/*
 * Draw a spinning bar at the top right of the terminal.
 *
 * Copyright (C) 2002 Tony Finch <dot@dotat.at>
 *
 * $dotat: things/spinner.c,v 1.15 2002/03/26 12:33:48 fanf Exp $
 */

#include <sys/ioctl.h>
#include <err.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

static const char copyright[] =
	"@(#) $Copyright: (C) 2002 Tony Finch (dot@dotat.at) $";

static const char version[] =
	"@(#) $dotat: things/spinner.c,v 1.15 2002/03/26 12:33:48 fanf Exp $";

static volatile sig_atomic_t winch = 1;

static void
sigwinch(int s)
{
	s = s;
	winch = 1;
}

static char *progname;

static void
usage(void)
{
	fprintf(stderr, "usage: %s [-n|-t format|-s string]"
	    " [-x offset] [-y offset] [delay]\n", progname);
	fprintf(stderr,
	    "	-n	non-intrusive -- just output a NUL character every interval\n"
	    "	-s	set the sequence of characters to use in the spinner\n"
	    "		e.g. <v>^ or -__-ŻŻ or ··+*0O0*+ or <<{([|])}>>})]|[({\n"
	    "	-t	display the time in the given format, as for strftime\n"
	    "	-x	set the horizontal position\n"
	    "	-y	set the vertical position\n"
	    "		positive numbers count from the top/left\n"
	    "		negative numbers count from the bottom/right\n"
	    "	delay	interval between display updates in seconds (may be fractional)\n");
	exit(2);
}

int
main(int argc, char *argv[])
{
	const char *bars = "|/-\\";
	const char *bar = "";
	const char *fmt = NULL;
	struct sigaction sa;
	struct timespec tv;
	struct winsize ws;
	char buf1[64], buf2[64];
	int len1, len2;
	int geom_y;
	int geom_x;
	int noop;
	int c, x, y;

	progname = strrchr(argv[0], '/');
	if(!progname) progname = argv[0];

	/* defaults */
	tv.tv_sec = 60;
	tv.tv_nsec = 0;
	geom_x = -1;
	geom_y = +1;
	noop = 0;

	while((c = getopt(argc, argv, "ns:t:x:y:")) != -1)
		switch(c) {
		case('n'):
			noop = 1;
			continue;
		case('s'):
			bars = optarg;
			continue;
		case('t'):
			fmt = optarg;
			continue;
		case('x'):
			geom_x = atoi(optarg);
			continue;
		case('y'):
			geom_y = atoi(optarg);
			continue;
		default:
			usage();
		}
	argc -= optind;
	argv += optind;

	if(argc > 1)
		usage();
	if(argc == 1) {
		tv.tv_sec = atoi(*argv);
		tv.tv_nsec = (atof(*argv) - tv.tv_sec) * 1000000000;
	}

	sa.sa_handler = sigwinch;
	sa.sa_flags = 0;
	sigemptyset(&sa.sa_mask);
	if(sigaction(SIGWINCH, &sa, NULL) < 0)
		err(1, "sigaction(SIGWINCH)");

	for(;;) {
		if(winch) {
			winch = 0;
			if(ioctl(1, TIOCGWINSZ, &ws) < 0)
				err(1, "ioctl(TIOCGWINSZ)");
		}
		if(noop) {
			buf2[0] = '\0';
			len2 = 1;
		} else {
			if(fmt) {
				time_t t;
				struct tm tm;
				time(&t);
				localtime_r(&t, &tm);
				len1 = strftime(buf1, sizeof(buf1), fmt, &tm);
			} else {
				if(*bar == '\0')
					bar = bars;
				buf1[0] = *bar++;
				buf1[1] = '\0';
				len1 = 1;
			}
			if(geom_y < 0)
				y = ws.ws_row + geom_y + 1;
			else
				y = geom_y;
			if(y > ws.ws_row)
				y = ws.ws_row;
			if(y < 1)
				y = 1;
			if(geom_x < 0)
				x = ws.ws_col + geom_x + 1;
			else
				x = geom_x;
			if(x + len1 > ws.ws_col)
				x = ws.ws_col - len1 + 1;
			if(x < 1)
				x = 1;
			len2 = snprintf(buf2, sizeof(buf2), "\0337\033[%d;%dH%s\0338",
			    y, x, buf1);
		}
		write(1, buf2, len2);
		nanosleep(&tv, NULL);
	}
}

/* EOF spinner.c */