core/homeassistant/components/sensor/sabnzbd.py

"""
Support for monitoring an SABnzbd NZB client.

For more details about this platform, please refer to the documentation at
https://home-assistant.io/components/sensor.sabnzbd/
"""
import logging

from homeassistant.components.sabnzbd import DATA_SABNZBD, \
    SIGNAL_SABNZBD_UPDATED, SENSOR_TYPES
from homeassistant.helpers.dispatcher import async_dispatcher_connect
from homeassistant.helpers.entity import Entity

DEPENDENCIES = ['sabnzbd']

_LOGGER = logging.getLogger(__name__)


async def async_setup_platform(hass, config, async_add_entities,
                               discovery_info=None):
    """Set up the SABnzbd sensors."""
    if discovery_info is None:
        return

    sab_api_data = hass.data[DATA_SABNZBD]
    sensors = sab_api_data.sensors
    client_name = sab_api_data.name
    async_add_entities([SabnzbdSensor(sensor, sab_api_data, client_name)
                        for sensor in sensors])


class SabnzbdSensor(Entity):
    """Representation of an SABnzbd sensor."""

    def __init__(self, sensor_type, sabnzbd_api_data, client_name):
        """Initialize the sensor."""
        self._client_name = client_name
        self._field_name = SENSOR_TYPES[sensor_type][2]
        self._name = SENSOR_TYPES[sensor_type][0]
        self._sabnzbd_api = sabnzbd_api_data
        self._state = None
        self._type = sensor_type
        self._unit_of_measurement = SENSOR_TYPES[sensor_type][1]

    async def async_added_to_hass(self):
        """Call when entity about to be added to hass."""
        async_dispatcher_connect(self.hass, SIGNAL_SABNZBD_UPDATED,
                                 self.update_state)

    @property
    def name(self):
        """Return the name of the sensor."""
        return '{} {}'.format(self._client_name, self._name)

    @property
    def state(self):
        """Return the state of the sensor."""
        return self._state

    def should_poll(self):
        """Don't poll. Will be updated by dispatcher signal."""
        return False

    @property
    def unit_of_measurement(self):
        """Return the unit of measurement of this entity, if any."""
        return self._unit_of_measurement

    def update_state(self, args):
        """Get the latest data and updates the states."""
        self._state = self._sabnzbd_api.get_queue_field(self._field_name)

        if self._type == 'speed':
            self._state = round(float(self._state) / 1024, 1)
        elif 'size' in self._type:
            self._state = round(float(self._state), 2)

        self.schedule_update_ha_state()