/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
 *
 * Copyright (C) 2007 William Jon McCann <mccann@jhu.edu>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 *
 * Authors: William Jon McCann <mccann@jhu.edu>
 *
 */

#include "config.h"

#include <stdlib.h>
#include <stdio.h>
#include <libintl.h>
#include <locale.h>

#ifdef HAVE_KVM_H
#include <kvm.h>
#endif

#ifdef HAVE_SYS_QUEUE_H
#include <sys/queue.h>
#endif

#ifdef HAVE_SYS_FCNTL_H
#include <sys/fcntl.h>
#endif
#ifdef HAVE_SYS_USER_H
#include <sys/user.h>
#endif
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#ifdef HAVE_SYS_SYSCTL_H
#include <sys/sysctl.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_LIMITS_H
#include <limits.h>
#endif

#include <X11/Xlib.h>
#include <X11/Xatom.h>
#include <glib.h>
#include <glib/gi18n.h>

#include "ck-sysdeps.h"

#ifdef __FreeBSD__
#include <libprocstat.h>


static char *
get_tty_for_pid (int pid)
{
        gchar *device = NULL;
        gboolean res;
        char errstr[_POSIX2_LINE_MAX];
        int cnt = 0;
        struct vnstat vn;
        struct filestat_list *head;
        struct filestat *fst;
        kvm_t* kd;
        struct kinfo_proc * prc;
        struct procstat *procstat;

        kd = kvm_openfiles (NULL, "/dev/null", NULL, O_RDONLY, errstr);
        prc = kvm_getprocs (kd, KERN_PROC_PID, pid, &cnt);
        procstat = procstat_open_sysctl ();

        for (int i = 0; i < cnt; i++) {
                head = procstat_getfiles (procstat,&prc[i], 0);

                STAILQ_FOREACH (fst, head, next) {
                        if (fst->fs_type == PS_FST_TYPE_VNODE) {
                                procstat_get_vnode_info (procstat, fst, &vn, NULL);

                                if (vn.vn_type == PS_FST_VTYPE_VCHR) {
                                        char *ctty = devname( prc[i].ki_tdev,S_IFCHR);
                                        const char * pre = "ttyv";

                                        if(strncmp (pre, vn.vn_devname, strlen (pre)) == 0 && strncmp (vn.vn_devname, ctty, strlen(ctty)) != 0) {
                                                device = g_strdup_printf ("/dev/%s", vn.vn_devname);
                                                procstat_freefiles (procstat, head);
                                                res = TRUE;
                                                return device;
                                        }
                                }
                        }
                }
        }

        procstat_freefiles(procstat, head);
        return device;
}
#else /* __FreeBSD__ */
static char *
get_tty_for_pid (int pid)
{
        GError        *error;
        char          *device;
        gboolean       res;
        CkProcessStat *xorg_stat;

        error = NULL;
        res = ck_process_stat_new_for_unix_pid (pid, &xorg_stat, &error);
        if (! res) {
                if (error != NULL) {
                        g_warning ("stat on pid %d failed: %s", pid, error->message);
                        g_error_free (error);
                }
                /* keep the tty value */
                return NULL;
        }

        device = ck_process_stat_get_tty (xorg_stat);
        ck_process_stat_free (xorg_stat);
        return device;
}
#endif /* __FreeBSD__ */

static Display *
display_init (const char *display_name)
{
        Display    *xdisplay;

        if (display_name == NULL) {
                display_name = g_getenv ("DISPLAY");
        }

        if (display_name == NULL) {
                g_warning ("DISPLAY is not set");
                exit (1);
        }

        xdisplay = XOpenDisplay (display_name);
        if (xdisplay == NULL) {
                g_warning ("cannot open display: %s", display_name ? display_name : "");
                exit (1);
        }

        return xdisplay;
}

static char *
get_tty_for_display (Display *xdisplay)
{
        Window root_window;
        Atom xfree86_vt_atom;
        Atom return_type_atom;
        int return_format;
        gulong return_count;
        gulong bytes_left;
        guchar *return_value;
        glong vt;
        char *display;

        display = NULL;

        xfree86_vt_atom = XInternAtom (xdisplay, "XFree86_VT", True);

        if (xfree86_vt_atom == None) {
                return NULL;
        }

        root_window = DefaultRootWindow (xdisplay);

        g_assert (root_window != None);

        return_value = NULL;
        if (XGetWindowProperty(xdisplay, root_window, xfree86_vt_atom,
                               0L, 1L, False, XA_INTEGER,
                               &return_type_atom, &return_format,
                               &return_count, &bytes_left,
                               &return_value) != Success) {
                goto out;
        }

        if (return_type_atom != XA_INTEGER) {
                goto out;
        }

        if (return_format != 32) {
                goto out;
        }

        if (return_count != 1) {
                goto out;
        }

        if (bytes_left != 0) {
                goto out;
        }

        memcpy(&vt, return_value, sizeof(glong));

        if (vt <= 0) {
                goto out;
        }

#if defined(__NetBSD__)
        display = g_strdup_printf ("/dev/ttyE%ld", vt - 1);
#elif defined(__FreeBSD__)
        display = g_strdup_printf ("/dev/ttyv%ld", vt - 1);
#elif defined(__OpenBSD__)
        display = g_strdup_printf ("/dev/ttyC%ld", vt - 1);
#else
        display = g_strdup_printf ("/dev/tty%ld", vt);
#endif

out:
        if (return_value != NULL) {
                XFree (return_value);
        }

        return display;
}

int
main (int    argc,
      char **argv)
{
        int      fd;
        int      ret;
        Display *xdisplay;
        static char *display = NULL;
        GError             *error;
        GOptionContext     *context;
        static GOptionEntry entries [] = {
                { "display", 0, 0, G_OPTION_ARG_STRING, &display, N_("display name"), NULL },
                { NULL }
        };

        /* Setup for i18n */
        setlocale(LC_ALL, "");
 
#ifdef ENABLE_NLS
        bindtextdomain(PACKAGE, LOCALEDIR);
        textdomain(PACKAGE);
#endif

        ret = 1;

        context = g_option_context_new (NULL);
        g_option_context_add_main_entries (context, entries, NULL);
        error = NULL;
        ret = g_option_context_parse (context, &argc, &argv, &error);
        g_option_context_free (context);

        xdisplay = display_init (display);

        fd = ConnectionNumber (xdisplay);

        if (fd > 0) {
                int      pid;
                char    *device;
                gboolean res;

                ret = 0;
                res = ck_get_socket_peer_credentials (fd, &pid, NULL, NULL);
                if (res) {
                        if (pid > 0) {
                                device = get_tty_for_pid (pid);

                                if (device == NULL) {
                                        device = get_tty_for_display (xdisplay);
                                }

                                if (device != NULL) {
                                        printf ("%s\n", device);
                                        g_free (device);
                                }
                        }
                }
        }

	return ret;
}