/*

 * (C)opyright MMVI Anselm R. Garbe <garbeam at gmail dot com>

 * See LICENSE file for license details.

 */

#include <stdarg.h>

#include <stdio.h>

#include <stdlib.h>

#include <X11/cursorfont.h>

#include <X11/Xatom.h>

#include <X11/Xproto.h>

#include "wm.h"

Display *dpy;

Window root;

XRectangle rect;

int screen, sel_screen;

Atom wm_atom[WMLast];

Atom net_atom[NetLast];

Cursor cursor[CurLast];

unsigned int kmask, numlock_mask;

Pixmap pmap;

enum { WM_PROTOCOL_DELWIN = 1 };

static Bool other_wm_running;

static int (*x_error_handler) (Display *, XErrorEvent *);

static char version[] = "gridwm - " VERSION ", (C)opyright MMVI Anselm R. Garbe\n";

static void

usage()

{

	fputs("usage: gridwm [-v]\n", stderr);

	exit(1);

}

void

error(char *errstr, ...) {

	va_list ap;

	va_start(ap, errstr);

	vfprintf(stderr, errstr, ap);

	va_end(ap);

	exit(1);

}

static void

scan_wins()

{

	unsigned int i, num;

	Window *wins;

	XWindowAttributes wa;

	Window d1, d2;

	if(XQueryTree(dpy, root, &d1, &d2, &wins, &num)) {

		for(i = 0; i < num; i++) {

			if(!XGetWindowAttributes(dpy, wins[i], &wa))

				continue;

			if(wa.override_redirect || XGetTransientForHint(dpy, wins[i], &d1))

				continue;

			if(wa.map_state == IsViewable)

				/*manage*/;

		}

	}

	if(wins)

		XFree(wins);

}

static int

win_property(Window w, Atom a, Atom t, long l, unsigned char **prop)

{

	Atom real;

	int format;

	unsigned long res, extra;

	int status;

	status = XGetWindowProperty(dpy, w, a, 0L, l, False, t, &real, &format,

			&res, &extra, prop);

	if(status != Success || *prop == 0) {

		return 0;

	}

	if(res == 0) {

		free((void *) *prop);

	}

	return res;

}

int

win_proto(Window w)

{

	Atom *protocols;

	long res;

	int protos = 0;

	int i;

	res = win_property(w, wm_atom[WMProtocols], XA_ATOM, 20L,

			((unsigned char **) &protocols));

	if(res <= 0) {

		return protos;

	}

	for(i = 0; i < res; i++) {

		if(protocols[i] == wm_atom[WMDelete])

			protos |= WM_PROTOCOL_DELWIN;

	}

	free((char *) protocols);

	return protos;

}

/*

 * There's no way to check accesses to destroyed windows, thus

 * those cases are ignored (especially on UnmapNotify's).

 * Other types of errors call Xlib's default error handler, which

 * calls exit().

 */

static int

error_handler(Display *dpy, XErrorEvent *error)

{

	if(error->error_code == BadWindow

			|| (error->request_code == X_SetInputFocus

				&& error->error_code == BadMatch)

			|| (error->request_code == X_PolyText8

				&& error->error_code == BadDrawable)

			|| (error->request_code == X_PolyFillRectangle

				&& error->error_code == BadDrawable)

			|| (error->request_code == X_PolySegment

				&& error->error_code == BadDrawable)

			|| (error->request_code == X_ConfigureWindow

				&& error->error_code == BadMatch)

			|| (error->request_code == X_GrabKey

				&& error->error_code == BadAccess))

		return 0;

	fprintf(stderr, "gridwm: fatal error: request code=%d, error code=%d\n",

			error->request_code, error->error_code);

	return x_error_handler(dpy, error); /* may call exit() */

}

/*

 * Startup Error handler to check if another window manager

 * is already running.

 */

static int

startup_error_handler(Display *dpy, XErrorEvent *error)

{

	other_wm_running = True;

	return -1;

}

static void

init_lock_keys()

{

	XModifierKeymap *modmap;

	KeyCode numlock;

	int i;

	static int masks[] = {

		ShiftMask, LockMask, ControlMask, Mod1Mask,

		Mod2Mask, Mod3Mask, Mod4Mask, Mod5Mask

	};

	numlock_mask = 0;

	modmap = XGetModifierMapping(dpy);

	numlock = XKeysymToKeycode(dpy, XStringToKeysym("Num_Lock"));

	if(modmap && modmap->max_keypermod > 0) {

		int max = (sizeof(masks) / sizeof(int)) * modmap->max_keypermod;

		for(i = 0; i < max; i++)

			if(numlock && (modmap->modifiermap[i] == numlock))

				numlock_mask = masks[i / modmap->max_keypermod];

	}

	XFreeModifiermap(modmap);

	kmask = 255 & ~(numlock_mask | LockMask);

}

static void

cleanup()

{

	/*

	Client *c;

	for(c=client; c; c=c->next)

		reparent_client(c, root, c->sel->rect.x, c->sel->rect.y);

	XSetInputFocus(dpy, PointerRoot, RevertToPointerRoot, CurrentTime);

	*/

}

int

main(int argc, char *argv[])

{

	int i;

	XSetWindowAttributes wa;

	unsigned int mask;

	Window w;

	/* command line args */

	for(i = 1; (i < argc) && (argv[i][0] == '-'); i++) {

		switch (argv[i][1]) {

		case 'v':

			fprintf(stdout, "%s", version);

			exit(0);

			break;

		default:

			usage();

			break;

		}

	}

	dpy = XOpenDisplay(0);

	if(!dpy)

		error("gridwm: cannot connect X server\n");

	screen = DefaultScreen(dpy);

	root = RootWindow(dpy, screen);

	/* check if another WM is already running */

	other_wm_running = False;

	XSetErrorHandler(startup_error_handler);

	/* this causes an error if some other WM is running */

	XSelectInput(dpy, root, SubstructureRedirectMask);

	XSync(dpy, False);

	if(other_wm_running)

		error("gridwm: another window manager is already running\n");

	rect.x = rect.y = 0;

	rect.width = DisplayWidth(dpy, screen);

	rect.height = DisplayHeight(dpy, screen);

	sel_screen = XQueryPointer(dpy, root, &w, &w, &i, &i, &i, &i, &mask);

	XSetErrorHandler(0);

	x_error_handler = XSetErrorHandler(error_handler);

	/* init atoms */

	wm_atom[WMState] = XInternAtom(dpy, "WM_STATE", False);

	wm_atom[WMProtocols] = XInternAtom(dpy, "WM_PROTOCOLS", False);

	wm_atom[WMDelete] = XInternAtom(dpy, "WM_DELETE_WINDOW", False);

	net_atom[NetSupported] = XInternAtom(dpy, "_NET_SUPPORTED", False);

	net_atom[NetWMName] = XInternAtom(dpy, "_NET_WM_NAME", False);

	XChangeProperty(dpy, root, net_atom[NetSupported], XA_ATOM, 32,

			PropModeReplace, (unsigned char *) net_atom, NetLast);

	/* init cursors */

	cursor[CurNormal] = XCreateFontCursor(dpy, XC_left_ptr);

	cursor[CurResize] = XCreateFontCursor(dpy, XC_sizing);

	cursor[CurMove] = XCreateFontCursor(dpy, XC_fleur);

	init_lock_keys();

	pmap = XCreatePixmap(dpy, root, rect.width, rect.height,

			DefaultDepth(dpy, screen));

	wa.event_mask = SubstructureRedirectMask | EnterWindowMask | LeaveWindowMask;

	wa.cursor = cursor[CurNormal];

	XChangeWindowAttributes(dpy, root, CWEventMask | CWCursor, &wa);

	scan_wins();

	cleanup();

	XCloseDisplay(dpy);

	return 0;

}