[ICD] Add OnPeerTypeChange for dynamic ICD

src/app/InteractionModelEngine.cpp

@@ -995,6 +995,22 @@ void InteractionModelEngine::OnActiveModeNotification(ScopedNodeId aPeer)
     }
 }
 
+void InteractionModelEngine::OnPeerTypeChange(ScopedNodeId aPeer, ReadClient::PeerType aType)
+{
+    // TODO: Follow up to use a iterator function to avoid copy/paste here.
+    for (ReadClient * pListItem = mpActiveReadClientList; pListItem != nullptr;)
+    {
+        // It is possible that pListItem is destroyed by the app in OnPeerTypeChange.
+        // Get the next item before invoking `OnPeerTypeChange`.
+        auto pNextItem = pListItem->GetNextClient();
+        if (ScopedNodeId(pListItem->GetPeerNodeId(), pListItem->GetFabricIndex()) == aPeer)
+        {
+            pListItem->OnPeerTypeChange(aType);
+        }
+        pListItem = pNextItem;
+    }
+}
+
 void InteractionModelEngine::AddReadClient(ReadClient * apReadClient)
 {
     apReadClient->SetNextClient(mpActiveReadClientList);

src/app/InteractionModelEngine.h

@@ -247,6 +247,14 @@ class InteractionModelEngine : public Messaging::UnsolicitedMessageHandler,
      */
     void OnActiveModeNotification(ScopedNodeId aPeer);
 
+    /**
+     *  Used to notify whether a peer becomes LIT ICD or vice versa.
+     *
+     *  The read client will call this function when it found any updates of the OperationMode attribute from ICD management
+     * cluster. The application don't need to call this function usually.
+     */
+    void OnPeerTypeChange(ScopedNodeId aPeer, ReadClient::PeerType aType);
+
     /**
      * Add a read client to the internally tracked list of weak references. This list is used to
      * correctly dispatch unsolicited reports to the right matching handler by subscription ID.

src/app/ReadClient.cpp

@@ -34,6 +34,10 @@
 #include <messaging/ReliableMessageProtocolConfig.h>
 #include <platform/LockTracker.h>
 
+#include <app-common/zap-generated/cluster-objects.h>
+#include <app-common/zap-generated/ids/Attributes.h>
+#include <app-common/zap-generated/ids/Clusters.h>
+
 namespace chip {
 namespace app {
 
@@ -451,6 +455,19 @@ void ReadClient::OnActiveModeNotification()
     TriggerResubscriptionForLivenessTimeout(CHIP_ERROR_TIMEOUT);
 }
 
+void ReadClient::OnPeerTypeChange(PeerType aType)
+{
+    VerifyOrDie(mpImEngine->InActiveReadClientList(this));
+
+    mIsPeerLIT = (aType == PeerType::kLITICD);
+
+    // If the peer is no longer LIT, try to wake up the subscription and do resubsribe when necessary.
+    if (!mIsPeerLIT)
+    {
+        OnActiveModeNotification();
+    }
+}
+
 CHIP_ERROR ReadClient::OnMessageReceived(Messaging::ExchangeContext * apExchangeContext, const PayloadHeader & aPayloadHeader,
                                          System::PacketBufferHandle && aPayload)
 {
@@ -663,6 +680,32 @@ void ReadClient::OnResponseTimeout(Messaging::ExchangeContext * apExchangeContex
     Close(CHIP_ERROR_TIMEOUT);
 }
 
+CHIP_ERROR ReadClient::ReadICDOperationModeFromAttributeDataIB(const TLV::TLVReader & aReader, PeerType & aType)
+{
+    TLV::TLVReader reader;
+    reader.Init(aReader);
+
+    Clusters::IcdManagement::Attributes::OperatingMode::TypeInfo::DecodableType operatingMode;
+
+    CHIP_ERROR err = DataModel::Decode(reader, operatingMode);
+    ReturnErrorOnFailure(err);
+
+    switch (operatingMode)
+    {
+    case Clusters::IcdManagement::OperatingModeEnum::kSit:
+        aType = PeerType::kNormal;
+        break;
+    case Clusters::IcdManagement::OperatingModeEnum::kLit:
+        aType = PeerType::kLITICD;
+        break;
+    default:
+        err = CHIP_ERROR_INVALID_ARGUMENT;
+        break;
+    }
+
+    return err;
+}
+
 CHIP_ERROR ReadClient::ProcessAttributePath(AttributePathIB::Parser & aAttributePathParser,
                                             ConcreteDataAttributePath & aAttributePath)
 {
@@ -757,6 +800,24 @@ CHIP_ERROR ReadClient::ProcessAttributeReportIBs(TLV::TLVReader & aAttributeRepo
                 attributePath.mListOp = ConcreteDataAttributePath::ListOperation::ReplaceAll;
             }
 
+            if (attributePath ==
+                ConcreteDataAttributePath(kRootEndpointId, Clusters::IcdManagement::Id,
+                                          Clusters::IcdManagement::Attributes::OperatingMode::Id))
+            {
+                PeerType peerType;
+                if (CHIP_NO_ERROR == ReadICDOperationModeFromAttributeDataIB(dataReader, peerType))
+                {
+                    // Since we are in the middle of parsing the attribute data, it is safe to call `OnPeerTypeChange`
+                    // As it will only update the LIT / SIT bit for us without triggerring resubscription on this read client.
+                    InteractionModelEngine::GetInstance()->OnPeerTypeChange(mPeer, peerType);
+                }
+                else
+                {
+                    ChipLogError(DataManagement, "Failed to get ICD state from attribute data with error'%" CHIP_ERROR_FORMAT "'",
+                                 err.Format());
+                }
+            }
+
             NoteReportingData();
             mpCallback.OnAttributeData(attributePath, &dataReader, statusIB);
         }

src/app/ReadClient.h

@@ -292,6 +292,12 @@ class ReadClient : public Messaging::ExchangeDelegate
         Subscribe,
     };
 
+    enum class PeerType : uint8_t
+    {
+        kNormal,
+        kLITICD,
+    };
+
     /**
      *
      *  Constructor.
@@ -524,6 +530,15 @@ class ReadClient : public Messaging::ExchangeDelegate
                                  System::PacketBufferHandle && aPayload) override;
     void OnResponseTimeout(Messaging::ExchangeContext * apExchangeContext) override;
 
+    /**
+     *  Updates the type (LIT ICD or not) of the peer.
+     *
+     *  When the subscription is active, this function will just set the flag. When the subscription is an InactiveICDSubscription,
+     * Setting the peer type to SIT or normal devices will also trigger resubscription.
+     *
+     */
+    void OnPeerTypeChange(PeerType aType);
+
     /**
      *  Check if current read client is being used
      *
@@ -544,6 +559,7 @@ class ReadClient : public Messaging::ExchangeDelegate
     CHIP_ERROR BuildDataVersionFilterList(DataVersionFilterIBs::Builder & aDataVersionFilterIBsBuilder,
                                           const Span<AttributePathParams> & aAttributePaths,
                                           const Span<DataVersionFilter> & aDataVersionFilters, bool & aEncodedDataVersionList);
+    CHIP_ERROR ReadICDOperationModeFromAttributeDataIB(const TLV::TLVReader & aReader, PeerType & aType);
     CHIP_ERROR ProcessAttributeReportIBs(TLV::TLVReader & aAttributeDataIBsReader);
     CHIP_ERROR ProcessEventReportIBs(TLV::TLVReader & aEventReportIBsReader);