#include <stdlib.h>
#include <stdio.h>
#include <X11/Xlib.h>
#include <X11/Xatom.h>

#include <glib.h>

static Display *dpy;
static GHashTable *atom_name_hash;
static Atom XA_UTF8_STRING;

/* TODO: have a version which takes an array of atoms */
static const char *
atom_name (Atom atom)
{
  char *name;
  
  name = g_hash_table_lookup (atom_name_hash, GINT_TO_POINTER (atom));
  if (name)
    return name;

  name = XGetAtomName (dpy, atom);
  
  g_hash_table_insert (atom_name_hash, GINT_TO_POINTER (atom), name);

  return name;
}

static void
dump_name (const char *indent, Window window)
{
  char *name;

  XFetchName (dpy, window, &name);
  
  if (name) {
    printf ("%s%s\n", indent, name);
    XFree (name);
  } else {
    printf ("%s[unnamed]\n", indent);
  }
}

static void
dump_size (const char *indent, Window window)
{
  Window ignore;
  int x, y;
  unsigned int width, height, border, depth;
  
  XGetGeometry (dpy, window, &ignore, &x, &y, &width, &height, &border, &depth);
  
  printf ("%s%dx%d+%u+%u (border %u)\n", indent, width, height, x, y, border);
}

static void
dump_properties (const char *indent, Window window)
{
  Atom *atoms;
  int i, n_atoms;

  atoms = XListProperties (dpy, window, &n_atoms);
  if (n_atoms == 0)
    return;

  for (i = 0; i < n_atoms; i++) {
    Atom real_type;
    int real_format;
    unsigned long nitems, bytes_after;
    unsigned char *prop;

    XGetWindowProperty (dpy, window, atoms[i], 0, G_MAXLONG, False, AnyPropertyType,
                        &real_type, &real_format, &nitems, &bytes_after, &prop);
    
    if (real_type == XA_STRING && real_format == 8) {
      /* TODO: convert to locale */
      printf ("%sAtom STRING %s \"%s\"\n", indent, atom_name (atoms[i]), prop);
      XFree (prop);
    } else if (real_type == XA_UTF8_STRING && real_format == 8) {
      if (g_utf8_validate ((char*)prop, -1, NULL)) {
        printf ("%sAtom UTF-8 %s \"%s\"\n", indent, atom_name (atoms[i]), prop);
      } else {
        /* TODO: dump bytes */
        printf ("%sAtom UTF-8 %s (invalid UTF-8)\n", indent, atom_name (atoms[i]));
      }
      XFree (prop);
    } else if (real_type == XA_CARDINAL) {
      unsigned int j, *cardinals;

      printf ("%sAtom %s %d\n", indent, atom_name (atoms[i]), real_format);

      if (real_format == 32) {
        cardinals = (unsigned int *)prop;
        for (j = 0; j < nitems; j++) {
          printf ("%s%u\n", indent, cardinals[j]);
        }
      }
      XFree (prop);
    } else {
      printf ("%sAtom %s [%s]\n", indent, atom_name (atoms[i]), atom_name (real_type));
    }
  }

  XFree (atoms);
}

static void
examine (Window window, int indent_size)
{
  char *indent;
  Window *children, ignore;
  unsigned int i, n_children;

  indent = g_strnfill (indent_size, ' ');

  dump_name (indent, window);
  dump_size (indent, window);
  dump_properties (indent, window);

  XQueryTree (dpy, window, &ignore, &ignore, &children, &n_children);

  printf ("%s%d children\n", indent, n_children);

  for (i = 0; i < n_children; i++) {
    examine (children[i], indent_size + 1);
  }

  XFree (children);
  free (indent);
}

int
main (int argc, char **argv)
{
  dpy = XOpenDisplay (NULL);
  if (!dpy)
    return EXIT_FAILURE;

  /* TODO: handle many screens somehow */

  XA_UTF8_STRING = XInternAtom (dpy, "UTF8_STRING", False);

  atom_name_hash = g_hash_table_new (NULL, NULL);

  examine (DefaultRootWindow (dpy), 0);

  return EXIT_SUCCESS;
}