"""Pencom relay control.

For more details about this component, please refer to the documentation at
http://home-assistant.io/components/switch.pencom
"""
import logging

import voluptuous as vol

from homeassistant.components.switch import SwitchDevice, PLATFORM_SCHEMA
from homeassistant.const import CONF_HOST, CONF_PORT, CONF_NAME
from homeassistant.exceptions import PlatformNotReady
import homeassistant.helpers.config_validation as cv

_LOGGER = logging.getLogger(__name__)

CONF_BOARDS = "boards"
CONF_BOARD = "board"
CONF_ADDR = "addr"
CONF_RELAYS = "relays"

RELAY_SCHEMA = vol.Schema(
    {
        vol.Required(CONF_NAME): cv.string,
        vol.Required(CONF_ADDR): cv.positive_int,
        vol.Optional(CONF_BOARD, default=0): cv.positive_int,
    }
)

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
    {
        vol.Required(CONF_HOST): cv.string,
        vol.Required(CONF_PORT): cv.port,
        vol.Optional(CONF_BOARDS, default=1): cv.positive_int,
        vol.Required(CONF_RELAYS): vol.All(cv.ensure_list, [RELAY_SCHEMA]),
    }
)


def setup_platform(hass, config, add_entities, discovery_info=None):
    """Pencom relay platform (pencompy)."""
    from pencompy.pencompy import Pencompy

    # Assign configuration variables.
    host = config[CONF_HOST]
    port = config[CONF_PORT]
    boards = config[CONF_BOARDS]

    # Setup connection
    try:
        hub = Pencompy(host, port, boards=boards)
    except OSError as error:
        _LOGGER.error("Could not connect to pencompy: %s", error)
        raise PlatformNotReady

    # Add devices.
    devs = []
    for relay in config[CONF_RELAYS]:
        name = relay[CONF_NAME]
        board = relay[CONF_BOARD]
        addr = relay[CONF_ADDR]
        devs.append(PencomRelay(hub, board, addr, name))
    add_entities(devs, True)


class PencomRelay(SwitchDevice):
    """Representation of a pencom relay."""

    def __init__(self, hub, board, addr, name):
        """Create a relay."""
        self._hub = hub
        self._board = board
        self._addr = addr
        self._name = name
        self._state = None

    @property
    def name(self):
        """Relay name."""
        return self._name

    @property
    def is_on(self):
        """Return a relay's state."""
        return self._state

    def turn_on(self, **kwargs):
        """Turn a relay on."""
        self._hub.set(self._board, self._addr, True)

    def turn_off(self, **kwargs):
        """Turn a relay off."""
        self._hub.set(self._board, self._addr, False)

    def update(self):
        """Refresh a relay's state."""
        self._state = self._hub.get(self._board, self._addr)

    @property
    def device_state_attributes(self):
        """Return supported attributes."""
        return {"board": self._board, "addr": self._addr}