src/app/server-cluster/testing/TestServerClusterContext.h

/*
 *    Copyright (c) 2025 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 <app/CASESessionManager.h>
#include <app/InteractionModelEngine.h>
#include <app/data-model-provider/ActionContext.h>
#include <app/data-model-provider/Context.h>
#include <app/data-model-provider/Provider.h>
#include <app/persistence/DefaultAttributePersistenceProvider.h>
#include <app/server-cluster/ServerClusterContext.h>
#include <app/server-cluster/testing/EmptyProvider.h>
#include <app/server-cluster/testing/TestAttributeChangeListener.h>
#include <app/server-cluster/testing/TestEventGenerator.h>
#include <app/server/Server.h>
#include <credentials/FabricTable.h>
#include <lib/support/TestPersistentStorageDelegate.h>
#include <platform/PlatformManager.h>
#include <protocols/interaction_model/StatusCode.h>

namespace chip {
namespace Testing {

/// An action context that does not have a current exchange (just returns nullptr)
class NullActionContext : public app::DataModel::ActionContext
{
public:
    Messaging::ExchangeContext * CurrentExchange() override { return nullptr; }
};

/// This is a ServerClusterContext that is initialized with VALID
/// entries that can then be used during testing
///
/// NOTE:
///   At this time, `interactionContext::actionContext::CurrentExchange` WILL return nullptr
///   in the existing implementation as the exchange is too heavy of an object
///   to create for testing
class TestServerClusterContext
{
public:
    TestServerClusterContext() :
        mTestContext{
            .eventsGenerator = mTestEventsGenerator,
            .actionContext   = mNullActionContext,
        },
        mContext{
            .provider           = mTestProvider,
            .storage            = mTestStorage,
            .attributeStorage   = mDefaultAttributePersistenceProvider,
            .interactionContext = mTestContext,
        },
        mFabricTable(Server::GetInstance().GetFabricTable()), mCaseSessionManager(*Server::GetInstance().GetCASESessionManager()),
        mPlatformManager(DeviceLayer::PlatformMgr()), mInteractionModelEngine(*app::InteractionModelEngine::GetInstance())
    {
        mTestProvider.RegisterAttributeChangeListener(mChangeListener);
        SuccessOrDie(mDefaultAttributePersistenceProvider.Init(&mTestStorage));
    }

    /// Get a stable pointer to the underlying context
    app::ServerClusterContext & Get() { return mContext; }

    LogOnlyEvents & EventsGenerator() { return mTestEventsGenerator; }
    TestAttributeChangeListener & ChangeListener() { return mChangeListener; };
    TestPersistentStorageDelegate & StorageDelegate() { return mTestStorage; }
    app::DefaultAttributePersistenceProvider & AttributePersistenceProvider() { return mDefaultAttributePersistenceProvider; }
    app::DataModel::InteractionModelContext & ImContext() { return mTestContext; }
    FabricTable & GetFabricTable() { return mFabricTable; }
    CASESessionManager & GetCASESessionManager() { return mCaseSessionManager; }
    DeviceLayer::PlatformManager & GetPlatformManager() { return mPlatformManager; }
    app::InteractionModelEngine & GetInteractionModelEngine() { return mInteractionModelEngine; }

    TestAttributeChangeListener & ReleaseListener()
    {
        mTestProvider.UnregisterAttributeChangeListener(mChangeListener);
        return mChangeListener;
    }

    void AddProviderListener(app::DataModel::AttributeChangeListener & listener)
    {
        mTestProvider.RegisterAttributeChangeListener(listener);
    }

private:
    NullActionContext mNullActionContext;
    LogOnlyEvents mTestEventsGenerator;
    TestAttributeChangeListener mChangeListener;
    EmptyProvider mTestProvider;
    TestPersistentStorageDelegate mTestStorage;
    app::DefaultAttributePersistenceProvider mDefaultAttributePersistenceProvider;
    app::DataModel::InteractionModelContext mTestContext;
    app::ServerClusterContext mContext;
    FabricTable & mFabricTable;
    CASESessionManager & mCaseSessionManager;
    DeviceLayer::PlatformManager & mPlatformManager;
    app::InteractionModelEngine & mInteractionModelEngine;
};

/// RAII class to register a TestAttributeChangeListener from a TestServerClusterContext
/// with a specific DataModel::Provider for the scope of this object's lifetime.
class ScopedAttributeChangeListenerRegistration
{
public:
    ScopedAttributeChangeListenerRegistration(app::DataModel::Provider & provider, TestServerClusterContext & context) :
        mProvider(provider), mContext(context)
    {
        mProvider.RegisterAttributeChangeListener(mContext.ReleaseListener());
    }

    ~ScopedAttributeChangeListenerRegistration()
    {
        // restore the previous state. We assume only one registration
        mProvider.UnregisterAttributeChangeListener(mContext.ChangeListener());
        mContext.AddProviderListener(mContext.ChangeListener());
    }

    // Non-copyable
    ScopedAttributeChangeListenerRegistration(const ScopedAttributeChangeListenerRegistration &)             = delete;
    ScopedAttributeChangeListenerRegistration & operator=(const ScopedAttributeChangeListenerRegistration &) = delete;

private:
    app::DataModel::Provider & mProvider;
    TestServerClusterContext & mContext;
};

} // namespace Testing
} // namespace chip