[Scenes] Scenes-Server on Fabric Removal (#30419)

Added Fabric Removal callback to the scenes-server

src/app/clusters/scenes-server/SceneTable.h

@@ -284,6 +284,14 @@ class SceneTable
     virtual CHIP_ERROR SceneApplyEFS(const SceneTableEntry & scene) = 0;
 
     // Fabrics
+
+    /**
+     * @brief Removes all scenes associated with a fabric index and the stored FabricSceneData that maps them
+     * @param fabric_index Fabric index to remove
+     * @return CHIP_ERROR, CHIP_NO_ERROR if successful or if the Fabric was not found, specific CHIP_ERROR otherwise
+     * @note This function is meant to be used after a fabric is removed from the device, the implementation MUST ensure that it
+     * won't interact with the actual fabric table as it will be removed beforehand.
+     */
     virtual CHIP_ERROR RemoveFabric(FabricIndex fabric_index) = 0;
     virtual CHIP_ERROR RemoveEndpoint()                       = 0;
 

src/app/clusters/scenes-server/scenes-server.cpp

@@ -104,6 +104,19 @@ ScenesServer & ScenesServer::Instance()
 }
 void ReportAttributeOnAllEndpoints(AttributeId attribute) {}
 
+class ScenesClusterFabricDelegate : public chip::FabricTable::Delegate
+{
+    void OnFabricRemoved(const FabricTable & fabricTable, FabricIndex fabricIndex) override
+    {
+        SceneTable * sceneTable = scenes::GetSceneTableImpl();
+        VerifyOrReturn(nullptr != sceneTable);
+        // The implementation of SceneTable::RemoveFabric() must not call back into the FabricTable
+        sceneTable->RemoveFabric(fabricIndex);
+    }
+};
+
+static ScenesClusterFabricDelegate gFabricDelegate;
+
 CHIP_ERROR ScenesServer::Init()
 {
     // Prevents re-initializing
@@ -115,6 +128,7 @@ CHIP_ERROR ScenesServer::Init()
 
     SceneTable * sceneTable = scenes::GetSceneTableImpl();
     ReturnErrorOnFailure(sceneTable->Init(&chip::Server::GetInstance().GetPersistentStorage()));
+    ReturnErrorOnFailure(chip::Server::GetInstance().GetFabricTable().AddFabricDelegate(&gFabricDelegate));
 
     mIsInitialized = true;
     return CHIP_NO_ERROR;