/*
 *
 *    Copyright (c) 2020-2021 Project CHIP Authors
 *    Copyright (c) 2013-2017 Nest Labs, Inc.
 *    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.
 */

/**
 *    @file
 *      Implementation of CHIP Device Controller, a common class
 *      that implements discovery, pairing and provisioning of CHIP
 *      devices.
 *
 */

#ifndef __STDC_LIMIT_MACROS
#define __STDC_LIMIT_MACROS
#endif
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif

// module header, comes first
#include <controller/CHIPDeviceController.h>

#include <app-common/zap-generated/enums.h>
#include <controller-clusters/zap-generated/CHIPClusters.h>

#if CONFIG_DEVICE_LAYER
#include <platform/CHIPDeviceLayer.h>
#include <platform/ConfigurationManager.h>
#endif

#include <app/InteractionModelEngine.h>
#include <app/util/DataModelHandler.h>
#include <app/util/error-mapping.h>
#include <credentials/CHIPCert.h>
#include <credentials/DeviceAttestationCredsProvider.h>
#include <crypto/CHIPCryptoPAL.h>
#include <lib/core/CHIPCore.h>
#include <lib/core/CHIPEncoding.h>
#include <lib/core/CHIPSafeCasts.h>
#include <lib/core/NodeId.h>
#include <lib/support/Base64.h>
#include <lib/support/CHIPArgParser.hpp>
#include <lib/support/CHIPMem.h>
#include <lib/support/CodeUtils.h>
#include <lib/support/ErrorStr.h>
#include <lib/support/PersistentStorageMacros.h>
#include <lib/support/SafeInt.h>
#include <lib/support/ScopedBuffer.h>
#include <lib/support/TimeUtils.h>
#include <lib/support/logging/CHIPLogging.h>
#include <messaging/ExchangeContext.h>
#include <protocols/secure_channel/MessageCounterManager.h>
#include <setup_payload/ManualSetupPayloadGenerator.h>
#include <setup_payload/QRCodeSetupPayloadGenerator.h>
#include <setup_payload/QRCodeSetupPayloadParser.h>

#if CONFIG_NETWORK_LAYER_BLE
#include <ble/BleLayer.h>
#include <transport/raw/BLE.h>
#endif

#include <app/util/af-enums.h>

#include <errno.h>
#include <inttypes.h>
#include <memory>
#include <stdint.h>
#include <stdlib.h>
#include <time.h>

using namespace chip::Inet;
using namespace chip::System;
using namespace chip::Transport;
using namespace chip::Credentials;

// For some applications those does not implement IMDelegate, the DeviceControllerInteractionModelDelegate will dispatch the
// response to IMDefaultResponseCallback CHIPClientCallbacks, for the applications those implemented IMDelegate, this function will
// not be used.
bool __attribute__((weak)) IMDefaultResponseCallback(const chip::app::Command * commandObj, EmberAfStatus status)
{
    return false;
}

namespace chip {
namespace Controller {

using namespace chip::Encoding;
#if CHIP_DEVICE_CONFIG_ENABLE_COMMISSIONER_DISCOVERY
using namespace chip::Protocols::UserDirectedCommissioning;
#endif // CHIP_DEVICE_CONFIG_ENABLE_COMMISSIONER_DISCOVERY

constexpr uint32_t kSessionEstablishmentTimeout = 30 * kMillisecondsPerSecond;

DeviceController::DeviceController()
{
    mState                    = State::NotInitialized;
    mStorageDelegate          = nullptr;
    mPairedDevicesInitialized = false;
}

CHIP_ERROR DeviceController::Init(ControllerInitParams params)
{
    VerifyOrReturnError(mState == State::NotInitialized, CHIP_ERROR_INCORRECT_STATE);
    VerifyOrReturnError(params.systemState != nullptr, CHIP_ERROR_INVALID_ARGUMENT);

    VerifyOrReturnError(params.systemState->SystemLayer() != nullptr, CHIP_ERROR_INVALID_ARGUMENT);
    VerifyOrReturnError(params.systemState->InetLayer() != nullptr, CHIP_ERROR_INVALID_ARGUMENT);

    mStorageDelegate = params.storageDelegate;
#if CONFIG_NETWORK_LAYER_BLE
    VerifyOrReturnError(params.systemState->BleLayer() != nullptr, CHIP_ERROR_INVALID_ARGUMENT);
#endif

    VerifyOrReturnError(params.systemState->TransportMgr() != nullptr, CHIP_ERROR_INVALID_ARGUMENT);

    // TODO Exchange Mgr needs to be able to track multiple delegates. Delegate API should be able to query for the right delegate
    // to handle events.
    ReturnErrorOnFailure(
        params.systemState->ExchangeMgr()->RegisterUnsolicitedMessageHandlerForProtocol(Protocols::TempZCL::Id, this));
    params.systemState->ExchangeMgr()->SetDelegate(this);

#if CHIP_DEVICE_CONFIG_ENABLE_DNSSD
    Dnssd::Resolver::Instance().Init(params.systemState->InetLayer());
    Dnssd::Resolver::Instance().SetResolverDelegate(this);
    RegisterDeviceAddressUpdateDelegate(params.deviceAddressUpdateDelegate);
    RegisterDeviceDiscoveryDelegate(params.deviceDiscoveryDelegate);
#endif // CHIP_DEVICE_CONFIG_ENABLE_DNSSD

    InitDataModelHandler(params.systemState->ExchangeMgr());

    VerifyOrReturnError(params.operationalCredentialsDelegate != nullptr, CHIP_ERROR_INVALID_ARGUMENT);
    mOperationalCredentialsDelegate = params.operationalCredentialsDelegate;

    ReturnErrorOnFailure(ProcessControllerNOCChain(params));

    mSystemState = params.systemState->Retain();
    mState       = State::Initialized;
    ReleaseAllDevices();
    return CHIP_NO_ERROR;
}

CHIP_ERROR DeviceController::ProcessControllerNOCChain(const ControllerInitParams & params)
{
    FabricInfo newFabric;

    ReturnErrorCodeIf(params.ephemeralKeypair == nullptr, CHIP_ERROR_INVALID_ARGUMENT);
    newFabric.SetEphemeralKey(params.ephemeralKeypair);

    constexpr uint32_t chipCertAllocatedLen = kMaxCHIPCertLength;
    chip::Platform::ScopedMemoryBuffer<uint8_t> chipCert;

    ReturnErrorCodeIf(!chipCert.Alloc(chipCertAllocatedLen), CHIP_ERROR_NO_MEMORY);
    MutableByteSpan chipCertSpan(chipCert.Get(), chipCertAllocatedLen);

    ReturnErrorOnFailure(ConvertX509CertToChipCert(params.controllerRCAC, chipCertSpan));
    ReturnErrorOnFailure(newFabric.SetRootCert(chipCertSpan));

    if (params.controllerICAC.empty())
    {
        ChipLogProgress(Controller, "Intermediate CA is not needed");
    }
    else
    {
        chipCertSpan = MutableByteSpan(chipCert.Get(), chipCertAllocatedLen);

        ReturnErrorOnFailure(ConvertX509CertToChipCert(params.controllerICAC, chipCertSpan));
        ReturnErrorOnFailure(newFabric.SetICACert(chipCertSpan));
    }

    chipCertSpan = MutableByteSpan(chipCert.Get(), chipCertAllocatedLen);

    ReturnErrorOnFailure(ConvertX509CertToChipCert(params.controllerNOC, chipCertSpan));
    ReturnErrorOnFailure(newFabric.SetNOCCert(chipCertSpan));
    newFabric.SetVendorId(params.controllerVendorId);

    FabricInfo * fabric = params.systemState->Fabrics()->FindFabricWithIndex(mFabricIndex);
    ReturnErrorCodeIf(fabric == nullptr, CHIP_ERROR_INCORRECT_STATE);

    ReturnErrorOnFailure(fabric->SetFabricInfo(newFabric));
    mLocalId  = fabric->GetPeerId();
    mVendorId = fabric->GetVendorId();

    mFabricId = fabric->GetFabricId();

    ChipLogProgress(Controller, "Joined the fabric at index %d. Compressed fabric ID is: 0x" ChipLogFormatX64, mFabricIndex,
                    ChipLogValueX64(GetCompressedFabricId()));

    return CHIP_NO_ERROR;
}

CHIP_ERROR DeviceController::Shutdown()
{
    VerifyOrReturnError(mState == State::Initialized, CHIP_ERROR_INCORRECT_STATE);

    ChipLogDetail(Controller, "Shutting down the controller");

    for (uint32_t i = 0; i < kNumMaxActiveDevices; i++)
    {
        mActiveDevices[i].Reset();
    }

    mState = State::NotInitialized;

#if CHIP_DEVICE_CONFIG_ENABLE_DNSSD
    Dnssd::Resolver::Instance().Shutdown();
#endif // CHIP_DEVICE_CONFIG_ENABLE_DNSSD

    mStorageDelegate = nullptr;

    ReleaseAllDevices();

    mSystemState->Fabrics()->ReleaseFabricIndex(mFabricIndex);
    mSystemState->Release();
    mSystemState = nullptr;

#if CHIP_DEVICE_CONFIG_ENABLE_DNSSD
    Dnssd::Resolver::Instance().SetResolverDelegate(nullptr);
    mDeviceAddressUpdateDelegate = nullptr;
    mDeviceDiscoveryDelegate     = nullptr;
#endif // CHIP_DEVICE_CONFIG_ENABLE_DNSSD

    return CHIP_NO_ERROR;
}

CHIP_ERROR DeviceController::GetDevice(NodeId deviceId, Device ** out_device)
{
    CHIP_ERROR err  = CHIP_NO_ERROR;
    Device * device = nullptr;
    uint16_t index  = 0;

    VerifyOrExit(out_device != nullptr, err = CHIP_ERROR_INVALID_ARGUMENT);
    index = FindDeviceIndex(deviceId);

    if (index < kNumMaxActiveDevices)
    {
        device = &mActiveDevices[index];
    }
    else
    {
        err = InitializePairedDeviceList();
        SuccessOrExit(err);

        VerifyOrExit(mPairedDevices.Contains(deviceId), err = CHIP_ERROR_NOT_CONNECTED);

        index = GetInactiveDeviceIndex();
        VerifyOrExit(index < kNumMaxActiveDevices, err = CHIP_ERROR_NO_MEMORY);
        device = &mActiveDevices[index];

        {
            SerializedDevice deviceInfo;
            uint16_t size = sizeof(deviceInfo.inner);

            PERSISTENT_KEY_OP(deviceId, kPairedDeviceKeyPrefix, key,
                              err = mStorageDelegate->SyncGetKeyValue(key, deviceInfo.inner, size));
            SuccessOrExit(err);
            VerifyOrExit(size <= sizeof(deviceInfo.inner), err = CHIP_ERROR_INVALID_DEVICE_DESCRIPTOR);

            err = device->Deserialize(deviceInfo);
            VerifyOrExit(err == CHIP_NO_ERROR, ReleaseDevice(device));

            device->Init(GetControllerDeviceInitParams(), mFabricIndex);
        }
    }

    *out_device = device;

exit:
    if (err != CHIP_NO_ERROR && device != nullptr)
    {
        ReleaseDevice(device);
    }
    return err;
}

bool DeviceController::DoesDevicePairingExist(const PeerId & deviceId)
{
    if (InitializePairedDeviceList() == CHIP_NO_ERROR)
    {
        return mPairedDevices.Contains(deviceId.GetNodeId());
    }

    return false;
}

CHIP_ERROR DeviceController::GetConnectedDevice(NodeId deviceId, Callback::Callback<OnDeviceConnected> * onConnection,
                                                Callback::Callback<OnDeviceConnectionFailure> * onFailure)
{
    CHIP_ERROR err  = CHIP_NO_ERROR;
    Device * device = nullptr;

    err = GetDevice(deviceId, &device);
    SuccessOrExit(err);

    if (device->IsSecureConnected())
    {
        onConnection->mCall(onConnection->mContext, device);
        return CHIP_NO_ERROR;
    }

    err = device->EstablishConnectivity(onConnection, onFailure);
    SuccessOrExit(err);

exit:
    if (err != CHIP_NO_ERROR)
    {
        onFailure->mCall(onFailure->mContext, deviceId, err);
    }

    return err;
}

CHIP_ERROR DeviceController::UpdateDevice(NodeId deviceId)
{
#if CHIP_DEVICE_CONFIG_ENABLE_DNSSD
    return Dnssd::Resolver::Instance().ResolveNodeId(PeerId().SetCompressedFabricId(GetCompressedFabricId()).SetNodeId(deviceId),
                                                     chip::Inet::IPAddressType::kAny);
#else
    return CHIP_ERROR_UNSUPPORTED_CHIP_FEATURE;
#endif // CHIP_DEVICE_CONFIG_ENABLE_DNSSD
}

void DeviceController::PersistDevice(Device * device)
{
    if (mState == State::Initialized)
    {
        device->Persist();
    }
    else
    {
        ChipLogError(Controller, "Failed to persist device. Controller not initialized.");
    }
}

CHIP_ERROR DeviceController::OnMessageReceived(Messaging::ExchangeContext * ec, const PayloadHeader & payloadHeader,
                                               System::PacketBufferHandle && msgBuf)
{
    uint16_t index;

    VerifyOrExit(mState == State::Initialized, ChipLogError(Controller, "OnMessageReceived was called in incorrect state"));
    VerifyOrExit(ec != nullptr, ChipLogError(Controller, "OnMessageReceived was called with null exchange"));

    index = FindDeviceIndex(ec->GetSessionHandle().GetPeerNodeId());
    VerifyOrExit(index < kNumMaxActiveDevices, ChipLogError(Controller, "OnMessageReceived was called for unknown device object"));

    mActiveDevices[index].OnMessageReceived(ec, payloadHeader, std::move(msgBuf));

exit:
    return CHIP_NO_ERROR;
}

void DeviceController::OnResponseTimeout(Messaging::ExchangeContext * ec)
{
    ChipLogProgress(Controller, "Time out! failed to receive response from Exchange: " ChipLogFormatExchange,
                    ChipLogValueExchange(ec));
}

void DeviceController::OnNewConnection(SessionHandle session, Messaging::ExchangeManager * mgr)
{
    VerifyOrReturn(mState == State::Initialized, ChipLogError(Controller, "OnNewConnection was called in incorrect state"));

    uint16_t index = FindDeviceIndex(mgr->GetSessionManager()->GetSecureSession(session)->GetPeerNodeId());
    VerifyOrReturn(index < kNumMaxActiveDevices,
                   ChipLogDetail(Controller, "OnNewConnection was called for unknown device, ignoring it."));

    mActiveDevices[index].OnNewConnection(session);
}

void DeviceController::OnConnectionExpired(SessionHandle session, Messaging::ExchangeManager * mgr)
{
    VerifyOrReturn(mState == State::Initialized, ChipLogError(Controller, "OnConnectionExpired was called in incorrect state"));

    uint16_t index = FindDeviceIndex(session);
    VerifyOrReturn(index < kNumMaxActiveDevices,
                   ChipLogDetail(Controller, "OnConnectionExpired was called for unknown device, ignoring it."));

    mActiveDevices[index].OnConnectionExpired(session);
}

uint16_t DeviceController::GetInactiveDeviceIndex()
{
    uint16_t i = 0;
    while (i < kNumMaxActiveDevices && mActiveDevices[i].IsActive())
        i++;
    if (i < kNumMaxActiveDevices)
    {
        mActiveDevices[i].SetActive(true);
    }

    return i;
}

void DeviceController::ReleaseDevice(Device * device)
{
    device->Reset();
}

void DeviceController::ReleaseDevice(uint16_t index)
{
    if (index < kNumMaxActiveDevices)
    {
        ReleaseDevice(&mActiveDevices[index]);
    }
}

void DeviceController::ReleaseDeviceById(NodeId remoteDeviceId)
{
    for (uint16_t i = 0; i < kNumMaxActiveDevices; i++)
    {
        if (mActiveDevices[i].GetDeviceId() == remoteDeviceId)
        {
            ReleaseDevice(&mActiveDevices[i]);
        }
    }
}

void DeviceController::ReleaseAllDevices()
{
    for (uint16_t i = 0; i < kNumMaxActiveDevices; i++)
    {
        ReleaseDevice(&mActiveDevices[i]);
    }
}

uint16_t DeviceController::FindDeviceIndex(SessionHandle session)
{
    uint16_t i = 0;
    while (i < kNumMaxActiveDevices)
    {
        if (mActiveDevices[i].IsActive() && mActiveDevices[i].IsSecureConnected() && mActiveDevices[i].MatchesSession(session))
        {
            return i;
        }
        i++;
    }
    return i;
}

uint16_t DeviceController::FindDeviceIndex(NodeId id)
{
    uint16_t i = 0;
    while (i < kNumMaxActiveDevices)
    {
        if (mActiveDevices[i].IsActive() && mActiveDevices[i].GetDeviceId() == id)
        {
            return i;
        }
        i++;
    }
    return i;
}

CHIP_ERROR DeviceController::InitializePairedDeviceList()
{
    CHIP_ERROR err   = CHIP_NO_ERROR;
    uint8_t * buffer = nullptr;

    VerifyOrExit(mStorageDelegate != nullptr, err = CHIP_ERROR_INCORRECT_STATE);

    if (!mPairedDevicesInitialized)
    {
        constexpr uint16_t max_size = sizeof(uint64_t) * kNumMaxPairedDevices;
        buffer                      = static_cast<uint8_t *>(chip::Platform::MemoryCalloc(max_size, 1));
        uint16_t size               = max_size;

        VerifyOrExit(buffer != nullptr, err = CHIP_ERROR_INVALID_ARGUMENT);

        CHIP_ERROR lookupError = CHIP_NO_ERROR;
        PERSISTENT_KEY_OP(static_cast<uint64_t>(0), kPairedDeviceListKeyPrefix, key,
                          lookupError = mStorageDelegate->SyncGetKeyValue(key, buffer, size));

        // It's ok to not have an entry for the Paired Device list. We treat it the same as having an empty list.
        if (lookupError != CHIP_ERROR_KEY_NOT_FOUND)
        {
            VerifyOrExit(size <= max_size, err = CHIP_ERROR_INVALID_DEVICE_DESCRIPTOR);
            err = SetPairedDeviceList(ByteSpan(buffer, size));
            SuccessOrExit(err);
        }
    }

exit:
    if (buffer != nullptr)
    {
        chip::Platform::MemoryFree(buffer);
    }
    if (err != CHIP_NO_ERROR)
    {
        ChipLogError(Controller, "Failed to initialize the device list with error: %" CHIP_ERROR_FORMAT, err.Format());
    }

    return err;
}

CHIP_ERROR DeviceController::SetPairedDeviceList(ByteSpan serialized)
{
    CHIP_ERROR err = mPairedDevices.Deserialize(serialized);

    if (err != CHIP_NO_ERROR)
    {
        ChipLogError(Controller, "Failed to recreate the device list with buffer %.*s\n", static_cast<int>(serialized.size()),
                     serialized.data());
    }
    else
    {
        mPairedDevicesInitialized = true;
    }

    return err;
}

void DeviceController::PersistNextKeyId()
{
    if (mStorageDelegate != nullptr && mState == State::Initialized)
    {
        uint16_t nextKeyID = mIDAllocator.Peek();
        mStorageDelegate->SyncSetKeyValue(kNextAvailableKeyID, &nextKeyID, sizeof(nextKeyID));
    }
}

CHIP_ERROR DeviceController::GetPeerAddressAndPort(PeerId peerId, Inet::IPAddress & addr, uint16_t & port)
{
    VerifyOrReturnError(GetCompressedFabricId() == peerId.GetCompressedFabricId(), CHIP_ERROR_INVALID_ARGUMENT);
    uint16_t index = FindDeviceIndex(peerId.GetNodeId());
    VerifyOrReturnError(index < kNumMaxActiveDevices, CHIP_ERROR_NOT_CONNECTED);
    VerifyOrReturnError(mActiveDevices[index].GetAddress(addr, port), CHIP_ERROR_NOT_CONNECTED);
    return CHIP_NO_ERROR;
}

#if CHIP_DEVICE_CONFIG_ENABLE_DNSSD
void DeviceController::OnNodeIdResolved(const chip::Dnssd::ResolvedNodeData & nodeData)
{
    CHIP_ERROR err  = CHIP_NO_ERROR;
    Device * device = nullptr;
    Inet::InterfaceId interfaceId;

    err = GetDevice(nodeData.mPeerId.GetNodeId(), &device);
    SuccessOrExit(err);

    // Only use the mDNS resolution's InterfaceID for addresses that are IPv6 LLA.
    // For all other addresses, we should rely on the device's routing table to route messages sent.
    // Forcing messages down an InterfaceId might fail. For example, in bridged networks like Thread,
    // mDNS advertisements are not usually received on the same interface the peer is reachable on.
    if (nodeData.mAddress.IsIPv6LinkLocal())
    {
        interfaceId = nodeData.mInterfaceId;
    }

    err = device->UpdateAddress(Transport::PeerAddress::UDP(nodeData.mAddress, nodeData.mPort, interfaceId));
    SuccessOrExit(err);

    PersistDevice(device);

exit:

    if (mDeviceAddressUpdateDelegate != nullptr)
    {
        mDeviceAddressUpdateDelegate->OnAddressUpdateComplete(nodeData.mPeerId.GetNodeId(), err);
    }
    return;
};

void DeviceController::OnNodeIdResolutionFailed(const chip::PeerId & peer, CHIP_ERROR error)
{
    ChipLogError(Controller, "Error resolving node id: %s", ErrorStr(error));

    if (mDeviceAddressUpdateDelegate != nullptr)
    {
        mDeviceAddressUpdateDelegate->OnAddressUpdateComplete(peer.GetNodeId(), error);
    }
};

#endif // CHIP_DEVICE_CONFIG_ENABLE_DNSSD

ControllerDeviceInitParams DeviceController::GetControllerDeviceInitParams()
{
    return ControllerDeviceInitParams{
        .transportMgr    = mSystemState->TransportMgr(),
        .sessionManager  = mSystemState->SessionMgr(),
        .exchangeMgr     = mSystemState->ExchangeMgr(),
        .inetLayer       = mSystemState->InetLayer(),
        .storageDelegate = mStorageDelegate,
        .idAllocator     = &mIDAllocator,
        .fabricsTable    = mSystemState->Fabrics(),
        .imDelegate      = mSystemState->IMDelegate(),
    };
}

DeviceCommissioner::DeviceCommissioner() :
    mSuccess(BasicSuccess, this), mFailure(BasicFailure, this), mCertificateChainResponseCallback(OnCertificateChainResponse, this),
    mAttestationResponseCallback(OnAttestationResponse, this), mOpCSRResponseCallback(OnOperationalCertificateSigningRequest, this),
    mNOCResponseCallback(OnOperationalCertificateAddResponse, this), mRootCertResponseCallback(OnRootCertSuccessResponse, this),
    mOnCertificateChainFailureCallback(OnCertificateChainFailureResponse, this),
    mOnAttestationFailureCallback(OnAttestationFailureResponse, this), mOnCSRFailureCallback(OnCSRFailureResponse, this),
    mOnCertFailureCallback(OnAddNOCFailureResponse, this), mOnRootCertFailureCallback(OnRootCertFailureResponse, this),
    mOnDeviceConnectedCallback(OnDeviceConnectedFn, this), mOnDeviceConnectionFailureCallback(OnDeviceConnectionFailureFn, this),
    mDeviceNOCChainCallback(OnDeviceNOCChainGeneration, this), mSetUpCodePairer(this)
{
    mPairingDelegate      = nullptr;
    mDeviceBeingPaired    = kNumMaxActiveDevices;
    mPairedDevicesUpdated = false;
}

CHIP_ERROR DeviceCommissioner::Init(CommissionerInitParams params)
{
    ReturnErrorOnFailure(DeviceController::Init(params));

    uint16_t nextKeyID = 0;
    uint16_t size      = sizeof(nextKeyID);
    CHIP_ERROR error   = mStorageDelegate->SyncGetKeyValue(kNextAvailableKeyID, &nextKeyID, size);
    if ((error != CHIP_NO_ERROR) || (size != sizeof(nextKeyID)))
    {
        nextKeyID = 0;
    }
    ReturnErrorOnFailure(mIDAllocator.ReserveUpTo(nextKeyID));
    mPairingDelegate = params.pairingDelegate;

#if CHIP_DEVICE_CONFIG_ENABLE_COMMISSIONER_DISCOVERY // make this commissioner discoverable
    mUdcTransportMgr = chip::Platform::New<DeviceIPTransportMgr>();
    ReturnErrorOnFailure(mUdcTransportMgr->Init(Transport::UdpListenParameters(mSystemState->InetLayer())
                                                    .SetAddressType(Inet::IPAddressType::kIPv6)
                                                    .SetListenPort((uint16_t)(mUdcListenPort))
#if INET_CONFIG_ENABLE_IPV4
                                                    ,
                                                Transport::UdpListenParameters(mSystemState->InetLayer())
                                                    .SetAddressType(Inet::IPAddressType::kIPv4)
                                                    .SetListenPort((uint16_t)(mUdcListenPort))
#endif // INET_CONFIG_ENABLE_IPV4
                                                    ));

    mUdcServer = chip::Platform::New<UserDirectedCommissioningServer>();
    mUdcTransportMgr->SetSessionManager(mUdcServer);

    mUdcServer->SetInstanceNameResolver(this);
    mUdcServer->SetUserConfirmationProvider(this);
#endif // CHIP_DEVICE_CONFIG_ENABLE_COMMISSIONER_DISCOVERY

#if CONFIG_NETWORK_LAYER_BLE
    mSetUpCodePairer.SetBleLayer(mSystemState->BleLayer());
#endif // CONFIG_NETWORK_LAYER_BLE
    return CHIP_NO_ERROR;
}

CHIP_ERROR DeviceCommissioner::Shutdown()
{
    VerifyOrReturnError(mState == State::Initialized, CHIP_ERROR_INCORRECT_STATE);

    ChipLogDetail(Controller, "Shutting down the commissioner");

    mPairingSession.Clear();

    PersistDeviceList();

#if CHIP_DEVICE_CONFIG_ENABLE_COMMISSIONER_DISCOVERY // make this commissioner discoverable
    if (mUdcTransportMgr != nullptr)
    {
        chip::Platform::Delete(mUdcTransportMgr);
        mUdcTransportMgr = nullptr;
    }
    if (mUdcServer != nullptr)
    {
        mUdcServer->SetInstanceNameResolver(nullptr);
        mUdcServer->SetUserConfirmationProvider(nullptr);
        chip::Platform::Delete(mUdcServer);
        mUdcServer = nullptr;
    }
#endif // CHIP_DEVICE_CONFIG_ENABLE_COMMISSIONER_DISCOVERY

    DeviceController::Shutdown();
    return CHIP_NO_ERROR;
}

CHIP_ERROR DeviceCommissioner::PairDevice(NodeId remoteDeviceId, const char * setUpCode)
{
    return mSetUpCodePairer.PairDevice(remoteDeviceId, setUpCode);
}

CHIP_ERROR DeviceCommissioner::PairDevice(NodeId remoteDeviceId, RendezvousParameters & params)
{
    CHIP_ERROR err                     = CHIP_NO_ERROR;
    Device * device                    = nullptr;
    Transport::PeerAddress peerAddress = Transport::PeerAddress::UDP(Inet::IPAddress::Any);

    Messaging::ExchangeContext * exchangeCtxt = nullptr;
    Optional<SessionHandle> session;

    uint16_t keyID = 0;

    FabricInfo * fabric = mSystemState->Fabrics()->FindFabricWithIndex(mFabricIndex);

    VerifyOrExit(IsOperationalNodeId(remoteDeviceId), err = CHIP_ERROR_INVALID_ARGUMENT);
    VerifyOrExit(mState == State::Initialized, err = CHIP_ERROR_INCORRECT_STATE);
    VerifyOrExit(mDeviceBeingPaired == kNumMaxActiveDevices, err = CHIP_ERROR_INCORRECT_STATE);
    VerifyOrExit(fabric != nullptr, err = CHIP_ERROR_INCORRECT_STATE);

    err = InitializePairedDeviceList();
    SuccessOrExit(err);

    // TODO: We need to specify the peer address for BLE transport in bindings.
    if (params.GetPeerAddress().GetTransportType() == Transport::Type::kBle ||
        params.GetPeerAddress().GetTransportType() == Transport::Type::kUndefined)
    {
#if CONFIG_NETWORK_LAYER_BLE
        if (!params.HasBleLayer())
        {
            params.SetPeerAddress(Transport::PeerAddress::BLE());
        }
        peerAddress = Transport::PeerAddress::BLE();
#endif // CONFIG_NETWORK_LAYER_BLE
    }
    else if (params.GetPeerAddress().GetTransportType() == Transport::Type::kTcp ||
             params.GetPeerAddress().GetTransportType() == Transport::Type::kUdp)
    {
        peerAddress = Transport::PeerAddress::UDP(params.GetPeerAddress().GetIPAddress(), params.GetPeerAddress().GetPort(),
                                                  params.GetPeerAddress().GetInterface());
    }

    mDeviceBeingPaired = GetInactiveDeviceIndex();
    VerifyOrExit(mDeviceBeingPaired < kNumMaxActiveDevices, err = CHIP_ERROR_NO_MEMORY);
    device = &mActiveDevices[mDeviceBeingPaired];

    // If the CSRNonce is passed in, using that else using a random one..
    if (params.HasCSRNonce())
    {
        ReturnErrorOnFailure(device->SetCSRNonce(params.GetCSRNonce().Value()));
    }
    else
    {
        uint8_t mCSRNonce[kOpCSRNonceLength];
        Crypto::DRBG_get_bytes(mCSRNonce, sizeof(mCSRNonce));
        ReturnErrorOnFailure(device->SetCSRNonce(ByteSpan(mCSRNonce)));
    }

    // If the AttestationNonce is passed in, using that else using a random one..
    if (params.HasAttestationNonce())
    {
        ReturnErrorOnFailure(device->SetAttestationNonce(params.GetAttestationNonce().Value()));
    }
    else
    {
        uint8_t mAttestationNonce[kAttestationNonceLength];
        Crypto::DRBG_get_bytes(mAttestationNonce, sizeof(mAttestationNonce));
        ReturnErrorOnFailure(device->SetAttestationNonce(ByteSpan(mAttestationNonce)));
    }

    mIsIPRendezvous = (params.GetPeerAddress().GetTransportType() != Transport::Type::kBle);

    err = mPairingSession.MessageDispatch().Init(mSystemState->SessionMgr());
    SuccessOrExit(err);

    device->Init(GetControllerDeviceInitParams(), remoteDeviceId, peerAddress, fabric->GetFabricIndex());

    mSystemState->SystemLayer()->StartTimer(chip::System::Clock::Milliseconds32(kSessionEstablishmentTimeout),
                                            OnSessionEstablishmentTimeoutCallback, this);
    if (params.GetPeerAddress().GetTransportType() != Transport::Type::kBle)
    {
        device->SetAddress(params.GetPeerAddress().GetIPAddress());
    }
#if CONFIG_NETWORK_LAYER_BLE
    else
    {
        if (params.HasConnectionObject())
        {
            SuccessOrExit(err = mSystemState->BleLayer()->NewBleConnectionByObject(params.GetConnectionObject()));
        }
        else if (params.HasDiscriminator())
        {
            SuccessOrExit(err = mSystemState->BleLayer()->NewBleConnectionByDiscriminator(params.GetDiscriminator()));
        }
        else
        {
            ExitNow(err = CHIP_ERROR_INVALID_ARGUMENT);
        }
    }
#endif
    session = mSystemState->SessionMgr()->CreateUnauthenticatedSession(params.GetPeerAddress());
    VerifyOrExit(session.HasValue(), err = CHIP_ERROR_NO_MEMORY);

    exchangeCtxt = mSystemState->ExchangeMgr()->NewContext(session.Value(), &mPairingSession);
    VerifyOrExit(exchangeCtxt != nullptr, err = CHIP_ERROR_INTERNAL);

    err = mIDAllocator.Allocate(keyID);
    SuccessOrExit(err);

    err = mPairingSession.Pair(params.GetPeerAddress(), params.GetSetupPINCode(), keyID, exchangeCtxt, this);
    // Immediately persist the updted mNextKeyID value
    // TODO maybe remove FreeRendezvousSession() since mNextKeyID is always persisted immediately
    PersistNextKeyId();

exit:
    if (err != CHIP_NO_ERROR)
    {
        // Delete the current rendezvous session only if a device is not currently being paired.
        if (mDeviceBeingPaired == kNumMaxActiveDevices)
        {
            FreeRendezvousSession();
        }

        if (device != nullptr)
        {
            ReleaseDevice(device);
            mDeviceBeingPaired = kNumMaxActiveDevices;
        }
    }

    return err;
}

CHIP_ERROR DeviceCommissioner::StopPairing(NodeId remoteDeviceId)
{
    VerifyOrReturnError(mState == State::Initialized, CHIP_ERROR_INCORRECT_STATE);
    VerifyOrReturnError(mDeviceBeingPaired < kNumMaxActiveDevices, CHIP_ERROR_INCORRECT_STATE);

    Device * device = &mActiveDevices[mDeviceBeingPaired];
    VerifyOrReturnError(device->GetDeviceId() == remoteDeviceId, CHIP_ERROR_INVALID_DEVICE_DESCRIPTOR);

    FreeRendezvousSession();

    ReleaseDevice(device);
    mDeviceBeingPaired = kNumMaxActiveDevices;
    return CHIP_NO_ERROR;
}

CHIP_ERROR DeviceCommissioner::UnpairDevice(NodeId remoteDeviceId)
{
    // TODO: Send unpairing message to the remote device.

    VerifyOrReturnError(mState == State::Initialized, CHIP_ERROR_INCORRECT_STATE);

    if (mDeviceBeingPaired < kNumMaxActiveDevices)
    {
        Device * device = &mActiveDevices[mDeviceBeingPaired];
        if (device->GetDeviceId() == remoteDeviceId)
        {
            FreeRendezvousSession();
        }
    }

    if (mStorageDelegate != nullptr)
    {
        PERSISTENT_KEY_OP(remoteDeviceId, kPairedDeviceKeyPrefix, key, mStorageDelegate->SyncDeleteKeyValue(key));
    }

    mPairedDevices.Remove(remoteDeviceId);
    mPairedDevicesUpdated = true;
    ReleaseDeviceById(remoteDeviceId);

    return CHIP_NO_ERROR;
}

CHIP_ERROR DeviceCommissioner::OperationalDiscoveryComplete(NodeId remoteDeviceId)
{
    ChipLogProgress(Controller, "OperationalDiscoveryComplete for device ID %" PRIu64, remoteDeviceId);
    VerifyOrReturnError(mState == State::Initialized, CHIP_ERROR_INCORRECT_STATE);

    Device * device = nullptr;
    ReturnErrorOnFailure(GetDevice(remoteDeviceId, &device));
    device->OperationalCertProvisioned();
    PersistDevice(device);
    PersistNextKeyId();

    return GetConnectedDevice(remoteDeviceId, &mOnDeviceConnectedCallback, &mOnDeviceConnectionFailureCallback);
}

CHIP_ERROR DeviceCommissioner::OpenCommissioningWindowWithCallback(NodeId deviceId, uint16_t timeout, uint16_t iteration,
                                                                   uint16_t discriminator, uint8_t option,
                                                                   Callback::Callback<OnOpenCommissioningWindow> * callback)
{
    ChipLogProgress(Controller, "OpenCommissioningWindow for device ID %" PRIu64, deviceId);
    VerifyOrReturnError(mState == State::Initialized, CHIP_ERROR_INCORRECT_STATE);

    Device * device = nullptr;
    ReturnErrorOnFailure(GetDevice(deviceId, &device));

    std::string QRCode;
    std::string manualPairingCode;
    SetupPayload payload;
    Device::CommissioningWindowOption commissioningWindowOption;
    ByteSpan salt(reinterpret_cast<const uint8_t *>(kSpake2pKeyExchangeSalt), strlen(kSpake2pKeyExchangeSalt));

    payload.discriminator = discriminator;

    switch (option)
    {
    case 0:
        commissioningWindowOption = Device::CommissioningWindowOption::kOriginalSetupCode;
        break;
    case 1:
        commissioningWindowOption = Device::CommissioningWindowOption::kTokenWithRandomPIN;
        break;
    case 2:
        commissioningWindowOption = Device::CommissioningWindowOption::kTokenWithProvidedPIN;
        break;
    default:
        ChipLogError(Controller, "Invalid Pairing Window option");
        return CHIP_ERROR_INVALID_ARGUMENT;
    }

    ReturnErrorOnFailure(device->OpenCommissioningWindow(timeout, iteration, commissioningWindowOption, salt, callback, payload));

    if (commissioningWindowOption != Device::CommissioningWindowOption::kOriginalSetupCode)
    {
        ReturnErrorOnFailure(ManualSetupPayloadGenerator(payload).payloadDecimalStringRepresentation(manualPairingCode));
        ChipLogProgress(Controller, "Manual pairing code: [%s]", manualPairingCode.c_str());

        ReturnErrorOnFailure(QRCodeSetupPayloadGenerator(payload).payloadBase38Representation(QRCode));
        ChipLogProgress(Controller, "SetupQRCode: [%s]", QRCode.c_str());
    }

    return CHIP_NO_ERROR;
}

void DeviceCommissioner::FreeRendezvousSession()
{
    PersistNextKeyId();
}

void DeviceCommissioner::RendezvousCleanup(CHIP_ERROR status)
{
    FreeRendezvousSession();

    // TODO: make mStorageDelegate mandatory once all controller applications implement the interface.
    if (mDeviceBeingPaired != kNumMaxActiveDevices && mStorageDelegate != nullptr)
    {
        // Let's release the device that's being paired.
        // If pairing was successful, its information is
        // already persisted. The application will use GetDevice()
        // method to get access to the device, which will fetch
        // the device information from the persistent storage.
        DeviceController::ReleaseDevice(mDeviceBeingPaired);
    }

    mDeviceBeingPaired = kNumMaxActiveDevices;

    if (mPairingDelegate != nullptr)
    {
        mPairingDelegate->OnPairingComplete(status);
    }
}

void DeviceCommissioner::OnSessionEstablishmentError(CHIP_ERROR err)
{
    mSystemState->SystemLayer()->CancelTimer(OnSessionEstablishmentTimeoutCallback, this);

    if (mPairingDelegate != nullptr)
    {
        mPairingDelegate->OnStatusUpdate(DevicePairingDelegate::SecurePairingFailed);
    }

    RendezvousCleanup(err);
}

void DeviceCommissioner::OnSessionEstablished()
{
    VerifyOrReturn(mDeviceBeingPaired < kNumMaxActiveDevices, OnSessionEstablishmentError(CHIP_ERROR_INVALID_DEVICE_DESCRIPTOR));

    Device * device = &mActiveDevices[mDeviceBeingPaired];

    // TODO: the session should know which peer we are trying to connect to when started
    mPairingSession.SetPeerNodeId(device->GetDeviceId());

    CHIP_ERROR err = mSystemState->SessionMgr()->NewPairing(
        Optional<Transport::PeerAddress>::Value(mPairingSession.GetPeerAddress()), mPairingSession.GetPeerNodeId(),
        &mPairingSession, CryptoContext::SessionRole::kInitiator, mFabricIndex);
    if (err != CHIP_NO_ERROR)
    {
        ChipLogError(Controller, "Failed in setting up secure channel: err %s", ErrorStr(err));
        OnSessionEstablishmentError(err);
        return;
    }

    ChipLogDetail(Controller, "Remote device completed SPAKE2+ handshake");

    // TODO: Add code to receive OpCSR from the device, and process the signing request
    // For IP rendezvous, this is sent as part of the state machine.
#if CONFIG_USE_CLUSTERS_FOR_IP_COMMISSIONING
    bool usingLegacyFlowWithImmediateStart = !mIsIPRendezvous;
#else
    bool usingLegacyFlowWithImmediateStart = true;
#endif

    if (usingLegacyFlowWithImmediateStart)
    {
        err = SendCertificateChainRequestCommand(device, CertificateType::kPAI);
        if (err != CHIP_NO_ERROR)
        {
            ChipLogError(Ble, "Failed in sending 'Certificate Chain request' command to the device: err %s", ErrorStr(err));
            OnSessionEstablishmentError(err);
            return;
        }
    }
    else
    {
        AdvanceCommissioningStage(CHIP_NO_ERROR);
    }
}

CHIP_ERROR DeviceCommissioner::SendCertificateChainRequestCommand(Device * device, Credentials::CertificateType certificateType)
{
    ChipLogDetail(Controller, "Sending Certificate Chain request to %p device", device);
    VerifyOrReturnError(device != nullptr, CHIP_ERROR_INVALID_ARGUMENT);
    chip::Controller::OperationalCredentialsCluster cluster;
    cluster.Associate(device, 0);

    mCertificateTypeBeingRequested = certificateType;

    Callback::Cancelable * successCallback = mCertificateChainResponseCallback.Cancel();
    Callback::Cancelable * failureCallback = mOnCertificateChainFailureCallback.Cancel();

    ReturnErrorOnFailure(cluster.CertificateChainRequest(successCallback, failureCallback, certificateType));
    ChipLogDetail(Controller, "Sent Certificate Chain request, waiting for the DAC Certificate");
    return CHIP_NO_ERROR;
}

void DeviceCommissioner::OnCertificateChainFailureResponse(void * context, uint8_t status)
{
    ChipLogProgress(Controller, "Device failed to receive the Certificate Chain request Response: 0x%02x", status);
    DeviceCommissioner * commissioner = reinterpret_cast<DeviceCommissioner *>(context);
    commissioner->mCertificateChainResponseCallback.Cancel();
    commissioner->mOnCertificateChainFailureCallback.Cancel();
    // TODO: Map error status to correct error code
    commissioner->OnSessionEstablishmentError(CHIP_ERROR_INTERNAL);
}

void DeviceCommissioner::OnCertificateChainResponse(void * context, ByteSpan certificate)
{
    ChipLogProgress(Controller, "Received certificate chain from the device");
    DeviceCommissioner * commissioner = reinterpret_cast<DeviceCommissioner *>(context);

    commissioner->mCertificateChainResponseCallback.Cancel();
    commissioner->mOnCertificateChainFailureCallback.Cancel();

    if (commissioner->ProcessCertificateChain(certificate) != CHIP_NO_ERROR)
    {
        // Handle error, and notify session failure to the commissioner application.
        ChipLogError(Controller, "Failed to process the certificate chain request");
        // TODO: Map error status to correct error code
        commissioner->OnSessionEstablishmentError(CHIP_ERROR_INTERNAL);
    }
}

CHIP_ERROR DeviceCommissioner::ProcessCertificateChain(const ByteSpan & certificate)
{
    VerifyOrReturnError(mState == State::Initialized, CHIP_ERROR_INCORRECT_STATE);
    VerifyOrReturnError(mDeviceBeingPaired < kNumMaxActiveDevices, CHIP_ERROR_INCORRECT_STATE);

    Device * device = &mActiveDevices[mDeviceBeingPaired];

    // PAI is being requested first - If PAI is not present, DAC will be requested next anyway.
    switch (mCertificateTypeBeingRequested)
    {
    case CertificateType::kDAC: {
        device->SetDAC(certificate);
        break;
    }
    case CertificateType::kPAI: {
        device->SetPAI(certificate);
        break;
    }
    case CertificateType::kUnknown:
    default: {
        return CHIP_ERROR_INTERNAL;
    }
    }

    if (device->AreCredentialsAvailable())
    {
        ChipLogProgress(Controller, "Sending Attestation Request to the device.");
        ReturnErrorOnFailure(SendAttestationRequestCommand(device, device->GetAttestationNonce()));
    }
    else
    {
        CHIP_ERROR err = SendCertificateChainRequestCommand(device, CertificateType::kDAC);
        if (err != CHIP_NO_ERROR)
        {
            ChipLogError(Controller, "Failed in sending Certificate Chain request command to the device: err %s", ErrorStr(err));
            OnSessionEstablishmentError(err);
            return err;
        }
    }

    return CHIP_NO_ERROR;
}

CHIP_ERROR DeviceCommissioner::SendAttestationRequestCommand(Device * device, const ByteSpan & attestationNonce)
{
    ChipLogDetail(Controller, "Sending Attestation request to %p device", device);
    VerifyOrReturnError(device != nullptr, CHIP_ERROR_INVALID_ARGUMENT);
    chip::Controller::OperationalCredentialsCluster cluster;
    cluster.Associate(device, 0);

    Callback::Cancelable * successCallback = mAttestationResponseCallback.Cancel();
    Callback::Cancelable * failureCallback = mOnAttestationFailureCallback.Cancel();

    ReturnErrorOnFailure(cluster.AttestationRequest(successCallback, failureCallback, attestationNonce));
    ChipLogDetail(Controller, "Sent Attestation request, waiting for the Attestation Information");
    return CHIP_NO_ERROR;
}

void DeviceCommissioner::OnAttestationFailureResponse(void * context, uint8_t status)
{
    ChipLogProgress(Controller, "Device failed to receive the Attestation Information Response: 0x%02x", status);
    DeviceCommissioner * commissioner = reinterpret_cast<DeviceCommissioner *>(context);
    commissioner->mAttestationResponseCallback.Cancel();
    commissioner->mOnAttestationFailureCallback.Cancel();
    // TODO: Map error status to correct error code
    commissioner->OnSessionEstablishmentError(CHIP_ERROR_INTERNAL);
}

void DeviceCommissioner::OnAttestationResponse(void * context, chip::ByteSpan attestationElements, chip::ByteSpan signature)
{
    ChipLogProgress(Controller, "Received Attestation Information from the device");
    DeviceCommissioner * commissioner = reinterpret_cast<DeviceCommissioner *>(context);

    commissioner->mAttestationResponseCallback.Cancel();
    commissioner->mOnAttestationFailureCallback.Cancel();

    commissioner->HandleAttestationResult(commissioner->ValidateAttestationInfo(attestationElements, signature));
}

CHIP_ERROR DeviceCommissioner::ValidateAttestationInfo(const ByteSpan & attestationElements, const ByteSpan & signature)
{
    VerifyOrReturnError(mState == State::Initialized, CHIP_ERROR_INCORRECT_STATE);
    VerifyOrReturnError(mDeviceBeingPaired < kNumMaxActiveDevices, CHIP_ERROR_INCORRECT_STATE);

    Device * device = &mActiveDevices[mDeviceBeingPaired];

    DeviceAttestationVerifier * dac_verifier = GetDeviceAttestationVerifier();

    // Retrieve attestation challenge
    ByteSpan attestationChallenge = mSystemState->SessionMgr()
                                        ->GetSecureSession({ mPairingSession.GetPeerNodeId(), mPairingSession.GetLocalSessionId(),
                                                             mPairingSession.GetPeerSessionId(), mFabricIndex })
                                        ->GetCryptoContext()
                                        .GetAttestationChallenge();

    AttestationVerificationResult result = dac_verifier->VerifyAttestationInformation(
        attestationElements, attestationChallenge, signature, device->GetPAI(), device->GetDAC(), device->GetAttestationNonce());
    if (result != AttestationVerificationResult::kSuccess)
    {
        if (result == AttestationVerificationResult::kNotImplemented)
        {
            ChipLogError(Controller,
                         "Failed in verifying 'Attestation Information' command received from the device due to default "
                         "DeviceAttestationVerifier Class not being overriden by a real implementation.");
            return CHIP_ERROR_NOT_IMPLEMENTED;
        }
        else
        {
            ChipLogError(Controller,
                         "Failed in verifying 'Attestation Information' command received from the device: err %hu. Look at "
                         "AttestationVerificationResult enum to understand the errors",
                         static_cast<uint16_t>(result));
            // Go look at AttestationVerificationResult enum in src/credentials/DeviceAttestationVerifier.h to understand the
            // errors.
            return CHIP_ERROR_INTERNAL;
        }
    }

    ChipLogProgress(Controller, "Successfully validated 'Attestation Information' command received from the device.");

    // TODO: Validate Certification Declaration
    // TODO: Validate Firmware Information

    return CHIP_NO_ERROR;
}

void DeviceCommissioner::HandleAttestationResult(CHIP_ERROR err)
{
    if (err != CHIP_NO_ERROR)
    {
        // Here we assume the Attestation Information validation always succeeds.
        // Spec mandates that commissioning shall continue despite attestation fails (in some cases).
        // TODO: Handle failure scenarios where commissioning may progress regardless.
        ChipLogError(Controller, "Failed to validate the Attestation Information");
    }

    VerifyOrReturn(mState == State::Initialized);
    VerifyOrReturn(mDeviceBeingPaired < kNumMaxActiveDevices);

    Device * device = &mActiveDevices[mDeviceBeingPaired];

    ChipLogProgress(Controller, "Sending 'CSR request' command to the device.");
    CHIP_ERROR error = SendOperationalCertificateSigningRequestCommand(device);
    if (error != CHIP_NO_ERROR)
    {
        ChipLogError(Controller, "Failed in sending 'CSR request' command to the device: err %s", ErrorStr(error));
        OnSessionEstablishmentError(error);
        return;
    }
}

CHIP_ERROR DeviceCommissioner::SendOperationalCertificateSigningRequestCommand(Device * device)
{
    ChipLogDetail(Controller, "Sending OpCSR request to %p device", device);
    VerifyOrReturnError(device != nullptr, CHIP_ERROR_INVALID_ARGUMENT);
    chip::Controller::OperationalCredentialsCluster cluster;
    cluster.Associate(device, 0);

    Callback::Cancelable * successCallback = mOpCSRResponseCallback.Cancel();
    Callback::Cancelable * failureCallback = mOnCSRFailureCallback.Cancel();

    ReturnErrorOnFailure(cluster.OpCSRRequest(successCallback, failureCallback, device->GetCSRNonce()));

    ChipLogDetail(Controller, "Sent OpCSR request, waiting for the CSR");
    return CHIP_NO_ERROR;
}

void DeviceCommissioner::OnCSRFailureResponse(void * context, uint8_t status)
{
    ChipLogProgress(Controller, "Device failed to receive the CSR request Response: 0x%02x", status);
    DeviceCommissioner * commissioner = static_cast<DeviceCommissioner *>(context);
    commissioner->mOpCSRResponseCallback.Cancel();
    commissioner->mOnCSRFailureCallback.Cancel();
    // TODO: Map error status to correct error code
    commissioner->OnSessionEstablishmentError(CHIP_ERROR_INTERNAL);
}

void DeviceCommissioner::OnOperationalCertificateSigningRequest(void * context, ByteSpan NOCSRElements,
                                                                ByteSpan AttestationSignature)
{
    ChipLogProgress(Controller, "Received certificate signing request from the device");
    DeviceCommissioner * commissioner = static_cast<DeviceCommissioner *>(context);

    commissioner->mOpCSRResponseCallback.Cancel();
    commissioner->mOnCSRFailureCallback.Cancel();

    if (commissioner->ProcessOpCSR(NOCSRElements, AttestationSignature) != CHIP_NO_ERROR)
    {
        // Handle error, and notify session failure to the commissioner application.
        ChipLogError(Controller, "Failed to process the certificate signing request");
        // TODO: Map error status to correct error code
        commissioner->OnSessionEstablishmentError(CHIP_ERROR_INTERNAL);
    }
}

void DeviceCommissioner::OnDeviceNOCChainGeneration(void * context, CHIP_ERROR status, const ByteSpan & noc, const ByteSpan & icac,
                                                    const ByteSpan & rcac)
{
    CHIP_ERROR err = CHIP_NO_ERROR;

    DeviceCommissioner * commissioner = static_cast<DeviceCommissioner *>(context);

    ChipLogProgress(Controller, "Received callback from the CA for NOC Chain generation. Status %s", ErrorStr(status));
    Device * device = nullptr;
    VerifyOrExit(commissioner->mState == State::Initialized, err = CHIP_ERROR_INCORRECT_STATE);
    VerifyOrExit(commissioner->mDeviceBeingPaired < kNumMaxActiveDevices, err = CHIP_ERROR_INCORRECT_STATE);

    // Check if the callback returned a failure
    VerifyOrExit(status == CHIP_NO_ERROR, err = status);

    // TODO - Verify that the generated root cert matches with commissioner's root cert

    device = &commissioner->mActiveDevices[commissioner->mDeviceBeingPaired];

    {
        // Reuse NOC Cert buffer for temporary store Root Cert.
        MutableByteSpan rootCert = device->GetMutableNOCCert();

        err = ConvertX509CertToChipCert(rcac, rootCert);
        SuccessOrExit(err);

        err = commissioner->SendTrustedRootCertificate(device, rootCert);
        SuccessOrExit(err);
    }

    if (!icac.empty())
    {
        MutableByteSpan icaCert = device->GetMutableICACert();

        err = ConvertX509CertToChipCert(icac, icaCert);
        SuccessOrExit(err);

        err = device->SetICACertBufferSize(icaCert.size());
        SuccessOrExit(err);
    }

    {
        MutableByteSpan nocCert = device->GetMutableNOCCert();

        err = ConvertX509CertToChipCert(noc, nocCert);
        SuccessOrExit(err);

        err = device->SetNOCCertBufferSize(nocCert.size());
        SuccessOrExit(err);
    }

exit:
    if (err != CHIP_NO_ERROR)
    {
        ChipLogError(Controller, "Failed in generating device's operational credentials. Error %s", ErrorStr(err));
        commissioner->OnSessionEstablishmentError(err);
    }
}

CHIP_ERROR DeviceCommissioner::ProcessOpCSR(const ByteSpan & NOCSRElements, const ByteSpan & AttestationSignature)
{
    VerifyOrReturnError(mState == State::Initialized, CHIP_ERROR_INCORRECT_STATE);
    VerifyOrReturnError(mDeviceBeingPaired < kNumMaxActiveDevices, CHIP_ERROR_INCORRECT_STATE);

    Device * device = &mActiveDevices[mDeviceBeingPaired];

    ChipLogProgress(Controller, "Getting certificate chain for the device from the issuer");

    mOperationalCredentialsDelegate->SetNodeIdForNextNOCRequest(device->GetDeviceId());
    mOperationalCredentialsDelegate->SetFabricIdForNextNOCRequest(0);

    return mOperationalCredentialsDelegate->GenerateNOCChain(NOCSRElements, AttestationSignature, ByteSpan(), ByteSpan(),
                                                             ByteSpan(), &mDeviceNOCChainCallback);
}

CHIP_ERROR DeviceCommissioner::SendOperationalCertificate(Device * device, const ByteSpan & nocCertBuf, const ByteSpan & icaCertBuf)
{
    VerifyOrReturnError(device != nullptr, CHIP_ERROR_INVALID_ARGUMENT);
    chip::Controller::OperationalCredentialsCluster cluster;
    cluster.Associate(device, 0);

    Callback::Cancelable * successCallback = mNOCResponseCallback.Cancel();
    Callback::Cancelable * failureCallback = mOnCertFailureCallback.Cancel();

    ReturnErrorOnFailure(cluster.AddNOC(successCallback, failureCallback, nocCertBuf, icaCertBuf, ByteSpan(nullptr, 0),
                                        mLocalId.GetNodeId(), mVendorId));

    ChipLogProgress(Controller, "Sent operational certificate to the device");

    return CHIP_NO_ERROR;
}

CHIP_ERROR DeviceCommissioner::ConvertFromNodeOperationalCertStatus(uint8_t err)
{
    switch (err)
    {
    case EMBER_ZCL_NODE_OPERATIONAL_CERT_STATUS_SUCCESS:
        return CHIP_NO_ERROR;
    case EMBER_ZCL_NODE_OPERATIONAL_CERT_STATUS_INVALID_PUBLIC_KEY:
        return CHIP_ERROR_INVALID_PUBLIC_KEY;
    case EMBER_ZCL_NODE_OPERATIONAL_CERT_STATUS_INVALID_NODE_OP_ID:
        return CHIP_ERROR_WRONG_NODE_ID;
    case EMBER_ZCL_NODE_OPERATIONAL_CERT_STATUS_INVALID_NOC:
        return CHIP_ERROR_CERT_LOAD_FAILED;
    case EMBER_ZCL_NODE_OPERATIONAL_CERT_STATUS_MISSING_CSR:
        return CHIP_ERROR_INCORRECT_STATE;
    case EMBER_ZCL_NODE_OPERATIONAL_CERT_STATUS_TABLE_FULL:
        return CHIP_ERROR_NO_MEMORY;
    case EMBER_ZCL_NODE_OPERATIONAL_CERT_STATUS_INSUFFICIENT_PRIVILEGE:
    case EMBER_ZCL_NODE_OPERATIONAL_CERT_STATUS_FABRIC_CONFLICT:
    case EMBER_ZCL_NODE_OPERATIONAL_CERT_STATUS_LABEL_CONFLICT:
        return CHIP_ERROR_INVALID_ARGUMENT;
    case EMBER_ZCL_NODE_OPERATIONAL_CERT_STATUS_INVALID_FABRIC_INDEX:
        return CHIP_ERROR_INVALID_FABRIC_ID;
    }

    return CHIP_ERROR_CERT_LOAD_FAILED;
}

void DeviceCommissioner::OnAddNOCFailureResponse(void * context, uint8_t status)
{
    ChipLogProgress(Controller, "Device failed to receive the operational certificate Response: 0x%02x", status);
    DeviceCommissioner * commissioner = static_cast<DeviceCommissioner *>(context);
    commissioner->mOpCSRResponseCallback.Cancel();
    commissioner->mOnCertFailureCallback.Cancel();
    // TODO: Map error status to correct error code
    commissioner->OnSessionEstablishmentError(CHIP_ERROR_INTERNAL);
}

void DeviceCommissioner::OnOperationalCertificateAddResponse(void * context, uint8_t StatusCode, uint8_t FabricIndex,
                                                             CharSpan DebugText)
{
    ChipLogProgress(Controller, "Device returned status %d on receiving the NOC", StatusCode);
    DeviceCommissioner * commissioner = static_cast<DeviceCommissioner *>(context);

    CHIP_ERROR err  = CHIP_NO_ERROR;
    Device * device = nullptr;

    VerifyOrExit(commissioner->mState == State::Initialized, err = CHIP_ERROR_INCORRECT_STATE);

    commissioner->mOpCSRResponseCallback.Cancel();
    commissioner->mOnCertFailureCallback.Cancel();

    VerifyOrExit(commissioner->mDeviceBeingPaired < kNumMaxActiveDevices, err = CHIP_ERROR_INCORRECT_STATE);

    err = ConvertFromNodeOperationalCertStatus(StatusCode);
    SuccessOrExit(err);

    device = &commissioner->mActiveDevices[commissioner->mDeviceBeingPaired];

    err = commissioner->OnOperationalCredentialsProvisioningCompletion(device);

exit:
    if (err != CHIP_NO_ERROR)
    {
        ChipLogProgress(Controller, "Add NOC failed with error %s", ErrorStr(err));
        commissioner->OnSessionEstablishmentError(err);
    }
}

CHIP_ERROR DeviceCommissioner::SendTrustedRootCertificate(Device * device, const ByteSpan & rcac)
{
    VerifyOrReturnError(device != nullptr, CHIP_ERROR_INVALID_ARGUMENT);

    ChipLogProgress(Controller, "Sending root certificate to the device");

    chip::Controller::OperationalCredentialsCluster cluster;
    cluster.Associate(device, 0);

    Callback::Cancelable * successCallback = mRootCertResponseCallback.Cancel();
    Callback::Cancelable * failureCallback = mOnRootCertFailureCallback.Cancel();

    ReturnErrorOnFailure(cluster.AddTrustedRootCertificate(successCallback, failureCallback, rcac));

    ChipLogProgress(Controller, "Sent root certificate to the device");

    return CHIP_NO_ERROR;
}

void DeviceCommissioner::OnRootCertSuccessResponse(void * context)
{
    ChipLogProgress(Controller, "Device confirmed that it has received the root certificate");
    DeviceCommissioner * commissioner = static_cast<DeviceCommissioner *>(context);

    CHIP_ERROR err  = CHIP_NO_ERROR;
    Device * device = nullptr;

    VerifyOrExit(commissioner->mState == State::Initialized, err = CHIP_ERROR_INCORRECT_STATE);

    commissioner->mRootCertResponseCallback.Cancel();
    commissioner->mOnRootCertFailureCallback.Cancel();

    VerifyOrExit(commissioner->mDeviceBeingPaired < kNumMaxActiveDevices, err = CHIP_ERROR_INCORRECT_STATE);

    device = &commissioner->mActiveDevices[commissioner->mDeviceBeingPaired];

    ChipLogProgress(Controller, "Sending operational certificate chain to the device");
    err = commissioner->SendOperationalCertificate(device, device->GetNOCCert(), device->GetICACert());
    SuccessOrExit(err);

exit:
    if (err != CHIP_NO_ERROR)
    {
        commissioner->OnSessionEstablishmentError(err);
    }
}

void DeviceCommissioner::OnRootCertFailureResponse(void * context, uint8_t status)
{
    ChipLogProgress(Controller, "Device failed to receive the root certificate Response: 0x%02x", status);
    DeviceCommissioner * commissioner = static_cast<DeviceCommissioner *>(context);
    commissioner->mRootCertResponseCallback.Cancel();
    commissioner->mOnRootCertFailureCallback.Cancel();
    // TODO: Map error status to correct error code
    commissioner->OnSessionEstablishmentError(CHIP_ERROR_INTERNAL);
}

CHIP_ERROR DeviceCommissioner::OnOperationalCredentialsProvisioningCompletion(Device * device)
{
    ChipLogProgress(Controller, "Operational credentials provisioned on device %p", device);
    VerifyOrReturnError(device != nullptr, CHIP_ERROR_INVALID_ARGUMENT);

#if CONFIG_USE_CLUSTERS_FOR_IP_COMMISSIONING
    if (mIsIPRendezvous)
    {
        AdvanceCommissioningStage(CHIP_NO_ERROR);
    }
    else
#endif
    {
        mPairingSession.ToSerializable(device->GetPairing());
        mSystemState->SystemLayer()->CancelTimer(OnSessionEstablishmentTimeoutCallback, this);

        mPairedDevices.Insert(device->GetDeviceId());
        mPairedDevicesUpdated = true;

        // Note - This assumes storage is synchronous, the device must be in storage before we can cleanup
        // the rendezvous session and mark pairing success
        PersistDevice(device);
        // Also persist the device list at this time
        // This makes sure that a newly added device is immediately available
        PersistDeviceList();
        if (mPairingDelegate != nullptr)
        {
            mPairingDelegate->OnStatusUpdate(DevicePairingDelegate::SecurePairingSuccess);
        }
        RendezvousCleanup(CHIP_NO_ERROR);
    }

    return CHIP_NO_ERROR;
}

void DeviceCommissioner::PersistDeviceList()
{
    if (mStorageDelegate != nullptr && mPairedDevicesUpdated && mState == State::Initialized)
    {
        mPairedDevices.Serialize([&](ByteSpan data) -> CHIP_ERROR {
            VerifyOrReturnError(data.size() <= UINT16_MAX, CHIP_ERROR_INVALID_ARGUMENT);
            PERSISTENT_KEY_OP(static_cast<uint64_t>(0), kPairedDeviceListKeyPrefix, key,
                              mStorageDelegate->SyncSetKeyValue(key, data.data(), static_cast<uint16_t>(data.size())));
            mPairedDevicesUpdated = false;
            return CHIP_NO_ERROR;
        });
    }
}

void DeviceCommissioner::ReleaseDevice(Device * device)
{
    PersistDeviceList();
    DeviceController::ReleaseDevice(device);
}

#if CONFIG_NETWORK_LAYER_BLE
CHIP_ERROR DeviceCommissioner::CloseBleConnection()
{
    // It is fine since we can only commission one device at the same time.
    // We should be able to distinguish different BLE connections if we want
    // to commission multiple devices at the same time over BLE.
    return mSystemState->BleLayer()->CloseAllBleConnections();
}
#endif

void DeviceCommissioner::OnSessionEstablishmentTimeout()
{
    VerifyOrReturn(mState == State::Initialized);
    VerifyOrReturn(mDeviceBeingPaired < kNumMaxActiveDevices);

    Device * device = &mActiveDevices[mDeviceBeingPaired];
    StopPairing(device->GetDeviceId());

    if (mPairingDelegate != nullptr)
    {
        mPairingDelegate->OnPairingComplete(CHIP_ERROR_TIMEOUT);
    }
}

void DeviceCommissioner::OnSessionEstablishmentTimeoutCallback(System::Layer * aLayer, void * aAppState)
{
    static_cast<DeviceCommissioner *>(aAppState)->OnSessionEstablishmentTimeout();
}
#if CHIP_DEVICE_CONFIG_ENABLE_DNSSD
CHIP_ERROR DeviceCommissioner::DiscoverCommissionableNodes(Dnssd::DiscoveryFilter filter)
{
    ReturnErrorOnFailure(SetUpNodeDiscovery());
    return chip::Dnssd::Resolver::Instance().FindCommissionableNodes(filter);
}

const Dnssd::DiscoveredNodeData * DeviceCommissioner::GetDiscoveredDevice(int idx)
{
    return GetDiscoveredNode(idx);
}

#endif // CHIP_DEVICE_CONFIG_ENABLE_DNSSD

#if CHIP_DEVICE_CONFIG_ENABLE_COMMISSIONER_DISCOVERY // make this commissioner discoverable

CHIP_ERROR DeviceCommissioner::SetUdcListenPort(uint16_t listenPort)
{
    if (mState == State::Initialized)
    {
        return CHIP_ERROR_INCORRECT_STATE;
    }

    mUdcListenPort = listenPort;
    return CHIP_NO_ERROR;
}

void DeviceCommissioner::FindCommissionableNode(char * instanceName)
{
    Dnssd::DiscoveryFilter filter(Dnssd::DiscoveryFilterType::kInstanceName, instanceName);
    DiscoverCommissionableNodes(filter);
}

void DeviceCommissioner::OnUserDirectedCommissioningRequest(UDCClientState state)
{
    ChipLogDetail(Controller, "------PROMPT USER!! OnUserDirectedCommissioningRequest instance=%s deviceName=%s",
                  state.GetInstanceName(), state.GetDeviceName());

    if (mUdcServer != nullptr)
    {
        mUdcServer->PrintUDCClients();
    }

    ChipLogDetail(Controller, "------To Accept Enter: discover udc-commission <pincode> <udc-client-index>");
}

void DeviceCommissioner::OnNodeDiscoveryComplete(const chip::Dnssd::DiscoveredNodeData & nodeData)
{
    if (mUdcServer != nullptr)
    {
        mUdcServer->OnCommissionableNodeFound(nodeData);
    }

    AbstractDnssdDiscoveryController::OnNodeDiscoveryComplete(nodeData);
}

#endif // CHIP_DEVICE_CONFIG_ENABLE_COMMISSIONER_DISCOVERY

void DeviceControllerInteractionModelDelegate::OnResponse(app::CommandSender * apCommandSender,
                                                          const app::ConcreteCommandPath & aPath,
                                                          const chip::app::StatusIB & aStatus, TLV::TLVReader * aData)
{
    // Generally IM has more detailed errors than ember library, here we always use the, the actual handling of the
    // commands should implement full IMDelegate.
    // #6308 By implement app side IM delegate, we should be able to accept detailed error codes.
    // Note: The IMDefaultResponseCallback is a bridge to the old CallbackMgr before IM is landed, so it still accepts EmberAfStatus
    // instead of IM status code.
    if (aData != nullptr)
    {
        chip::app::DispatchSingleClusterResponseCommand(aPath, *aData, apCommandSender);
    }
    else
    {
        IMDefaultResponseCallback(apCommandSender, EMBER_ZCL_STATUS_SUCCESS);
    }
}

void DeviceControllerInteractionModelDelegate::OnError(const app::CommandSender * apCommandSender,
                                                       const chip::app::StatusIB & aStatus, CHIP_ERROR aError)
{
    // The IMDefaultResponseCallback started out life as an Ember function, so it only accepted
    // Ember status codes. Consequently, let's convert the IM code over to a meaningful Ember status before dispatching.
    //
    // This however, results in loss (aError is completely discarded). When full cluster-specific status codes are implemented as
    // well, this will be an even bigger problem.
    //
    // For now, #10331 tracks this issue.
    IMDefaultResponseCallback(apCommandSender, app::ToEmberAfStatus(aStatus.mStatus));
}

void DeviceControllerInteractionModelDelegate::OnDone(app::CommandSender * apCommandSender)
{
    return chip::Platform::Delete(apCommandSender);
}

void DeviceControllerInteractionModelDelegate::OnAttributeData(const app::ReadClient * apReadClient,
                                                               const app::ConcreteAttributePath & aPath, TLV::TLVReader * apData,
                                                               const app::StatusIB & aStatus)
{
    IMReadReportAttributesResponseCallback(apReadClient, &aPath, apData, aStatus.mStatus);
}

void DeviceControllerInteractionModelDelegate::OnSubscriptionEstablished(const app::ReadClient * apReadClient)
{
    IMSubscribeResponseCallback(apReadClient, EMBER_ZCL_STATUS_SUCCESS);
}

void DeviceControllerInteractionModelDelegate::OnError(const app::ReadClient * apReadClient, CHIP_ERROR aError)
{
    app::ClusterInfo path;
    path.mNodeId = apReadClient->GetPeerNodeId();
    IMReadReportAttributesResponseCallback(apReadClient, nullptr, nullptr, Protocols::InteractionModel::Status::Failure);
}

void DeviceControllerInteractionModelDelegate::OnDone(app::ReadClient * apReadClient)
{
    if (apReadClient->IsSubscriptionType())
    {
        this->FreeAttributePathParam(reinterpret_cast<uint64_t>(apReadClient));
    }
}

void DeviceControllerInteractionModelDelegate::OnResponse(const app::WriteClient * apWriteClient,
                                                          const app::ConcreteAttributePath & aPath, app::StatusIB attributeStatus)
{
    IMWriteResponseCallback(apWriteClient, attributeStatus.mStatus);
}
void DeviceControllerInteractionModelDelegate::OnError(const app::WriteClient * apWriteClient, CHIP_ERROR aError)
{
    IMWriteResponseCallback(apWriteClient, Protocols::InteractionModel::Status::Failure);
}

void DeviceControllerInteractionModelDelegate::OnDone(app::WriteClient * apWriteClient) {}

void BasicSuccess(void * context, uint16_t val)
{
    ChipLogProgress(Controller, "Received success response 0x%x\n", val);
    DeviceCommissioner * commissioner = static_cast<DeviceCommissioner *>(context);
    commissioner->AdvanceCommissioningStage(CHIP_NO_ERROR);
}

void BasicFailure(void * context, uint8_t status)
{
    ChipLogProgress(Controller, "Received failure response %d\n", (int) status);
    DeviceCommissioner * commissioner = static_cast<DeviceCommissioner *>(context);
    commissioner->OnSessionEstablishmentError(static_cast<CHIP_ERROR>(status));
}

#if CHIP_DEVICE_CONFIG_ENABLE_DNSSD
void DeviceCommissioner::OnNodeIdResolved(const chip::Dnssd::ResolvedNodeData & nodeData)
{
    DeviceController::OnNodeIdResolved(nodeData);
    OperationalDiscoveryComplete(nodeData.mPeerId.GetNodeId());
}

void DeviceCommissioner::OnNodeIdResolutionFailed(const chip::PeerId & peer, CHIP_ERROR error)
{
    if (mDeviceBeingPaired < kNumMaxActiveDevices)
    {
        Device * device = &mActiveDevices[mDeviceBeingPaired];
        if (device->GetDeviceId() == peer.GetNodeId() && mCommissioningStage == CommissioningStage::kFindOperational)
        {
            OnSessionEstablishmentError(error);
        }
    }
    DeviceController::OnNodeIdResolutionFailed(peer, error);
}

#endif

void DeviceCommissioner::OnDeviceConnectedFn(void * context, Device * device)
{
    DeviceCommissioner * commissioner = static_cast<DeviceCommissioner *>(context);
    VerifyOrReturn(commissioner != nullptr, ChipLogProgress(Controller, "Device connected callback with null context. Ignoring"));

    if (commissioner->mDeviceBeingPaired < kNumMaxActiveDevices)
    {
        Device * deviceBeingPaired = &commissioner->mActiveDevices[commissioner->mDeviceBeingPaired];
        if (device == deviceBeingPaired && commissioner->mIsIPRendezvous)
        {
            if (commissioner->mCommissioningStage == CommissioningStage::kFindOperational)
            {
                commissioner->AdvanceCommissioningStage(CHIP_NO_ERROR);
            }
            // For IP rendezvous, we don't want to call commissioning complete below because IP commissioning
            // has more steps currently.
            return;
        }
    }

    VerifyOrReturn(commissioner->mPairingDelegate != nullptr,
                   ChipLogProgress(Controller, "Device connected callback with null pairing delegate. Ignoring"));
    commissioner->mPairingDelegate->OnCommissioningComplete(device->GetDeviceId(), CHIP_NO_ERROR);
}

void DeviceCommissioner::OnDeviceConnectionFailureFn(void * context, NodeId deviceId, CHIP_ERROR error)
{
    DeviceCommissioner * commissioner = static_cast<DeviceCommissioner *>(context);
    ChipLogProgress(Controller, "Device connection failed. Error %s", ErrorStr(error));
    VerifyOrReturn(commissioner != nullptr,
                   ChipLogProgress(Controller, "Device connection failure callback with null context. Ignoring"));
    VerifyOrReturn(commissioner->mPairingDelegate != nullptr,
                   ChipLogProgress(Controller, "Device connection failure callback with null pairing delegate. Ignoring"));
    commissioner->mPairingDelegate->OnCommissioningComplete(deviceId, error);
}

CommissioningStage DeviceCommissioner::GetNextCommissioningStage()
{
    switch (mCommissioningStage)
    {
    case CommissioningStage::kSecurePairing:
        return CommissioningStage::kArmFailsafe;
    case CommissioningStage::kArmFailsafe:
        return CommissioningStage::kConfigRegulatory;
    case CommissioningStage::kConfigRegulatory:
        return CommissioningStage::kDeviceAttestation;
    case CommissioningStage::kDeviceAttestation:
        // TODO(cecille): device attestation casues operational cert provisioinging to happen, This should be a separate stage.
        // For thread and wifi, this should go to network setup then enable. For on-network we can skip right to finding the
        // operational network because the provisioning of certificates will trigger the device to start operational advertising.
#if CHIP_DEVICE_CONFIG_ENABLE_DNSSD
        return CommissioningStage::kFindOperational; // TODO : once case is working, need to add stages to find and reconnect
                                                     // here.
#else
        return CommissioningStage::kSendComplete;
#endif
    case CommissioningStage::kFindOperational:
        return CommissioningStage::kSendComplete;
    case CommissioningStage::kSendComplete:
        return CommissioningStage::kCleanup;

    // Currently unimplemented.
    case CommissioningStage::kConfigACL:
    case CommissioningStage::kNetworkSetup:
    case CommissioningStage::kNetworkEnable:
    case CommissioningStage::kScanNetworks:
    case CommissioningStage::kCheckCertificates:
        return CommissioningStage::kError;
    // Neither of these have a next stage so return kError;
    case CommissioningStage::kCleanup:
    case CommissioningStage::kError:
        return CommissioningStage::kError;
    }
    return CommissioningStage::kError;
}

void DeviceCommissioner::AdvanceCommissioningStage(CHIP_ERROR err)
{
    // For now, we ignore errors coming in from the device since not all commissioning clusters are implemented on the device
    // side.
    CommissioningStage nextStage = GetNextCommissioningStage();
    if (nextStage == CommissioningStage::kError)
    {
        return;
    }

    if (!mIsIPRendezvous)
    {
        return;
    }
    Device * device = nullptr;
    if (mDeviceBeingPaired >= kNumMaxActiveDevices)
    {
        return;
    }

    device = &mActiveDevices[mDeviceBeingPaired];

    // TODO(cecille): We probably want something better than this for breadcrumbs.
    uint64_t breadcrumb = static_cast<uint64_t>(nextStage);

    // TODO(cecille): This should be customized per command.
    constexpr uint32_t kCommandTimeoutMs = 3000;

    switch (nextStage)
    {
    case CommissioningStage::kArmFailsafe: {
        // TODO(cecille): This is NOT the right way to do this - we should consider attaching an im delegate per command or
        // something. Per exchange context?
        ChipLogProgress(Controller, "Arming failsafe");
        // TODO(cecille): Find a way to enumerate the clusters here.
        GeneralCommissioningCluster genCom;
        // TODO: should get the endpoint information from the descriptor cluster.
        genCom.Associate(device, 0);
        // TODO(cecille): Make this a parameter
        uint16_t commissioningExpirySeconds = 60;
        genCom.ArmFailSafe(mSuccess.Cancel(), mFailure.Cancel(), commissioningExpirySeconds, breadcrumb, kCommandTimeoutMs);
    }
    break;
    case CommissioningStage::kConfigRegulatory: {
        // To set during config phase:
        // UTC time
        // time zone
        // dst offset
        // Regulatory config
        // TODO(cecille): Set time as well once the time cluster is implemented
        // TODO(cecille): Worthwhile to keep this around as part of the class?
        // TODO(cecille): Where is the country config actually set?
        ChipLogProgress(Controller, "Setting Regulatory Config");
        uint32_t regulatoryLocation = EMBER_ZCL_REGULATORY_LOCATION_TYPE_OUTDOOR;
#if CONFIG_DEVICE_LAYER
        CHIP_ERROR status = DeviceLayer::ConfigurationMgr().GetRegulatoryLocation(regulatoryLocation);
#else
        CHIP_ERROR status = CHIP_ERROR_NOT_IMPLEMENTED;
#endif
        if (status != CHIP_NO_ERROR)
        {
            ChipLogError(Controller, "Unable to find regulatory location, defaulting to outdoor");
        }

        static constexpr size_t kMaxCountryCodeSize = 3;
        char countryCodeStr[kMaxCountryCodeSize]    = "WW";
        size_t actualCountryCodeSize                = 2;

#if CONFIG_DEVICE_LAYER
        status = DeviceLayer::ConfigurationMgr().GetCountryCode(countryCodeStr, kMaxCountryCodeSize, actualCountryCodeSize);
#else
        status            = CHIP_ERROR_NOT_IMPLEMENTED;
#endif
        if (status != CHIP_NO_ERROR)
        {
            ChipLogError(Controller, "Unable to find country code, defaulting to WW");
        }
        chip::CharSpan countryCode(countryCodeStr, actualCountryCodeSize);

        GeneralCommissioningCluster genCom;
        genCom.Associate(device, 0);
        genCom.SetRegulatoryConfig(mSuccess.Cancel(), mFailure.Cancel(), static_cast<uint8_t>(regulatoryLocation), countryCode,
                                   breadcrumb, kCommandTimeoutMs);
    }
    break;
    case CommissioningStage::kDeviceAttestation: {
        ChipLogProgress(Controller, "Exchanging vendor certificates");
        CHIP_ERROR status = SendCertificateChainRequestCommand(device, CertificateType::kPAI);
        if (status != CHIP_NO_ERROR)
        {
            ChipLogError(Controller, "Failed in sending 'Certificate Chain Request' command to the device: err %s", ErrorStr(err));
            OnSessionEstablishmentError(err);
            return;
        }
    }
    break;
    case CommissioningStage::kCheckCertificates: {
        ChipLogProgress(Controller, "Exchanging certificates");
        // TODO(cecille): Once this is implemented through the clusters, it should be moved to the proper stage and the callback
        // should advance the commissioning stage
        CHIP_ERROR status = SendOperationalCertificateSigningRequestCommand(device);
        if (status != CHIP_NO_ERROR)
        {
            ChipLogError(Controller, "Failed in sending 'CSR Request' command to the device: err %s", ErrorStr(err));
            OnSessionEstablishmentError(err);
            return;
        }
    }
    break;
    // TODO: Right now, these stages are not implemented as a separate stage because they are no-ops.
    // Once these are implemented through the clusters, these should be moved into their separate stages and the callbacks
    // should advance the commissioning stage.
    case CommissioningStage::kConfigACL:
    case CommissioningStage::kNetworkSetup:
    case CommissioningStage::kScanNetworks:
        // TODO: Implement
        break;
    case CommissioningStage::kNetworkEnable: {
        ChipLogProgress(Controller, "Enabling Network");
        // For on-network, this is a NO-OP becuase we now start operational advertising once credentials are provisioned.
        // This is a placeholder for thread and wifi networks once that is implemented.
    }
    break;
    case CommissioningStage::kFindOperational: {
#if CHIP_DEVICE_CONFIG_ENABLE_DNSSD
        ChipLogProgress(Controller, "Finding node on operational network");
        Dnssd::Resolver::Instance().ResolveNodeId(
            PeerId().SetCompressedFabricId(GetCompressedFabricId()).SetNodeId(device->GetDeviceId()), Inet::IPAddressType::kAny);
#endif
    }
    break;
    case CommissioningStage::kSendComplete: {
        // TODO this is actualy not correct - we must reconnect over CASE to send this command.
        ChipLogProgress(Controller, "Calling commissioning complete");
        GeneralCommissioningCluster genCom;
        genCom.Associate(device, 0);
        genCom.CommissioningComplete(mSuccess.Cancel(), mFailure.Cancel());
    }
    break;
    case CommissioningStage::kCleanup:
        ChipLogProgress(Controller, "Rendezvous cleanup");
        mPairingSession.ToSerializable(device->GetPairing());
        mSystemState->SystemLayer()->CancelTimer(OnSessionEstablishmentTimeoutCallback, this);

        mPairedDevices.Insert(device->GetDeviceId());
        mPairedDevicesUpdated = true;

        // Note - This assumes storage is synchronous, the device must be in storage before we can cleanup
        // the rendezvous session and mark pairing success
        PersistDevice(device);
        // Also persist the device list at this time
        // This makes sure that a newly added device is immediately available
        PersistDeviceList();
        if (mPairingDelegate != nullptr)
        {
            mPairingDelegate->OnStatusUpdate(DevicePairingDelegate::SecurePairingSuccess);
        }
        RendezvousCleanup(CHIP_NO_ERROR);
        break;
    case CommissioningStage::kSecurePairing:
    case CommissioningStage::kError:
        break;
    }
    mCommissioningStage = nextStage;
}

} // namespace Controller
} // namespace chip