text: """Config flow for Z-Wave JS integration."""
  import asyncio
  import logging
  from typing import Any, Dict, Optional
  
  import aiohttp
  from async_timeout import timeout
  import voluptuous as vol
  from zwave_js_server.version import VersionInfo, get_server_version
  
  from homeassistant import config_entries, core, exceptions
  from homeassistant.const import CONF_URL
  from homeassistant.helpers.aiohttp_client import async_get_clientsession
  
  from .const import DOMAIN, NAME  # pylint:disable=unused-import
  
  _LOGGER = logging.getLogger(__name__)
  
  STEP_USER_DATA_SCHEMA = vol.Schema({CONF_URL: str})
  
  
  async def validate_input(hass: core.HomeAssistant, user_input: dict) -> VersionInfo:
      """Validate if the user input allows us to connect."""
      ws_address = user_input[CONF_URL]
  
      if not ws_address.startswith(("ws://", "wss://")):
          raise InvalidInput("invalid_ws_url")
  
      async with timeout(10):
          try:
              return await get_server_version(ws_address, async_get_clientsession(hass))
          except (asyncio.TimeoutError, aiohttp.ClientError) as err:
              raise InvalidInput("cannot_connect") from err
  
  
  class ConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
      """Handle a config flow for Z-Wave JS."""
  
      VERSION = 1
      CONNECTION_CLASS = config_entries.CONN_CLASS_LOCAL_PUSH
  
      async def async_step_user(
          self, user_input: Optional[Dict[str, Any]] = None
      ) -> Dict[str, Any]:
          """Handle the initial step."""
          if user_input is None:
              return self.async_show_form(
                  step_id="user", data_schema=STEP_USER_DATA_SCHEMA
              )
  
          errors = {}
  
          assert self.hass  # typing
  
          try:
              version_info = await validate_input(self.hass, user_input)
          except InvalidInput as err:
              errors["base"] = err.error
          except Exception:  # pylint: disable=broad-except
              _LOGGER.exception("Unexpected exception")
              errors["base"] = "unknown"
          else:
              await self.async_set_unique_id(version_info.home_id)
              self._abort_if_unique_id_configured(user_input)
              return self.async_create_entry(title=NAME, data=user_input)
  
          return self.async_show_form(
              step_id="user", data_schema=STEP_USER_DATA_SCHEMA, errors=errors
          )
  
  
  class InvalidInput(exceptions.HomeAssistantError):
      """Error to indicate input data is invalid."""
  
      def __init__(self, error: str) -> None:
          """Initialize error."""
          super().__init__()
          self.error = error
  