"""Support for retrieving meteorological data from Dark Sky."""
from datetime import datetime, timedelta
import logging

from requests.exceptions import ConnectionError as ConnectError, HTTPError, Timeout
import voluptuous as vol

from homeassistant.components.weather import (
    ATTR_FORECAST_CONDITION,
    ATTR_FORECAST_PRECIPITATION,
    ATTR_FORECAST_TEMP,
    ATTR_FORECAST_TEMP_LOW,
    ATTR_FORECAST_TIME,
    ATTR_FORECAST_WIND_BEARING,
    ATTR_FORECAST_WIND_SPEED,
    PLATFORM_SCHEMA,
    WeatherEntity,
)
from homeassistant.const import (
    CONF_API_KEY,
    CONF_LATITUDE,
    CONF_LONGITUDE,
    CONF_MODE,
    CONF_NAME,
    PRESSURE_HPA,
    PRESSURE_INHG,
    TEMP_CELSIUS,
    TEMP_FAHRENHEIT,
)
import homeassistant.helpers.config_validation as cv
from homeassistant.util import Throttle
from homeassistant.util.pressure import convert as convert_pressure

_LOGGER = logging.getLogger(__name__)

ATTRIBUTION = "Powered by Dark Sky"

FORECAST_MODE = ["hourly", "daily"]

MAP_CONDITION = {
    "clear-day": "sunny",
    "clear-night": "clear-night",
    "rain": "rainy",
    "snow": "snowy",
    "sleet": "snowy-rainy",
    "wind": "windy",
    "fog": "fog",
    "cloudy": "cloudy",
    "partly-cloudy-day": "partlycloudy",
    "partly-cloudy-night": "partlycloudy",
    "hail": "hail",
    "thunderstorm": "lightning",
    "tornado": None,
}

CONF_UNITS = "units"

DEFAULT_NAME = "Dark Sky"

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
    {
        vol.Required(CONF_API_KEY): cv.string,
        vol.Optional(CONF_LATITUDE): cv.latitude,
        vol.Optional(CONF_LONGITUDE): cv.longitude,
        vol.Optional(CONF_MODE, default="hourly"): vol.In(FORECAST_MODE),
        vol.Optional(CONF_UNITS): vol.In(["auto", "si", "us", "ca", "uk", "uk2"]),
        vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
    }
)

MIN_TIME_BETWEEN_UPDATES = timedelta(minutes=3)


def setup_platform(hass, config, add_entities, discovery_info=None):
    """Set up the Dark Sky weather."""
    latitude = config.get(CONF_LATITUDE, hass.config.latitude)
    longitude = config.get(CONF_LONGITUDE, hass.config.longitude)
    name = config.get(CONF_NAME)
    mode = config.get(CONF_MODE)

    units = config.get(CONF_UNITS)
    if not units:
        units = "ca" if hass.config.units.is_metric else "us"

    dark_sky = DarkSkyData(config.get(CONF_API_KEY), latitude, longitude, units)

    add_entities([DarkSkyWeather(name, dark_sky, mode)], True)


class DarkSkyWeather(WeatherEntity):
    """Representation of a weather condition."""

    def __init__(self, name, dark_sky, mode):
        """Initialize Dark Sky weather."""
        self._name = name
        self._dark_sky = dark_sky
        self._mode = mode

        self._ds_data = None
        self._ds_currently = None
        self._ds_hourly = None
        self._ds_daily = None

    @property
    def attribution(self):
        """Return the attribution."""
        return ATTRIBUTION

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

    @property
    def temperature(self):
        """Return the temperature."""
        return self._ds_currently.get("temperature")

    @property
    def temperature_unit(self):
        """Return the unit of measurement."""
        if self._dark_sky.units is None:
            return None
        return TEMP_FAHRENHEIT if "us" in self._dark_sky.units else TEMP_CELSIUS

    @property
    def humidity(self):
        """Return the humidity."""
        return round(self._ds_currently.get("humidity") * 100.0, 2)

    @property
    def wind_speed(self):
        """Return the wind speed."""
        return self._ds_currently.get("windSpeed")

    @property
    def wind_bearing(self):
        """Return the wind bearing."""
        return self._ds_currently.get("windBearing")

    @property
    def ozone(self):
        """Return the ozone level."""
        return self._ds_currently.get("ozone")

    @property
    def pressure(self):
        """Return the pressure."""
        pressure = self._ds_currently.get("pressure")
        if "us" in self._dark_sky.units:
            return round(convert_pressure(pressure, PRESSURE_HPA, PRESSURE_INHG), 2)
        return pressure

    @property
    def visibility(self):
        """Return the visibility."""
        return self._ds_currently.get("visibility")

    @property
    def condition(self):
        """Return the weather condition."""
        return MAP_CONDITION.get(self._ds_currently.get("icon"))

    @property
    def forecast(self):
        """Return the forecast array."""
        # Per conversation with Joshua Reyes of Dark Sky, to get the total
        # forecasted precipitation, you have to multiple the intensity by
        # the hours for the forecast interval
        def calc_precipitation(intensity, hours):
            amount = None
            if intensity is not None:
                amount = round((intensity * hours), 1)
            return amount if amount > 0 else None

        data = None

        if self._mode == "daily":
            data = [
                {
                    ATTR_FORECAST_TIME: datetime.fromtimestamp(
                        entry.d.get("time")
                    ).isoformat(),
                    ATTR_FORECAST_TEMP: entry.d.get("temperatureHigh"),
                    ATTR_FORECAST_TEMP_LOW: entry.d.get("temperatureLow"),
                    ATTR_FORECAST_PRECIPITATION: calc_precipitation(
                        entry.d.get("precipIntensity"), 24
                    ),
                    ATTR_FORECAST_WIND_SPEED: entry.d.get("windSpeed"),
                    ATTR_FORECAST_WIND_BEARING: entry.d.get("windBearing"),
                    ATTR_FORECAST_CONDITION: MAP_CONDITION.get(entry.d.get("icon")),
                }
                for entry in self._ds_daily.data
            ]
        else:
            data = [
                {
                    ATTR_FORECAST_TIME: datetime.fromtimestamp(
                        entry.d.get("time")
                    ).isoformat(),
                    ATTR_FORECAST_TEMP: entry.d.get("temperature"),
                    ATTR_FORECAST_PRECIPITATION: calc_precipitation(
                        entry.d.get("precipIntensity"), 1
                    ),
                    ATTR_FORECAST_CONDITION: MAP_CONDITION.get(entry.d.get("icon")),
                }
                for entry in self._ds_hourly.data
            ]

        return data

    def update(self):
        """Get the latest data from Dark Sky."""
        self._dark_sky.update()

        self._ds_data = self._dark_sky.data
        self._ds_currently = self._dark_sky.currently.d
        self._ds_hourly = self._dark_sky.hourly
        self._ds_daily = self._dark_sky.daily


class DarkSkyData:
    """Get the latest data from Dark Sky."""

    def __init__(self, api_key, latitude, longitude, units):
        """Initialize the data object."""
        self._api_key = api_key
        self.latitude = latitude
        self.longitude = longitude
        self.requested_units = units

        self.data = None
        self.currently = None
        self.hourly = None
        self.daily = None

    @Throttle(MIN_TIME_BETWEEN_UPDATES)
    def update(self):
        """Get the latest data from Dark Sky."""
        import forecastio

        try:
            self.data = forecastio.load_forecast(
                self._api_key, self.latitude, self.longitude, units=self.requested_units
            )
            self.currently = self.data.currently()
            self.hourly = self.data.hourly()
            self.daily = self.data.daily()
        except (ConnectError, HTTPError, Timeout, ValueError) as error:
            _LOGGER.error("Unable to connect to Dark Sky. %s", error)
            self.data = None

    @property
    def units(self):
        """Get the unit system of returned data."""
        if self.data is None:
            return None
        return self.data.json.get("flags").get("units")
