Add config entry for Met.no (#24608)

* Add config entry for Met.no

* Fixed tests

homeassistant/components/met/config_flow.py

@@ -0,0 +1,63 @@
+"""Config flow to configure Met component."""
+import voluptuous as vol
+
+from homeassistant import config_entries, data_entry_flow
+from homeassistant.const import (
+    CONF_ELEVATION, CONF_LATITUDE, CONF_LONGITUDE, CONF_NAME)
+from homeassistant.core import callback
+import homeassistant.helpers.config_validation as cv
+
+from .const import DOMAIN, HOME_LOCATION_NAME
+
+
+@callback
+def configured_instances(hass):
+    """Return a set of configured SimpliSafe instances."""
+    return set(
+        entry.data[CONF_NAME]
+        for entry in hass.config_entries.async_entries(DOMAIN))
+
+
+@config_entries.HANDLERS.register(DOMAIN)
+class MetFlowHandler(data_entry_flow.FlowHandler):
+    """Config flow for Met component."""
+
+    VERSION = 1
+    CONNECTION_CLASS = config_entries.CONN_CLASS_CLOUD_POLL
+
+    def __init__(self):
+        """Init MetFlowHandler."""
+        self._errors = {}
+
+    async def async_step_user(self, user_input=None):
+        """Handle a flow initialized by the user."""
+        self._errors = {}
+
+        if user_input is not None:
+            if user_input[CONF_NAME] not in configured_instances(self.hass):
+                return self.async_create_entry(
+                    title=user_input[CONF_NAME],
+                    data=user_input,
+                )
+
+            self._errors[CONF_NAME] = 'name_exists'
+
+        return await self._show_config_form(
+            name=HOME_LOCATION_NAME,
+            latitude=self.hass.config.latitude,
+            longitude=self.hass.config.longitude,
+            elevation=self.hass.config.elevation)
+
+    async def _show_config_form(self, name=None, latitude=None,
+                                longitude=None, elevation=None):
+        """Show the configuration form to edit location data."""
+        return self.async_show_form(
+            step_id='user',
+            data_schema=vol.Schema({
+                vol.Required(CONF_NAME, default=name): str,
+                vol.Required(CONF_LATITUDE, default=latitude): cv.latitude,
+                vol.Required(CONF_LONGITUDE, default=longitude): cv.longitude,
+                vol.Required(CONF_ELEVATION, default=elevation): int
+            }),
+            errors=self._errors,
+        )