"""Handle August connection setup and authentication."""

import asyncio
import logging

from august.api import Api
from august.authenticator import AuthenticationState, Authenticator
from requests import RequestException, Session

from homeassistant.const import CONF_PASSWORD, CONF_TIMEOUT, CONF_USERNAME
from homeassistant.core import callback

from .const import (
    CONF_ACCESS_TOKEN_CACHE_FILE,
    CONF_INSTALL_ID,
    CONF_LOGIN_METHOD,
    DEFAULT_AUGUST_CONFIG_FILE,
    VERIFICATION_CODE_KEY,
)
from .exceptions import CannotConnect, InvalidAuth, RequireValidation

_LOGGER = logging.getLogger(__name__)


class AugustGateway:
    """Handle the connection to August."""

    def __init__(self, hass):
        """Init the connection."""
        self._api_http_session = Session()
        self._token_refresh_lock = asyncio.Lock()
        self._hass = hass
        self._config = None
        self._api = None
        self._authenticator = None
        self._authentication = None

    @property
    def authenticator(self):
        """August authentication object from py-august."""
        return self._authenticator

    @property
    def authentication(self):
        """August authentication object from py-august."""
        return self._authentication

    @property
    def access_token(self):
        """Access token for the api."""
        return self._authentication.access_token

    @property
    def api(self):
        """August api object from py-august."""
        return self._api

    def config_entry(self):
        """Config entry."""
        return {
            CONF_LOGIN_METHOD: self._config[CONF_LOGIN_METHOD],
            CONF_USERNAME: self._config[CONF_USERNAME],
            CONF_PASSWORD: self._config[CONF_PASSWORD],
            CONF_INSTALL_ID: self._config.get(CONF_INSTALL_ID),
            CONF_TIMEOUT: self._config.get(CONF_TIMEOUT),
            CONF_ACCESS_TOKEN_CACHE_FILE: self._config[CONF_ACCESS_TOKEN_CACHE_FILE],
        }

    @callback
    def async_setup(self, conf):
        """Create the api and authenticator objects."""
        if conf.get(VERIFICATION_CODE_KEY):
            return
        if conf.get(CONF_ACCESS_TOKEN_CACHE_FILE) is None:
            conf[
                CONF_ACCESS_TOKEN_CACHE_FILE
            ] = f".{conf[CONF_USERNAME]}{DEFAULT_AUGUST_CONFIG_FILE}"
        self._config = conf

        self._api = Api(
            timeout=self._config.get(CONF_TIMEOUT), http_session=self._api_http_session,
        )

        self._authenticator = Authenticator(
            self._api,
            self._config[CONF_LOGIN_METHOD],
            self._config[CONF_USERNAME],
            self._config[CONF_PASSWORD],
            install_id=self._config.get(CONF_INSTALL_ID),
            access_token_cache_file=self._hass.config.path(
                self._config[CONF_ACCESS_TOKEN_CACHE_FILE]
            ),
        )

    def authenticate(self):
        """Authenticate with the details provided to setup."""
        self._authentication = None
        try:
            self._authentication = self.authenticator.authenticate()
        except RequestException as ex:
            _LOGGER.error("Unable to connect to August service: %s", str(ex))
            raise CannotConnect

        if self._authentication.state == AuthenticationState.BAD_PASSWORD:
            raise InvalidAuth

        if self._authentication.state == AuthenticationState.REQUIRES_VALIDATION:
            raise RequireValidation

        if self._authentication.state != AuthenticationState.AUTHENTICATED:
            _LOGGER.error(
                "Unknown authentication state: %s", self._authentication.state
            )
            raise InvalidAuth

        return self._authentication

    async def async_refresh_access_token_if_needed(self):
        """Refresh the august access token if needed."""
        if self.authenticator.should_refresh():
            async with self._token_refresh_lock:
                await self._hass.async_add_executor_job(self._refresh_access_token)

    def _refresh_access_token(self):
        refreshed_authentication = self.authenticator.refresh_access_token(force=False)
        _LOGGER.info(
            "Refreshed august access token. The old token expired at %s, and the new token expires at %s",
            self.authentication.access_token_expires,
            refreshed_authentication.access_token_expires,
        )
        self._authentication = refreshed_authentication

    def _close_http_session(self):
        """Close API sessions used to connect to August."""
        if self._api_http_session:
            try:
                self._api_http_session.close()
            except RequestException:
                pass

    def __del__(self):
        """Close out the http session on destroy."""
        self._close_http_session()