/**
 * @file
 *
 * @author  Mamadou Babaei <mamadou@senseglove.com>
 *
 * @section LICENSE
 *
 * (The MIT License)
 *
 * Copyright (c) 2020 - 2026 SenseGlove
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * @section DESCRIPTION
 *
 *
 */


#include "SGBackend/SGBackend.h"

#include "Engine/Engine.h"
#include "Templates/Atomic.h"

#if PLATFORM_ANDROID
#include "SGConnect/SGConnect.h"
#endif  /* PLATFORM_ANDROID */

#include "SGCore/SGDeviceList.h"
#include "SGCore/SGHandLayer.h"
#include "SGLog/SGLog.h"

struct USGBackend::FImpl
{
    /************************
     * Member variables
     ************************/

    TAtomic<bool> bInitialized;

    /************************
     * Owner object
     ************************/

    USGBackend* Owner;

    /************************
     * Constructor / Destructor
     ************************/

    explicit FImpl(USGBackend* InOwner);
    ~FImpl();

    /************************
     * Default copy constructor & copy assignment operator
     ************************/

    FImpl(const FImpl& Rhs) = delete;
    FImpl& operator=(const FImpl& Rhs) = delete;
};

USGBackend* USGBackend::GetInstance()
{
    if (!ensureAlwaysMsgf(GEngine, TEXT("The engine has not been initialized!")))
    {
        return nullptr;
    }

    USGBackend* Instance{GEngine->GetEngineSubsystem<USGBackend>()};
    return Instance;
}

USGBackend::USGBackend()
    : Pimpl(TUniquePtr<FImpl, FImplDeleter>(new FImpl{this}, PimplDeleter))
{
}

bool USGBackend::IsBackendInitialized() const
{
    return Pimpl->bInitialized;
}

bool USGBackend::InitializeBackend()
{
    if (!IsBackendInitialized())
    {
#if PLATFORM_ANDROID
        const int32 Result = FSGConnect::Init();
        switch (Result)
        {
        case -103:
            SGLOG_ERROR("Android JNI-specific Error: Invalid Java method ID!");
            return false;
        case -102:
            SGLOG_ERROR("Android JNI-specific Error: Invalid Java class!");
            return false;
        case -101:
            SGLOG_ERROR("Android JNI-specific Error: Invalid Java environment!");
            return false;
        case -100:
            SGLOG_ERROR("Android JNI-specific Error: Generic Error! Note: you should never see this!");
            return false;
        case -3:
            SGLOG_ERROR("An Unexpected error occurred. Please try again.");
            return false;
        case -2:
            SGLOG_ERROR("Device Scanning is already running within a different program.");
            return false;
        case -1:
            SGLOG_ERROR("Device Scanning already being initialized (function called twice in short succession).");
            return false;
        case 0:
            SGLOG_ERROR("Device Scanning is already running within this program.");
            return false;
        case 1:
            SGLOG("Successfully started up DeviceScanning from the current program.");
            break;
        default:
            ensureAlwaysMsgf(false, TEXT("Unhandled Init return status code!"));
            return false;
        }
#endif  /* PLATFORM_ANDROID */

        // Ensure that the device list is empty before doing anything.
        FSGDeviceList::Dispose();
        FSGDeviceList::Reinitialize();

        Pimpl->bInitialized = true;

        return true;
    }

    return false;
}

bool USGBackend::UninitializeBackend()
{
    if (IsBackendInitialized())
    {
        FSGDeviceList::Dispose();

#if PLATFORM_ANDROID
        const int32 Result = FSGConnect::Dispose();
        switch (Result)
        {
        case -103:
            SGLOG_ERROR("Android JNI-specific Error: Invalid Java method ID!");
            return false;
        case -102:
            SGLOG_ERROR("Android JNI-specific Error: Invalid Java class!");
            return false;
        case -101:
            SGLOG_ERROR("Android JNI-specific Error: Invalid Java environment!");
            return false;
        case -100:
            SGLOG_ERROR("Android JNI-specific Error: Generic Error! Note: you should never see this!");
            return false;
        case -3:
            SGLOG_ERROR("An Unexpected error occurred. Please try again.");
            return false;
        case -2:
            SGLOG_ERROR("Not allowed to dispose of Device Scanning because this is not the program which started it.");
            return false;
        case -1:
            SGLOG_ERROR("Device Scanning is currently being disposed off. This takes a second or two. (function called twice in short succession).");
            return false;
        case 0:
            SGLOG_ERROR("There is no deviceScanner running from any program, so disposing is skipped.");
            return false;
        case 1:
            SGLOG("Successfully disposed of DeviceScanner resources.");
            break;
        default:
            ensureAlwaysMsgf(false, TEXT("Unhandled Dispose return status code!"));
            return false;
        }
#endif  /* PLATFORM_ANDROID */

        Pimpl->bInitialized = false;

        return true;
    }

    return false;
}

bool USGBackend::ShouldCreateSubsystem(UObject* Outer) const
{
    return true;
}

void USGBackend::Initialize(FSubsystemCollectionBase& Collection)
{
    SGLOG("Initializing the SenseGlove Backend singleton with the engine lifetime...");

    Super::Initialize(Collection);

    SGLOG("Initializing the SenseGlove Backend singleton with the engine lifetime...");

    if (InitializeBackend())
    {
        SGLOG("The bridge to the SenseGlove Backend has been initialized successfully!")
    }
    else
    {
        SGLOG_ERROR("Failed to initialize the bridge to the SenseGlove Backend!")
    }

    SGLOG("The SenseGlove Backend singleton has been successfully initialized with the engine lifetime!");
}

void USGBackend::Deinitialize()
{
    SGLOG("De-initializing the SenseGlove Backend singleton due to the engine lifetime expiration...");

    Super::Deinitialize();

    if (UninitializeBackend())
    {
        SGLOG("The bridge to the SenseGlove Backend has been uninitialized successfully!")
    }
    else
    {
        SGLOG_ERROR("Failed to uninitialize the bridge to the SenseGlove Backend!")
    }

    (void) Pimpl.Release();

    SGLOG("The SenseGlove Backend singleton has been successfully de-initialized!");
}

USGBackend::FImpl::FImpl(USGBackend* InOwner)
    : bInitialized(false),
      Owner(InOwner)
{
}

USGBackend::FImpl::~FImpl() = default;

void USGBackend::FImplDeleter::operator()(const FImpl* P) const
{
    delete P;
}