/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1980, 1992, 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/param.h>
#include <sys/time.h>
#include <sys/sysctl.h>
#include <sys/queue.h>

#include <err.h>
#include <limits.h>
#include <locale.h>
#include <nlist.h>
#include <paths.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "systat.h"
#include "extern.h"

static int     dellave;

kvm_t *kd;
double avenrun[3];
int     col;
unsigned int    delay = 5000000;        /* in microseconds */
int     verbose = 1;                    /* to report kvm read errs */
static struct   clockinfo clkinfo;
double  hertz;
char    c;
char    *namp;
char    hostname[MAXHOSTNAMELEN];
WINDOW  *wnd;
int     CMDLINE;

static  WINDOW *wload;                  /* one line window for load average */

struct cmdentry {
        SLIST_ENTRY(cmdentry) link;
        char            *cmd;           /* Command name */
        char            *argv;          /* Arguments vector for a command */
};
static SLIST_HEAD(, cmdentry) commands;

static void
parse_cmd_args (int argc, char **argv)
{
        int in_command = 0;
        struct cmdentry *cmd = NULL;
        double t;

        while (argc) {
                if (argv[0][0] == '-') {
                        if (in_command)
                                        SLIST_INSERT_HEAD(&commands, cmd, link);

                        if (memcmp(argv[0], "--", 3) == 0) {
                                in_command = 0; /*-- ends a command explicitly*/
                                argc --, argv ++;
                                continue;
                        }
                        cmd = calloc(1, sizeof(struct cmdentry));
                        if (cmd == NULL)
                                errx(1, "memory allocating failure");
                        cmd->cmd = strdup(&argv[0][1]);
                        if (cmd->cmd == NULL)
                                errx(1, "memory allocating failure");
                        in_command = 1;
                }
                else if (!in_command) {
                        t = strtod(argv[0], NULL) * 1000000.0;
                        if (t > 0 && t < (double)UINT_MAX)
                                delay = (unsigned int)t;
                }
                else if (cmd != NULL) {
                        cmd->argv = strdup(argv[0]);
                        if (cmd->argv == NULL)
                                errx(1, "memory allocating failure");
                        in_command = 0;
                        SLIST_INSERT_HEAD(&commands, cmd, link);
                }
                else
                        errx(1, "invalid arguments list");

                argc--, argv++;
        }
        if (in_command && cmd != NULL)
                SLIST_INSERT_HEAD(&commands, cmd, link);

}

static void
resize(int signo __unused)
{

        endwin();
        refresh();
        clear();

        CMDLINE = LINES - 1;
        labels();
        display();
        status();
}


int
main(int argc, char **argv)
{
        char errbuf[_POSIX2_LINE_MAX], dummy;
        size_t  size;
        struct cmdentry *cmd = NULL;
        short cf, cb;

        (void) setlocale(LC_ALL, "");

        SLIST_INIT(&commands);
        argc--, argv++;
        if (argc > 0) {
                if (argv[0][0] == '-') {
                        struct cmdtab *p;

                        p = lookup(&argv[0][1]);
                        if (p == (struct cmdtab *)-1)
                                errx(1, "%s: ambiguous request", &argv[0][1]);
                        if (p == (struct cmdtab *)0)
                                errx(1, "%s: unknown request", &argv[0][1]);
                        curcmd = p;
                        argc--, argv++;
                }
                parse_cmd_args (argc, argv);
                
        }
        kd = kvm_openfiles(NULL, NULL, NULL, O_RDONLY, errbuf);
        if (kd != NULL) {
                struct nlist namelist[] = { { .n_name = "allproc" },
                    { .n_name = NULL } };

                /*
                 * Try to actually read something, we may be in a jail, and
                 * have /dev/null opened as /dev/mem.
                 */
                if (kvm_nlist(kd, namelist) != 0 || namelist[0].n_value == 0 ||
                    kvm_read(kd, namelist[0].n_value, &dummy, sizeof(dummy)) !=
                    sizeof(dummy)) {
                        kvm_close(kd);
                        kd = NULL;
                }
        }
        if (kd == NULL) {
                /*
                 * Maybe we are lacking permissions? Retry, this time with bogus
                 * devices. We can now use sysctl only.
                 */
                kd = kvm_openfiles(_PATH_DEVNULL, _PATH_DEVNULL, _PATH_DEVNULL,
                    O_RDONLY, errbuf);
                if (kd == NULL) {
                        error("%s", errbuf);
                        exit(1);
                }
        }
        signal(SIGHUP, die);
        signal(SIGINT, die);
        signal(SIGQUIT, die);
        signal(SIGTERM, die);
        signal(SIGWINCH, resize);

        /*
         * Initialize display.  Load average appears in a one line
         * window of its own.  Current command's display appears in
         * an overlapping sub-window of stdscr configured by the display
         * routines to minimize update work by curses.
         */
        initscr();
        start_color();
        use_default_colors();
        pair_content(0, &cf, &cb);
        init_pair(1, COLOR_GREEN, cb);
        init_pair(2, COLOR_MAGENTA, cb);
        init_pair(3, COLOR_RED, cb);
        init_pair(4, COLOR_BLUE, cb);
        CMDLINE = LINES - 1;
        wnd = (*curcmd->c_open)();
        if (wnd == NULL) {
                warnx("couldn't initialize display");
                die(0);
        }
        wload = newwin(1, 0, 1, 20);
        if (wload == NULL) {
                warnx("couldn't set up load average window");
                die(0);
        }
        gethostname(hostname, sizeof (hostname));
        size = sizeof(clkinfo);
        if (sysctlbyname("kern.clockrate", &clkinfo, &size, NULL, 0)
            || size != sizeof(clkinfo)) {
                error("kern.clockrate");
                die(0);
        }
        hertz = clkinfo.stathz;
        (*curcmd->c_init)();
        curcmd->c_flags |= CF_INIT;
        labels();

        if (curcmd->c_cmd != NULL)
                SLIST_FOREACH (cmd, &commands, link)
                        if (!curcmd->c_cmd(cmd->cmd, cmd->argv))
                                warnx("command is not understood");

        dellave = 0.0;
        display();
        noecho();
        crmode();
        keyboard();
        /*NOTREACHED*/

        return EXIT_SUCCESS;
}

void
labels(void)
{
        if (curcmd->c_flags & CF_LOADAV) {
                mvaddstr(0, 20,
                    "/0   /1   /2   /3   /4   /5   /6   /7   /8   /9   /10");
                mvaddstr(1, 5, "Load Average");
        }
        if (curcmd->c_flags & CF_ZFSARC) {
                mvaddstr(0, 20,
                    "   Total     MFU     MRU    Anon     Hdr   L2Hdr   Other");
                mvaddstr(1, 5, "ZFS ARC     ");
        }
        (*curcmd->c_label)();
#ifdef notdef
        mvprintw(21, 25, "CPU usage on %s", hostname);
#endif
        refresh();
}

void
display(void)
{
        uint64_t arc_stat;
        unsigned int ui;
        int i, j;

        /* Get the load average over the last minute. */
        (void) getloadavg(avenrun, nitems(avenrun));
        (*curcmd->c_fetch)();
        if (curcmd->c_flags & CF_LOADAV) {
                j = 5.0*avenrun[0] + 0.5;
                dellave -= avenrun[0];
                if (dellave >= 0.0)
                        c = '<';
                else {
                        c = '>';
                        dellave = -dellave;
                }
                if (dellave < 0.1)
                        c = '|';
                dellave = avenrun[0];
                wmove(wload, 0, 0); wclrtoeol(wload);
                for (i = MIN(j, 50); i > 0; i--)
                        waddch(wload, c);
                if (j > 50)
                        wprintw(wload, " %4.1f", avenrun[0]);
        }
        if (curcmd->c_flags & CF_ZFSARC) {
            uint64_t arc[7] = {};
            size_t size = sizeof(arc[0]);
            if (sysctlbyname("kstat.zfs.misc.arcstats.size",
                &arc[0], &size, NULL, 0) == 0 ) {
                    GETSYSCTL("kstat.zfs.misc.arcstats.mfu_size", arc[1]);
                    GETSYSCTL("kstat.zfs.misc.arcstats.mru_size", arc[2]);
                    GETSYSCTL("kstat.zfs.misc.arcstats.anon_size", arc[3]);
                    GETSYSCTL("kstat.zfs.misc.arcstats.hdr_size", arc[4]);
                    GETSYSCTL("kstat.zfs.misc.arcstats.l2_hdr_size", arc[5]);
                    GETSYSCTL("kstat.zfs.misc.arcstats.bonus_size", arc[6]);
                    GETSYSCTL("kstat.zfs.misc.arcstats.dnode_size", arc_stat);
                    arc[6] += arc_stat;
                    GETSYSCTL("kstat.zfs.misc.arcstats.dbuf_size", arc_stat);
                    arc[6] += arc_stat;
                    wmove(wload, 0, 0); wclrtoeol(wload);
                    for (ui = 0 ; ui < nitems(arc); ui++)
                        sysputuint64(wload, 0, ui*8+2, 6, arc[ui], 0);
            }
        }
        (*curcmd->c_refresh)();
        if (curcmd->c_flags & (CF_LOADAV |CF_ZFSARC))
                wrefresh(wload);
        wrefresh(wnd);
        move(CMDLINE, col);
        refresh();
}

void
load(void)
{

        (void) getloadavg(avenrun, nitems(avenrun));
        mvprintw(CMDLINE, 0, "%4.1f %4.1f %4.1f",
            avenrun[0], avenrun[1], avenrun[2]);
        clrtoeol();
}

void
die(int signo __unused)
{
        move(CMDLINE, 0);
        clrtoeol();
        refresh();
        endwin();
        exit(0);
}

#include <stdarg.h>

void
error(const char *fmt, ...)
{
        va_list ap;
        char buf[255];
        int oy, ox;

        va_start(ap, fmt);
        if (wnd) {
                getyx(stdscr, oy, ox);
                (void) vsnprintf(buf, sizeof(buf), fmt, ap);
                clrtoeol();
                standout();
                mvaddstr(CMDLINE, 0, buf);
                standend();
                move(oy, ox);
                refresh();
        } else {
                (void) vfprintf(stderr, fmt, ap);
                fprintf(stderr, "\n");
        }
        va_end(ap);
}

void
nlisterr(struct nlist n_list[])
{
        int i, n;

        n = 0;
        clear();
        mvprintw(2, 10, "systat: nlist: can't find following symbols:");
        for (i = 0;
            n_list[i].n_name != NULL && *n_list[i].n_name != '\0'; i++)
                if (n_list[i].n_value == 0)
                        mvprintw(2 + ++n, 10, "%s", n_list[i].n_name);
        move(CMDLINE, 0);
        clrtoeol();
        refresh();
        endwin();
        exit(1);
}