/*      $NetBSD: leave.c,v 1.15 2011/09/16 15:39:27 joerg Exp $ */

/*
* Copyright (c) 1980, 1988, 1993
*      The Regents of the University of California.  All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1980, 1988, 1993\
The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)leave.c     8.1 (Berkeley) 6/6/93";
#else
__RCSID("$NetBSD: leave.c,v 1.15 2011/09/16 15:39:27 joerg Exp $");
#endif
#endif /* not lint */

#include <sys/param.h>
#include <sys/time.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <err.h>
#include <unistd.h>

#define SECOND  1
#define MINUTE  (SECOND * 60)
#define HOUR    (MINUTE * 60)

/*
* leave [[+]hhmm]
*
* Reminds you when you have to leave.
* Leave prompts for input and goes away if you hit return.
* It nags you like a mother hen.
*/

__dead static void doalarm(u_int);
__dead static void usage(void);

int
main(int argc, char **argv)
{
       u_int secs;
       int hours, minutes;
       char c, *cp;
       struct tm *t = NULL;
       time_t now;
       int plusnow;
       char buf[50];

       if (setvbuf(stdout, NULL, _IONBF, 0) != 0)
               errx(1, "Cannot set stdout to unbuffered.");

       if (argc < 2) {
               (void)puts("When do you have to leave? ");
               cp = fgets(buf, sizeof(buf), stdin);
               if (cp == NULL || *cp == '\n')
                       exit(0);
       } else
               cp = argv[1];

       if (*cp == '+') {
               plusnow = 1;
               ++cp;
       } else {
               plusnow = 0;
               (void)time(&now);
               t = localtime(&now);
       }

       for (hours = 0; (c = *cp) && c != '\n'; ++cp) {
               if (!isdigit((unsigned char)c))
                       usage();
               hours = hours * 10 + (c - '0');
       }
       minutes = hours % 100;
       hours /= 100;

       if (minutes < 0 || minutes > 59)
               usage();
       if (plusnow)
               secs = (hours * HOUR) + (minutes * MINUTE);
       else {
               if (hours > 23)
                       usage();
               if (t->tm_hour >= 12)
                       t->tm_hour -= 12;
               if (hours >= 12)
                       hours -= 12;
               if (t->tm_hour > hours ||
                   (t->tm_hour == hours && minutes <= t->tm_min))
                       hours += 12;
               secs = (hours - t->tm_hour) * HOUR;
               secs += (minutes - t->tm_min) * MINUTE;
       }
       doalarm(secs);
       exit(0);
}

static void
doalarm(u_int secs)
{
       int bother;
       time_t daytime;

       switch (fork()) {
       case 0:
               break;
       case -1:
               err(1, "Fork failed");
               /*NOTREACHED*/
       default:
               exit(0);
       }

       (void)time(&daytime);
       daytime += secs;
       printf("Alarm set for %.16s. (pid %u)\n",
           ctime(&daytime), (unsigned)getpid());

       /*
        * if write fails, we've lost the terminal through someone else
        * causing a vhangup by logging in.
        */
#define FIVEMIN (5 * MINUTE)
       if (secs >= FIVEMIN) {
               sleep(secs - FIVEMIN);
               if (puts("\07\07You have to leave in 5 minutes.\n") == EOF)
                       exit(0);
               secs = FIVEMIN;
       }

#define ONEMIN  (MINUTE)
       if (secs >= ONEMIN) {
               sleep(secs - ONEMIN);
               if (puts("\07\07Just one more minute!\n") == EOF)
                       exit(0);
       }

       for (bother = 10; bother--;) {
               sleep((u_int)ONEMIN);
               if (puts("\07\07Time to leave!\n") == EOF)
                       exit(0);
       }

       (void)puts("\07\07That was the last time I'll tell you.  Bye.\n");
       exit(0);
}

static void
usage(void)
{
       (void)fprintf(stderr, "usage: %s [[+]hhmm]\n", getprogname());
       exit(1);
}