"""Support for Blockchain.info sensors."""
from datetime import timedelta
import logging

from pyblockchain import get_balance, validate_address
import voluptuous as vol

from homeassistant.components.sensor import PLATFORM_SCHEMA
from homeassistant.const import ATTR_ATTRIBUTION, CONF_NAME
import homeassistant.helpers.config_validation as cv
from homeassistant.helpers.entity import Entity

_LOGGER = logging.getLogger(__name__)

ATTRIBUTION = "Data provided by blockchain.info"

CONF_ADDRESSES = "addresses"

DEFAULT_NAME = "Bitcoin Balance"

ICON = "mdi:currency-btc"

SCAN_INTERVAL = timedelta(minutes=5)

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
    {
        vol.Required(CONF_ADDRESSES): [cv.string],
        vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
    }
)


def setup_platform(hass, config, add_entities, discovery_info=None):
    """Set up the Blockchain.info sensors."""

    addresses = config.get(CONF_ADDRESSES)
    name = config.get(CONF_NAME)

    for address in addresses:
        if not validate_address(address):
            _LOGGER.error("Bitcoin address is not valid: %s", address)
            return False

    add_entities([BlockchainSensor(name, addresses)], True)


class BlockchainSensor(Entity):
    """Representation of a Blockchain.info sensor."""

    def __init__(self, name, addresses):
        """Initialize the sensor."""
        self._name = name
        self.addresses = addresses
        self._state = None
        self._unit_of_measurement = "BTC"

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

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

    @property
    def unit_of_measurement(self):
        """Return the unit of measurement this sensor expresses itself in."""
        return self._unit_of_measurement

    @property
    def icon(self):
        """Return the icon to use in the frontend, if any."""
        return ICON

    @property
    def device_state_attributes(self):
        """Return the state attributes of the sensor."""
        return {ATTR_ATTRIBUTION: ATTRIBUTION}

    def update(self):
        """Get the latest state of the sensor."""

        self._state = get_balance(self.addresses)