#!/usr/bin/env python3
"""Merges sources of a Dart target and its dependencies"""

# Copyright 2013 The Flutter 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 json
import os
import sys


def main():
    parser = argparse.ArgumentParser(
        'Merges sources of a Dart target and its dependencies',
        fromfile_prefix_chars='@')
    parser.add_argument(
        '--output',
        help='Path to output the final list',
        type=argparse.FileType('w'),
        required=True)
    parser.add_argument(
        '--depfile',
        help='Path to the depfile to generate',
        type=argparse.FileType('w'),
        required=True)
    parser.add_argument(
        '--sources',
        help='Sources of this target',
        nargs='*',
    )
    parser.add_argument(
        '--source_lists',
        help='Files containing lists of Dart sources',
        nargs='*')
    args = parser.parse_args()

    args.depfile.write(
        '{}: {}\n'.format(args.output.name, ' '.join(args.source_lists)))

    # Merges sources of this target, and all of its dependencies.
    all_sources = set(args.sources)
    for f in args.source_lists:
        with open(f, 'r') as f:
            all_sources.update(json.load(f))
    json.dump(sorted(all_sources), args.output)


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