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#include <sharedimageprovider.h>
#include <qsharedimageloader_p.h>
#include <private/qquickpixmapcache_p.h>
#include <private/qimage_p.h>
#include <QImageReader>
#include <QFileInfo>
#include <QDir>

Q_DECLARE_METATYPE(QQuickImageProviderOptions)

class QuickSharedImageLoader : public QSharedImageLoader
{
    Q_OBJECT
    friend class SharedImageProvider;

public:
    enum ImageParameter {
        OriginalSize = 0,
        RequestedSize,
        ProviderOptions,
        NumImageParameters
    };

    QuickSharedImageLoader(QObject *parent = nullptr)
        : QSharedImageLoader(parent)
    {
    }

protected:
    QImage loadFile(const QString &path, ImageParameters *params) override
    {
        QImageReader imgio(path);
        QSize realSize = imgio.size();
        QSize requestSize;
        QQuickImageProviderOptions options;
        if (params) {
            requestSize = params->value(RequestedSize).toSize();
            options = params->value(ProviderOptions).value<QQuickImageProviderOptions>();
        }

        QSize scSize = QQuickImageProviderWithOptions::loadSize(imgio.size(), requestSize, imgio.format(), options);

        if (scSize.isValid())
            imgio.setScaledSize(scSize);

        QImage image;
        if (imgio.read(&image)) {
            if (realSize.isEmpty())
                realSize = image.size();
            // Make sure we have acceptable format for texture uploader, or it will convert & lose sharing
            // This mimics the testing & conversion normally done by the quick pixmapcache & texturefactory
            if (image.format() != QImage::Format_RGB32 && image.format() != QImage::Format_ARGB32_Premultiplied) {
                QImage::Format newFmt = QImage::Format_RGB32;
                if (image.hasAlphaChannel() && image.data_ptr()->checkForAlphaPixels())
                    newFmt = QImage::Format_ARGB32_Premultiplied;
                qCDebug(lcSharedImage) << "Convert on load from format" << image.format() << "to" << newFmt;
                image = image.convertToFormat(newFmt);
            }
        }

        if (params && params->count() > OriginalSize)
            params->replace(OriginalSize, realSize);

        return image;
    }

    QString key(const QString &path, ImageParameters *params) override
    {
        QSize reqSz;
        QQuickImageProviderOptions opts;
        if (params) {
            reqSz = params->value(RequestedSize).toSize();
            opts = params->value(ProviderOptions).value<QQuickImageProviderOptions>();
        }
        if (!reqSz.isValid())
            return path;
        int aspect = opts.preserveAspectRatioCrop() || opts.preserveAspectRatioFit() ? 1 : 0;

        QString key = path + QStringLiteral("_%1x%2_%3").arg(reqSz.width()).arg(reqSz.height()).arg(aspect);
        qCDebug(lcSharedImage) << "KEY:" << key;
        return key;
    }
};


SharedImageProvider::SharedImageProvider()
    : QQuickImageProviderWithOptions(QQuickImageProvider::Image), loader(new QuickSharedImageLoader)
{
}

QImage SharedImageProvider::requestImage(const QString &id, QSize *size, const QSize &requestedSize, const QQuickImageProviderOptions &options)
{
    QFileInfo fi(QDir::root(), id);
    QString path = fi.canonicalFilePath();
    if (path.isEmpty())
        return QImage();

    QSharedImageLoader::ImageParameters params(QuickSharedImageLoader::NumImageParameters);
    params[QuickSharedImageLoader::RequestedSize].setValue(requestedSize);
    params[QuickSharedImageLoader::ProviderOptions].setValue(options);

    QImage img = loader->load(path, &params);
    if (img.isNull()) {
        // May be sharing problem, fall back to normal local load
        img = loader->loadFile(path, &params);
        if (!img.isNull())
            qCWarning(lcSharedImage) << "Sharing problem; loading" << id << "unshared";
    }

    //... QSize realSize = params.value(QSharedImageLoader::OriginalSize).toSize();
    // quickpixmapcache's readImage() reports back the original size, prior to requestedSize scaling, in the *size
    // parameter. That value is currently ignored by quick however, which only cares about the present size of the
    // returned image. So handling and sharing of info on pre-scaled size is currently not implemented.
    if (size) {
        *size = img.size();
    }

    return img;
}

#include "sharedimageprovider.moc"