#!/usr/bin/env python3

import json
from urllib.request import urlopen, Request
import argparse
from datetime import datetime
from subprocess import check_call

def run():
    parser = argparse.ArgumentParser()
    parser.add_argument('-z', "--hosted-zone", metavar='HOSTED_ZONE_ID', required=True,
                        help="Specify the hosted zone id")
    parser.add_argument('-d', "--domain", metavar='DOMAIN_NAME', required=True,
                        help="Specify domain name")
    parser.add_argument('-t', "--type", metavar='DNS_TYPE', default='A',
                        help="Specify DNS type")
    parser.add_argument('-l', "--ttl", metavar='TTL_S', type=int, default=300,
                        help="Specify time-to-live in seconds")

    args = parser.parse_args()

    url = "http://v4.ipv6-test.com/api/myip.php"
    request = Request(url)
    with urlopen(request) as request:
        public_ip = request.read().decode()
    date = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    params = {
        'Comment': f'Auto update by awsdyndns on {date}',
        'Changes': [
            {
                'Action': 'UPSERT',
                'ResourceRecordSet': {
                    'ResourceRecords': [{'Value': public_ip}],
                    'Name': args.domain,
                    'Type': args.type,
                    'TTL': args.ttl
                }
            }
        ]
    }
    check_call(['aws', 'route53', 'change-resource-record-sets', '--hosted-zone-id', args.hosted_zone, '--change-batch', json.dumps(params)])

if __name__ == "__main__":
    run()