#include "DesktopIconProvider.hpp"

#include <QFileInfo>
#include <QIcon>
#include <QPixmap>
#include <QUrl>

namespace {

QIcon resolveDesktopIcon(const QString &name)
{
    if (name.isEmpty())
        return {};

    const QFileInfo direct(name);
    if (direct.isAbsolute() && direct.exists())
        return QIcon(name);

    QIcon themed = QIcon::fromTheme(name);
    if (!themed.isNull())
        return themed;

    QString base = name;
    if (base.endsWith(QLatin1String(".png"), Qt::CaseInsensitive)
        || base.endsWith(QLatin1String(".svg"), Qt::CaseInsensitive)
        || base.endsWith(QLatin1String(".xpm"), Qt::CaseInsensitive)) {
        base = QFileInfo(base).completeBaseName();
        themed = QIcon::fromTheme(base);
        if (!themed.isNull())
            return themed;
    }

    const QStringList pixmapDirs = {
        QStringLiteral("/usr/share/pixmaps"),
        QStringLiteral("/usr/share/icons/hicolor/48x48/apps"),
        QStringLiteral("/usr/share/icons/hicolor/scalable/apps"),
    };
    const QStringList suffixes = {
        QString(),
        QStringLiteral(".png"),
        QStringLiteral(".svg"),
        QStringLiteral(".xpm"),
    };

    for (const QString &dir : pixmapDirs) {
        for (const QString &suffix : suffixes) {
            const QString candidate = dir + QLatin1Char('/') + (suffix.isEmpty() ? name : base) + suffix;
            if (QFileInfo::exists(candidate))
                return QIcon(candidate);
        }
    }

    return {};
}

} // namespace

DesktopIconProvider::DesktopIconProvider()
    : QQuickImageProvider(QQuickImageProvider::Pixmap)
{
}

QPixmap DesktopIconProvider::requestPixmap(const QString &id, QSize *size, const QSize &requestedSize)
{
    const QString iconName = QUrl::fromPercentEncoding(id.toUtf8());
    const QIcon icon = resolveDesktopIcon(iconName);
    const QSize target = requestedSize.isValid() && requestedSize.width() > 0 && requestedSize.height() > 0
        ? requestedSize
        : QSize(48, 48);

    if (icon.isNull()) {
        if (size)
            *size = target;
        return {};
    }

    const QPixmap pixmap = icon.pixmap(target);
    if (pixmap.isNull()) {
        if (size)
            *size = target;
        return {};
    }

    if (size)
        *size = pixmap.size();
    return pixmap;
}