#include <QApplication>
#include <QtCore/private/qsystemlibrary_p.h>
#include <QFunctionPointer>
#include "TestMainWindow.h"

#include <dwrite_2.h>
#include <d2d1.h>

IDWriteFactory *directWriteFactory = nullptr;
IDWriteGdiInterop *directWriteGdiInterop = nullptr;

typedef HRESULT(WINAPI *DWriteCreateFactoryType)(DWRITE_FACTORY_TYPE, const IID &, IUnknown **);

static inline DWriteCreateFactoryType resolveDWriteCreateFactory()
{
    QSystemLibrary library(QStringLiteral("dwrite"));
    QFunctionPointer result = library.resolve("DWriteCreateFactory");
    if (Q_UNLIKELY(!result))
    {
        qWarning("Unable to load dwrite.dll");
        return nullptr;
    }
    return reinterpret_cast<DWriteCreateFactoryType>(result);
}

static void createDirectWriteFactory(IDWriteFactory *&factory)
{
    factory = nullptr;

    static const DWriteCreateFactoryType dWriteCreateFactory = resolveDWriteCreateFactory();
    if (!dWriteCreateFactory)
        return;

    IUnknown *result = NULL;

    dWriteCreateFactory(DWRITE_FACTORY_TYPE_SHARED, __uuidof(IDWriteFactory2), &result);

    if (result == NULL)
    {
        if (FAILED(dWriteCreateFactory(DWRITE_FACTORY_TYPE_SHARED, __uuidof(IDWriteFactory), &result)))
        {
            qErrnoWarning("DWriteCreateFactory failed");
            return;
        }
    }

    factory = static_cast<IDWriteFactory *>(result);
}

static inline bool initDirectWrite()
{
    if (!directWriteFactory)
    {
        createDirectWriteFactory(directWriteFactory);
        if (!directWriteFactory)
            return false;
    }
    if (!directWriteGdiInterop)
    {
        const HRESULT hr = directWriteFactory->GetGdiInterop(&directWriteGdiInterop);
        if (FAILED(hr))
        {
            qErrnoWarning("%s: GetGdiInterop failed", __FUNCTION__);
            return false;
        }
    }
    return true;
}

int main(int argc, char *argv[])
{

    HDC displayDC = GetDC(0);
    auto hdc = CreateCompatibleDC(displayDC);
    ReleaseDC(0, displayDC);

    initDirectWrite();

    IDWriteFontFace *directWriteFontFace = NULL;
    HRESULT hr = directWriteGdiInterop->CreateFontFaceFromHdc(hdc, &directWriteFontFace);

    QApplication a(argc, argv);

    TestMainWindow w;
    w.show();

    return a.exec();
}