#!/usr/bin/env python
# Copyright 2014 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.

"""Simple tool to generate NMF file by just reformatting given arguments.

This tool is similar to native_client_sdk/src/tools/create_nmf.py.
create_nmf.py handles most cases, with the exception of Non-SFI nexes.
create_nmf.py tries to auto-detect nexe and pexe types based on their contents,
but it does not work for Non-SFI nexes (which don't have a marker to
distinguish them from SFI nexes).

This script simply reformats the command line arguments into NMF JSON format.
"""

import argparse
import collections
import json
import logging
import os

_FILES_KEY = 'files'
_PORTABLE_KEY = 'portable'
_PROGRAM_KEY = 'program'
_URL_KEY = 'url'
_X86_32_NONSFI_KEY = 'x86-32-nonsfi'


def ParseArgs():
  parser = argparse.ArgumentParser()
  parser.add_argument(
      '--program', metavar='FILE', help='Main program nexe')
  # To keep compatibility with create_nmf.py, we use -x and --extra-files
  # as flags.
  parser.add_argument(
      '-x', '--extra-files', action='append', metavar='KEY:FILE', default=[],
      help=('Add extra key:file tuple to the "files" '
            'section of the .nmf'))
  parser.add_argument(
      '--output', metavar='FILE', help='Path to the output nmf file.')

  return parser.parse_args()


def BuildNmfMap(root_path, program, extra_files):
  """Build simple map representing nmf json."""
  result = {
    _PROGRAM_KEY: {
      _X86_32_NONSFI_KEY: {
        # The program path is relative to the root_path.
        _URL_KEY: os.path.relpath(program, root_path)
      }
    }
  }

  if extra_files:
    files = {}
    for named_file in extra_files:
      name, path = named_file.split(':', 1)
      files[name] = {
        _PORTABLE_KEY: {
          # Note: use path as is, unlike program path.
          _URL_KEY: path
        }
      }
    if files:
      result[_FILES_KEY] = files

  return result


def OutputNmf(nmf_map, output_path):
  """Writes the nmf to an output file at given path in JSON format."""
  with open(output_path, 'w') as output:
    json.dump(nmf_map, output, indent=2)


def main():
  args = ParseArgs()
  if not args.program:
    logging.error('--program is not specified.')
    sys.exit(1)
  if not args.output:
    logging.error('--output is not specified.')
    sys.exit(1)

  nmf_map = BuildNmfMap(os.path.dirname(args.output),
                        args.program, args.extra_files)
  OutputNmf(nmf_map, args.output)


if __name__ == '__main__':
  main()