/*
 * Copyright (C) 2005-2007 Carsten Haitzler
 * Copyright (C) 2006-2021 Kim Woelders
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies of the Software, its documentation and marketing & publicity
 * materials, and acknowledgment shall be given in the documentation, materials
 * and software packages that this Software was used.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
/*
 * Basic hack mechanism (dlopen etc.) taken from e_hack.c in e17.
 */
#include <stdio.h>
#include <stdlib.h>
#include <dlfcn.h>
#include <X11/Xlib.h>
#include <X11/X.h>

#include "config.h"
#include "util.h"

/* dlopened xlib so we can find the symbols in the real xlib to call them */
static void        *lib_xlib = NULL;

static Window       root = None;

/* Find our root window */
static              Window
MyRoot(Display * dpy)
{
   char               *s;

   if (root != None)
      return root;

   root = DefaultRootWindow(dpy);

   s = getenv("ENL_WM_ROOT");
   if (!s)
      return root;

   sscanf(s, "%lx", &root);
   return root;
}

/* find the real Xlib and the real X function */
static void        *
GetFunc(const char *name)
{
   void               *func;

   if (!lib_xlib)
      lib_xlib = dlopen("libX11.so", RTLD_GLOBAL | RTLD_LAZY);

   func = dlsym(lib_xlib, name);

   return func;
}

/*
 * XCreateWindow interception
 */

typedef             Window(CWF) (Display * _display, Window _parent, int _x,
				 int _y, unsigned int _width,
				 unsigned int _height,
				 unsigned int _border_width, int _depth,
				 unsigned int _class, Visual * _visual,
				 unsigned long _valuemask,
				 XSetWindowAttributes * _attributes);

__EXPORT__          Window
XCreateWindow(Display * display, Window parent, int x, int y,
	      unsigned int width, unsigned int height,
	      unsigned int border_width,
	      int depth, unsigned int clss, Visual * visual,
	      unsigned long valuemask, XSetWindowAttributes * attributes)
{
   static CWF         *func = NULL;

   if (!func)
      func = (CWF *) GetFunc("XCreateWindow");

   if (parent == DefaultRootWindow(display))
      parent = MyRoot(display);

   return (*func) (display, parent, x, y, width, height, border_width, depth,
		   clss, visual, valuemask, attributes);
}

/*
 * XCreateSimpleWindow interception
 */

typedef             Window(CSWF) (Display * _display, Window _parent, int _x,
				  int _y, unsigned int _width,
				  unsigned int _height,
				  unsigned int _border_width,
				  unsigned long _border,
				  unsigned long _background);

__EXPORT__          Window
XCreateSimpleWindow(Display * display, Window parent, int x, int y,
		    unsigned int width, unsigned int height,
		    unsigned int border_width,
		    unsigned long border, unsigned long background)
{
   static CSWF        *func = NULL;

   if (!func)
      func = (CSWF *) GetFunc("XCreateSimpleWindow");

   if (parent == DefaultRootWindow(display))
      parent = MyRoot(display);

   return (*func) (display, parent, x, y, width, height,
		   border_width, border, background);
}

/*
 * XReparentWindow interception
 */

typedef int         (RWF) (Display * _display, Window _window, Window _parent,
			   int x, int y);

__EXPORT__ int
XReparentWindow(Display * display, Window window, Window parent, int x, int y)
{
   static RWF         *func = NULL;

   if (!func)
      func = (RWF *) GetFunc("XReparentWindow");

   if (parent == DefaultRootWindow(display))
      parent = MyRoot(display);

   return (*func) (display, window, parent, x, y);
}

/*
 * XSendEvent interception
 */

typedef int         (SEF) (Display * display, Window window, Bool propagate,
			   long event_mask, XEvent * event_send);

__EXPORT__ int
XSendEvent(Display * display, Window window, Bool propagate,
	   long event_mask, XEvent * event_send)
{
   static SEF         *func = NULL;

   if (!func)
      func = (SEF *) GetFunc("XSendEvent");

   if (window == DefaultRootWindow(display))
      window = MyRoot(display);

   return (*func) (display, window, propagate, event_mask, event_send);
}

/*
 * XGetWindowProperty interception
 */

typedef int         (GWPF) (Display * display, Window w,
			    Atom property,
			    long long_offset, long long_length,
			    Bool delete_, Atom req_type,
			    Atom * actual_type_return,
			    int *actual_format_return,
			    unsigned long *nitems_return,
			    unsigned long *bytes_after_return,
			    unsigned char **prop_return);

__EXPORT__ int
XGetWindowProperty(Display * display, Window w, Atom property,
		   long long_offset, long long_length, Bool delete_,
		   Atom req_type, Atom * actual_type_return,
		   int *actual_format_return,
		   unsigned long *nitems_return,
		   unsigned long *bytes_after_return,
		   unsigned char **prop_return)
{
   static GWPF        *func = NULL;

   if (!func)
      func = (GWPF *) GetFunc("XGetWindowProperty");

   if (w == DefaultRootWindow(display))
      w = MyRoot(display);

   return func(display, w, property, long_offset, long_length, delete_,
	       req_type, actual_type_return, actual_format_return,
	       nitems_return, bytes_after_return, prop_return);
}