#!/usr/bin/env python
# Copyright (c) 2018 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 os
import re
import shutil
import sys


CIPD_SUBDIR_RE = '@Subdir (.*)'


def parse_cipd(root, contents):
  tree = {}
  current_subdir = None
  for line in contents:
    line = line.strip()
    match = re.match(CIPD_SUBDIR_RE, line)
    if match:
      current_subdir = os.path.join(root, *match.group(1).split('/'))
    elif line and current_subdir:
      tree.setdefault(current_subdir, []).append(line)
  return tree


def main():
  assert sys.argv[1] == 'ensure'
  parser = argparse.ArgumentParser()
  parser.add_argument('-ensure-file')
  parser.add_argument('-root')
  args, _ = parser.parse_known_args()

  with open(args.ensure_file) as f:
    new_content = parse_cipd(args.root, f.readlines())

  # Install new packages
  for path, packages in new_content.iteritems():
    if not os.path.exists(path):
      os.makedirs(path)
    with open(os.path.join(path, '_cipd'), 'w') as f:
      f.write('\n'.join(packages))

  # Save the ensure file that we got
  shutil.copy(args.ensure_file, os.path.join(args.root, '_cipd'))

  return 0


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