core/homeassistant/components/london_underground/sensor.py

"""
Sensor for checking the status of London Underground tube lines.

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

import voluptuous as vol

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

REQUIREMENTS = ['london-tube-status==0.2']

_LOGGER = logging.getLogger(__name__)

ATTRIBUTION = "Powered by TfL Open Data"

CONF_LINE = 'line'

SCAN_INTERVAL = timedelta(seconds=30)

TUBE_LINES = [
    'Bakerloo',
    'Central',
    'Circle',
    'District',
    'DLR',
    'Hammersmith & City',
    'Jubilee',
    'London Overground',
    'Metropolitan',
    'Northern',
    'Piccadilly',
    'TfL Rail',
    'Victoria',
    'Waterloo & City',
]

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
    vol.Required(CONF_LINE):
        vol.All(cv.ensure_list, [vol.In(list(TUBE_LINES))]),
})


def setup_platform(hass, config, add_entities, discovery_info=None):
    """Set up the Tube sensor."""
    from london_tube_status import TubeData
    data = TubeData()
    data.update()
    sensors = []
    for line in config.get(CONF_LINE):
        sensors.append(LondonTubeSensor(line, data))

    add_entities(sensors, True)


class LondonTubeSensor(Entity):
    """Sensor that reads the status of a line from TubeData."""

    ICON = 'mdi:subway'

    def __init__(self, name, data):
        """Initialize the sensor."""
        self._name = name
        self._data = data
        self._state = None
        self._description = None

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

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

    @property
    def icon(self):
        """Icon to use in the frontend, if any."""
        return self.ICON

    @property
    def device_state_attributes(self):
        """Return other details about the sensor state."""
        attrs = {}
        attrs['Description'] = self._description
        return attrs

    def update(self):
        """Update the sensor."""
        self._data.update()
        self._state = self._data.data[self.name]['State']
        self._description = self._data.data[self.name]['Description']