/*
$info$
tags: thunklibs|GL
desc: Uses glXGetProcAddress instead of dlsym
$end_info$
*/

#include <cstdio>
#include <cstdlib>
#include <string_view>

#define GL_GLEXT_PROTOTYPES 1
#define GLX_GLXEXT_PROTOTYPES 1

#include "glcorearb.h"

#include <GL/glx.h>
#include <GL/glxext.h>
#include <GL/gl.h>
#include <GL/glext.h>
#include <xcb/xcb.h>

#include "common/Host.h"
#include "common/X11Manager.h"

template<>
struct host_layout<_XDisplay*> {
  _XDisplay* data;
  _XDisplay* guest_display;

  host_layout(guest_layout<_XDisplay*>&);

  ~host_layout();
};

static X11Manager x11_manager;

static void* (*GuestMalloc)(size_t) = nullptr;

host_layout<_XDisplay*>::host_layout(guest_layout<_XDisplay*>& guest)
  : guest_display(guest.force_get_host_pointer()) {
  data = x11_manager.GuestToHostDisplay(guest_display);
}

host_layout<_XDisplay*>::~host_layout() {
  // Flush host-side event queue to make effects of the guest-side connection visible
  x11_manager.HostXFlush(data);
}

static void fexfn_impl_libGL_SetGuestMalloc(uintptr_t GuestTarget, uintptr_t GuestUnpacker) {
  MakeHostTrampolineForGuestFunctionAt(GuestTarget, GuestUnpacker, &GuestMalloc);
}

static void fexfn_impl_libGL_SetGuestXGetVisualInfo(uintptr_t GuestTarget, uintptr_t GuestUnpacker) {
  MakeHostTrampolineForGuestFunctionAt(GuestTarget, GuestUnpacker, &x11_manager.GuestXGetVisualInfo);
}

static void fexfn_impl_libGL_SetGuestXSync(uintptr_t GuestTarget, uintptr_t GuestUnpacker) {
  MakeHostTrampolineForGuestFunctionAt(GuestTarget, GuestUnpacker, &x11_manager.GuestXSync);
}

static void fexfn_impl_libGL_SetGuestXDisplayString(uintptr_t GuestTarget, uintptr_t GuestUnpacker) {
  MakeHostTrampolineForGuestFunctionAt(GuestTarget, GuestUnpacker, &x11_manager.GuestXDisplayString);
}

#include "thunkgen_host_libGL.inl"

auto fexfn_impl_libGL_glXGetProcAddress(const GLubyte* name) -> void (*)() {
  using VoidFn = void (*)();
  std::string_view name_sv {reinterpret_cast<const char*>(name)};
  if (name_sv == "glXChooseFBConfig") {
    return (VoidFn)fexfn_impl_libGL_glXChooseFBConfig;
  } else if (name_sv == "glXChooseFBConfigSGIX") {
    return (VoidFn)fexfn_impl_libGL_glXChooseFBConfigSGIX;
  } else if (name_sv == "glXGetFBConfigs") {
    return (VoidFn)fexfn_impl_libGL_glXGetFBConfigs;
  } else if (name_sv == "glXGetFBConfigFromVisualSGIX") {
    return (VoidFn)fexfn_impl_libGL_glXGetFBConfigFromVisualSGIX;
  } else if (name_sv == "glXGetVisualFromFBConfigSGIX") {
    return (VoidFn)fexfn_impl_libGL_glXGetVisualFromFBConfigSGIX;
  } else if (name_sv == "glXChooseVisual") {
    return (VoidFn)fexfn_impl_libGL_glXChooseVisual;
  } else if (name_sv == "glXCreateContext") {
    return (VoidFn)fexfn_impl_libGL_glXCreateContext;
  } else if (name_sv == "glXCreateGLXPixmap") {
    return (VoidFn)fexfn_impl_libGL_glXCreateGLXPixmap;
  } else if (name_sv == "glXCreateGLXPixmapMESA") {
    return (VoidFn)fexfn_impl_libGL_glXCreateGLXPixmapMESA;
  } else if (name_sv == "glXGetConfig") {
    return (VoidFn)fexfn_impl_libGL_glXGetConfig;
  } else if (name_sv == "glXGetVisualFromFBConfig") {
    return (VoidFn)fexfn_impl_libGL_glXGetVisualFromFBConfig;
  }
  return (VoidFn)glXGetProcAddress((const GLubyte*)name);
}

// Relocate data to guest heap so it can be called with XFree.
// The memory at the given host location will be de-allocated.
template<typename T>
T* RelocateArrayToGuestHeap(T* Data, int NumItems) {
  if (!Data) {
    return nullptr;
  }

  guest_layout<T*> GuestData;
  GuestData.data = reinterpret_cast<uintptr_t>(GuestMalloc(sizeof(guest_layout<T>) * NumItems));
  for (int Index = 0; Index < NumItems; ++Index) {
    GuestData.get_pointer()[Index] = to_guest(to_host_layout(Data[Index]));
  }
  x11_manager.HostXFree(Data);
  return GuestData.force_get_host_pointer();
}

// Maps to a host-side XVisualInfo, which must be XFree'ed by the caller.
static XVisualInfo* LookupHostVisualInfo(Display* HostDisplay, guest_layout<XVisualInfo*> GuestInfo) {
  if (!GuestInfo.data) {
    return nullptr;
  }

  int num_matches;
  auto ret = x11_manager.HostXGetVisualInfo(HostDisplay, VisualScreenMask | VisualIDMask, GuestInfo.force_get_host_pointer(), &num_matches);
  if (num_matches != 1) {
    fprintf(stderr, "ERROR: Did not find unique host XVisualInfo\n");
    std::abort();
  }
  return ret;
}

// Maps to a guest-side XVisualInfo and destroys the host argument.
static guest_layout<XVisualInfo*> MapToGuestVisualInfo(Display* HostDisplay, XVisualInfo* HostInfo) {
  if (!HostInfo) {
    return guest_layout<XVisualInfo*> {.data = 0};
  }

  int num_matches;
  auto guest_display = x11_manager.HostToGuestDisplay(HostDisplay);
  auto ret = x11_manager.GuestXGetVisualInfo(guest_display.get_pointer(), VisualScreenMask | VisualIDMask, HostInfo, &num_matches);
  if (num_matches != 1) {
    fprintf(stderr, "ERROR: Did not find unique guest XVisualInfo\n");
    std::abort();
  }

  // We effectively relocated the VisualInfo, so free the original one now
  x11_manager.HostXFree(HostInfo);
  guest_layout<XVisualInfo*> GuestRet;
  GuestRet.data = reinterpret_cast<uintptr_t>(ret);
  return GuestRet;
}

GLXFBConfig* fexfn_impl_libGL_glXChooseFBConfig(Display* Display, int Screen, const int* Attributes, int* NumItems) {
  auto ret = fexldr_ptr_libGL_glXChooseFBConfig(Display, Screen, Attributes, NumItems);
  return RelocateArrayToGuestHeap(ret, *NumItems);
}

GLXFBConfigSGIX* fexfn_impl_libGL_glXChooseFBConfigSGIX(Display* Display, int Screen, int* Attributes, int* NumItems) {
  auto ret = fexldr_ptr_libGL_glXChooseFBConfigSGIX(Display, Screen, Attributes, NumItems);
  return RelocateArrayToGuestHeap(ret, *NumItems);
}

GLXFBConfig* fexfn_impl_libGL_glXGetFBConfigs(Display* Display, int Screen, int* NumItems) {
  auto ret = fexldr_ptr_libGL_glXGetFBConfigs(Display, Screen, NumItems);
  return RelocateArrayToGuestHeap(ret, *NumItems);
}

GLXFBConfigSGIX fexfn_impl_libGL_glXGetFBConfigFromVisualSGIX(Display* Display, guest_layout<XVisualInfo*> Info) {
  auto HostInfo = LookupHostVisualInfo(Display, Info);
  auto ret = fexldr_ptr_libGL_glXGetFBConfigFromVisualSGIX(Display, HostInfo);
  x11_manager.HostXFree(HostInfo);
  return ret;
}

guest_layout<XVisualInfo*> fexfn_impl_libGL_glXGetVisualFromFBConfigSGIX(Display* Display, GLXFBConfigSGIX Config) {
  return MapToGuestVisualInfo(Display, fexldr_ptr_libGL_glXGetVisualFromFBConfigSGIX(Display, Config));
}

guest_layout<XVisualInfo*> fexfn_impl_libGL_glXChooseVisual(Display* Display, int Screen, int* Attributes) {
  return MapToGuestVisualInfo(Display, fexldr_ptr_libGL_glXChooseVisual(Display, Screen, Attributes));
}

GLXContext fexfn_impl_libGL_glXCreateContext(Display* Display, guest_layout<XVisualInfo*> Info, GLXContext ShareList, Bool Direct) {
  auto HostInfo = LookupHostVisualInfo(Display, Info);
  auto ret = fexldr_ptr_libGL_glXCreateContext(Display, HostInfo, ShareList, Direct);
  x11_manager.HostXFree(HostInfo);
  return ret;
}

GLXPixmap fexfn_impl_libGL_glXCreateGLXPixmap(Display* Display, guest_layout<XVisualInfo*> Info, Pixmap Pixmap) {
  auto HostInfo = LookupHostVisualInfo(Display, Info);
  auto ret = fexldr_ptr_libGL_glXCreateGLXPixmap(Display, HostInfo, Pixmap);
  x11_manager.HostXFree(HostInfo);
  return ret;
}

GLXPixmap fexfn_impl_libGL_glXCreateGLXPixmapMESA(Display* Display, guest_layout<XVisualInfo*> Info, Pixmap Pixmap, Colormap Colormap) {
  auto HostInfo = LookupHostVisualInfo(Display, Info);
  auto ret = fexldr_ptr_libGL_glXCreateGLXPixmapMESA(Display, HostInfo, Pixmap, Colormap);
  x11_manager.HostXFree(HostInfo);
  return ret;
}

int fexfn_impl_libGL_glXGetConfig(Display* Display, guest_layout<XVisualInfo*> Info, int Attribute, int* Value) {
  auto HostInfo = LookupHostVisualInfo(Display, Info);
  auto ret = fexldr_ptr_libGL_glXGetConfig(Display, HostInfo, Attribute, Value);
  x11_manager.HostXFree(HostInfo);
  return ret;
}

guest_layout<XVisualInfo*> fexfn_impl_libGL_glXGetVisualFromFBConfig(Display* Display, GLXFBConfig Config) {
  return MapToGuestVisualInfo(Display, fexldr_ptr_libGL_glXGetVisualFromFBConfig(Display, Config));
}

EXPORTS(libGL)