Add config flow to transmission (#26434)

* Add config flow to transmission

* Reworked code to add all sensors and switches

* applied fixes

* final touches

* Add tests

* fixed tests

* fix get_api errors and entities availabilty update

* update config_flows.py

* fix pylint error

* update .coveragerc

* add codeowner

* add test_options

* fixed test_options

homeassistant/components/transmission/config_flow.py

@@ -0,0 +1,104 @@
+"""Config flow for Transmission Bittorent Client."""
+import voluptuous as vol
+
+from homeassistant import config_entries
+from homeassistant.const import (
+    CONF_HOST,
+    CONF_NAME,
+    CONF_PASSWORD,
+    CONF_PORT,
+    CONF_SCAN_INTERVAL,
+    CONF_USERNAME,
+)
+from homeassistant.core import callback
+
+from . import get_api
+from .const import DEFAULT_NAME, DEFAULT_PORT, DEFAULT_SCAN_INTERVAL, DOMAIN
+from .errors import AuthenticationError, CannotConnect, UnknownError
+
+
+class TransmissionFlowHandler(config_entries.ConfigFlow, domain=DOMAIN):
+    """Handle a UniFi config flow."""
+
+    VERSION = 1
+    CONNECTION_CLASS = config_entries.CONN_CLASS_LOCAL_POLL
+
+    @staticmethod
+    @callback
+    def async_get_options_flow(config_entry):
+        """Get the options flow for this handler."""
+        return TransmissionOptionsFlowHandler(config_entry)
+
+    def __init__(self):
+        """Initialize the Transmission flow."""
+        self.config = {}
+        self.errors = {}
+
+    async def async_step_user(self, user_input=None):
+        """Handle a flow initialized by the user."""
+        if self.hass.config_entries.async_entries(DOMAIN):
+            return self.async_abort(reason="one_instance_allowed")
+
+        if user_input is not None:
+
+            self.config[CONF_NAME] = user_input.pop(CONF_NAME)
+            try:
+                await get_api(self.hass, **user_input)
+                self.config.update(user_input)
+                if "options" not in self.config:
+                    self.config["options"] = {CONF_SCAN_INTERVAL: DEFAULT_SCAN_INTERVAL}
+                return self.async_create_entry(
+                    title=self.config[CONF_NAME], data=self.config
+                )
+            except AuthenticationError:
+                self.errors[CONF_USERNAME] = "wrong_credentials"
+                self.errors[CONF_PASSWORD] = "wrong_credentials"
+            except (CannotConnect, UnknownError):
+                self.errors["base"] = "cannot_connect"
+
+        return self.async_show_form(
+            step_id="user",
+            data_schema=vol.Schema(
+                {
+                    vol.Required(CONF_NAME, default=DEFAULT_NAME): str,
+                    vol.Required(CONF_HOST): str,
+                    vol.Optional(CONF_USERNAME): str,
+                    vol.Optional(CONF_PASSWORD): str,
+                    vol.Required(CONF_PORT, default=DEFAULT_PORT): int,
+                }
+            ),
+            errors=self.errors,
+        )
+
+    async def async_step_import(self, import_config):
+        """Import from Transmission client config."""
+        self.config["options"] = {
+            CONF_SCAN_INTERVAL: import_config.pop(CONF_SCAN_INTERVAL).seconds
+        }
+
+        return await self.async_step_user(user_input=import_config)
+
+
+class TransmissionOptionsFlowHandler(config_entries.OptionsFlow):
+    """Handle Transmission client options."""
+
+    def __init__(self, config_entry):
+        """Initialize Transmission options flow."""
+        self.config_entry = config_entry
+
+    async def async_step_init(self, user_input=None):
+        """Manage the Transmission options."""
+        if user_input is not None:
+            return self.async_create_entry(title="", data=user_input)
+
+        options = {
+            vol.Optional(
+                CONF_SCAN_INTERVAL,
+                default=self.config_entry.options.get(
+                    CONF_SCAN_INTERVAL,
+                    self.config_entry.data["options"][CONF_SCAN_INTERVAL],
+                ),
+            ): int
+        }
+
+        return self.async_show_form(step_id="init", data_schema=vol.Schema(options))