#!/usr/bin/python
# Copyright 2016 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.

"""Converts CSV files to machine-readable JSON.

Example usage:

./csv_to_json input.csv --output directory_owners.json\
--skip-keys number-tests\
-f directory test-number team notification-email other-contact component
"""

import argparse
import csv
import json
import sys


def main(argv):
    parser = argparse.ArgumentParser()
    parser.add_argument('filename', metavar='filename',
                        help='The path to the input CSV file.')
    parser.add_argument('-o', '--output',
                        help='The output file name.')
    parser.add_argument('-f', '--field-names', nargs='*',
                        help='The ordered field names of the CSV file. Defaults to first row.')
    parser.add_argument('-s', '--skip-keys', nargs='*',
                        help='Fields that should be skipped.')
    args = parser.parse_args()
    convert_csv_to_json(args.filename, args.output, args.field_names, args.skip_keys)


def convert_csv_to_json(filename, output_filename=None, field_names=None, skip_keys=None):
    out = output_filename or (filename + '.json')
    dict_list = []
    json_file = open(out, 'w')
    with open(filename) as csv_file:
        reader = csv.DictReader(csv_file, fieldnames=field_names)
        for row in reader:
            if not row['directory'].startswith('imported'):
                continue
            if skip_keys:
                for s in skip_keys:
                    del row[s]
            dict_list.append(row)
        json.dump(dict_list, json_file, indent=4)


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