import urllib.request
import argparse
import json
from pyotp import TOTP

class ungleichDNS(object):
    def __init__(self, parser, parents):
        self.parser = parser

        self.parser['dns'] = self.parser['sub'].add_parser(
            'dns',
            help="Manage DNS entries @ ungleich",
            parents=[parents])

        self.parser['dns'].add_argument('--set-reverse', help='REQUIRED: IPv6 Address of your VM', required=True)
        self.parser['dns'].add_argument('--user', help='Your stored user ID', required=True)
        self.parser['dns'].add_argument('--name', help='Hostname', required=True)
        self.parser['dns'].add_argument('--email', help='registered email', required=True)
        self.parser['dns'].set_defaults(func=self._handle_dns)

    def _handle_dns(self, args):
        """Reverse dns endpoint."""
        f = open('users.json', 'r')
        data = json.loads(f.read())[args.user]

        url = 'https://dns.service.ungleich.ch'
        req = urllib.request.Request(
            url=url,
            method='POST',
            headers={
                "Content-Type": "application/json"
            },
            data=json.dumps({
                'username': data['name'],
                'token': TOTP(data['seed']).now(),
                'ipaddress': args.set_reverse,
                'name': args.name,
                'email': args.email,
                'realm': data['realm']
            }).encode('utf-8')
        )
        try:
            response = urllib.request.urlopen(req).read()
            print(response)
        except urllib.error.HTTPError as e:
            error_message = e.read()
            print(json.loads(error_message))