"""Get your own public IP address or that of any host."""
from datetime import timedelta
import logging

import aiodns
from aiodns.error import DNSError
import voluptuous as vol

from homeassistant.components.sensor import PLATFORM_SCHEMA
from homeassistant.const import CONF_NAME
import homeassistant.helpers.config_validation as cv
from homeassistant.helpers.entity import Entity

_LOGGER = logging.getLogger(__name__)

CONF_HOSTNAME = "hostname"
CONF_IPV6 = "ipv6"
CONF_RESOLVER = "resolver"
CONF_RESOLVER_IPV6 = "resolver_ipv6"

DEFAULT_HOSTNAME = "myip.opendns.com"
DEFAULT_IPV6 = False
DEFAULT_NAME = "myip"
DEFAULT_RESOLVER = "208.67.222.222"
DEFAULT_RESOLVER_IPV6 = "2620:0:ccc::2"

SCAN_INTERVAL = timedelta(seconds=120)

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
    {
        vol.Optional(CONF_NAME): cv.string,
        vol.Optional(CONF_HOSTNAME, default=DEFAULT_HOSTNAME): cv.string,
        vol.Optional(CONF_RESOLVER, default=DEFAULT_RESOLVER): cv.string,
        vol.Optional(CONF_RESOLVER_IPV6, default=DEFAULT_RESOLVER_IPV6): cv.string,
        vol.Optional(CONF_IPV6, default=DEFAULT_IPV6): cv.boolean,
    }
)


async def async_setup_platform(hass, config, async_add_devices, discovery_info=None):
    """Set up the DNS IP sensor."""
    hostname = config[CONF_HOSTNAME]
    name = config.get(CONF_NAME)
    if not name:
        if hostname == DEFAULT_HOSTNAME:
            name = DEFAULT_NAME
        else:
            name = hostname
    ipv6 = config[CONF_IPV6]
    if ipv6:
        resolver = config[CONF_RESOLVER_IPV6]
    else:
        resolver = config[CONF_RESOLVER]

    async_add_devices([WanIpSensor(hass, name, hostname, resolver, ipv6)], True)


class WanIpSensor(Entity):
    """Implementation of a DNS IP sensor."""

    def __init__(self, hass, name, hostname, resolver, ipv6):
        """Initialize the DNS IP sensor."""

        self.hass = hass
        self._name = name
        self.hostname = hostname
        self.resolver = aiodns.DNSResolver()
        self.resolver.nameservers = [resolver]
        self.querytype = "AAAA" if ipv6 else "A"
        self._state = None

    @property
    def name(self):
        """Return the name of the sensor."""
        return self._name

    @property
    def state(self):
        """Return the current DNS IP address for hostname."""
        return self._state

    async def async_update(self):
        """Get the current DNS IP address for hostname."""

        try:
            response = await self.resolver.query(self.hostname, self.querytype)
        except DNSError as err:
            _LOGGER.warning("Exception while resolving host: %s", err)
            response = None
        if response:
            self._state = response[0].host
        else:
            self._state = None