"""
Support for tracking the online status of a UPS.

For more details about this platform, please refer to the documentation at
https://home-assistant.io/components/binary_sensor.apcupsd/
"""
import voluptuous as vol

from homeassistant.components.binary_sensor import (
    BinarySensorDevice, PLATFORM_SCHEMA)
from homeassistant.const import CONF_NAME
import homeassistant.helpers.config_validation as cv
from homeassistant.components import apcupsd

DEFAULT_NAME = 'UPS Online Status'
DEPENDENCIES = [apcupsd.DOMAIN]

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
    vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
})


def setup_platform(hass, config, add_entities, discovery_info=None):
    """Set up an APCUPSd Online Status binary sensor."""
    add_entities([OnlineStatus(config, apcupsd.DATA)], True)


class OnlineStatus(BinarySensorDevice):
    """Representation of an UPS online status."""

    def __init__(self, config, data):
        """Initialize the APCUPSd binary device."""
        self._config = config
        self._data = data
        self._state = None

    @property
    def name(self):
        """Return the name of the UPS online status sensor."""
        return self._config.get(CONF_NAME)

    @property
    def is_on(self):
        """Return true if the UPS is online, else false."""
        return self._state == apcupsd.VALUE_ONLINE

    def update(self):
        """Get the status report from APCUPSd and set this entity's state."""
        self._state = self._data.status[apcupsd.KEY_STATUS]