#include	<X11/X.h>
#include	<X11/Xlib.h>
#include	<X11/Xutil.h>
#include	<X11/keysym.h>

#include	<ctype.h>
#include	<stdio.h>
#include	<stdlib.h>

#ifdef LINUX
#include <fcntl.h>
#include <sys/vt.h>
#endif

#include	"lock.h"

/* Dispatcher for main event loop. */
typedef struct Disp Disp;
struct Disp {
	int	type;
	void	(*handler)(XEvent *);
};

static void expose(XEvent *);
static void exposeScreen(ScreenInfo *);
static void keypress(XEvent *);
static void mappingnotify(XEvent *);
static void raiseLockWindows(void);

static Disp disps[] =
{
	{Expose, expose},
	{KeyPress, keypress},
	{KeyRelease, 0},
	{MappingNotify, mappingnotify},
};

extern void
dispatch(XEvent *ev) {
	Disp *p;

	for (p = disps; p < disps + sizeof disps / sizeof disps[0]; p++)
		if (p->type == ev->type) {
			if (p->handler != 0)
				p->handler(ev);
			return;
		}

	raiseLockWindows();
}

static char password[14];
static char stars[14] = "*************";
static int chars = 0;

static void
expose(XEvent * ev) {
	/* Only handle the last in a group of Expose events. */
	if (ev->xexpose.count != 0)
		return;
	
	exposeScreen(getScreenForWindow(ev->xexpose.window));
}

static void
exposeScreen(ScreenInfo * screen) {
	int len;
	int width;
	
	if (screen != &screens[0])
		return;
	
	/* Do the redraw. */
	len = strlen(lock_string);
	width = XTextWidth(font, lock_string, len);
	XDrawString(dpy, screen->window, screen->gc,
		(screen->width - width)/2, screen->height/4,
		lock_string, len);

	width = XTextWidth(font, stars, chars);
	XSetForeground(dpy, screen->gc, screen->black);
	XFillRectangle(dpy, screen->window, screen->gc,
		0, screen->height/2 - 100, screen->width, 100);
	XSetForeground(dpy, screen->gc, screen->white);
	XDrawString(dpy, screen->window, screen->gc,
		(screen->width - width)/2, screen->height/2,
		stars, chars);
}

static void
keypress(XEvent * ev) {
	char buffer[1];
	KeySym keysym;
	int c;
	
	c = XLookupString((XKeyEvent *) ev, buffer, sizeof buffer, &keysym, 0);
	
	if (keysym == XK_Return) {
		password[chars] = 0;
		if (check_password(password)) {
			XUngrabKeyboard(dpy, CurrentTime);
#ifdef LINUX
			{
				int fd = open("/dev/console", O_RDWR);
				if (fd != -1)
					ioctl(fd, VT_UNLOCKSWITCH, 0);
			}
#endif
			exit(EXIT_SUCCESS);
		} else {
			chars = 0;
		}
	} else if (keysym == XK_BackSpace) {
		if (chars > 0)
			chars--;
	} else if (keysym == XK_Escape)
		chars = 0;
	else if (isprint(*buffer) && chars + 1 <= 13)
		password[chars++] = *buffer;
	
	exposeScreen(&screens[0]);
}

static void
mappingnotify(XEvent * ev) {
	XRefreshKeyboardMapping((XMappingEvent *) ev);
}

static void
raiseLockWindows(void) {
	int screen;
	for (screen = 0; screen < screen_count; screen++)
		XRaiseWindow(dpy, screens[screen].window);
}