#!/usr/bin/env python

"""This script generates DNS TXT records containing ASN information.

The idea comes from asn.cymru.com.  Example:

  dig +short AS1.asn.cymru.com TXT

The output looks like this:

  "1 | US | arin | 2001-09-20 | LVLT-1 - Level 3 Communications, Inc."

In dn42, we try to respect this format. Fields 2 and 3 are set to "DN42"
and "dn42", respectively.  The date field is left empty, as we currently
do not record this information in the registry. For the last field, we use
"[as-name] [descr]" from the registry.

"""

import sys
import time

from registry import AutNum

REGISTRYPATH = "/home/zorun/net.dn42.registry"
OUT = "/home/zorun/tmp/asn.dn42.zone"

ORIGIN = "asn.dn42."
TTL = "1h"
NS = ["tuxmachine.polynome.dn42.", "ns1.allowed.dn42.", "ns1.pyropeter.dn42.", "beta.synhacx.dn42."]

def gen_zone(registrypath, out):
    # SOA and stuff
    out.write("$ORIGIN {}\n".format(ORIGIN))
    out.write("$TTL {}\n".format(TTL))
    serial = int(time.time())
    out.write("@ IN SOA tuxmachine.polynome.dn42. dn42.polyno.me. ({} 1d 1h 1w 5m)\n".format(serial))

    # NS
    for ns in NS:
        out.write("@ NS {}\n".format(ns))

    # TXT data
    autnum = AutNum(registrypath)
    for (asn, data) in autnum.data.items():
        comment = ""
        if "as-name" in data:
            comment = data["as-name"][0]
            if "descr" in data:
                comment += " " + data["descr"][0]
        comment.replace('"', '')
        out.write('{} TXT "{} | DN42 | dn42 |  | {}"\n'.format(asn, asn[2:], comment))

if __name__ == "__main__":
    with open(OUT, "w") as f:
        gen_zone(REGISTRYPATH, f)