"""Config flow for Dexcom integration."""

import logging
from typing import Any, override

from pydexcom import Dexcom, Region
from pydexcom.errors import AccountError, SessionError
import voluptuous as vol

from homeassistant.config_entries import ConfigFlow, ConfigFlowResult
from homeassistant.const import CONF_PASSWORD, CONF_USERNAME

from .const import CONF_SERVER, DOMAIN, SERVER_OUS, SERVER_US

_LOGGER = logging.getLogger(__name__)

DATA_SCHEMA = vol.Schema(
    {
        vol.Required(CONF_USERNAME): str,
        vol.Required(CONF_PASSWORD): str,
        vol.Required(CONF_SERVER): vol.In({SERVER_US, SERVER_OUS}),
    }
)


class DexcomConfigFlow(ConfigFlow, domain=DOMAIN):
    """Handle a config flow for Dexcom."""

    VERSION = 1

    @override
    async def async_step_user(
        self, user_input: dict[str, Any] | None = None
    ) -> ConfigFlowResult:
        """Handle the initial step."""
        errors = {}
        if user_input is not None:
            try:
                await self.hass.async_add_executor_job(
                    lambda: Dexcom(
                        username=user_input[CONF_USERNAME],
                        password=user_input[CONF_PASSWORD],
                        region=Region.OUS
                        if user_input[CONF_SERVER] == SERVER_OUS
                        else Region.US,
                    )
                )
            except SessionError:
                errors["base"] = "cannot_connect"
            except AccountError:
                errors["base"] = "invalid_auth"
            except Exception:
                _LOGGER.exception("Unexpected error")
                errors["base"] = "unknown"

            if "base" not in errors:
                await self.async_set_unique_id(user_input[CONF_USERNAME])
                self._abort_if_unique_id_configured()
                return self.async_create_entry(
                    title=user_input[CONF_USERNAME], data=user_input
                )

        return self.async_show_form(
            step_id="user", data_schema=DATA_SCHEMA, errors=errors
        )