/*      $NetBSD: job.c,v 1.3 2020/04/18 19:32:19 christos Exp $ */

/* Copyright 1988,1990,1993,1994 by Paul Vixie
* All rights reserved
*/

/*
* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 1997,2000 by Internet Software Consortium, Inc.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/cdefs.h>

#if !defined(lint) && !defined(LINT)
#if 0
static char rcsid[] = "Id: job.c,v 1.6 2004/01/23 18:56:43 vixie Exp";
#else
__RCSID("$NetBSD: job.c,v 1.3 2020/04/18 19:32:19 christos Exp $");
#endif
#endif

#include "cron.h"

typedef struct _job {
       SIMPLEQ_ENTRY(_job) entries;
       entry           *e;
       user            *u;
       time_t          t;
       pid_t           pid;
} job;

static SIMPLEQ_HEAD(job_queue, _job) jobs = SIMPLEQ_HEAD_INITIALIZER(jobs);

static int okay_to_go(job *);

void
job_add(entry *e, user *u, time_t target_time) {
       job *j;

       /* if already on queue, keep going */
       SIMPLEQ_FOREACH(j, &jobs, entries) {
               if (j->e == e && j->u == u) {
                       j->t = target_time;
                       return;
               }
       }

       /* build a job queue element */
       if ((j = calloc(1, sizeof(*j))) == NULL)
               return;
       j->e = e;
       j->u = u;
       j->t = target_time;
       j->pid = -1;

       /* add it to the tail */
       SIMPLEQ_INSERT_TAIL(&jobs, j, entries);
}

void
job_remove(entry *e, user *u)
{
       job *j, *prev = NULL;

       SIMPLEQ_FOREACH(j, &jobs, entries) {
               if (j->e == e && j->u == u) {
                       if (prev == NULL)
                               SIMPLEQ_REMOVE_HEAD(&jobs, entries);
                       else
                               SIMPLEQ_REMOVE_AFTER(&jobs, prev, entries);
                       free(j);
                       break;
               }
               prev = j;
       }
}

void
job_exit(pid_t jobpid)
{
       job *j, *prev = NULL;

       /* If a singleton exited, remove and free it. */
       SIMPLEQ_FOREACH(j, &jobs, entries) {
               if (jobpid == j->pid) {
                       if (prev == NULL)
                               SIMPLEQ_REMOVE_HEAD(&jobs, entries);
                       else
                               SIMPLEQ_REMOVE_AFTER(&jobs, prev, entries);
                       free(j);
                       break;
               }
               prev = j;
       }
}

int
job_runqueue(void) {
       struct job_queue singletons = SIMPLEQ_HEAD_INITIALIZER(singletons);
       job *j;
       int run = 0;

       while ((j = SIMPLEQ_FIRST(&jobs))) {
               SIMPLEQ_REMOVE_HEAD(&jobs, entries);
               if (okay_to_go(j)) {
                       j->pid = do_command(j->e, j->u);
                       run++;
               } else {
                       char *x = mkprints(j->e->cmd, strlen(j->e->cmd));
                       char *usernm = env_get("LOGNAME", j->e->envp);

                       log_it(usernm, getpid(), "CMD (skipped)", x);
                       free(x);
               }
               if (j->pid != -1)
                       SIMPLEQ_INSERT_TAIL(&singletons, j, entries);
               else
                       free(j);
       }
       SIMPLEQ_CONCAT(&jobs, &singletons);
       return (run);
}


static int
okay_to_go(job *j)
{
       char *within, *t;
       long delta;

       if (j->pid != -1)
               return 0;

       if (j->e->flags & WHEN_REBOOT)
               return (1);

       within = env_get("CRON_WITHIN", j->e->envp);
       if (within == NULL)
               return (1);

       /* XXX handle 2m, 4h, etc? */
       errno = 0;
       delta = strtol(within, &t, 10);
       if (errno == ERANGE || *t != '\0' || delta <= 0)
               return (1);

       return ((j->t + delta) > time(NULL));
}