#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# Copyright 2020 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Create the package information file in JSON format.

To get the package information, use the library at
https://cos.googlesource.com/cos/tools/+/refs/heads/master/src/pkg/cos/pkg_info.go
instead of accessing the JSON file directly.

For information on the JSON format, see http://go/cos-package-list-design .
"""

from __future__ import print_function

import collections
import getopt
import json
import re
import sys


# The following regular expresssions are used for extracting the category name,
# the package name, the package version without the revision, and the package
# revision from a string that looks like
#
#   category_name/package_name-1.2.3.4_beta1_rc2-r1
#
# These regular expressions follow the Gentoo package manager specification at
# https://www.gentoo.org/proj/en/qa/pms.xml . They are similar to what SplitPV
# function (in chromite/lib/portage_util.py) uses.

CATEGORY_RE = r'(?P<category>\w[\w\+\.\-]*)'
PACKAGE_RE = r'(?P<package>\w[\w+-]*)'
VERSION_NUMLETTER_RE = r'\d+(\.\d+)*[a-z]?'
VERSION_SUFFIX_RE = r'_(pre|p|beta|alpha|rc)\d*'
VERSION_NO_REV_RE = r'(?P<version_no_rev>%s(%s)*)' % (VERSION_NUMLETTER_RE,
                                                      VERSION_SUFFIX_RE)
REVISION_RE = r'-r(?P<revision>\d+)'
CPV_RE = r'^%s\/%s-%s(%s)?$' % (CATEGORY_RE, PACKAGE_RE,
                                VERSION_NO_REV_RE, REVISION_RE)


def PrintHelp():
  print('usage: create_pkg_list.py --input=<input file> --output=<output file>')


def CreateList(input_lines):
  cpv_re = re.compile(CPV_RE, re.VERBOSE)
  package_list = []
  for line in input_lines:
    match = cpv_re.match(line.strip())
    if match is not None:
      package_list.append(match.groupdict())
  return package_list


def WriteJson(package_list, output_file):
  installed_packages = []
  for p in package_list:
    package_info = collections.OrderedDict(
        [('category', p['category']),
         ('name', p['package']),
         ('version', p['version_no_rev'])
        ]
    )
    if 'revision' in p and p['revision'] is not None:
      package_info['revision'] = p['revision']

    installed_packages.append(package_info)

  result = {}
  result['installedPackages'] = installed_packages
  json.dump(result, output_file, indent=4)

  return 0


def main(argv):
  input_fn = ''
  output_fn = ''

  try:
    opts, args_left = getopt.getopt(argv, '', ['help', 'input=', 'output='])
  except getopt.GetoptError:
    PrintHelp()
    return -1
  if len(args_left) != 0:
    PrintHelp()
    return -1

  for opt, arg in opts:
    if opt == '--help':
      PrintHelp()
    elif opt == '--input':
      input_fn = arg
    elif opt == '--output':
      output_fn = arg

  if input_fn == '' or output_fn == '':
    PrintHelp()
    return -1

  input_lines = []
  try:
    with open(input_fn) as input_file:
      input_lines = input_file.readlines()
  except OSError:
    print('error: Failed to open input file: %s' % input_fn)
    return -1
  if len(input_lines) == 0:
    print('error: No input lines')
    return -1

  package_list = CreateList(input_lines)
  if len(package_list) == 0:
    print('error: Empty package list')
    return -1

  try:
    with open(output_fn, 'w') as output_file:
      ret = WriteJson(package_list, output_file)
      if ret != 0:
        print('error: Failed to write package list')
        return ret
  except OSError:
    print('error: Failed to open input file: %s' % input_fn)
    return -1

  return 0


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