"""Sensor for Fedex packages."""
import logging
from collections import defaultdict
from datetime import timedelta

import voluptuous as vol

import homeassistant.helpers.config_validation as cv
from homeassistant.components.sensor import PLATFORM_SCHEMA
from homeassistant.const import (CONF_NAME, CONF_USERNAME, CONF_PASSWORD,
                                 ATTR_ATTRIBUTION, CONF_SCAN_INTERVAL)
from homeassistant.helpers.entity import Entity
from homeassistant.util import Throttle
from homeassistant.util import slugify
from homeassistant.util.dt import now, parse_date

_LOGGER = logging.getLogger(__name__)

COOKIE = 'fedexdeliverymanager_cookies.pickle'

DOMAIN = 'fedex'

ICON = 'mdi:package-variant-closed'

STATUS_DELIVERED = 'delivered'

SCAN_INTERVAL = timedelta(seconds=1800)

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
    vol.Required(CONF_USERNAME): cv.string,
    vol.Required(CONF_PASSWORD): cv.string,
    vol.Optional(CONF_NAME): cv.string,
})


def setup_platform(hass, config, add_entities, discovery_info=None):
    """Set up the Fedex platform."""
    import fedexdeliverymanager

    name = config.get(CONF_NAME)
    update_interval = config.get(CONF_SCAN_INTERVAL, SCAN_INTERVAL)

    try:
        cookie = hass.config.path(COOKIE)
        session = fedexdeliverymanager.get_session(
            config.get(CONF_USERNAME), config.get(CONF_PASSWORD),
            cookie_path=cookie)
    except fedexdeliverymanager.FedexError:
        _LOGGER.exception("Could not connect to Fedex Delivery Manager")
        return False

    add_entities([FedexSensor(session, name, update_interval)], True)


class FedexSensor(Entity):
    """Fedex Sensor."""

    def __init__(self, session, name, interval):
        """Initialize the sensor."""
        self._session = session
        self._name = name
        self._attributes = None
        self._state = None
        self.update = Throttle(interval)(self._update)

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

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

    @property
    def unit_of_measurement(self):
        """Return the unit of measurement of this entity, if any."""
        return 'packages'

    def _update(self):
        """Update device state."""
        import fedexdeliverymanager
        status_counts = defaultdict(int)
        for package in fedexdeliverymanager.get_packages(self._session):
            status = slugify(package['primary_status'])
            skip = status == STATUS_DELIVERED and \
                parse_date(package['delivery_date']) < now().date()
            if skip:
                continue
            status_counts[status] += 1
        self._attributes = {
            ATTR_ATTRIBUTION: fedexdeliverymanager.ATTRIBUTION
        }
        self._attributes.update(status_counts)
        self._state = sum(status_counts.values())

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

    @property
    def icon(self):
        """Icon to use in the frontend."""
        return ICON