"""
Support for Enviro pHAT sensors.

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

import voluptuous as vol

from homeassistant.components.sensor import PLATFORM_SCHEMA
from homeassistant.const import (TEMP_CELSIUS, CONF_DISPLAY_OPTIONS, CONF_NAME)
import homeassistant.helpers.config_validation as cv
from homeassistant.helpers.entity import Entity
from homeassistant.util import Throttle

REQUIREMENTS = ['envirophat==0.0.6',
                'smbus-cffi==0.5.1']

_LOGGER = logging.getLogger(__name__)

DEFAULT_NAME = 'envirophat'
CONF_USE_LEDS = 'use_leds'

MIN_TIME_BETWEEN_UPDATES = timedelta(seconds=60)

SENSOR_TYPES = {
    'light': ['light', ' ', 'mdi:weather-sunny'],
    'light_red': ['light_red', ' ', 'mdi:invert-colors'],
    'light_green': ['light_green', ' ', 'mdi:invert-colors'],
    'light_blue': ['light_blue', ' ', 'mdi:invert-colors'],
    'accelerometer_x': ['accelerometer_x', 'G', 'mdi:earth'],
    'accelerometer_y': ['accelerometer_y', 'G', 'mdi:earth'],
    'accelerometer_z': ['accelerometer_z', 'G', 'mdi:earth'],
    'magnetometer_x': ['magnetometer_x', ' ', 'mdi:magnet'],
    'magnetometer_y': ['magnetometer_y', ' ', 'mdi:magnet'],
    'magnetometer_z': ['magnetometer_z', ' ', 'mdi:magnet'],
    'temperature': ['temperature', TEMP_CELSIUS, 'mdi:thermometer'],
    'pressure': ['pressure', 'hPa', 'mdi:gauge'],
    'voltage_0': ['voltage_0', 'V', 'mdi:flash'],
    'voltage_1': ['voltage_1', 'V', 'mdi:flash'],
    'voltage_2': ['voltage_2', 'V', 'mdi:flash'],
    'voltage_3': ['voltage_3', 'V', 'mdi:flash'],
}

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
    vol.Required(CONF_DISPLAY_OPTIONS, default=SENSOR_TYPES):
        [vol.In(SENSOR_TYPES)],
    vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
    vol.Optional(CONF_USE_LEDS, default=False): cv.boolean
})


def setup_platform(hass, config, add_devices, discovery_info=None):
    """Set up the Sense HAT sensor platform."""
    try:
        # pylint: disable=import-error
        import envirophat
    except OSError:
        _LOGGER.error("No Enviro pHAT was found.")
        return False

    data = EnvirophatData(envirophat, config.get(CONF_USE_LEDS))

    dev = []
    for variable in config[CONF_DISPLAY_OPTIONS]:
        dev.append(EnvirophatSensor(data, variable))

    add_devices(dev, True)


class EnvirophatSensor(Entity):
    """Representation of an Enviro pHAT sensor."""

    def __init__(self, data, sensor_types):
        """Initialize the sensor."""
        self.data = data
        self._name = SENSOR_TYPES[sensor_types][0]
        self._unit_of_measurement = SENSOR_TYPES[sensor_types][1]
        self.type = sensor_types
        self._state = 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 SENSOR_TYPES[self.type][2]

    @property
    def unit_of_measurement(self):
        """Return the unit the value is expressed in."""
        return self._unit_of_measurement

    def update(self):
        """Get the latest data and updates the states."""
        self.data.update()

        if self.type == 'light':
            self._state = self.data.light
        if self.type == 'light_red':
            self._state = self.data.light_red
        if self.type == 'light_green':
            self._state = self.data.light_green
        if self.type == 'light_blue':
            self._state = self.data.light_blue
        if self.type == 'accelerometer_x':
            self._state = self.data.accelerometer_x
        if self.type == 'accelerometer_y':
            self._state = self.data.accelerometer_y
        if self.type == 'accelerometer_z':
            self._state = self.data.accelerometer_z
        if self.type == 'magnetometer_x':
            self._state = self.data.magnetometer_x
        if self.type == 'magnetometer_y':
            self._state = self.data.magnetometer_y
        if self.type == 'magnetometer_z':
            self._state = self.data.magnetometer_z
        if self.type == 'temperature':
            self._state = self.data.temperature
        if self.type == 'pressure':
            self._state = self.data.pressure
        if self.type == 'voltage_0':
            self._state = self.data.voltage_0
        if self.type == 'voltage_1':
            self._state = self.data.voltage_1
        if self.type == 'voltage_2':
            self._state = self.data.voltage_2
        if self.type == 'voltage_3':
            self._state = self.data.voltage_3


class EnvirophatData(object):
    """Get the latest data and update."""

    def __init__(self, envirophat, use_leds):
        """Initialize the data object."""
        self.envirophat = envirophat
        self.use_leds = use_leds
        # sensors readings
        self.light = None
        self.light_red = None
        self.light_green = None
        self.light_blue = None
        self.accelerometer_x = None
        self.accelerometer_y = None
        self.accelerometer_z = None
        self.magnetometer_x = None
        self.magnetometer_y = None
        self.magnetometer_z = None
        self.temperature = None
        self.pressure = None
        self.voltage_0 = None
        self.voltage_1 = None
        self.voltage_2 = None
        self.voltage_3 = None

    @Throttle(MIN_TIME_BETWEEN_UPDATES)
    def update(self):
        """Get the latest data from Enviro pHAT."""
        # Light sensor reading: 16-bit integer
        self.light = self.envirophat.light.light()
        if self.use_leds:
            self.envirophat.leds.on()
        # the three color values scaled against the overall light, 0-255
        self.light_red, self.light_green, self.light_blue = \
            self.envirophat.light.rgb()
        if self.use_leds:
            # pylint: disable=no-value-for-parameter
            self.envirophat.leds.off()

        # accelerometer readings in G
        self.accelerometer_x, self.accelerometer_y, self.accelerometer_z = \
            self.envirophat.motion.accelerometer()

        # raw magnetometer reading
        self.magnetometer_x, self.magnetometer_y, self.magnetometer_z = \
            self.envirophat.motion.magnetometer()

        # temperature resolution of BMP280 sensor: 0.01°C
        self.temperature = round(self.envirophat.weather.temperature(), 2)

        # pressure resolution of BMP280 sensor: 0.16 Pa, rounding to 0.1 Pa
        # with conversion to 100 Pa = 1 hPa
        self.pressure = round(self.envirophat.weather.pressure() / 100.0, 3)

        # Voltage sensor, reading between 0-3.3V
        self.voltage_0, self.voltage_1, self.voltage_2, self.voltage_3 = \
            self.envirophat.analog.read_all()
