src/include/platform/NFCOnboardingPayloadManager.h

/*
 *
 *    Copyright (c) 2021 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.
 */

/**
 * @file
 *   API for managing a programmable NFC Tag.
 */

#pragma once

#include <lib/core/CHIPError.h>

#include <cstddef>

namespace chip {
namespace DeviceLayer {

class NFCOnboardingPayloadManagerImpl;

/**
 * @brief Defines an abstract interface for programming an NFC Tag with onboarding payload.
 *
 * NFC Tag can be used in Project CHIP to share the onboarding payload, including
 * the device discriminator and PIN code, with a commissioner. This class
 * provides an interface to set contents of a programmable NFC Tag.
 */
class NFCOnboardingPayloadManager
{
public:
    /**
     * Initializes the NFCOnboardingPayloadManager singleton object.
     *
     * @return CHIP_NO_ERROR On success.
     */
    CHIP_ERROR Init();

    /**
     * Starts NFC Tag emulation using the specified payload.
     *
     * @param[in] payload       Address of the payload to be written to the NFC Tag.
     * @param[in] payloadLength Length of the payload.
     *
     * @return CHIP_NO_ERROR On success.
     *         CHIP_ERROR_BUFFER_TOO_SMALL Payload could not fit in an internal buffer.
     */
    CHIP_ERROR StartTagEmulation(const char * payload, size_t payloadLength);

    /**
     * Stops NFC Tag emulation.
     *
     * @return CHIP_NO_ERROR On success.
     */
    CHIP_ERROR StopTagEmulation();

    /** Determines whether NFC Tag emulation is started
     *
     * @return true NFC Tag is enabled.
     *         false NFC Tag is disabled.
     */
    bool IsTagEmulationStarted() const;

protected:
    // Construction/destruction limited to subclasses.
    NFCOnboardingPayloadManager()  = default;
    ~NFCOnboardingPayloadManager() = default;

    // No copy, move or assignment.
    NFCOnboardingPayloadManager(const NFCOnboardingPayloadManager &) = delete;
    NFCOnboardingPayloadManager(NFCOnboardingPayloadManager &&)      = delete;
    void operator=(const NFCOnboardingPayloadManager &)              = delete;

    // NFCOnboardingPayloadManager implementation getters.
    NFCOnboardingPayloadManagerImpl * Impl();
    const NFCOnboardingPayloadManagerImpl * Impl() const;
};

/**
 * Returns a reference to the public interface of the NFCOnboardingPayloadManager singleton object.
 */
extern NFCOnboardingPayloadManager & NFCOnboardingPayloadMgr();

/**
 * Returns a reference to the platform-specific NFCOnboardingPayloadManager singleton object.
 */
extern NFCOnboardingPayloadManagerImpl & NFCOnboardingPayloadMgrImpl();

} // namespace DeviceLayer
} // namespace chip

#ifdef EXTERNAL_NFC_ONBOARDING_PAYLOAD_MANAGER_IMPL_HEADER
#include EXTERNAL_NFC_ONBOARDING_PAYLOAD_MANAGER_IMPL_HEADER
#elif defined(CHIP_DEVICE_LAYER_TARGET)
#define NFC_ONBOARDING_PAYLOAD_MANAGER_IMPL_HEADER <platform/CHIP_DEVICE_LAYER_TARGET/NFCOnboardingPayloadManagerImpl.h>
#include NFC_ONBOARDING_PAYLOAD_MANAGER_IMPL_HEADER
#endif // defined(CHIP_DEVICE_LAYER_TARGET)

namespace chip {
namespace DeviceLayer {

inline CHIP_ERROR NFCOnboardingPayloadManager::Init()
{
    return Impl()->_Init();
}

inline CHIP_ERROR NFCOnboardingPayloadManager::StartTagEmulation(const char * payload, size_t payloadLength)
{
    return Impl()->_StartTagEmulation(payload, payloadLength);
}

inline CHIP_ERROR NFCOnboardingPayloadManager::StopTagEmulation()
{
    return Impl()->_StopTagEmulation();
}

inline bool NFCOnboardingPayloadManager::IsTagEmulationStarted() const
{
    return Impl()->_IsTagEmulationStarted();
}

inline NFCOnboardingPayloadManagerImpl * NFCOnboardingPayloadManager::Impl()
{
    return static_cast<NFCOnboardingPayloadManagerImpl *>(this);
}

inline const NFCOnboardingPayloadManagerImpl * NFCOnboardingPayloadManager::Impl() const
{
    return static_cast<const NFCOnboardingPayloadManagerImpl *>(this);
}

} // namespace DeviceLayer
} // namespace chip