#!/usr/bin/env python3

import functools
import json
import socket
import sys

'''
Takes as input a list of domain names to test. Return wether they are
IPv4/IPv6-compatible.

Usage:

> cat test.txt
baionet.fr
google.com

> cat test.txt | ./dns-sacha.py  | jq

[
  {
    "host": "baionet.fr",
    "v4": true,
    "v6": false
  },
  {
    "host": "google.com",
    "v4": true,
    "v6": true
  }
]
'''

class UrlIp:
    '''
    Struct wrapping a single record entry. Does it have IPv4 support?
    IPv6 support?
    '''
    def __init__(self, host, v4, v6):
       self.host = host
       self.v4 = v4
       self.v6 = v6

def get_host_records(host):
    '''
    Folds all the DNS entries of a Host and looks whether or not we
    can find v4 and v6 records.

    reduce == left fold in the python world btw...
    '''
    records = socket.getaddrinfo(host, 80)
    return(functools.reduce(_test_record,records,UrlIp(host,False,False)))

def _test_record(urlip, rec):
    '''
    Fold function for get_host_records. Too big for a lambda not to
    get messy.

    Gotta love Python...
    '''
    (family, _rtype,  proto, _canonname, _sockaddr) = rec
    if family == socket.AF_INET:
        urlip.v4 = True
    elif family == socket.AF_INET6:
        urlip.v6 = True
    return urlip

def parse_hosts(file_name):
    with open(file_name, 'r') as f:
        return f.readlines()

def render_results(results):
    '''
    Takes an array of UrlIp and renders that to json.

    Python's json.dumps only works with dictionnaries, not classes.
    Extracting the dictionnary representation of the class.
    '''
    return(json.dumps([r.__dict__ for r in results]))

if __name__ == '__main__':
    entries = [l.strip() for l in sys.stdin.readlines()]
    test_results = [get_host_records(entry) for entry in entries]
    print(render_results(test_results))