core/homeassistant/components/sensor/wunderground.py

"""Support for Wunderground weather service."""
from datetime import timedelta
import logging
import requests
from homeassistant.helpers.entity import Entity
from homeassistant.util import Throttle
from homeassistant.const import CONF_API_KEY
from homeassistant.const import TEMP_FAHRENHEIT
from homeassistant.const import TEMP_CELSIUS

CONF_PWS_ID = 'pws_id'
_URLCONST = '/conditions/q/pws:'
_RESOURCE = 'http://api.wunderground.com/api/'
_LOGGER = logging.getLogger(__name__)

# Return cached results if last scan was less then this time ago.
MIN_TIME_BETWEEN_UPDATES = timedelta(seconds=300)

# Sensor types are defined like: Name, units
SENSOR_TYPES = {
    'weather': ['Weather Summary', None],
    'station_id': ['Station ID', None],
    'feelslike_c': ['Feels Like (°C)', TEMP_CELSIUS],
    'feelslike_f': ['Feels Like (°F)', TEMP_FAHRENHEIT],
    'feelslike_string': ['Feels Like', None],
    'heat_index_c': ['Dewpoint (°C)', TEMP_CELSIUS],
    'heat_index_f': ['Dewpoint (°F)', TEMP_FAHRENHEIT],
    'heat_index_string': ['Heat Index Summary', None],
    'dewpoint_c': ['Dewpoint (°C)', TEMP_CELSIUS],
    'dewpoint_f': ['Dewpoint (°F)', TEMP_FAHRENHEIT],
    'dewpoint_string': ['Dewpoint Summary', None],
    'wind_kph': ['Wind Speed', 'kpH'],
    'wind_mph': ['Wind Speed', 'mpH'],
    'UV': ['UV', None],
    'pressure_in': ['Pressure', 'in'],
    'pressure_mb': ['Pressure', 'mbar'],
    'wind_dir': ['Wind Direction', None],
    'wind_string': ['Wind Summary', None],
    'temp_c': ['Temperature (°C)', TEMP_CELSIUS],
    'temp_f': ['Temperature (°F)', TEMP_FAHRENHEIT],
    'relative_humidity': ['Relative Humidity', '%'],
    'visibility_mi': ['Visibility (miles)', 'mi'],
    'visibility_km': ['Visibility (km)', 'km'],
    'precip_today_in': ['Precipation Today', 'in'],
    'precip_today_metric': ['Precipation Today', 'mm'],
    'precip_today_string': ['Precipation today', None],
    'solarradiation': ['Solar Radiation', None]
}


def setup_platform(hass, config, add_devices, discovery_info=None):
    """Setup the Wundeground sensor."""
    payload = config.get('payload', None)
    rest = WUndergroundData(_RESOURCE,
                            config.get(CONF_PWS_ID),
                            config.get(CONF_API_KEY),
                            payload)
    sensors = []
    for variable in config['monitored_conditions']:
        if variable in SENSOR_TYPES:
            sensors.append(WUndergroundSensor(rest, variable))
        else:
            _LOGGER.error('Wunderground sensor: "%s" does not exist', variable)
    response = requests.get(_RESOURCE + config.get(CONF_API_KEY) +
                            _URLCONST + config.get(CONF_PWS_ID) +
                            '.json', timeout=10)
    if "error" in response.json()["response"]:
        _LOGGER.error("Check your Wunderground API")
        return False
    else:
        add_devices(sensors)
        rest.update()


class WUndergroundSensor(Entity):
    """Implementing the Wunderground sensor."""

    def __init__(self, rest, condition):
        """Initialize the sensor."""
        self.rest = rest
        self._condition = condition
        self._unit_of_measurement = None
        self.update()

    @property
    def name(self):
        """Return the name of the sensor."""
        return "PWS_" + str(self._condition)

    @property
    def state(self):
        """Return the state of the sensor."""
        self.weather = self.rest.data
        return self.weather[str(self._condition)]

    @property
    def entity_picture(self):
        """Return the entity picture."""
        self.weather = self.rest.data
        if self._condition == 'weather':
            return self.weather['icon_url']

    @property
    def unit_of_measurement(self):
        """Return the units of measurement."""
        return SENSOR_TYPES[self._condition][1]

    def update(self):
        """Update current conditions."""
        self.rest.update()
        self._state = self.rest.data

# pylint: disable=too-few-public-methods


class WUndergroundData(object):
    """Get data from Wunderground."""

    def __init__(self, resource, pws_id, api_key, data):
        """Initialize the data object."""
        self._resource = resource
        self._api_key = api_key
        self._pws_id = pws_id
        self.data = None
        self.unit_system = None

    @Throttle(MIN_TIME_BETWEEN_UPDATES)
    def update(self):
        """Get the latest data from wunderground"""
        try:
            result = requests.get(self._resource + self._api_key +
                                  '/conditions/q/pws:' + self._pws_id + 
                                  '.json', timeout=10)
            if "error" in result.json():
                raise ValueError(result.json()["response"]["error"]
                                 ["description"])
            else:
                self.data = result.json()["current_observation"]
        except ValueError as err:
            _LOGGER.error("Check Wunderground API %s", err.args)
            self.data = None