#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# Copyright 2018 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.

"""Wrapper of pkg-config like command line to format output for gn.

Parses the output and filter the flags with a certain prefix like "-l", "-L",
so that it can be used in GN files easily.

Usage:
  arg_prefix_filter_wrapper.py --prefix=-l gtest-config --libs
"""

from __future__ import print_function

import argparse
import shlex
import sys
import subprocess


def get_parser():
  parser = argparse.ArgumentParser(description=__doc__)
  parser.add_argument('--prefix', type=str, default='-l')
  return parser


def main(argv):
  parser = get_parser()
  opts, cmd_list = parser.parse_known_args(argv)

  prefix_len = len(opts.prefix)
  # TODO(vapier): Move decode('utf-8') to encoding='utf-8' in check_output once
  # .gn uses shebangs.
  flags = shlex.split(subprocess.check_output(cmd_list).decode('utf-8'))
  filtered = [x[prefix_len:] for x in flags if x.startswith(opts.prefix)]
  print('\n'.join(filtered))


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