#include <X11/XF86keysym.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <X11/keysym.h>
#include <X11/Xlib.h>

static int running = 1;
static int lastkeysym = NULL;
static int lastkeyn = 0;
static int oldbrightness = 10;
static int screenon = 1;
static char screentogglecommand[100];
static char pineledcommand[100];
static char * brightnessfile = "/sys/devices/platform/backlight/backlight/backlight/brightness";



void updatepineled(int red, int brightness) {
	sprintf(
		pineledcommand, 
		"sh -c 'echo %d > /sys/class/leds/%s:indicator/brightness'",
		brightness, 
		red ? "red" : "blue"
	);
	system(pineledcommand);
}

void updatescreenon(int on) {
	int b = on ? oldbrightness : 0;
	sprintf(screentogglecommand, "sh -c 'echo %d > %s'", b, brightnessfile);
	system(screentogglecommand);
	updatepineled(0, b ? 1 : 0);
	updatepineled(1, b ? 0 : 1);
}

void cleanup() {
	updatescreenon(1);
	updatepineled(1, 0);
	updatepineled(0, 0);
}

static void die(const char *err, ...) {
	fprintf(stderr, "Error: %s", err);
	cleanup();
	exit(1);
}
static void usage(void) {
	die("usage: slock [-v] [cmd [arg ...]]\n");
}

// Loosely derived from suckless' slock's lockscreen binding logic but
// alot more coarse, intentionally so can be triggered while grab_key
// for dwm multikey path already holding..
void lockscreen(Display *dpy, int screen) {
	int i, ptgrab, kbgrab;
	//XSetWindowAttributes wa;
	Window root;
	//win,
	root = RootWindow(dpy, screen);
	//wa.override_redirect = 1;
	//win = XCreateWindow(dpy, root, 0, 0,
	//                          DisplayWidth(dpy, screen),
	//                          DisplayHeight(dpy, screen),
	//                          0, DefaultDepth(dpy, screen),
	//                          CopyFromParent,
	//                          DefaultVisual(dpy, screen),
	//                          CWOverrideRedirect | CWBackPixel, &wa);
	for (i = 0, ptgrab = kbgrab = -1; i < 9999999; i++) {
		if (ptgrab != GrabSuccess) {
			ptgrab = XGrabPointer(dpy, root, False,
				ButtonPressMask | ButtonReleaseMask |
				PointerMotionMask, GrabModeAsync,
				GrabModeAsync, None, None, CurrentTime);
		}
		if (kbgrab != GrabSuccess) {
			kbgrab = XGrabKeyboard(dpy, root, True,
				GrabModeAsync, GrabModeAsync, CurrentTime);
		}
		if (ptgrab == GrabSuccess && kbgrab == GrabSuccess) {
			XSelectInput(dpy, root, SubstructureNotifyMask);
			return;
		}
		usleep(100000);
	}
}


void
readinputloop(Display *dpy, int screen) {
	KeySym keysym;
	XEvent ev;
	char buf[32];

	while (running && !XNextEvent(dpy, &ev)) {
		if (ev.type == KeyPress) {
			XLookupString(&ev.xkey, buf, sizeof(buf), &keysym, 0);
			if (lastkeysym == keysym) {
				lastkeyn++;
			} else {
				lastkeysym = keysym;
				lastkeyn = 1;
			}

			if (lastkeyn < 3)
				continue;

			lastkeyn = 0;
			lastkeysym = NULL;

			switch (keysym) {
				case XF86XK_AudioRaiseVolume:
				case XF86XK_AudioLowerVolume:
					screenon = !screenon;
					updatescreenon(screenon);
					break;
				case XF86XK_PowerOff:
					cleanup();
					running = 0;
					break;
			}
		}
	}
}

int
getoldbrightness() {
	char * buffer = 0;
	long length;
	FILE * f = fopen(brightnessfile, "rb");
	if (f) {
		fseek(f, 0, SEEK_END);
		length = ftell(f);
		fseek(f, 0, SEEK_SET);
		buffer = malloc(length);
		if (buffer) {
			fread(buffer, 1, length, f);
		}
		fclose(f);
	}
	if (buffer) {
		oldbrightness = atoi(buffer);
	}
}

int
main(int argc, char **argv) {
	Display *dpy;
	Screen *screen;

	if (setuid(0))
		die("setuid(0) failed\n");
	if (!(dpy = XOpenDisplay(NULL)))
		die("Cannot open display\n");

	screen = XDefaultScreen(dpy);
	XSync(dpy, 0);
	getoldbrightness();
	updatescreenon(1);
	lockscreen(dpy, screen);
	readinputloop(dpy, screen);
	return 0;
}