// Copyright (C) 2018 The Qt Company Ltd.

// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

#include "private/qimagereaderwriterhelpers_p.h"

#include <qcborarray.h>

#include <qmutex.h>

#include <private/qfactoryloader_p.h>

QT_BEGIN_NAMESPACE

using namespace Qt::StringLiterals;

namespace QImageReaderWriterHelpers {

#ifndef QT_NO_IMAGEFORMATPLUGIN

Q_GLOBAL_STATIC_WITH_ARGS(QFactoryLoader, irhLoader,

                          (QImageIOHandlerFactoryInterface_iid, "/imageformats"_L1))

Q_GLOBAL_STATIC(QMutex, irhLoaderMutex)

static void appendImagePluginFormats(QFactoryLoader *loader,

                                     QImageIOPlugin::Capability cap,

                                     QList<QByteArray> *result)

{

    typedef QMultiMap<int, QString> PluginKeyMap;

    typedef PluginKeyMap::const_iterator PluginKeyMapConstIterator;

    const PluginKeyMap keyMap = loader->keyMap();

    const PluginKeyMapConstIterator cend = keyMap.constEnd();

    int i = -1;

    QImageIOPlugin *plugin = nullptr;

    result->reserve(result->size() + keyMap.size());

    for (PluginKeyMapConstIterator it = keyMap.constBegin(); it != cend; ++it) {

        if (it.key() != i) {

            i = it.key();

            plugin = qobject_cast<QImageIOPlugin *>(loader->instance(i));

        }

        const QByteArray key = it.value().toLatin1();

        if (plugin && (plugin->capabilities(nullptr, key) & cap) != 0)

            result->append(key);

    }

}

static void appendImagePluginMimeTypes(QFactoryLoader *loader,

                                       QImageIOPlugin::Capability cap,

                                       QList<QByteArray> *result,

                                       QList<QByteArray> *resultKeys = nullptr)

{

    QList<QPluginParsedMetaData> metaDataList = loader->metaData();

    const int pluginCount = metaDataList.size();

    for (int i = 0; i < pluginCount; ++i) {

        const QCborMap metaData = metaDataList.at(i).value(QtPluginMetaDataKeys::MetaData).toMap();

        const QCborArray keys = metaData.value("Keys"_L1).toArray();

        const QCborArray mimeTypes = metaData.value("MimeTypes"_L1).toArray();

        QImageIOPlugin *plugin = qobject_cast<QImageIOPlugin *>(loader->instance(i));

        const int keyCount = keys.size();

        for (int k = 0; k < keyCount; ++k) {

            const QByteArray key = keys.at(k).toString().toLatin1();

            if (plugin && (plugin->capabilities(nullptr, key) & cap) != 0) {

                result->append(mimeTypes.at(k).toString().toLatin1());

                if (resultKeys)

                    resultKeys->append(key);

            }

        }

    }

}

QSharedPointer<QFactoryLoader> pluginLoader()

{

    irhLoaderMutex()->lock();

    return QSharedPointer<QFactoryLoader>(irhLoader(), [](QFactoryLoader *) {

        irhLoaderMutex()->unlock();

    });

}

static inline QImageIOPlugin::Capability pluginCapability(Capability cap)

{

    return cap == CanRead ? QImageIOPlugin::CanRead : QImageIOPlugin::CanWrite;

}

#endif // QT_NO_IMAGEFORMATPLUGIN

QList<QByteArray> supportedImageFormats(Capability cap)

{

    QList<QByteArray> formats;

    formats.reserve(_qt_NumFormats);

    for (int i = 0; i < _qt_NumFormats; ++i)

        formats << _qt_BuiltInFormats[i].extension;

#ifndef QT_NO_IMAGEFORMATPLUGIN

    appendImagePluginFormats(irhLoader(), pluginCapability(cap), &formats);

#endif // QT_NO_IMAGEFORMATPLUGIN

    std::sort(formats.begin(), formats.end());

    formats.erase(std::unique(formats.begin(), formats.end()), formats.end());

    return formats;

}

static constexpr QByteArrayView imagePrefix() noexcept { return "image/"; }

QList<QByteArray> supportedMimeTypes(Capability cap)

{

    QList<QByteArray> mimeTypes;

    mimeTypes.reserve(_qt_NumFormats);

    for (const auto &fmt : _qt_BuiltInFormats)

        mimeTypes.emplace_back(imagePrefix() + fmt.mimeType);

#ifndef QT_NO_IMAGEFORMATPLUGIN

    appendImagePluginMimeTypes(irhLoader(), pluginCapability(cap), &mimeTypes);

#endif // QT_NO_IMAGEFORMATPLUGIN

    std::sort(mimeTypes.begin(), mimeTypes.end());

    mimeTypes.erase(std::unique(mimeTypes.begin(), mimeTypes.end()), mimeTypes.end());

    return mimeTypes;

}

QList<QByteArray> imageFormatsForMimeType(QByteArrayView mimeType, Capability cap)

{

    QList<QByteArray> formats;

    if (mimeType.startsWith(imagePrefix())) {

        const QByteArrayView type = mimeType.mid(imagePrefix().size());

        for (const auto &fmt : _qt_BuiltInFormats) {

            if (fmt.mimeType == type && !formats.contains(fmt.extension))

                formats << fmt.extension;

        }

    }

#ifndef QT_NO_IMAGEFORMATPLUGIN

    QList<QByteArray> mimeTypes;

    QList<QByteArray> keys;

    appendImagePluginMimeTypes(irhLoader(), pluginCapability(cap), &mimeTypes, &keys);

    for (int i = 0; i < mimeTypes.size(); ++i) {

        if (mimeTypes.at(i) == mimeType) {

            const auto &key = keys.at(i);

            if (!formats.contains(key))

                formats << key;

        }

    }

#endif // QT_NO_IMAGEFORMATPLUGIN

    return formats;

}

} // QImageReaderWriterHelpers

QT_END_NAMESPACE