#!/usr/bin/env python3

import json
import logging
from argparse import ArgumentParser
from copy import deepcopy

import requests

FORMAT = "%(message)s"
logging.basicConfig(
    level="INFO", format=FORMAT, datefmt="[%X]"
)
log = logging.getLogger()


def create_session(api_key):
    s = requests.Session()
    s.headers = {
        "Content-Type": "application/json",
        "Auth-API-Token": api_key,
    }
    return s


def get_current_public_ip(version=4):
    log.debug(f"Asking clara for our current ipv{version}")
    response = requests.get(f"https://ip{version}.clerie.de/")
    log.debug(f"Got {response.text} as answer")
    response.raise_for_status()
    return response.text


def get_zone_matching_name(session, name):
    response = session.get(url="https://dns.hetzner.com/api/v1/zones")
    response.raise_for_status()
    log.debug(response.json())
    for z in response.json().get("zones", {}):
        if z.get("name", None) == name:
            id = z["id"]
            log.debug(f"ID of the requested zone is {id}.")
            break
    return id


def get_records_matching_name(session, zone, name):
    response = session.get(
        url="https://dns.hetzner.com/api/v1/records",
        params={
            "zone_id": zone,
        },
    )
    response.raise_for_status()
    record_objects = []
    for r in response.json()["records"]:
        if r.get("name", None) == name:
            record_objects.append(r)
    log.debug(record_objects)
    return record_objects


def update_records(session, records, ipv4, ipv6):
    for record in records:
        r = deepcopy(record)
        log.debug("before modification:")
        log.debug(record)
        if record["type"] == "A":
            r["value"] = ipv4
            log.info("updating ipv4")
        elif record["type"] == "AAAA":
            r["value"] = ipv6
            log.info("updating ipv6")
        r.pop("id")
        log.debug("after modification:")
        log.debug(r)
        response = session.put(
            url=f"https://dns.hetzner.com/api/v1/records/{record['id']}",
            data=json.dumps(r),
        )
        response.raise_for_status()
        log.info(f"got {response.status_code}")


def main():
    parser = ArgumentParser()
    parser.add_argument("--api_key", "-k")
    parser.add_argument("--record", "-r")
    parser.add_argument("--zone", "-z")
    parser.add_argument("--verbose", help="increase output verbosity",
                    action="store_true")
    args = parser.parse_args()
    if args.verbose:
        log.setLevel(logging.DEBUG)
    session = create_session(args.api_key)
    log.info("Getting IPs")
    ipv4 = get_current_public_ip(4)
    log.info(f"Found ipv4: {ipv4}")
    ipv6 = get_current_public_ip(6)
    log.info(f"Found ipv6: {ipv6}")
    zone_id = get_zone_matching_name(session, args.zone)
    records = get_records_matching_name(session, zone_id, args.record)
    log.info("gathered all data, let's try to use it")
    update_records(session, records, ipv4, ipv6)
    log.info("Dyndns entries updated if everything went smoothly.")


if __name__ == "__main__":
    main()