#include <stdio.h>
#include <stdlib.h>
#include <X11/Xlibint.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/cursorfont.h>
#include <X11/keysymdef.h>
#include <X11/keysym.h>
#include <X11/extensions/record.h>
#include <X11/extensions/XTest.h>
#include <X11/Xproto.h>

/*
  The typical communication model for a recording client is to open two
  connections to the server and use one for RC control and the other for reading protocol data.
  https://www.x.org/releases/X11R7.6/doc/recordproto/record.html#Record_Client_Connections
*/

Display *data_disp = NULL;
Display *ctrl_disp = NULL;

int stop = 0;

void event_callback (XPointer, XRecordInterceptData*);

int main (int argc, char **argv)
{
  ctrl_disp = XOpenDisplay (NULL);
  data_disp = XOpenDisplay (NULL);

  if (!ctrl_disp || !data_disp) {
    fprintf (stderr, "Error to open local display!\n");
    exit (1);
  }

  /* without this the record context is sent before we have the display */
  /* there must be a better solution to this */
  XSynchronize(ctrl_disp,True);

  int major, minor;
  if (!XRecordQueryVersion (ctrl_disp, &major, &minor)) {
    fprintf (stderr, "RECORD extension not supported on this X server!\n");
    exit (2);
  }
 
  printf ("RECORD extension for local server is version is %d.%d\n", major, minor);

  XRecordRange  *rr;
  XRecordClientSpec  rcs;
  XRecordContext   rc;

  rr = XRecordAllocRange ();
  if (!rr) {
    fprintf (stderr, "Could not alloc record range object!\n");
    exit (3);
  }

  rr->core_requests.first = X_GrabPointer;
  rr->core_requests.last = X_UngrabKey;
  rcs = XRecordAllClients;

  rc = XRecordCreateContext (ctrl_disp, 0, &rcs, 1, &rr, 1);
  if (!rc) {
    fprintf (stderr, "Could not create a record context!\n");
    exit (4);
  }
 
  if (!XRecordEnableContext (data_disp, rc, event_callback, NULL)) {
    fprintf (stderr, "Cound not enable the record context!\n");
    exit (5);
  }

  while (stop != 1) {
    XRecordProcessReplies (data_disp);
  }

  XRecordDisableContext (ctrl_disp, rc);
  XRecordFreeContext (ctrl_disp, rc);
  XFree (rr);
 
  XCloseDisplay (data_disp);
  XCloseDisplay (ctrl_disp);
  return 0;
}

void event_callback(XPointer priv, XRecordInterceptData *hook) {
    if (hook->category != XRecordFromServer && hook->category != XRecordFromClient) {
        XRecordFreeData(hook);
        return;
    }

    xReq *request = (xReq *)hook->data;

    switch (request->reqType) {
        case X_GrabPointer:
            printf("GrabPointer request detected\n");
            break;
        case X_UngrabPointer:
            printf("UngrabPointer request detected\n");
            break;
		/* these occur way too frequently on my system */
        /* case X_GrabButton: */
        /*     printf("GrabButton request detected\n"); */
        /*     break; */
        /* case X_UngrabButton: */
        /*     printf("UngrabButton request detected\n"); */
        /*     break; */
        case X_ChangeActivePointerGrab:
            printf("ChangeActivePointerGrab request detected\n");
            break;
        case X_GrabKeyboard:
		{
			xGrabKeyboardReq *grab_req = (xGrabKeyboardReq *)hook->data;
            printf("GrabKeyboard request detected for Window ID: %i\n", grab_req->grabWindow);
            break;	
		}
        case X_UngrabKeyboard:
            printf("UngrabKeyboard request detected\n");
            break;
        case X_GrabKey:
            printf("GrabKey request detected\n");
            break;
        case X_UngrabKey:
            printf("UngrabKey request detected\n");
            break;
        default:
            break;
    }

    XRecordFreeData(hook);
}