core/homeassistant/components/sun.py

140 lines
4.1 KiB
Python

"""
homeassistant.components.sun
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Provides functionality to keep track of the sun.
"""
import logging
from datetime import datetime, timedelta
import homeassistant as ha
from homeassistant.const import CONF_LATITUDE, CONF_LONGITUDE
from homeassistant.helpers import validate_config
from homeassistant.util import str_to_datetime, datetime_to_str
DEPENDENCIES = []
DOMAIN = "sun"
ENTITY_ID = "sun.sun"
STATE_ABOVE_HORIZON = "above_horizon"
STATE_BELOW_HORIZON = "below_horizon"
STATE_ATTR_NEXT_RISING = "next_rising"
STATE_ATTR_NEXT_SETTING = "next_setting"
def is_on(hass, entity_id=None):
""" Returns if the sun is currently up based on the statemachine. """
entity_id = entity_id or ENTITY_ID
return hass.states.is_state(entity_id, STATE_ABOVE_HORIZON)
def next_setting(hass, entity_id=None):
""" Returns the datetime object representing the next sun setting. """
entity_id = entity_id or ENTITY_ID
state = hass.states.get(ENTITY_ID)
try:
return str_to_datetime(state.attributes[STATE_ATTR_NEXT_SETTING])
except (AttributeError, KeyError):
# AttributeError if state is None
# KeyError if STATE_ATTR_NEXT_SETTING does not exist
return None
def next_rising(hass, entity_id=None):
""" Returns the datetime object representing the next sun rising. """
entity_id = entity_id or ENTITY_ID
state = hass.states.get(ENTITY_ID)
try:
return str_to_datetime(state.attributes[STATE_ATTR_NEXT_RISING])
except (AttributeError, KeyError):
# AttributeError if state is None
# KeyError if STATE_ATTR_NEXT_RISING does not exist
return None
def setup(hass, config):
""" Tracks the state of the sun. """
logger = logging.getLogger(__name__)
if not validate_config(config,
{ha.DOMAIN: [CONF_LATITUDE, CONF_LONGITUDE]},
logger):
return False
try:
import ephem
except ImportError:
logger.exception("Error while importing dependency ephem.")
return False
sun = ephem.Sun() # pylint: disable=no-member
latitude = config[ha.DOMAIN][CONF_LATITUDE]
longitude = config[ha.DOMAIN][CONF_LONGITUDE]
# Validate latitude and longitude
observer = ephem.Observer()
errors = []
try:
observer.lat = latitude # pylint: disable=assigning-non-slot
except ValueError:
errors.append("invalid value for latitude given: {}".format(latitude))
try:
observer.long = longitude # pylint: disable=assigning-non-slot
except ValueError:
errors.append("invalid value for latitude given: {}".format(latitude))
if errors:
logger.error("Error setting up: %s", ", ".join(errors))
return False
def update_sun_state(now):
""" Method to update the current state of the sun and
set time of next setting and rising. """
utc_offset = datetime.utcnow() - datetime.now()
utc_now = now + utc_offset
observer = ephem.Observer()
observer.lat = latitude # pylint: disable=assigning-non-slot
observer.long = longitude # pylint: disable=assigning-non-slot
next_rising_dt = ephem.localtime(
observer.next_rising(sun, start=utc_now))
next_setting_dt = ephem.localtime(
observer.next_setting(sun, start=utc_now))
if next_rising_dt > next_setting_dt:
new_state = STATE_ABOVE_HORIZON
next_change = next_setting_dt
else:
new_state = STATE_BELOW_HORIZON
next_change = next_rising_dt
logger.info("%s. Next change: %s",
new_state, next_change.strftime("%H:%M"))
state_attributes = {
STATE_ATTR_NEXT_RISING: datetime_to_str(next_rising_dt),
STATE_ATTR_NEXT_SETTING: datetime_to_str(next_setting_dt)
}
hass.states.set(ENTITY_ID, new_state, state_attributes)
# +1 second so Ephem will report it has set
hass.track_point_in_time(update_sun_state,
next_change + timedelta(seconds=1))
update_sun_state(datetime.now())
return True