Implement config flow in the Broadlink integration (#36914)

* Implement config flow in the Broadlink integration

* General improvements to the Broadlink config flow

* Remove unnecessary else after return

* Fix translations

* Rename device to device_entry

* Add tests for the config flow

* Improve docstrings

* Test we do not accept more than one config entry per device

* Improve helpers

* Allow empty packets

* Allow multiple config files for switches related to the same device

* Rename mock_device to mock_api

* General improvements

* Make new attempts before marking the device as unavailable

* Let the name be the template for the entity_id

* Handle OSError

* Test network unavailable in the configuration flow

* Rename lock attribute

* Update manifest.json

* Import devices from platforms

* Test import flow

* Add deprecation warnings

* General improvements

* Rename deprecate to discontinue

* Test device setup

* Add type attribute to mock api

* Test we handle an update failure at startup

* Remove BroadlinkDevice from tests

* Remove device.py from .coveragerc

* Add tests for the config flow

* Add tests for the device

* Test device registry and update listener

* Test MAC address validation

* Add tests for the device

* Extract domains and types to a helper function

* Do not patch integration details

* Add tests for the device

* Set device classes where appropriate

* Set an appropriate connection class

* Do not set device class for custom switches

* Fix tests and improve code readability

* Use RM4 to test authentication errors

* Handle BroadlinkException in the authentication

homeassistant/components/broadlink/helpers.py

@@ -0,0 +1,49 @@
+"""Helper functions for the Broadlink integration."""
+from base64 import b64decode
+
+from homeassistant import config_entries
+from homeassistant.const import CONF_HOST
+import homeassistant.helpers.config_validation as cv
+
+from .const import DOMAIN
+
+
+def data_packet(value):
+    """Decode a data packet given for a Broadlink remote."""
+    value = cv.string(value)
+    extra = len(value) % 4
+    if extra > 0:
+        value = value + ("=" * (4 - extra))
+    return b64decode(value)
+
+
+def mac_address(mac):
+    """Validate and convert a MAC address to bytes."""
+    mac = cv.string(mac)
+    if len(mac) == 17:
+        mac = "".join(mac[i : i + 2] for i in range(0, 17, 3))
+    elif len(mac) == 14:
+        mac = "".join(mac[i : i + 4] for i in range(0, 14, 5))
+    elif len(mac) != 12:
+        raise ValueError("Invalid MAC address")
+    return bytes.fromhex(mac)
+
+
+def format_mac(mac):
+    """Format a MAC address."""
+    return ":".join([format(octet, "02x") for octet in mac])
+
+
+def import_device(hass, host):
+    """Create a config flow for a device."""
+    configured_hosts = {
+        entry.data.get(CONF_HOST) for entry in hass.config_entries.async_entries(DOMAIN)
+    }
+
+    if host not in configured_hosts:
+        task = hass.config_entries.flow.async_init(
+            DOMAIN,
+            context={"source": config_entries.SOURCE_IMPORT},
+            data={CONF_HOST: host},
+        )
+        hass.async_create_task(task)