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

/**
 *
 *    Copyright (c) 2022 Project CHIP Authors
 *
 *    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/clusters/scenes-server/ExtensionFieldSetsImpl.h>
#include <app/clusters/scenes-server/SceneHandlerImpl.h>
#include <app/clusters/scenes-server/SceneTable.h>
#include <app/util/attribute-storage.h>
#include <app/util/config.h>
#include <lib/core/DataModelTypes.h>
#include <lib/support/CommonIterator.h>
#include <lib/support/PersistentData.h>
#include <lib/support/Pool.h>

namespace chip {
namespace scenes {

#ifdef SCENES_MANAGEMENT_TABLE_SIZE
static constexpr uint16_t kMaxScenesPerEndpoint = SCENES_MANAGEMENT_TABLE_SIZE;
#else
static constexpr uint16_t kMaxScenesPerEndpoint = CHIP_CONFIG_MAX_SCENES_TABLE_SIZE;
#endif

static_assert(kMaxScenesPerEndpoint <= CHIP_CONFIG_MAX_SCENES_TABLE_SIZE,
              "CHIP_CONFIG_MAX_SCENES_TABLE_SIZE is smaller than the zap configuration, please increase "
              "CHIP_CONFIG_MAX_SCENES_TABLE_SIZE in CHIPConfig.h if you really need more scenes");
static_assert(kMaxScenesPerEndpoint >= 16, "Per spec, kMaxScenesPerEndpoint must be at least 16");
static constexpr uint16_t kMaxScenesPerFabric = (kMaxScenesPerEndpoint - 1) / 2;

/**
 * @brief Implementation of a storage in nonvolatile storage of the scene table.
 *
 * DefaultSceneTableImpl is an implementation that allows to store scenes using PersistentStorageDelegate.
 * It handles the storage of scenes by their ID, GroupID and EnpointID over multiple fabrics.
 * It is meant to be used exclusively when the scene cluster is enable for at least one endpoint
 * on the device.
 */
class DefaultSceneTableImpl : public SceneTable<scenes::ExtensionFieldSetsImpl>
{
public:
    DefaultSceneTableImpl() {}
    ~DefaultSceneTableImpl() { Finish(); };

    CHIP_ERROR Init(PersistentStorageDelegate * storage) override;
    void Finish() override;

    // Scene count
    CHIP_ERROR GetEndpointSceneCount(uint8_t & scene_count) override;
    CHIP_ERROR GetFabricSceneCount(FabricIndex fabric_index, uint8_t & scene_count) override;

    // Data
    CHIP_ERROR GetRemainingCapacity(FabricIndex fabric_index, uint8_t & capacity) override;
    CHIP_ERROR SetSceneTableEntry(FabricIndex fabric_index, const SceneTableEntry & entry) override;
    CHIP_ERROR GetSceneTableEntry(FabricIndex fabric_index, SceneStorageId scene_id, SceneTableEntry & entry) override;
    CHIP_ERROR RemoveSceneTableEntry(FabricIndex fabric_index, SceneStorageId scene_id) override;
    CHIP_ERROR RemoveSceneTableEntryAtPosition(EndpointId endpoint, FabricIndex fabric_index, SceneIndex scene_idx) override;

    // Groups
    CHIP_ERROR GetAllSceneIdsInGroup(FabricIndex fabric_index, GroupId group_id, Span<SceneId> & scene_list) override;
    CHIP_ERROR DeleteAllScenesInGroup(FabricIndex fabric_index, GroupId group_id) override;

    // SceneHandlers
    void RegisterHandler(SceneHandler * handler) override;
    void UnregisterHandler(SceneHandler * handler) override;
    void UnregisterAllHandlers() override;

    // Extension field sets operation
    CHIP_ERROR SceneSaveEFS(SceneTableEntry & scene) override;
    CHIP_ERROR SceneApplyEFS(const SceneTableEntry & scene) override;

    // Fabrics
    CHIP_ERROR RemoveFabric(FabricIndex fabric_index) override;
    CHIP_ERROR RemoveEndpoint() override;

    // Iterators
    SceneEntryIterator * IterateSceneEntries(FabricIndex fabric_index) override;

    void SetEndpoint(EndpointId endpoint);
    void SetTableSize(uint16_t endpointSceneTableSize);
    bool IsInitialized() { return (mStorage != nullptr); }

protected:
    // This constructor is meant for test purposes, it allows to change the defined max for scenes per fabric and global, which
    // allows to simulate OTA where this value was changed
    DefaultSceneTableImpl(uint16_t maxScenesPerFabric, uint16_t maxScenesPerEndpoint) :
        mMaxScenesPerFabric(maxScenesPerFabric), mMaxScenesPerEndpoint(maxScenesPerEndpoint)
    {}

    // Global scene count
    CHIP_ERROR SetEndpointSceneCount(const uint8_t & scene_count);

    // wrapper function around emberAfGetClustersFromEndpoint to allow override when testing
    virtual uint8_t GetClustersFromEndpoint(ClusterId * clusterList, uint8_t listLen);

    // wrapper function around emberAfGetClusterCountForEndpoint to allow override when testing
    virtual uint8_t GetClusterCountFromEndpoint();

    class SceneEntryIteratorImpl : public SceneEntryIterator
    {
    public:
        SceneEntryIteratorImpl(DefaultSceneTableImpl & provider, FabricIndex fabricIdx, EndpointId endpoint,
                               uint16_t maxScenesPerFabric, uint16_t maxScenesPerEndpoint);
        size_t Count() override;
        bool Next(SceneTableEntry & output) override;
        void Release() override;

    protected:
        DefaultSceneTableImpl & mProvider;
        FabricIndex mFabric  = kUndefinedFabricIndex;
        EndpointId mEndpoint = kInvalidEndpointId;
        SceneIndex mNextSceneIdx;
        SceneIndex mSceneIndex = 0;
        uint8_t mTotalScenes   = 0;
        uint16_t mMaxScenesPerFabric;
        uint16_t mMaxScenesPerEndpoint;
    };

    uint16_t mMaxScenesPerFabric               = kMaxScenesPerFabric;
    uint16_t mMaxScenesPerEndpoint             = kMaxScenesPerEndpoint;
    EndpointId mEndpointId                     = kInvalidEndpointId;
    chip::PersistentStorageDelegate * mStorage = nullptr;
    ObjectPool<SceneEntryIteratorImpl, kIteratorsMax> mSceneEntryIterators;
}; // class DefaultSceneTableImpl

/// @brief Gets a pointer to the instance of Scene Table Impl, providing EndpointId and Table Size for said endpoint
/// @param endpoint Endpoint ID, optional only if getting the Table to initialize it, any storage action will require an endpoint
/// different than kInvalidEndpoint ID and WILL fail if an endpoint wasn't provided here.
/// @param endpointTableSize Size of the scene table for a specific endpoint. Must be lower than restriction set in CHIPConfig to
/// match device restrictions, if it is higher than permitted by CHIPConfig, will be capped at kMaxScenesPerEndpoint
/// @return Pointer to the instance of the Scene Table
DefaultSceneTableImpl * GetSceneTableImpl(EndpointId endpoint        = kInvalidEndpointId,
                                          uint16_t endpointTableSize = kMaxScenesPerEndpoint);

} // namespace scenes
} // namespace chip