#include <stdio.h>
#include <string.h>
#include <dlfcn.h>

#include <X11/Xlib.h>
#include <X11/keysym.h>
#include <X11/Xutil.h>
#include <X11/XF86keysym.h>	/* XF86XK_* */

#include "keycodes.h" /* from ui module */

#define X_LIBRARY_NAME "/usr/X11R6/lib/libX11.so.6"

#if !DEBUG
#define OVERRIDE_KEY(x) 								\
	buf[0] = (char)x;									\
	buf[1] = '\0';										\
	ret = 1;
#define OVERRIDE_KEYSYM(x)								\
	*keysym = x;
#else
#define OVERRIDE_KEY(x) 								\
	buf[0] = (char)x;									\
	buf[1] = '\0';										\
	ret = 1;											\
	fprintf(stderr, "\t\tOVERRODE KEY TO: %d\n", x);
#define OVERRIDE_KEYSYM(x)								\
	*keysym = x;										\
	fprintf(stderr, "\t\tOVERRODE KEYSYM TO: %d\n", x);
#endif

static void *xlib;
typedef int (XLookupString_t)(XKeyEvent *, char *, int, KeySym *, XComposeStatus *);
static XLookupString_t *real_XLookupString = NULL;
static int key_down[2]; /* pressed state for keys we really mangle */

static int q3keyfix_init(void) __attribute__((constructor));
static void q3keyfix_fini(void) __attribute__((destructor));

static int q3keyfix_init(void)
{
	if ((xlib = dlopen(X_LIBRARY_NAME, RTLD_NOW)) == NULL) {
		fprintf(stderr, "q3keyfix: failed to open %s: %s\n", X_LIBRARY_NAME, dlerror());
		return -1;
	}

	if ((real_XLookupString = (XLookupString_t *)dlsym(xlib, "XLookupString")) == NULL) {
		fprintf(stderr, "q3keyfix: failed to get useful XLookupString symbol: %s\n", dlerror());
		return -1;
	}

	memset(key_down, 0, sizeof(key_down));

	return 0;
}

static void q3keyfix_fini(void)
{
	if (xlib != NULL) {
		if (dlclose(xlib) != 0)
			fprintf(stderr, "q3keyfix: couldn't dlclose() %s!\n", X_LIBRARY_NAME);
		xlib = NULL;
	}
}

int XLookupString(XKeyEvent *xkeyevent, char *buf, int bufsize, KeySym *keysym, XComposeStatus *xcomposestatus)
{
	int ret;

	if (real_XLookupString == NULL)
		if (q3keyfix_init() < 0)
			return 0;
	
	ret = real_XLookupString(xkeyevent, buf, bufsize, keysym, xcomposestatus);

#if DEBUG
	fprintf(stderr, "XLookupString(%p, %p, %d, %p, %p) = %d\n",
		(void *)xkeyevent, (void *)buf, bufsize, (void *)keysym,
		(void *)xcomposestatus, ret);
	if (xkeyevent != NULL) {
		fprintf(stderr, "\txkeyevent:\n");
		fprintf(stderr, "\t\ttype: ");
		switch (xkeyevent->type) {
			case KeyPress:
				fprintf(stderr, "KeyPress");
				break;
			case KeyRelease:
				fprintf(stderr, "KeyRelease");
				break;
			default:
				fprintf(stderr, "??? (0x%04x)", xkeyevent->type);
				break;
		}
		fprintf(stderr, ", serial: %ld, synthetic: %s, display: %p\n",
			xkeyevent->serial, xkeyevent->send_event == True ? "yes" : "no",
			(void *)xkeyevent->display);
		fprintf(stderr, "\t\twindow: 0x%08lx, root window: 0x%08lx, subwindow: 0x%08lx\n",
			xkeyevent->window, xkeyevent->root, xkeyevent->subwindow);
		fprintf(stderr, "\t\ttime: %ld, window pos: +%d+%d, root pos: +%d+%d\n",
			xkeyevent->time, xkeyevent->x, xkeyevent->y, xkeyevent->x_root,
			xkeyevent->y_root);
		fprintf(stderr, "\t\tstate: 0x%02x, raw keycode: %d, same_screen: %s\n",
			xkeyevent->state, xkeyevent->keycode,
			xkeyevent->same_screen == True ? "yes" : "no");
	}
	fprintf(stderr, "\tbuffer: %s\n", buf);
	if (keysym != NULL)
		fprintf(stderr, "\tkeysym: %s (0x%04lx)\n", XKeysymToString(*keysym), *keysym);
#endif

	/* we can't do anything in these cases */
	if (keysym == NULL || xkeyevent == NULL || bufsize < 2)
		return ret;
	
	switch (*keysym) {
		/* OMISSIONS - These are keys the engine just fails to handle */

		case XK_Caps_Lock:
			OVERRIDE_KEY(K_CAPSLOCK);
			break;
		case XK_F13:
			OVERRIDE_KEY(K_F13);
			break;
		case XK_F14:
			OVERRIDE_KEY(K_F14);
			break;
		case XK_F15:
			OVERRIDE_KEY(K_F15);
			break;
		case XK_Num_Lock:
			OVERRIDE_KEY(K_KP_NUMLOCK);
			break;
		case XK_KP_Equal:
			OVERRIDE_KEY(K_KP_EQUALS);
			break;

		/* ADDITIONS - These are keys the engine offers no way to bind */
		case XK_Print:
			OVERRIDE_KEY(K_AUX1);
			break;
		case XK_Scroll_Lock:
			OVERRIDE_KEY(K_AUX2);
			break;
		case XK_Hyper_L:
		case XK_Super_L:
			OVERRIDE_KEY(K_AUX3);
			break;
		case XK_Hyper_R:
		case XK_Super_R:
			OVERRIDE_KEY(K_AUX4);
			break;
		case XK_Multi_key:
		case XK_Menu:
			OVERRIDE_KEY(K_AUX5);
			break;
#ifdef XF86XK_PowerOff
		case XF86XK_PowerOff:
			OVERRIDE_KEY(K_AUX6);
			break;
#endif
#ifdef XF86XK_Sleep
		case XF86XK_Sleep:
			OVERRIDE_KEY(K_AUX7);
			break;
#endif
#ifdef XF86XK_WakeUp
		case XF86XK_WakeUp:
			OVERRIDE_KEY(K_AUX8);
			break;
#endif

		/* OVERRIDES - These are cases where the in-game behavior is undesirable */
		case XK_grave: /* Control + ` = NUL, but the engine expects ` */
			if (!(xkeyevent->state & ControlMask))
				break;
			OVERRIDE_KEY('`');
			break;
		case XK_Meta_L: /* maintain what the game thinks the meta state is */
		case XK_Meta_R:
		case XK_Alt_L:
		case XK_Alt_R:
			key_down[0] = xkeyevent->type == KeyPress;
			break;
		case XK_Return:
			/*
			 * Mod1 + Enter = fullscreen toggle, but I hate this; AUX9 so
			 * you can bind it yourself.
			 */
			if (!key_down[0] && !key_down[1])
				break;
			OVERRIDE_KEY(K_AUX9);
			OVERRIDE_KEYSYM(XK_VoidSymbol);
			key_down[1] = xkeyevent->type == KeyPress;
			break;

		default:
			break;
	}

	return ret;
}