"""
Interfaces with the myLeviton API for Decora Smart WiFi products.

See:
http://www.leviton.com/en/products/lighting-controls/decora-smart-with-wifi

Uses Leviton's cloud services API for cloud-to-cloud integration.

"""

import logging

import voluptuous as vol

from homeassistant.components.light import (
    ATTR_BRIGHTNESS, ATTR_TRANSITION, Light,
    PLATFORM_SCHEMA, SUPPORT_BRIGHTNESS, SUPPORT_TRANSITION)
from homeassistant.const import (
    CONF_USERNAME, CONF_PASSWORD,
    EVENT_HOMEASSISTANT_STOP)
import homeassistant.helpers.config_validation as cv

REQUIREMENTS = ['decora_wifi==1.3']

_LOGGER = logging.getLogger(__name__)

# Validation of the user's configuration
PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
    vol.Required(CONF_USERNAME): cv.string,
    vol.Required(CONF_PASSWORD): cv.string,
})

NOTIFICATION_ID = 'leviton_notification'
NOTIFICATION_TITLE = 'myLeviton Decora Setup'


def setup_platform(hass, config, add_devices, discovery_info=None):
    """Set up the Decora WiFi platform."""
    # pylint: disable=import-error
    from decora_wifi import DecoraWiFiSession
    from decora_wifi.models.person import Person
    from decora_wifi.models.residential_account import ResidentialAccount

    email = config.get(CONF_USERNAME)
    password = config.get(CONF_PASSWORD)
    session = DecoraWiFiSession()

    try:
        success = session.login(email, password)

        # If login failed, notify user.
        if success is None:
            msg = 'Failed to log into myLeviton Services. Check credentials.'
            _LOGGER.error(msg)
            hass.components.persistent_notification.create(
                msg, title=NOTIFICATION_TITLE, notification_id=NOTIFICATION_ID)
            return False

        # Gather all the available devices...
        perms = session.user.get_residential_permissions()
        all_switches = []
        for permission in perms:
            acct = ResidentialAccount(session, permission.residentialAccountId)
            for residence in acct.get_residences():
                for switch in residence.get_iot_switches():
                    all_switches.append(switch)

        add_devices(DecoraWifiLight(sw) for sw in all_switches)
    except ValueError:
        _LOGGER.error('Failed to communicate with myLeviton Service.')

    # Listen for the stop event and log out.
    def logout(event):
        """Log out..."""
        try:
            if session is not None:
                Person.logout(session)
        except ValueError:
            _LOGGER.error('Failed to log out of myLeviton Service.')

    hass.bus.listen(EVENT_HOMEASSISTANT_STOP, logout)


class DecoraWifiLight(Light):
    """Representation of a Decora WiFi switch."""

    def __init__(self, switch):
        """Initialize the switch."""
        self._switch = switch

    @property
    def supported_features(self):
        """Return supported features."""
        if self._switch.canSetLevel:
            return SUPPORT_BRIGHTNESS | SUPPORT_TRANSITION
        else:
            return 0

    @property
    def name(self):
        """Return the display name of this switch."""
        return self._switch.name

    @property
    def brightness(self):
        """Return the brightness of the dimmer switch."""
        return int(self._switch.brightness * 255 / 100)

    @property
    def is_on(self):
        """Return true if switch is on."""
        return self._switch.power == 'ON'

    def turn_on(self, **kwargs):
        """Instruct the switch to turn on & adjust brightness."""
        attribs = {'power': 'ON'}

        if ATTR_BRIGHTNESS in kwargs:
            min_level = self._switch.data.get('minLevel', 0)
            max_level = self._switch.data.get('maxLevel', 100)
            brightness = int(kwargs[ATTR_BRIGHTNESS] * max_level / 255)
            brightness = max(brightness, min_level)
            attribs['brightness'] = brightness

        if ATTR_TRANSITION in kwargs:
            transition = int(kwargs[ATTR_TRANSITION])
            attribs['fadeOnTime'] = attribs['fadeOffTime'] = transition

        try:
            self._switch.update_attributes(attribs)
        except ValueError:
            _LOGGER.error('Failed to turn on myLeviton switch.')

    def turn_off(self, **kwargs):
        """Instruct the switch to turn off."""
        attribs = {'power': 'OFF'}
        try:
            self._switch.update_attributes(attribs)
        except ValueError:
            _LOGGER.error('Failed to turn off myLeviton switch.')

    def update(self):
        """Fetch new state data for this switch."""
        try:
            self._switch.refresh()
        except ValueError:
            _LOGGER.error('Failed to update myLeviton switch data.')
