Add diagnostics support for Asuswrt (#65605)

Co-authored-by: Paulus Schoutsen <paulus@home-assistant.io>

.coveragerc

@@ -80,6 +80,7 @@ omit =
     homeassistant/components/asterisk_cdr/mailbox.py
     homeassistant/components/asterisk_mbox/*
     homeassistant/components/asuswrt/__init__.py
+    homeassistant/components/asuswrt/diagnostics.py
     homeassistant/components/asuswrt/router.py
     homeassistant/components/aten_pe/*
     homeassistant/components/atome/*

homeassistant/components/asuswrt/diagnostics.py

@@ -0,0 +1,84 @@
+"""Diagnostics support for Asuswrt."""
+from __future__ import annotations
+
+from typing import Any
+
+from homeassistant.components.diagnostics import async_redact_data
+from homeassistant.config_entries import ConfigEntry
+from homeassistant.const import CONF_PASSWORD, CONF_USERNAME
+from homeassistant.core import HomeAssistant
+from homeassistant.helpers import device_registry as dr, entity_registry as er
+
+from .const import DATA_ASUSWRT, DOMAIN
+from .router import AsusWrtRouter
+
+TO_REDACT = {CONF_PASSWORD, CONF_USERNAME}
+
+
+async def async_get_config_entry_diagnostics(
+    hass: HomeAssistant, entry: ConfigEntry
+) -> dict[str, dict[str, Any]]:
+    """Return diagnostics for a config entry."""
+    data = {"entry": async_redact_data(entry.as_dict(), TO_REDACT)}
+
+    router: AsusWrtRouter = hass.data[DOMAIN][entry.entry_id][DATA_ASUSWRT]
+
+    # Gather information how this AsusWrt device is represented in Home Assistant
+    device_registry = dr.async_get(hass)
+    entity_registry = er.async_get(hass)
+    hass_device = device_registry.async_get_device(
+        identifiers=router.device_info["identifiers"]
+    )
+    if not hass_device:
+        return data
+
+    data["device"] = {
+        "name": hass_device.name,
+        "name_by_user": hass_device.name_by_user,
+        "disabled": hass_device.disabled,
+        "disabled_by": hass_device.disabled_by,
+        "device_info": async_redact_data(dict(router.device_info), {"identifiers"}),
+        "entities": {},
+        "tracked_devices": [],
+    }
+
+    hass_entities = er.async_entries_for_device(
+        entity_registry,
+        device_id=hass_device.id,
+        include_disabled_entities=True,
+    )
+
+    for entity_entry in hass_entities:
+        state = hass.states.get(entity_entry.entity_id)
+        state_dict = None
+        if state:
+            state_dict = dict(state.as_dict())
+            # The entity_id is already provided at root level.
+            state_dict.pop("entity_id", None)
+            # The context doesn't provide useful information in this case.
+            state_dict.pop("context", None)
+
+        data["device"]["entities"][entity_entry.entity_id] = {
+            "name": entity_entry.name,
+            "original_name": entity_entry.original_name,
+            "disabled": entity_entry.disabled,
+            "disabled_by": entity_entry.disabled_by,
+            "entity_category": entity_entry.entity_category,
+            "device_class": entity_entry.device_class,
+            "original_device_class": entity_entry.original_device_class,
+            "icon": entity_entry.icon,
+            "original_icon": entity_entry.original_icon,
+            "unit_of_measurement": entity_entry.unit_of_measurement,
+            "state": state_dict,
+        }
+
+    for device in router.devices.values():
+        data["device"]["tracked_devices"].append(
+            {
+                "name": device.name or "Unknown device",
+                "ip_address": device.ip_address,
+                "last_activity": device.last_activity,
+            }
+        )
+
+    return data