"""
homeassistant.components.isy994
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Connects to an ISY-994 controller and loads relevant components to control its
devices. Also contains the base classes for ISY Sensors, Lights, and Switches.
"""
# system imports
import logging
from urllib.parse import urlparse

# homeassistant imports
from homeassistant import bootstrap
from homeassistant.loader import get_component
from homeassistant.helpers import validate_config
from homeassistant.helpers.entity import ToggleEntity
from homeassistant.const import (
    CONF_HOST, CONF_USERNAME, CONF_PASSWORD, EVENT_PLATFORM_DISCOVERED,
    EVENT_HOMEASSISTANT_STOP, ATTR_SERVICE, ATTR_DISCOVERED,
    ATTR_FRIENDLY_NAME)

# homeassistant constants
DOMAIN = "isy994"
DEPENDENCIES = []
REQUIREMENTS = ['PyISY>=1.0.5']
DISCOVER_LIGHTS = "isy994.lights"
DISCOVER_SWITCHES = "isy994.switches"
DISCOVER_SENSORS = "isy994.sensors"
ISY = None
SENSOR_STRING = 'Sensor'
HIDDEN_STRING = '{HIDE ME}'
CONF_TLS_VER = 'tls'

# setup logger
_LOGGER = logging.getLogger(__name__)


def setup(hass, config):
    """
    Setup ISY994 component.
    This will automatically import associated lights, switches, and sensors.
    """
    try:
        import PyISY
    except ImportError:
        _LOGGER.error("Error while importing dependency PyISY.")
        return False

    # pylint: disable=global-statement
    # check for required values in configuration file
    if not validate_config(config,
                           {DOMAIN: [CONF_HOST, CONF_USERNAME, CONF_PASSWORD]},
                           _LOGGER):
        return False

    # pull and parse standard configuration
    user = config[DOMAIN][CONF_USERNAME]
    password = config[DOMAIN][CONF_PASSWORD]
    host = urlparse(config[DOMAIN][CONF_HOST])
    addr = host.geturl()
    if host.scheme == 'http':
        addr = addr.replace('http://', '')
        https = False
    elif host.scheme == 'https':
        addr = addr.replace('https://', '')
        https = True
    else:
        _LOGGER.error('isy994 host value in configuration file is invalid.')
        return False
    port = host.port
    addr = addr.replace(':{}'.format(port), '')

    # pull and parse optional configuration
    global SENSOR_STRING
    global HIDDEN_STRING
    SENSOR_STRING = str(config[DOMAIN].get('sensor_string', SENSOR_STRING))
    HIDDEN_STRING = str(config[DOMAIN].get('hidden_string', HIDDEN_STRING))
    tls_version = config[DOMAIN].get(CONF_TLS_VER, None)

    # connect to ISY controller
    global ISY
    ISY = PyISY.ISY(addr, port, user, password, use_https=https,
                    tls_ver=tls_version, log=_LOGGER)
    if not ISY.connected:
        return False

    # listen for HA stop to disconnect
    hass.bus.listen_once(EVENT_HOMEASSISTANT_STOP, stop)

    # Load components for the devices in the ISY controller that we support
    for comp_name, discovery in ((('sensor', DISCOVER_SENSORS),
                                  ('light', DISCOVER_LIGHTS),
                                  ('switch', DISCOVER_SWITCHES))):
        component = get_component(comp_name)
        bootstrap.setup_component(hass, component.DOMAIN, config)
        hass.bus.fire(EVENT_PLATFORM_DISCOVERED,
                      {ATTR_SERVICE: discovery,
                       ATTR_DISCOVERED: {}})

    ISY.auto_update = True
    return True


def stop(event):
    """ Cleanup the ISY subscription. """
    ISY.auto_update = False


class ISYDeviceABC(ToggleEntity):
    """ Abstract Class for an ISY device. """

    _attrs = {}
    _onattrs = []
    _states = []
    _dtype = None
    _domain = None
    _name = None

    def __init__(self, node):
        # setup properties
        self.node = node
        self.hidden = HIDDEN_STRING in self.raw_name

        # track changes
        self._change_handler = self.node.status. \
            subscribe('changed', self.on_update)

    def __del__(self):
        """ cleanup subscriptions because it is the right thing to do. """
        self._change_handler.unsubscribe()

    @property
    def domain(self):
        """ Returns the domain of the entity. """
        return self._domain

    @property
    def dtype(self):
        """ Returns the data type of the entity (binary or analog). """
        if self._dtype in ['analog', 'binary']:
            return self._dtype
        return 'binary' if self.unit_of_measurement is None else 'analog'

    @property
    def should_poll(self):
        """ Tells Home Assistant not to poll this entity. """
        return False

    @property
    def value(self):
        """ Returns the unclean value from the controller. """
        # pylint: disable=protected-access
        return self.node.status._val

    @property
    def state_attributes(self):
        """ Returns the state attributes for the node. """
        attr = {ATTR_FRIENDLY_NAME: self.name}
        for name, prop in self._attrs.items():
            attr[name] = getattr(self, prop)
        return attr

    @property
    def unique_id(self):
        """ Returns the id of this ISY sensor. """
        # pylint: disable=protected-access
        return self.node._id

    @property
    def raw_name(self):
        """ Returns the unclean node name. """
        return str(self._name) \
            if self._name is not None else str(self.node.name)

    @property
    def name(self):
        """ Returns the cleaned name of the node. """
        return self.raw_name.replace(HIDDEN_STRING, '').strip() \
            .replace('_', ' ')

    def update(self):
        """ Update state of the sensor. """
        # ISY objects are automatically updated by the ISY's event stream
        pass

    def on_update(self, event):
        """ Handles the update received event. """
        self.update_ha_state()

    @property
    def is_on(self):
        """ Returns boolean response if the node is on. """
        return bool(self.value)

    @property
    def is_open(self):
        """ Returns boolean respons if the node is open. On = Open. """
        return self.is_on

    @property
    def state(self):
        """ Returns the state of the node. """
        if len(self._states) > 0:
            return self._states[0] if self.is_on else self._states[1]
        return self.value

    def turn_on(self, **kwargs):
        """ Turns the device on. """
        if self.domain is not 'sensor':
            attrs = [kwargs.get(name) for name in self._onattrs]
            self.node.on(*attrs)
        else:
            _LOGGER.error('ISY cannot turn on sensors.')

    def turn_off(self, **kwargs):
        """ Turns the device off. """
        if self.domain is not 'sensor':
            self.node.off()
        else:
            _LOGGER.error('ISY cannot turn off sensors.')

    @property
    def unit_of_measurement(self):
        """ Returns the defined units of measurement or None. """
        try:
            return self.node.units
        except AttributeError:
            return None