"""Tesla Config Flow."""
import logging

from teslajsonpy import Controller as TeslaAPI, TeslaException
import voluptuous as vol

from homeassistant import config_entries, core, exceptions
from homeassistant.const import (
    CONF_ACCESS_TOKEN,
    CONF_PASSWORD,
    CONF_SCAN_INTERVAL,
    CONF_TOKEN,
    CONF_USERNAME,
)
from homeassistant.core import callback
from homeassistant.helpers import aiohttp_client, config_validation as cv

from .const import DEFAULT_SCAN_INTERVAL, DOMAIN, MIN_SCAN_INTERVAL

_LOGGER = logging.getLogger(__name__)

DATA_SCHEMA = vol.Schema(
    {vol.Required(CONF_USERNAME): str, vol.Required(CONF_PASSWORD): str}
)


@callback
def configured_instances(hass):
    """Return a set of configured Tesla instances."""
    return set(entry.title for entry in hass.config_entries.async_entries(DOMAIN))


class TeslaConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
    """Handle a config flow for Tesla."""

    VERSION = 1
    CONNECTION_CLASS = config_entries.CONN_CLASS_CLOUD_POLL

    async def async_step_import(self, import_config):
        """Import a config entry from configuration.yaml."""
        return await self.async_step_user(import_config)

    async def async_step_user(self, user_input=None):
        """Handle the start of the config flow."""

        if not user_input:
            return self.async_show_form(
                step_id="user",
                data_schema=DATA_SCHEMA,
                errors={},
                description_placeholders={},
            )

        if user_input[CONF_USERNAME] in configured_instances(self.hass):
            return self.async_show_form(
                step_id="user",
                data_schema=DATA_SCHEMA,
                errors={CONF_USERNAME: "identifier_exists"},
                description_placeholders={},
            )

        try:
            info = await validate_input(self.hass, user_input)
        except CannotConnect:
            return self.async_show_form(
                step_id="user",
                data_schema=DATA_SCHEMA,
                errors={"base": "connection_error"},
                description_placeholders={},
            )
        except InvalidAuth:
            return self.async_show_form(
                step_id="user",
                data_schema=DATA_SCHEMA,
                errors={"base": "invalid_credentials"},
                description_placeholders={},
            )
        return self.async_create_entry(title=user_input[CONF_USERNAME], data=info)

    @staticmethod
    @callback
    def async_get_options_flow(config_entry):
        """Get the options flow for this handler."""
        return OptionsFlowHandler(config_entry)


class OptionsFlowHandler(config_entries.OptionsFlow):
    """Handle a option flow for Tesla."""

    def __init__(self, config_entry: config_entries.ConfigEntry):
        """Initialize options flow."""
        self.config_entry = config_entry

    async def async_step_init(self, user_input=None):
        """Handle options flow."""
        if user_input is not None:
            return self.async_create_entry(title="", data=user_input)

        data_schema = vol.Schema(
            {
                vol.Optional(
                    CONF_SCAN_INTERVAL,
                    default=self.config_entry.options.get(
                        CONF_SCAN_INTERVAL, DEFAULT_SCAN_INTERVAL
                    ),
                ): vol.All(cv.positive_int, vol.Clamp(min=MIN_SCAN_INTERVAL))
            }
        )
        return self.async_show_form(step_id="init", data_schema=data_schema)


async def validate_input(hass: core.HomeAssistant, data):
    """Validate the user input allows us to connect.

    Data has the keys from DATA_SCHEMA with values provided by the user.
    """

    config = {}
    websession = aiohttp_client.async_get_clientsession(hass)
    try:
        controller = TeslaAPI(
            websession,
            email=data[CONF_USERNAME],
            password=data[CONF_PASSWORD],
            update_interval=DEFAULT_SCAN_INTERVAL,
        )
        (config[CONF_TOKEN], config[CONF_ACCESS_TOKEN]) = await controller.connect(
            test_login=True
        )
    except TeslaException as ex:
        if ex.code == 401:
            _LOGGER.error("Invalid credentials: %s", ex)
            raise InvalidAuth()
        _LOGGER.error("Unable to communicate with Tesla API: %s", ex)
        raise CannotConnect()
    _LOGGER.debug("Credentials successfully connected to the Tesla API")
    return config


class CannotConnect(exceptions.HomeAssistantError):
    """Error to indicate we cannot connect."""


class InvalidAuth(exceptions.HomeAssistantError):
    """Error to indicate there is invalid auth."""
