"""DNS plugin."""
import collections
import logging

import zope.interface
from acme import challenges
from certbot import interfaces
from certbot.plugins import common

from certbot_dns.PdnsApiAuthenticator import PdnsApiAuthenticator

logger = logging.getLogger(__name__)


@zope.interface.implementer(interfaces.IAuthenticator)
@zope.interface.provider(interfaces.IPluginFactory)
class Authenticator(common.Plugin):
    """DNS Authenticator."""

    description = "Place challenges in DNS records"

    MORE_INFO = """\
Authenticator plugin that performs dns-01 challenge by saving
necessary validation resources to appropriate records in DNS server.
It expects that there is some other DNS server configured
to serve all records."""

    backend = None

    def more_info(self):  # pylint: disable=missing-docstring,no-self-use
        return self.MORE_INFO

    @classmethod
    def add_parser_arguments(cls, add):
        add("certbot-dns-config", "-f", default="/etc/letsencrypt/certbot-dns.json",
            help="Path to certbot-dns configuration file")

    def get_chall_pref(self, domain):  # pragma: no cover
        # pylint: disable=missing-docstring,no-self-use,unused-argument
        return [challenges.DNS01]

    def __init__(self, *args, **kwargs):
        super(Authenticator, self).__init__(*args, **kwargs)
        self.full_roots = {}
        self.performed = collections.defaultdict(set)

    def prepare(self):  # pylint: disable=missing-docstring
        self.backend = PdnsApiAuthenticator()
        conf_path = self.conf("certbot-dns-config")
        self.backend.prepare(conf_path)
        pass

    def perform(self, achalls):  # pylint: disable=missing-docstring
        return [self._perform_single(achall) for achall in achalls]

    def _perform_single(self, achall):
        response, validation = achall.response_and_validation()
        return self.backend.perform_single(achall, response, validation)

    def cleanup(self, achalls):  # pylint: disable=missing-docstring
        for achall in achalls:
            self.backend.cleanup(achall)