/* $OpenBSD$ */

/*
* Copyright (c) 2009 Nicholas Marriott <[email protected]>
*
* 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 THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF MIND, 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/param.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/user.h>

#include <err.h>
#include <errno.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

struct kinfo_proc       *cmp_procs(struct kinfo_proc *, struct kinfo_proc *);
char                    *osdep_get_name(int, char *);
char                    *osdep_get_cwd(int);
struct event_base       *osdep_event_init(void);

#ifndef nitems
#define nitems(_a) (sizeof((_a)) / sizeof((_a)[0]))
#endif

#define is_runnable(p) \
       ((p)->kp_stat == SACTIVE || (p)->kp_stat == SIDL)
#define is_stopped(p) \
       ((p)->kp_stat == SSTOP || (p)->kp_stat == SZOMB)

struct kinfo_proc *
cmp_procs(struct kinfo_proc *p1, struct kinfo_proc *p2)
{
       if (is_runnable(p1) && !is_runnable(p2))
               return (p1);
       if (!is_runnable(p1) && is_runnable(p2))
               return (p2);

       if (is_stopped(p1) && !is_stopped(p2))
               return (p1);
       if (!is_stopped(p1) && is_stopped(p2))
               return (p2);

       if (strcmp(p1->kp_comm, p2->kp_comm) < 0)
               return (p1);
       if (strcmp(p1->kp_comm, p2->kp_comm) > 0)
               return (p2);

       if (p1->kp_pid > p2->kp_pid)
               return (p1);
       return (p2);
}

char *
osdep_get_name(int fd, char *tty)
{
       int              mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_PGRP, 0 };
       struct stat      sb;
       size_t           len;
       struct kinfo_proc *buf, *newbuf, *bestp;
       u_int            i;
       char            *name;

       buf = NULL;

       if (stat(tty, &sb) == -1)
               return (NULL);
       if ((mib[3] = tcgetpgrp(fd)) == -1)
               return (NULL);

retry:
       if (sysctl(mib, nitems(mib), NULL, &len, NULL, 0) == -1)
               return (NULL);
       len = (len * 5) / 4;

       if ((newbuf = realloc(buf, len)) == NULL)
               goto error;
       buf = newbuf;

       if (sysctl(mib, nitems(mib), buf, &len, NULL, 0) == -1) {
               if (errno == ENOMEM)
                       goto retry;
               goto error;
       }

       bestp = NULL;
       for (i = 0; i < len / sizeof (struct kinfo_proc); i++) {
               if (buf[i].kp_tdev != sb.st_rdev)
                       continue;
               if (bestp == NULL)
                       bestp = &buf[i];
               else
                       bestp = cmp_procs(&buf[i], bestp);
       }

       name = NULL;
       if (bestp != NULL)
               name = strdup(bestp->kp_comm);

       free(buf);
       return (name);

error:
       free(buf);
       return (NULL);
}

char *
osdep_get_cwd(int fd)
{
       return (NULL);
}

struct event_base *
osdep_event_init(void)
{
       return (event_init());
}