// Copyright (C) 2021 The Qt Company Ltd.
// Copyright (C) 2019 Luxoft Sweden AB
// Copyright (C) 2018 Pelagicore AG
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
// Qt-Security score:critical reason:execute-external-code

#include "qifservicemanager.h"

#include "qtinterfaceframeworkmodule.h"
#include "qifproxyserviceobject.h"
#include "qifservicemanager_p.h"
#include "qifconfiguration_p.h"

#include <QAbstractEventDispatcher>
#include <QCoreApplication>
#include <QDebug>
#include <QDir>
#include <QElapsedTimer>
#include <QJsonObject>
#include <QLibrary>
#include <QModelIndex>
#include <QStringList>
#include <QThread>

using namespace Qt::StringLiterals;

#define QIF_PLUGIN_DIRECTORY "interfaceframework"

QT_BEGIN_NAMESPACE

#if QT_VERSION < QT_VERSION_CHECK(6, 9, 0)
#  define Q_STATIC_LOGGING_CATEGORY(cat, rule) Q_LOGGING_CATEGORY(cat, rule)
#endif

Q_LOGGING_CATEGORY(qLcIfServiceManagement, "qt.if.servicemanagement");
Q_STATIC_LOGGING_CATEGORY(qLcIfPerf, "qt.if.servicemanagement.perf");

namespace qtif_helper {
// AXIVION DISABLE Qt-NonPodGlobalStatic
#ifdef QT_DEBUG
    static const bool loadDebug = true;
#else
    static const bool loadDebug = false;
#endif
    static const QString interfacesLiteral = u"interfaces"_s;
    static const QString fileNameLiteral = u"fileName"_s;
    static const QString metaDataLiteral = u"MetaData"_s;
    static const QString classNameLiteral = u"className"_s;
    static const QString simulationLiteral = u"simulation"_s;
    static const QString debugLiteral = u"debug"_s;
#ifdef Q_OS_WIN
    static const QString debugSuffixLiteral = u"d"_s;
#else
    static const QString debugSuffixLiteral = u"_debug"_s;
#endif
// AXIVION ENABLE Qt-NonPodGlobalStatic

    QString backendBaseName(const QString &fileName)
    {
        if (fileName.isEmpty())
            return fileName;
        const QFileInfo fi(fileName);
        //remove the library suffix
        QString baseName = fileName;
        baseName.chop(fi.suffix().size() + 1);

        //remove the configuration suffix
        if (baseName.endsWith(debugSuffixLiteral))
            baseName.chop(debugSuffixLiteral.size());

        return baseName;
    }
}

using namespace qtif_helper;

Backend::~Backend()
{
    if (thread) {
        thread->deleteLater();
        thread = nullptr;
    }
    delete interface;
    delete proxyServiceObject;
    delete loader;
}

QIfServiceManagerPrivate::QIfServiceManagerPrivate(QIfServiceManager *parent)
    : QObject(parent)
    , m_staticLoaded(false)
    , q_ptr(parent)
{
}

QIfServiceManagerPrivate *QIfServiceManagerPrivate::get(QIfServiceManager *serviceManager)
{
    Q_ASSERT(serviceManager);
    return serviceManager->d_ptr;
}

bool QIfServiceManagerPrivate::isSimulation(const QVariantMap &metaData)
{
    QString fileName = metaData[fileNameLiteral].toString();
    return fileName.contains(QLatin1String("_simulation")) ||
            fileName.contains(QLatin1String("_simulator")) ||
            metaData[simulationLiteral].toBool();
}

QIfProxyServiceObject *QIfServiceManagerPrivate::createServiceObject(struct Backend *backend) const
{
    if (!backend)
        return nullptr;

    // The plugin is currently loaded asynchronously in a different thread.
    // We need to wait until the thread is finished and for the queued connection to be triggered
    // until all the data is written to the backend object.
    if (Q_UNLIKELY(backend->loading)) {
        qCDebug(qLcIfServiceManagement) << "Backend is already loading asynchronously. Waiting for it to finish.";
        Q_ASSERT(backend->thread);
        backend->thread->wait();
        // Depending on how full the event loop is currently we need to wait multiple cycles
        // until the queued connection is triggered.
        while (backend->loading)
            QAbstractEventDispatcher::instance()->processEvents(QEventLoop::WaitForMoreEvents);
    }
    if (!backend->proxyServiceObject) {
        QIfServiceInterface *backendInterface = loadServiceBackendInterface(backend);
        if (backendInterface)
            backend->proxyServiceObject = new QIfProxyServiceObject(backendInterface);
    }

    if (backend->proxyServiceObject) {
        QString fileName = backend->metaData[fileNameLiteral].toString();
        if (fileName.isEmpty())
            fileName = u"static plugin"_s;

        qCDebug(qLcIfServiceManagement) << "Found: " << backend->proxyServiceObject << "from: " << fileName;

        const QString configurationId = backend->proxyServiceObject->configurationId();
        if (!configurationId.isEmpty()) {
            // This will also apply the current serviceSettings to the serviceObject
            QIfConfigurationManager::instance()->addServiceObject(configurationId, backend->proxyServiceObject);
        }
        return backend->proxyServiceObject;
    }

    return nullptr;
}

QList<QIfServiceObjectHandle> QIfServiceManagerPrivate::findServiceByInterface(const QString &interface, QIfServiceManager::SearchFlags searchFlags, const QStringList &preferredBackends) const
{
    QList<QIfServiceObjectHandle> list;
    qCDebug(qLcIfServiceManagement) << "Searching for a backend for:" << interface << "SearchFlags:" << searchFlags << "PreferredBackends:" << preferredBackends;

    QList<Backend *> foundBackends;
    for (Backend *backend : m_backends) {

        if (backend->metaData[interfacesLiteral].toStringList().contains(interface)) {
            bool isSimulation = QIfServiceManagerPrivate::isSimulation(backend->metaData);
            if ((searchFlags & QIfServiceManager::IncludeSimulationBackends && isSimulation) ||
                (searchFlags & QIfServiceManager::IncludeProductionBackends && !isSimulation)) {
                foundBackends.append(backend);
            }
        }
    }

    // Filter the list ouf matching backends
    // The wildcards in the disambiguation list are checked in order
    // Once a wildcard founds matches those are returned.
    // In case of no match the next wildcard is used.
    for (const QString &wildCard : std::as_const(preferredBackends)) {
        qCDebug(qLcIfServiceManagement) << "Dissambiguate found backends with wildcard:" << wildCard;
        const auto regexp = QRegularExpression(QRegularExpression::wildcardToRegularExpression(wildCard));
        for (Backend *backend : std::as_const(foundBackends)) {
            const auto fileInfo = QFileInfo(backend->metaData[fileNameLiteral].toString());
            QIfServiceObjectHandle handle;
            QString identifier = fileInfo.fileName();

            if (identifier.isEmpty() && backend->interface) {
                //static plugin
                identifier = backend->interface->id();
            }

            if (regexp.match(identifier).hasMatch())
                handle.m_handle = backend;

            if (handle.m_handle)
                list.append(handle);
            else
                qCDebug(qLcIfServiceManagement) << "Wildcard doesn't contain:" << identifier;
        }

        if (!list.isEmpty())
            return list;
    }

    if (list.isEmpty()) {
        qCDebug(qLcIfServiceManagement) << "Didn't find any preferred backends. Returning all found.";
        for (Backend *backend : std::as_const(foundBackends)) {
            QIfServiceObjectHandle handle;
            handle.m_handle = backend;
            list.append(handle);
        }
    }

    return list;
}

void QIfServiceManagerPrivate::searchPlugins()
{
    bool found = false;

    qCDebug(qLcIfServiceManagement) << "Start to search for backend plugins";
    QElapsedTimer timer;
    if (qLcIfPerf().isDebugEnabled())
        timer.start();
    const auto pluginDirs = QCoreApplication::libraryPaths();
    for (const QString &pluginDir : pluginDirs) {
        // Already loaded, skip it...
        if (m_loadedPaths.contains(pluginDir))
            continue;
        m_loadedPaths << pluginDir;
        qCDebug(qLcIfServiceManagement) << "Checking folder:" << pluginDir;

#ifdef Q_OS_ANDROID
        QString path = pluginDir;
#else
        QString path = pluginDir + QDir::separator() + QLatin1String(QIF_PLUGIN_DIRECTORY);
#endif
        QDir dir(path);
        //Check whether the directory exists
        if (!dir.exists())
            continue;

        const QStringList plugins = QDir(path).entryList(
#ifdef Q_OS_ANDROID
                    QStringList(QLatin1String("libplugins_%1_*.so").arg(QLatin1String(QIF_PLUGIN_DIRECTORY))),
#endif
                    QDir::Files);
        for (const QString &pluginFileName : plugins) {
            if (!QLibrary::isLibrary(pluginFileName)) {
                qCDebug(qLcIfServiceManagement) << "Skipping:" << pluginFileName;
                continue;
            }
            qCDebug(qLcIfServiceManagement) << "Found:" << pluginFileName;

            const QFileInfo info(dir, pluginFileName);
            const QString absFile = info.canonicalFilePath();
            QPluginLoader loader(absFile);

            registerBackend(absFile, loader.metaData());
            found = true;
        }
    }

    // Only load the static plugins once
    if (!m_staticLoaded) {
        qCDebug(qLcIfServiceManagement) << "Searching for static backend plugins";
        m_staticLoaded = true;
        const auto staticPlugins = QPluginLoader::staticPlugins();
        for (const QStaticPlugin &plugin : staticPlugins) {
            qCDebug(qLcIfServiceManagement) << "Found static plugin:" << plugin.metaData().value(classNameLiteral).toString();
            registerStaticBackend(plugin);
        }
    }

    qCDebug(qLcIfPerf) << "Searching for backend plugins done in" << timer.elapsed() << "ms";
    if (Q_UNLIKELY(!found && m_backends.count() == 0))
        qWarning() << "No plugins found in search path: " << QCoreApplication::libraryPaths().join(QLatin1String(":"));
}

void QIfServiceManagerPrivate::registerBackend(const QString &fileName, const QJsonObject &metaData)
{
    QVariantMap backendMetaData = metaData.value(metaDataLiteral).toVariant().toMap();

    if (Q_UNLIKELY(backendMetaData[interfacesLiteral].isNull() ||
                   backendMetaData[interfacesLiteral].toList().isEmpty())) {
        qCWarning(qLcIfServiceManagement, "PluginManager - Malformed metaData in '%s'. MetaData must contain a list of interfaces", qPrintable(fileName));
        return;
    }

    backendMetaData.insert(fileNameLiteral, fileName);

    auto *backend = new Backend;
    backend->name =  metaData.value(classNameLiteral).toString();
    backend->debug = metaData.value(debugLiteral).toBool();
    backend->metaData = backendMetaData;
    addBackend(backend);
}

void QIfServiceManagerPrivate::registerStaticBackend(const QStaticPlugin &plugin)
{
    QVariantMap backendMetaData = plugin.metaData().value(metaDataLiteral).toVariant().toMap();
    const char* pluginName = plugin.instance()->metaObject()->className();

    if (Q_UNLIKELY(backendMetaData[interfacesLiteral].isNull() ||
                   backendMetaData[interfacesLiteral].toList().isEmpty())) {
        qCWarning(qLcIfServiceManagement, "PluginManager - Malformed metaData in static plugin '%s'. MetaData must contain a list of interfaces", pluginName);
        return;
    }

    QIfServiceInterface *backendInterface = qobject_cast<QIfServiceInterface*>(plugin.instance());
    if (Q_UNLIKELY(!backendInterface))
        qCWarning(qLcIfServiceManagement, "ServiceManager::serviceObjects - failed to cast to interface from '%s'", pluginName);

    //TODO check for other metaData like name etc.

    auto *backend = new Backend;
    backend->name = plugin.metaData().value(classNameLiteral).toString();
    backend->debug = plugin.metaData().value(debugLiteral).toBool();
    backend->metaData = backendMetaData;
    backend->interface = backendInterface;
    addBackend(backend);
}

bool QIfServiceManagerPrivate::registerBackend(QObject *serviceBackendInterface, const QStringList &interfaces, QIfServiceManager::BackendType backendType)
{
    if (interfaces.isEmpty()) {
        return false;
    }

    // Verify that the object implements the ServiceBackendInterface
    QIfServiceInterface *interface = qobject_cast<QIfServiceInterface*>(serviceBackendInterface);
    if (!interface) {
        return false;
    }

    QVariantMap metaData = QVariantMap();

    metaData.insert(interfacesLiteral, interfaces);
    if (backendType == QIfServiceManager::SimulationBackend)
        metaData.insert(simulationLiteral, true);

    auto *backend = new Backend;
    backend->name = QString::fromLocal8Bit(serviceBackendInterface->metaObject()->className());
    backend->metaData = metaData;
    backend->interface = interface;

    addBackend(backend);
    return true;
}

void QIfServiceManagerPrivate::unloadAllBackends()
{
    Q_Q(QIfServiceManager);

    q->beginResetModel();
    for (Backend* backend : std::as_const(m_backends)) {
        if (backend->proxyServiceObject) {
            auto configurationId = backend->proxyServiceObject->configurationId();
            QIfConfigurationManager::instance()->removeServiceObject(configurationId, backend->proxyServiceObject);
        }

        delete backend;
    }
    m_backends.clear();
    q->endResetModel();

    m_interfaceNames.clear();
    m_loadedPaths.clear();
    m_staticLoaded = false;
}

void QIfServiceManagerPrivate::addBackend(Backend *backend)
{
    Q_Q(QIfServiceManager);
    //Check whether the same plugin is already in (maybe also in a different configuration)
    //The current configuration of QtInterfaceFramework decides which configuration takes precedence

    const QString newBackendFile = backend->metaData.value(fileNameLiteral).toString();
    const QString newBackendFileBase = qtif_helper::backendBaseName(newBackendFile);
    const QStringList ifaceList = backend->metaData.value(interfacesLiteral).toStringList();
    const QSet<QString> newInterfaces = QSet<QString>(ifaceList.begin(), ifaceList.end());

    bool addBackend = true;
    if (!newBackendFile.isEmpty()) {
        for (int i = 0; i < m_backends.count(); i++) {
            Backend *b = m_backends[i];
            const QStringList curIfaceList = backend->metaData.value(interfacesLiteral).toStringList();
            const QSet<QString> interfaces = QSet<QString>(curIfaceList.begin(), curIfaceList.end());
            if (interfaces == newInterfaces && b->name == backend->name) {
                const QString fileName = b->metaData.value(fileNameLiteral).toString();
                if (fileName == newBackendFile) {
                    qCDebug(qLcIfServiceManagement, "Skipping backend %s: already in the list", qPrintable(newBackendFile));
                    return;
                }

                QString base = backendBaseName(fileName);
                //check whether the plugins name are the same after removing the debug and library suffixes
                if (newBackendFileBase == base) {
                    qCInfo(qLcIfServiceManagement, "Found the same plugin in two configurations. "
                                                    "Using the '%s' configuration: %s",
                                                    qtif_helper::loadDebug ? "debug" : "release",
                                                    qPrintable(b->debug == qtif_helper::loadDebug ? fileName : newBackendFile));
                    if (b->debug != qtif_helper::loadDebug) {
                        qCDebug(qLcIfServiceManagement, "Replacing backend %s with %s", qPrintable(fileName), qPrintable(newBackendFile));
                        addBackend = false;
                        m_backends[i] = backend;
                        emit q->dataChanged(q->index(i, 0), q->index(i, 0));
                        delete b;
                        break;
                    } else {
                        qCDebug(qLcIfServiceManagement, "Skipping backend %s: wrong configuration", qPrintable(newBackendFile));
                        return;
                    }
                }
            }
        }
    }
    if (addBackend) {
        qCDebug(qLcIfServiceManagement, "Adding %s %s", qPrintable(newBackendFile.isEmpty() ? backend->name : newBackendFile),
                QIfServiceManagerPrivate::isSimulation(backend->metaData) ? "as simulation backend" : "as production backend");
        q->beginInsertRows(QModelIndex(), int(m_backends.count()), int(m_backends.count()));
        m_backends.append(backend);
        q->endInsertRows();
    }

    for (const QString &interface : newInterfaces)
        m_interfaceNames.insert(interface);
}

namespace {
Q_NEVER_INLINE
static QIfServiceInterface *warn(const char *what, const QPluginLoader *loader)
{
    qWarning("ServiceManager::serviceObjects - failed to %s '%s'",
             what, qPrintable(loader->fileName()));
    return nullptr;
}
} // unnamed namespace

QIfServiceInterface *QIfServiceManagerPrivate::loadServiceBackendInterface(struct Backend *backend) const
{
    if (backend->interface) {
        return backend->interface;
    }

    const QString pluginFile = backend->metaData[fileNameLiteral].toString();

    auto [backendInterface, loader] = loadPlugin(pluginFile);

    backend->interface = backendInterface;
    backend->loader = loader;
    return backend->interface;
}

void QIfServiceManagerPrivate::loadServiceBackendInterfaceAsync(struct Backend *backend)
{
    Q_Q(QIfServiceManager);

    auto emitServiceObjectLoaded = [this] (struct Backend *backend) {
        backend->loading = false;
        if (backend->interface) {
            backend->proxyServiceObject = new QIfProxyServiceObject(backend->interface);
            // We just created the serviceObject, but we still call this function to make sure
            // the debug messages are printed and it is correctly registered to the QIfConfigurationManager
            createServiceObject(backend);
        } else {
            delete backend->loader;
            backend->loader = nullptr;
        }
        Q_Q(QIfServiceManager);
        QIfServiceObjectHandle handle;
        handle.m_handle = backend;
        emit q->serviceObjectLoaded(handle);
    };

    if (backend->loading)
        return;
    backend->loading = true;

    // The backend is already loaded, register it and emit the loaded signal in the next event
    // loop run
    if (backend->interface) {
        QMetaObject::invokeMethod(q, [=]() {
            emitServiceObjectLoaded(backend);
        }, Qt::QueuedConnection);
        return;
    }

    const QString pluginFile = backend->metaData[fileNameLiteral].toString();

    auto thread = QThread::create([backend, q, emitServiceObjectLoaded](const QString &pluginFile) {
        // Load the plugin in the new thread
        auto [backendInterface, loader] = QIfServiceManagerPrivate::loadPlugin(pluginFile);

        // register the serviceObject in the main thread
        QMetaObject::invokeMethod(q, [emitServiceObjectLoaded](struct Backend *backend, QIfServiceInterface * interface, QPluginLoader *loader) {
            backend->interface = interface;
            backend->loader = loader;
            emitServiceObjectLoaded(backend);
        }, Qt::QueuedConnection, backend, backendInterface, loader);
    }, pluginFile);
    backend->thread = thread;
    connect(thread, &QThread::finished, thread, [thread]() {
        thread->deleteLater();
        qCDebug(qLcIfServiceManagement) << "Loading Thread finished";
    });
    backend->thread->start();
}

std::tuple<QIfServiceInterface *, QPluginLoader*> QIfServiceManagerPrivate::loadPlugin(const QString &pluginFile)
{
    qCDebug(qLcIfServiceManagement) << "Loading plugin:" << pluginFile << "in thread" << QThread::currentThread();
    std::unique_ptr<QPluginLoader> loader(new QPluginLoader(pluginFile));
    QElapsedTimer elapsedTimer;
    if (qLcIfPerf().isDebugEnabled())
        elapsedTimer.start();

    loader->load();
    if (elapsedTimer.isValid()) {
        qCDebug(qLcIfPerf) << "Loaded " << pluginFile << "in" << elapsedTimer.elapsed() << "ms";
        elapsedTimer.start();
    }

    QObject *plugin = loader->instance();
    if (Q_UNLIKELY(!plugin))
        return {warn("load", loader.get()), nullptr};

    if (elapsedTimer.isValid())
        qCDebug(qLcIfPerf) << "Instantiated ServiceInterface in" << elapsedTimer.elapsed() << "ms";

    QThread *mainThread = QCoreApplication::instance()->thread();
    if (loader->thread() != mainThread) {
        loader->moveToThread(mainThread);
        plugin->moveToThread(mainThread);
    }

    QIfServiceInterface *backendInterface = qobject_cast<QIfServiceInterface*>(plugin);
    if (Q_UNLIKELY(!backendInterface))
        return {warn("cast to interface from", loader.get()), nullptr};

    return { backendInterface, loader.release() };
}

Backend *QIfServiceManagerPrivate::verifyHandle(void *handle)
{
    if (!m_backends.contains(handle))
        return nullptr;
    return static_cast<Backend*>(handle);
}

/*!
    \class QIfServiceObjectHandle
    \inmodule QtInterfaceFramework
    \since 6.8
    \brief The QIfServiceObjectHandle class is a handle to a ServiceObject.

    The QIfServiceObjectHandle class is a handle to a ServiceObject. It can be used to load the
    backend asynchronously using the \l {QIfServiceManager::}{loadServiceObject()} function.
*/
/*!
    \qmltype ServiceObjectHandle
    \nativetype QIfServiceObjectHandle
    \inqmlmodule QtInterfaceFramework
    \since 6.8
    \brief The handle to a ServiceObject.

    The ServiceObjectHandle is a handle to a ServiceObject. It can be used to load the backend
    asynchronously using the \l {ServiceManager::}{loadServiceObject()} function.
*/

/*!
    \qmlproperty bool ServiceObjectHandle::valid

    Returns \c true if the handle is valid; otherwise \c false.
*/
/*!
    \property QIfServiceObjectHandle::valid

    Returns \c true if the handle is valid; otherwise \c false.
*/
bool QIfServiceObjectHandle::isValid() const
{
    if (!m_handle)
        return false;
    return QIfServiceManager::instance()->d_ptr->verifyHandle(m_handle);
}

/*!
    \qmlproperty bool ServiceObjectHandle::loaded

    Returns \c true if the backend is loaded; otherwise \c false.
*/
/*!
    \property QIfServiceObjectHandle::loaded

    Returns \c true if the backend is loaded; otherwise \c false.
*/
bool QIfServiceObjectHandle::isLoaded() const
{
    return bool(serviceObject());
}

/*!
    \qmlproperty ServiceObject ServiceObjectHandle::serviceObject

    Returns the ServiceObject associated with this handle.
*/
/*!
    \property QIfServiceObjectHandle::serviceObject

    Returns the ServiceObject associated with this handle.
*/
QIfServiceObject *QIfServiceObjectHandle::serviceObject() const
{
    if (!m_handle)
        return nullptr;

    Backend *backend = QIfServiceManager::instance()->d_ptr->verifyHandle(m_handle);
    if (!backend)
        return nullptr;

    return backend->proxyServiceObject;
}

QIfServiceObjectHandle::QIfServiceObjectHandle(void *handle)
    : m_handle(handle)
{
}


/*!
    \class QIfServiceManager
    \inmodule QtInterfaceFramework
    \brief QIfServiceManager provides the backends to QIfAbstractFeature.

    QIfServiceManager is the heart of QtInterfaceFramework and provides you with an easy way to detect which
    backends and interfaces are available.

    By default, QIfServiceManager reads the metaData of all plugins within the \e interfaceframework folder
    in your plugin path. The plugin itself is loaded when you request for it explicitly, using
    findServiceByInterface().

    The manager can distinguish between \e Production and \e Simulation backends, using the
    filename or the metaData.

    Simulation Backends can set the \c simulation key in their plugin metadata to \c true or use
    one of two supported plugin postfixes (_simulation, _simulator) in the plugin filename.

    The registerService() function can be used to add Backend classes without putting them into
    a plugin.

    The service manager is a process-wide singleton and can be accessed through the \l instance
    method.

    If you require more detailed information on which plugins are recognized, make sure you enable
    the \c{qt.if.servicemanagement} logging category.

    For more information on how backends are loaded, see \l {Dynamic Backend System}.

    \note The QIfServiceManager only accepts plugins that match the build configuration used
    for building qtinterfaceframework. This means a qtinterfaceframework "release" build won't accept plugins from a
    "debug" build.
*/

/*!
    \enum QIfServiceManager::Roles

    \value NameRole
           The backend's name, such as MediaPlugin.
    \value ServiceObjectRole
           The actual QIfServiceObject, which can be used to connect a frontend API to this
           backend.
           \note When using this role in the data() function, the backend plugin is loaded and
           instantiated. Since 6.8 you can use the ServiceObjectHandleRole to have more control
           over loading the backend.
    \value InterfacesRole
           A list of interfaces that the backend implements.
    \value ServiceObjectHandleRole
           The handle to the backend, which can be used to load the backend asynchronously.
*/

/*!
    \enum QIfServiceManager::SearchFlag

    \value IncludeProductionBackends
           Include production backends in the search result. \sa ProductionBackend
    \value IncludeSimulationBackends
           Include simulation backends in the search result. \sa SimulationBackend
    \value IncludeAll
           Include both production and simulation backends in the search result.
*/

/*!
    \enum QIfServiceManager::BackendType

    \value ProductionBackend
           A backend controlling a real automotive interface, such as a climate control connected
           over the CAN bus.
    \value SimulationBackend
           A backend used for development, that only returns simulation values and won't be
           deployed to the final hardware.
*/

/*!
    \qmltype ServiceManager
    \nativetype QIfServiceManager
    \inqmlmodule QtInterfaceFramework
    \brief The central instance that loads the backends and provides ServiceObjects.

    The ServiceManager singleton provides a model which can be used to list all available backends
    and their interfaces.

    This class can be useful when you want to query all available backends for a specific interface.
    For example, to show a list of all available backends which implement the MediaPlayer interface.
    The use can then be presented with an option to select between local playback, or playback using
    a bluetooth device.

    The ServiceManager implements the QAbstractListModel interface and provides the following roles:

    \table
    \header
        \li Role Name
        \li Type
        \li Description
    \row
        \li \c name
        \li string
        \li The backend's name, such as MediaPlugin.
    \row
        \li \c serviceObject
        \li ServiceObject
        \li The actual QIfServiceObject, which can be used to connect a frontend API to this backend.
            \note When using this role in the data() function, the backend plugin is loaded and
            instantiated.
    \row
        \li \c interfaces
        \li list<string>
        \li A list of interfaces implemented by the backend.
    \endtable

    For more information about QIfServiceManager and how it works, see its \l{QIfServiceManager}{C++ documentation}.
*/

QIfServiceManager::QIfServiceManager(QObject *parent)
    : QAbstractListModel(parent)
    , d_ptr(new QIfServiceManagerPrivate(this))
{
    QtInterfaceFrameworkModule::registerTypes();
    d_ptr->searchPlugins();
}

/*!
    Returns the global service manager instance.
*/
QIfServiceManager *QIfServiceManager::instance()
{
    static auto *instance = new QIfServiceManager(qApp);
    return instance;
}

QIfServiceManager *QIfServiceManager::create(QQmlEngine *, QJSEngine *)
{
    auto manager = QIfServiceManager::instance();
    QQmlEngine::setObjectOwnership(manager, QQmlEngine::CppOwnership);
    return manager;
}

QIfServiceManager::~QIfServiceManager()
{
    unloadAllBackends();
    delete d_ptr;
}

/*!
    \qmlmethod list<ServiceObject> ServiceManager::findServiceByInterface(interface, searchFlags, preferredBackends)

    Returns a list of backends implementing the specified \a interface.

    The \a searchFlags argument can be used to control which type of backends are included in the
    search result:

    \value IncludeProductionBackends
           Include production backends in the search result. See also \l {QIfServiceManager::}{ProductionBackend}
    \value IncludeSimulationBackends
           Include simulation backends in the search result. See also \l {QIfServiceManager::}{SimulationBackend}
    \value IncludeAll
           Include both production and simulation backends in the search result.

    The \a preferredBackends argument is used to select a backend when multiple backends implement
    the specified interface.
    The wildcards are applied in order to the found backends. If the wildcard matches some backends
    those backends will be loaded, otherwise the next wildcard is used.
*/
/*!
    Returns a list of backends implementing the specified \a interface.

    The \a searchFlags argument can be used to control which type of backends are included in the
    search result.

    The \a preferredBackends argument is used to select a backend when multiple backends implement
    the specified interface.
    The wildcards are applied in order to the found backends. If the wildcard matches some backends
    those backends will be loaded, otherwise the next wildcard is used.

    \sa findServiceHandleByInterface()
*/
QList<QIfServiceObject *> QIfServiceManager::findServiceByInterface(const QString &interface, SearchFlags searchFlags, const QStringList &preferredBackends)
{
    Q_D(QIfServiceManager);
    d->searchPlugins();
    QList<QIfServiceObject *> serviceObjects;
    const QList<QIfServiceObjectHandle> handles = d->findServiceByInterface(interface, searchFlags, preferredBackends);
    for (auto handle : handles) {
        auto backend = d->createServiceObject(static_cast<Backend*>(handle.m_handle));
        if (backend)
            serviceObjects.append(backend);
    }

    return serviceObjects;
}

/*!
    \qmlmethod list<ServiceObjectHandle> ServiceManager::findServiceHandleByInterface(interface, searchFlags, preferredBackends)
    \since 6.8

    Returns a list of backend handles implementing the specified \a interface, which can be used to
    load the backend asynchronously using the \l {QIfServiceManager::}{loadServiceObject()} function.

    The \a searchFlags argument can be used to control which type of backends are included in the
    search result:

    \value IncludeProductionBackends
           Include production backends in the search result. See also \l {QIfServiceManager::}{ProductionBackend}
    \value IncludeSimulationBackends
           Include simulation backends in the search result. See also \l {QIfServiceManager::}{SimulationBackend}
    \value IncludeAll
           Include both production and simulation backends in the search result.

    The \a preferredBackends argument is used to select a backend when multiple backends implement
    the specified interface.
    The wildcards are applied in order to the found backends. If the wildcard matches some backends
    those backends will be returned, otherwise the next wildcard is used.
*/
/*!
    Returns a list of backend handles implementing the specified \a interface, which can be used to
    load the backend asynchronously using the \l {QIfServiceManager::}{loadServiceObject()} function.

    The \a searchFlags argument can be used to control which type of backends are included in the
    search result.

    The \a preferredBackends argument is used to select a backend when multiple backends implement
    the specified interface.
    The wildcards are applied in order to the found backends. If the wildcard matches some backends
    those backends will be returned, otherwise the next wildcard is used.

    \since 6.8
    \sa findServiceByInterface() loadServiceObject()
*/
QList<QIfServiceObjectHandle> QIfServiceManager::findServiceHandleByInterface(const QString &interface, QIfServiceManager::SearchFlags searchFlags, const QStringList &preferredBackends)
{
    Q_D(QIfServiceManager);
    d->searchPlugins();
    return d->findServiceByInterface(interface, searchFlags, preferredBackends);
}

/*!
    Registers a backend. The \a serviceBackendInterface specified must implement the
    QIfServiceInterface, otherwise the registration will fail. \a interfaces is a list of at least
    one interface, supported by the backend. The \a backendType indicates the type of the backend
    and influences whether the backend can be found by the Feature's auto discovery option.

    The ownership of \a serviceBackendInterface is transferred to the QIfServiceManager.

    Returns \c true if the backend was successfully registered; otherwise \c false.

    \sa QIfServiceInterface
*/
bool QIfServiceManager::registerService(QObject *serviceBackendInterface, const QStringList &interfaces, BackendType backendType)
{
    Q_D(QIfServiceManager);
    return d->registerBackend(serviceBackendInterface, interfaces, backendType);
}

/*!
    \internal

    Unloads all backends currently loaded . Commonly only used for unit testing.
*/
void QIfServiceManager::unloadAllBackends()
{
    Q_D(QIfServiceManager);
    d->unloadAllBackends();
}

/*!
    \qmlmethod bool ServiceManager::hasInterface(interface)

    Returns \c true if the specified \a interface has been registered.
*/
/*!
    Returns \c true if the specified \a interface has been registered.
*/
bool QIfServiceManager::hasInterface(const QString &interface) const
{
    Q_D(const QIfServiceManager);
    return d->m_interfaceNames.contains(interface);
}

/*!
    Returns the number of rows for the given \a parent. Typically \a parent is an empty model
    index.

    \sa QAbstractListModel::data()
*/
int QIfServiceManager::rowCount(const QModelIndex &parent) const
{
    Q_D(const QIfServiceManager);
    return parent.isValid() ? 0 : int(d->m_backends.count());
}

/*!
    Returns the data for the \a index and \a role specified.

    \sa QAbstractListModel::data()
*/
QVariant QIfServiceManager::data(const QModelIndex &index, int role) const
{
    Q_D(const QIfServiceManager);

    if (!index.isValid())
        return QVariant();

    int row = index.row();

    if (row < 0 || row >= d->m_backends.count())
        return QVariant();

    Backend *backend = d->m_backends.at(row);

    switch (role) {
    case NameRole: return backend->name;
    case ServiceObjectRole: return QVariant::fromValue(d->createServiceObject(backend));
    case InterfacesRole: return backend->metaData[interfacesLiteral];
    case ServiceObjectHandleRole: return QVariant::fromValue(QIfServiceObjectHandle(backend));
    }

    return QVariant();
}


/*!
    \reimp
*/
QHash<int, QByteArray> QIfServiceManager::roleNames() const
{
    static QHash<int, QByteArray> roles;
    if (roles.isEmpty()) {
        roles[NameRole] = "name";
        roles[ServiceObjectRole] = "serviceObject";
        roles[InterfacesRole] = "interfaces";
        roles[ServiceObjectHandleRole] = "serviceObjectHandle";
    }
    return roles;
}

/*!
    \qmlmethod void ServiceManager::loadServiceObject(handle, async)
    \since 6.8

    Loads the backend specified by the \a handle. If \a async is \c true, the backend
    is loaded asynchronously.

    Emits serviceObjectLoaded() once the backend is loaded successfully or an error occurred.

    \note The signal is always emitted, even if the backend is already loaded or could not be loaded
    at all.
*/
/*!
    Loads the backend specified by the \a handle. If \a async is \c true, the backend
    is loaded asynchronously.

    Emits serviceObjectLoaded() once the backend is loaded successfully or an error occurred.

    \since 6.8
    \note The signal is always emitted, even if the backend is already loaded or could not be loaded
    at all.
*/
void QIfServiceManager::loadServiceObject(QIfServiceObjectHandle handle, bool async)
{
    Q_D(QIfServiceManager);

    if (!d->m_backends.contains(handle.m_handle))
        return;

    Backend *backend = static_cast<Backend*>(handle.m_handle);
    if (async) {
        d->loadServiceBackendInterfaceAsync(backend);
    } else {
        d->createServiceObject(backend);
        emit serviceObjectLoaded(handle);
    }
}

/*!
    \qmlsignal ServiceManager::serviceObjectLoaded(handle)
    \since 6.8

    This signal is emitted when a backend identified by \a handle is loaded successfully or an
    error occurred as a result of calling loadServiceObject().
*/
/*!
    \fn void QIfServiceManager::serviceObjectLoaded(QIfServiceObjectHandle handle)
    This signal is emitted when a backend identified by \a handle is loaded successfully or an
    error occurred as a result of calling loadServiceObject().

    \since 6.8
*/

QT_END_NAMESPACE

#include "moc_qifservicemanager.cpp"