dexlayout binary. There should be a lib/ directory at '
            'the same path with shared libraries (shared with dexlayout).'))
  group.add_argument('--dexdump-path', help='Path to dexdump binary.')
  group.add_argument(
      '--proguard-mapping-path',
      help=('Path to proguard map from obfuscated symbols in the jar to '
            'unobfuscated symbols present in the code. If not present, the jar '
            'is assumed not to be obfuscated.'))

  options = parser.parse_args(args)

  if options.dexlayout_profile:
    build_utils.CheckOptions(
        options,
        parser,
        required=('profman_path', 'dexlayout_path', 'dexdump_path'))
  elif options.proguard_mapping_path is not None:
    parser.error('Unexpected proguard mapping without dexlayout')

  if options.main_dex_list_path and not options.multi_dex:
    parser.error('--main-dex-list-path is unused if multidex is not enabled')

  if options.input_list:
    options.inputs += build_utils.ParseGnList(options.input_list)

  return options


def _RunD8(dex_cmd, input_paths, output_path):
  dex_cmd = dex_cmd + ['--output', output_path] + input_paths
  build_utils.CheckOutput(dex_cmd, print_stderr=False)


def _EnvWithArtLibPath(binary_path):
  """Return an environment dictionary for ART host shared libraries.

  Args:
    binary_path: the path to an ART host binary.

  Returns:
    An environment dictionary where LD_LIBRARY_PATH has been augmented with the
    shared library path for the binary. This assumes that there is a lib/
    directory in the same location as the binary.
  """
  lib_path = os.path.join(os.path.dirname(binary_path), 'lib')
  env = os.environ.copy()
  libraries = [l for l in env.get('LD_LIBRARY_PATH', '').split(':') if l]
  libraries.append(lib_path)
  env['LD_LIBRARY_PATH'] = ':'.join(libraries)
  return env


def _CreateBinaryProfile(text_profile, input_dex, profman_path, temp_dir):
  """Create a binary profile for dexlayout.

  Args:
    text_profile: The ART text profile that will be converted to a binary
        profile.
    input_dex: The input dex file to layout.
    profman_path: Path to the profman binary.
    temp_dir: Directory to work in.

  Returns:
    The name of the binary profile, which will live in temp_dir.
  """
  binary_profile = os.path.join(
      temp_dir, 'binary_profile-for-' + os.path.basename(text_profile))
  open(binary_profile, 'w').close()  # Touch binary_profile.
  profman_cmd = [profman_path,
                 '--apk=' + input_dex,
                 '--dex-location=' + input_dex,
                 '--create-profile-from=' + text_profile,
                 '--reference-profile-file=' + binary_profile]
  build_utils.CheckOutput(
    profman_cmd,
    env=_EnvWithArtLibPath(profman_path),
    stderr_filter=lambda output:
        build_utils.FilterLines(output, '|'.join(
            [r'Could not find (method_id|proto_id|name):',
             r'Could not create type list'])))
  return binary_profile


def _LayoutDex(binary_profile, input_dex, dexlayout_path, temp_dir):
  """Layout a dexfile using a profile.

  Args:
    binary_profile: An ART binary profile, eg output from _CreateBinaryProfile.
    input_dex: The dex file used to create the binary profile.
    dexlayout_path: Path to the dexlayout binary.
    temp_dir: Directory to work in.

  Returns:
    List of output files produced by dexlayout. This will be one if the input
    was a single dexfile, or multiple files if the input was a multidex
    zip. These output files are located in temp_dir.
  """
  dexlayout_output_dir = os.path.join(temp_dir, 'dexlayout_output')
  os.mkdir(dexlayout_output_dir)
  dexlayout_cmd = [ dexlayout_path,
                    '-u',  # Update checksum
                    '-p', binary_profile,
                    '-w', dexlayout_output_dir,
                    input_dex ]
  build_utils.CheckOutput(
      dexlayout_cmd,
      env=_EnvWithArtLibPath(dexlayout_path),
      stderr_filter=lambda output:
          build_utils.FilterLines(output,
                                  r'Can.t mmap dex file.*please zipalign'))
  output_files = os.listdir(dexlayout_output_dir)
  if not output_files:
    raise Exception('dexlayout unexpectedly produced no output')
  return sorted([os.path.join(dexlayout_output_dir, f) for f in output_files])


def _ZipMultidex(file_dir, dex_files):
  """Zip dex files into a multidex.

  Args:
    file_dir: The directory into which to write the output.
    dex_files: The dexfiles forming the multizip. Their names must end with
      classes.dex, classes2.dex, ...

  Returns:
    The name of the multidex file, which will live in file_dir.
  """
  ordered_files = []  # List of (archive name, file name)
  for f in dex_files:
    if f.endswith('classes.dex.zip'):
      ordered_files.append(('classes.dex', f))
      break
  if not ordered_files:
    raise Exception('Could not find classes.dex multidex file in %s',
                    dex_files)
  for dex_idx in xrange(2, len(dex_files) + 1):
    archive_name = 'classes%d.dex' % dex_idx
    for f in dex_files:
      if f.endswith(archive_name):
        ordered_files.append((archive_name, f))
        break
    else:
      raise Exception('Could not find classes%d.dex multidex file in %s',
                      dex_files)
  if len(set(f[1] for f in ordered_files)) != len(ordered_files):
    raise Exception('Unexpected clashing filenames for multidex in %s',
                    dex_files)

  zip_name = os.path.join(file_dir, 'multidex_classes.zip')
  build_utils.DoZip(((archive_name, os.path.join(file_dir, file_name))
                     for archive_name, file_name in ordered_files),
                    zip_name)
  return zip_name


def _ZipAligned(dex_files, output_path):
  """Creates a .dex.jar with 4-byte aligned files.

  Args:
    dex_files: List of dex files.
    output_path: The output file in which to write the zip.
  """
  with zipfile.ZipFile(output_path, 'w') as z:
    for i, dex_file in enumerate(dex_files):
      name = 'classes{}.dex'.format(i + 1 if i > 0 else '')
      zipalign.AddToZipHermetic(z, name, src_path=dex_file, alignment=4)


def _PerformDexlayout(tmp_dir, tmp_dex_output, options):
  if options.proguard_mapping_path is not None:
    matching_profile = os.path.join(tmp_dir, 'obfuscated_profile')
    convert_dex_profile.ObfuscateProfile(
        options.dexlayout_profile, tmp_dex_output,
        options.proguard_mapping_path, options.dexdump_path, matching_profile)
  else:
    logging.warning('No obfuscation for %s', options.dexlayout_profile)
    matching_profile = options.dexlayout_profile
  binary_profile = _CreateBinaryProfile(matching_profile, tmp_dex_output,
                                        options.profman_path, tmp_dir)
  output_files = _LayoutDex(binary_profile, tmp_dex_output,
                            options.dexlayout_path, tmp_dir)
  if len(output_files) > 1:
    return _ZipMultidex(tmp_dir, output_files)

  if zipfile.is_zipfile(output_files[0]):
    return output_files[0]

  final_output = os.path.join(tmp_dir, 'dex_classes.zip')
  _ZipAligned(output_files, final_output)
  return final_output


def _PerformDexing(options):
  dex_cmd = ['java', '-jar', options.r8_jar_path, 'd8', '--no-desugaring']
  if options.multi_dex and options.main_dex_list_path:
    dex_cmd += ['--main-dex-list', options.main_dex_list_path]
  if options.release:
    dex_cmd += ['--release']
  if options.min_api:
    dex_cmd += ['--min-api', options.min_api]

  with build_utils.TempDir() as tmp_dir:
    tmp_dex_dir = os.path.join(tmp_dir, 'tmp_dex_dir')
    os.mkdir(tmp_dex_dir)
    _RunD8(dex_cmd, options.inputs, tmp_dex_dir)
    dex_files = [os.path.join(tmp_dex_dir, f) for f in os.listdir(tmp_dex_dir)]

    if not options.output.endswith('.dex'):
      tmp_dex_output = os.path.join(tmp_dir, 'tmp_dex_output.zip')
      _ZipAligned(sorted(dex_files), tmp_dex_output)
    else:
      # Output to a .dex file.
      if len(dex_files) > 1:
        raise Exception('%d files created, expected 1' % len(dex_files))
      tmp_dex_output = dex_files[0]

    if options.dexlayout_profile:
      tmp_dex_output = _PerformDexlayout(tmp_dir, tmp_dex_output, options)

    # The dex file is complete and can be moved out of tmp_dir.
    shutil.move(tmp_dex_output, options.output)


def main(args):
  options = _ParseArgs(args)

  input_paths = list(options.inputs)
  if options.multi_dex and options.main_dex_list_path:
    input_paths.append(options.main_dex_list_path)

  _PerformDexing(options)

  build_utils.WriteDepfile(
      options.depfile, options.output, input_paths, add_pydeps=False)


if __name__ == '__main__':
  sys.exit(main(sys.argv[1:]))