"""
A component which allows you to send data to Datadog.

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

import voluptuous as vol

from homeassistant.const import (
    CONF_HOST, CONF_PORT, CONF_PREFIX, EVENT_LOGBOOK_ENTRY,
    EVENT_STATE_CHANGED, STATE_UNKNOWN)
from homeassistant.helpers import state as state_helper
import homeassistant.helpers.config_validation as cv

REQUIREMENTS = ['datadog==0.15.0']

_LOGGER = logging.getLogger(__name__)

CONF_RATE = 'rate'
DEFAULT_HOST = 'localhost'
DEFAULT_PORT = 8125
DEFAULT_PREFIX = 'hass'
DEFAULT_RATE = 1
DOMAIN = 'datadog'

CONFIG_SCHEMA = vol.Schema({
    DOMAIN: vol.Schema({
        vol.Required(CONF_HOST, default=DEFAULT_HOST): cv.string,
        vol.Optional(CONF_PORT, default=DEFAULT_PORT): cv.port,
        vol.Optional(CONF_PREFIX, default=DEFAULT_PREFIX): cv.string,
        vol.Optional(CONF_RATE, default=DEFAULT_RATE):
            vol.All(vol.Coerce(int), vol.Range(min=1)),
    }),
}, extra=vol.ALLOW_EXTRA)


def setup(hass, config):
    """Set up the Datadog component."""
    from datadog import initialize, statsd

    conf = config[DOMAIN]
    host = conf.get(CONF_HOST)
    port = conf.get(CONF_PORT)
    sample_rate = conf.get(CONF_RATE)
    prefix = conf.get(CONF_PREFIX)

    initialize(statsd_host=host, statsd_port=port)

    def logbook_entry_listener(event):
        """Listen for logbook entries and send them as events."""
        name = event.data.get('name')
        message = event.data.get('message')

        statsd.event(
            title="Home Assistant",
            text="%%% \n **{}** {} \n %%%".format(name, message),
            tags=[
                "entity:{}".format(event.data.get('entity_id')),
                "domain:{}".format(event.data.get('domain'))
            ]
        )

        _LOGGER.debug('Sent event %s', event.data.get('entity_id'))

    def state_changed_listener(event):
        """Listen for new messages on the bus and sends them to Datadog."""
        state = event.data.get('new_state')

        if state is None or state.state == STATE_UNKNOWN:
            return

        if state.attributes.get('hidden') is True:
            return

        states = dict(state.attributes)
        metric = "{}.{}".format(prefix, state.domain)
        tags = ["entity:{}".format(state.entity_id)]

        for key, value in states.items():
            if isinstance(value, (float, int)):
                attribute = "{}.{}".format(metric, key.replace(' ', '_'))
                statsd.gauge(
                    attribute, value, sample_rate=sample_rate, tags=tags)

                _LOGGER.debug(
                    "Sent metric %s: %s (tags: %s)", attribute, value, tags)

        try:
            value = state_helper.state_as_number(state)
        except ValueError:
            _LOGGER.debug(
                "Error sending %s: %s (tags: %s)", metric, state.state, tags)
            return

        statsd.gauge(metric, value, sample_rate=sample_rate, tags=tags)

        _LOGGER.debug('Sent metric %s: %s (tags: %s)', metric, value, tags)

    hass.bus.listen(EVENT_LOGBOOK_ENTRY, logbook_entry_listener)
    hass.bus.listen(EVENT_STATE_CHANGED, state_changed_listener)

    return True
