From ada781025b27c4a9ad7e32c4a80329381dd240f7 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Mon, 25 Mar 2024 00:28:26 -1000
Subject: [PATCH] Avoid homekit random id generation for existing entries
 (#114144)

---
 homeassistant/components/homekit/__init__.py    | 3 +++
 homeassistant/components/homekit/accessories.py | 5 ++++-
 homeassistant/components/homekit/const.py       | 1 +
 tests/components/homekit/test_accessories.py    | 5 ++++-
 4 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/homeassistant/components/homekit/__init__.py b/homeassistant/components/homekit/__init__.py
index 7d1297e1307..51b3f5f376d 100644
--- a/homeassistant/components/homekit/__init__.py
+++ b/homeassistant/components/homekit/__init__.py
@@ -12,6 +12,7 @@ import socket
 from typing import Any, cast
 
 from aiohttp import web
+from pyhap import util as pyhap_util
 from pyhap.characteristic import Characteristic
 from pyhap.const import STANDALONE_AID
 from pyhap.loader import get_loader
@@ -580,6 +581,8 @@ class HomeKit:
             self.driver.load()
             return True
 
+        # If there is no persist file, we need to generate a mac
+        self.driver.state.mac = pyhap_util.generate_mac()
         return False
 
     async def async_reset_accessories(self, entity_ids: Iterable[str]) -> None:
diff --git a/homeassistant/components/homekit/accessories.py b/homeassistant/components/homekit/accessories.py
index f39bf32744a..63575189946 100644
--- a/homeassistant/components/homekit/accessories.py
+++ b/homeassistant/components/homekit/accessories.py
@@ -72,6 +72,7 @@ from .const import (
     CONF_LINKED_BATTERY_SENSOR,
     CONF_LOW_BATTERY_THRESHOLD,
     DEFAULT_LOW_BATTERY_THRESHOLD,
+    EMPTY_MAC,
     EVENT_HOMEKIT_CHANGED,
     HK_CHARGING,
     HK_NOT_CHARGABLE,
@@ -683,7 +684,9 @@ class HomeDriver(AccessoryDriver):  # type: ignore[misc]
         **kwargs: Any,
     ) -> None:
         """Initialize a AccessoryDriver object."""
-        super().__init__(**kwargs)
+        # Always set an empty mac of pyhap will incur
+        # the cost of generating a new one for every driver
+        super().__init__(**kwargs, mac=EMPTY_MAC)
         self.hass = hass
         self.entry_id = entry_id
         self._bridge_name = bridge_name
diff --git a/homeassistant/components/homekit/const.py b/homeassistant/components/homekit/const.py
index 5a7ee1d9576..149d2aedd67 100644
--- a/homeassistant/components/homekit/const.py
+++ b/homeassistant/components/homekit/const.py
@@ -10,6 +10,7 @@ PERSIST_LOCK_DATA = f"{DOMAIN}_persist_lock"
 HOMEKIT_FILE = ".homekit.state"
 SHUTDOWN_TIMEOUT = 30
 CONF_ENTRY_INDEX = "index"
+EMPTY_MAC = "00:00:00:00:00:00"
 
 # ### Codecs ####
 VIDEO_CODEC_COPY = "copy"
diff --git a/tests/components/homekit/test_accessories.py b/tests/components/homekit/test_accessories.py
index a148ab9f61c..5d8b940a7cd 100644
--- a/tests/components/homekit/test_accessories.py
+++ b/tests/components/homekit/test_accessories.py
@@ -28,6 +28,7 @@ from homeassistant.components.homekit.const import (
     CONF_LINKED_BATTERY_CHARGING_SENSOR,
     CONF_LINKED_BATTERY_SENSOR,
     CONF_LOW_BATTERY_THRESHOLD,
+    EMPTY_MAC,
     MANUFACTURER,
     SERV_ACCESSORY_INFO,
 )
@@ -747,7 +748,9 @@ def test_home_driver(iid_storage) -> None:
             persist_file=path,
         )
 
-    mock_driver.assert_called_with(address=ip_address, port=port, persist_file=path)
+    mock_driver.assert_called_with(
+        address=ip_address, port=port, persist_file=path, mac=EMPTY_MAC
+    )
     driver.state = Mock(pincode=pin, paired=False)
     xhm_uri_mock = Mock(return_value="X-HM://0")
     driver.accessory = Mock(display_name="any", xhm_uri=xhm_uri_mock)