"""
Support for the Tank Utility propane monitor.

For more details about this platform, please refer to the documentation at
https://home-assistant.io/components/sensor.tank_utility/
"""

import datetime
import logging

import requests
import voluptuous as vol

import homeassistant.helpers.config_validation as cv
from homeassistant.components.sensor import PLATFORM_SCHEMA
from homeassistant.const import (CONF_DEVICES, CONF_EMAIL, CONF_PASSWORD,
                                 STATE_UNKNOWN)
from homeassistant.helpers.entity import Entity


REQUIREMENTS = [
    "tank_utility==1.4.0"
]

_LOGGER = logging.getLogger(__name__)

SCAN_INTERVAL = datetime.timedelta(hours=1)

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
    vol.Required(CONF_EMAIL): cv.string,
    vol.Required(CONF_PASSWORD): cv.string,
    vol.Required(CONF_DEVICES): vol.All(cv.ensure_list, vol.Length(min=1))
})

SENSOR_TYPE = "tank"
SENSOR_ROUNDING_PRECISION = 1
SENSOR_UNIT_OF_MEASUREMENT = "%"
SENSOR_ATTRS = [
    "name",
    "address",
    "capacity",
    "fuelType",
    "orientation",
    "status",
    "time",
    "time_iso"
]


def setup_platform(hass, config, add_devices, discovery_info=None):
    """Set up the Tank Utility sensor."""
    from tank_utility import auth
    email = config.get(CONF_EMAIL)
    password = config.get(CONF_PASSWORD)
    devices = config.get(CONF_DEVICES)

    try:
        token = auth.get_token(email, password)
    except requests.exceptions.HTTPError as http_error:
        if (http_error.response.status_code ==
                requests.codes.unauthorized):  # pylint: disable=no-member
            _LOGGER.error("Invalid credentials")
            return

    all_sensors = []
    for device in devices:
        sensor = TankUtilitySensor(email, password, token, device)
        all_sensors.append(sensor)
    add_devices(all_sensors, True)


class TankUtilitySensor(Entity):
    """Representation of a Tank Utility sensor."""

    def __init__(self, email, password, token, device):
        """Initialize the sensor."""
        self._email = email
        self._password = password
        self._token = token
        self._device = device
        self._state = STATE_UNKNOWN
        self._name = "Tank Utility " + self.device
        self._unit_of_measurement = SENSOR_UNIT_OF_MEASUREMENT
        self._attributes = {}

    @property
    def device(self):
        """Return the device identifier."""
        return self._device

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

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

    @property
    def unit_of_measurement(self):
        """Return the unit of measurement of the device."""
        return self._unit_of_measurement

    @property
    def device_state_attributes(self):
        """Return the attributes of the device."""
        return self._attributes

    def get_data(self):
        """Get data from the device.

        Flatten dictionary to map device to map of device data.

        """
        from tank_utility import auth, device
        data = {}
        try:
            data = device.get_device_data(self._token, self.device)
        except requests.exceptions.HTTPError as http_error:
            if (http_error.response.status_code ==
                    requests.codes.unauthorized):  # pylint: disable=no-member
                _LOGGER.info("Getting new token")
                self._token = auth.get_token(self._email, self._password,
                                             force=True)
                data = device.get_device_data(self._token, self.device)
            else:
                raise http_error
        data.update(data.pop("device", {}))
        data.update(data.pop("lastReading", {}))
        return data

    def update(self):
        """Set the device state and attributes."""
        data = self.get_data()
        self._state = round(data[SENSOR_TYPE], SENSOR_ROUNDING_PRECISION)
        self._attributes = {k: v for k, v in data.items() if k in SENSOR_ATTRS}