#include "pixmap.hpp"

#include <windows.h>

namespace t5de {

namespace {

using Getter = unsigned(__thiscall*)(const imvu::Pixmap*);
using PixelsGetter = std::uint32_t*(__thiscall*)(const imvu::Pixmap*);

struct Methods {
    Getter width = nullptr;
    Getter height = nullptr;
    Getter rowBytes = nullptr;
    PixelsGetter pixels = nullptr;
};

const Methods& methods()
{
    static const Methods methods = [] {
        Methods found;
        if (HMODULE module = GetModuleHandleW(L"pixmap.dll")) {
            found.width = reinterpret_cast<Getter>(GetProcAddress(module, "?width@Pixmap@@QBEIXZ"));
            found.height = reinterpret_cast<Getter>(GetProcAddress(module, "?height@Pixmap@@QBEIXZ"));
            found.rowBytes = reinterpret_cast<Getter>(GetProcAddress(module, "?rowBytes@Pixmap@@QBEIXZ"));
            found.pixels = reinterpret_cast<PixelsGetter>(GetProcAddress(module, "?pixels@Pixmap@@QBEPAIXZ"));
        }
        return found;
    }();
    return methods;
}

} // namespace

std::optional<PixmapPixels> pixmap_pixels(const imvu::Pixmap& pixmap)
{
    const Methods& m = methods();
    if (m.width == nullptr || m.height == nullptr || m.rowBytes == nullptr || m.pixels == nullptr) {
        return std::nullopt;
    }
    return PixmapPixels{m.width(&pixmap), m.height(&pixmap), m.rowBytes(&pixmap), m.pixels(&pixmap)};
}

} // namespace t5de