Add zeroconf discovery support to Brother Printer integration (#30959)

* Add zeroconf discovery support

* Fix data for config_entry

* Add sting for zeroconf confirm dialog

* Add and fix tests

* Fix pylint errors

* Suggested changes

* Tests

* Remove unnecessary object

* Add error handling

* Remove unnecessary objects

* Suggested change

* Suggested change

* Use core interfaces for tests

homeassistant/components/brother/config_flow.py

@@ -34,6 +34,11 @@ class BrotherConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
     VERSION = 1
     CONNECTION_CLASS = config_entries.CONN_CLASS_LOCAL_POLL
 
+    def __init__(self):
+        """Initialize."""
+        self.brother = None
+        self.host = None
+
     async def async_step_user(self, user_input=None):
         """Handle the initial step."""
         errors = {}
@@ -64,6 +69,58 @@ class BrotherConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
             step_id="user", data_schema=DATA_SCHEMA, errors=errors
         )
 
+    async def async_step_zeroconf(self, user_input=None):
+        """Handle zeroconf discovery."""
+        if user_input is None:
+            return self.async_abort(reason="connection_error")
+
+        if not user_input.get("name") or not user_input["name"].startswith("Brother"):
+            return self.async_abort(reason="not_brother_printer")
+
+        # Hostname is format: brother.local.
+        self.host = user_input["hostname"].rstrip(".")
+
+        self.brother = Brother(self.host)
+        try:
+            await self.brother.async_update()
+        except (ConnectionError, SnmpError, UnsupportedModel):
+            return self.async_abort(reason="connection_error")
+
+        # Check if already configured
+        await self.async_set_unique_id(self.brother.serial.lower())
+        self._abort_if_unique_id_configured()
+
+        # pylint: disable=no-member # https://github.com/PyCQA/pylint/issues/3167
+        self.context.update(
+            {
+                "title_placeholders": {
+                    "serial_number": self.brother.serial,
+                    "model": self.brother.model,
+                }
+            }
+        )
+        return await self.async_step_zeroconf_confirm()
+
+    async def async_step_zeroconf_confirm(self, user_input=None):
+        """Handle a flow initiated by zeroconf."""
+        if user_input is not None:
+            title = f"{self.brother.model} {self.brother.serial}"
+            # pylint: disable=no-member # https://github.com/PyCQA/pylint/issues/3167
+            return self.async_create_entry(
+                title=title,
+                data={CONF_HOST: self.host, CONF_TYPE: user_input[CONF_TYPE]},
+            )
+        return self.async_show_form(
+            step_id="zeroconf_confirm",
+            data_schema=vol.Schema(
+                {vol.Optional(CONF_TYPE, default="laser"): vol.In(PRINTER_TYPES)}
+            ),
+            description_placeholders={
+                "serial_number": self.brother.serial,
+                "model": self.brother.model,
+            },
+        )
+
 
 class InvalidHost(exceptions.HomeAssistantError):
     """Error to indicate that hostname/IP address is invalid."""