Test for Removing Thread credentials after last fabric remove

config/nrfconnect/chip-module/Kconfig

@@ -99,6 +99,34 @@ config CHIP_DEBUG_SYMBOLS
 config CHIP_MALLOC_SYS_HEAP
 	default y if !ARCH_POSIX
 
+choice CHIP_LAST_FABRIC_REMOVED_ACTION
+	prompt "An action to perform after removing the last fabric"
+	default CHIP_LAST_FABRIC_REMOVED_ERASE_AND_REBOOT
+
+	config CHIP_LAST_FABRIC_REMOVED_ERASE_AND_REBOOT
+	bool "After removing the last fabric erase NVS and reboot"
+	help
+	  After removing the last fabric the device will perform the factory reset and
+	  then reboot. The current RAM state will be removed and the new commissioning to
+	  the new fabric will use the initial fabric index. This option is the most safe.
+
+	config CHIP_LAST_FABRIC_REMOVED_ERASE_AND_PAIRING_START
+	bool "After removing the last fabric erase NVS and start Bluetooth LE advertising"
+	help
+	  After removing the last fabric the device will perform the factory reset without 
+	  rebooting and start the Bluetooth LE advertisement automatically.
+	  The current RAM state will be saved and the new commissioning to the next 
+	  fabric will use the next possible fabric index. 
+
+	config CHIP_LAST_FABRIC_REMOVED_ERASE_ONLY
+	bool "After removing the last fabric erase NVS only"
+	help
+	  After removing the last fabric the device will perform the factory reset only without
+	  rebooting. The current RAM state will be saved and the new commissioning to the next 
+	  fabric will use the next possible fabric index.
+
+endchoice
+
 config CHIP_FACTORY_DATA
 	bool "Factory data provider"
 	select ZCBOR

examples/lock-app/nrfconnect/main/AppTask.cpp

@@ -19,6 +19,7 @@
 #include "AppTask.h"
 #include "AppConfig.h"
 #include "BoltLockManager.h"
+#include "FabricTableDelegate.h"
 #include "LEDUtil.h"
 #include "LEDWidget.h"
 
@@ -212,6 +213,7 @@ CHIP_ERROR AppTask::Init()
     (void) initParams.InitializeStaticResourcesBeforeServerInit();
     initParams.testEventTriggerDelegate = &testEventTriggerDelegate;
     ReturnErrorOnFailure(chip::Server::GetInstance().Init(initParams));
+    AppFabricTableDelegate::Init();
 
     gExampleDeviceInfoProvider.SetStorageDelegate(&Server::GetInstance().GetPersistentStorage());
     chip::DeviceLayer::SetDeviceInfoProvider(&gExampleDeviceInfoProvider);

examples/lock-app/nrfconnect/main/include/AppTask.h

@@ -56,6 +56,8 @@ class AppTask
     static void IdentifyStartHandler(Identify *);
     static void IdentifyStopHandler(Identify *);
 
+    static void StartBLEAdvertisementHandler(const AppEvent & event);
+
 private:
     CHIP_ERROR Init();
 
@@ -67,7 +69,6 @@ class AppTask
     static void FunctionHandler(const AppEvent & event);
     static void StartBLEAdvertisementAndLockActionEventHandler(const AppEvent & event);
     static void LockActionEventHandler(const AppEvent & event);
-    static void StartBLEAdvertisementHandler(const AppEvent & event);
     static void UpdateLedStateEventHandler(const AppEvent & event);
 
     static void ChipEventHandler(const chip::DeviceLayer::ChipDeviceEvent * event, intptr_t arg);

examples/platform/nrfconnect/util/include/FabricTableDelegate.h

@@ -0,0 +1,65 @@
+/*
+ *
+ *    Copyright (c) 2023 Project CHIP Authors
+ *    All rights reserved.
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+#pragma once
+
+#include "AppTask.h"
+
+#include <app/server/Server.h>
+#include <app/util/attribute-storage.h>
+
+namespace chip {
+
+class AppFabricTableDelegate : public FabricTable::Delegate
+{
+public:
+    ~AppFabricTableDelegate() { Server::GetInstance().GetFabricTable().RemoveFabricDelegate(this); }
+
+    static void Init()
+    {
+        static AppFabricTableDelegate sAppFabricDelegate;
+        Server::GetInstance().GetFabricTable().AddFabricDelegate(&sAppFabricDelegate);
+    }
+
+private:
+    void OnFabricRemoved(const FabricTable & fabricTable, FabricIndex fabricIndex)
+    {
+        if (Server::GetInstance().GetFabricTable().FabricCount() == 0)
+        {
+#ifdef CONFIG_CHIP_LAST_FABRIC_REMOVED_ERASE_AND_REBOOT
+            Server::GetInstance().ScheduleFactoryReset();
+#elif defined(CONFIG_CHIP_LAST_FABRIC_REMOVED_ERASE_ONLY) || defined(CONFIG_CHIP_LAST_FABRIC_REMOVED_ERASE_AND_PAIRING_START)
+            DeviceLayer::PlatformMgr().ScheduleWork([](intptr_t) {
+                // Delete all fabrics and emit Leave event.
+                Server::GetInstance().GetFabricTable().DeleteAllFabrics();
+                /* Erase Matter data */
+                DeviceLayer::PersistedStorage::KeyValueStoreMgrImpl().DoFactoryReset();
+                /* Erase Thread credentials and disconnect */
+                DeviceLayer::ConnectivityMgr().ErasePersistentInfo();
+#ifdef CONFIG_CHIP_LAST_FABRIC_REMOVED_ERASE_AND_PAIRING_START
+                /* Start the New BLE advertising */
+                AppEvent event;
+                event.Handler = AppTask::StartBLEAdvertisementHandler;
+                AppTask::Instance().PostEvent(event);
+#endif
+            });
+#endif
+        }
+    }
+};
+} // namespace chip