/* $OpenBSD: progressmeter.c,v 1.54 2024/09/22 12:56:21 jsg Exp $ */
/*
 * Copyright (c) 2003 Nils Nordman.  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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 "includes.h"

#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/uio.h>

#include <errno.h>
#include <limits.h>
#include <signal.h>
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "progressmeter.h"
#include "atomicio.h"
#include "misc.h"
#include "utf8.h"

#define DEFAULT_WINSIZE 80
#define MAX_WINSIZE 512
#define UPDATE_INTERVAL 1       /* update the progress meter every second */
#define STALL_TIME 5            /* we're stalled after this many seconds */

/* determines whether we can output to the terminal */
static int can_output(void);

/* window resizing */
static void sig_winch(int);
static void setscreensize(void);

/* signal handler for updating the progress meter */
static void sig_alarm(int);

static double start;            /* start progress */
static double last_update;      /* last progress update */
static const char *file;        /* name of the file being transferred */
static off_t start_pos;         /* initial position of transfer */
static off_t end_pos;           /* ending position of transfer */
static off_t cur_pos;           /* transfer position as of last refresh */
static volatile off_t *counter; /* progress counter */
static long stalled;            /* how long we have been stalled */
static int bytes_per_second;    /* current speed in bytes per second */
static int win_size;            /* terminal window size */
static volatile sig_atomic_t win_resized; /* for window resizing */
static volatile sig_atomic_t alarm_fired;

/* units for format_size */
static const char unit[] = " KMGT";

static int
can_output(void)
{
        return (getpgrp() == tcgetpgrp(STDOUT_FILENO));
}

/* size needed to format integer type v, using (nbits(v) * log2(10) / 10) */
#define STRING_SIZE(v) (((sizeof(v) * 8 * 4) / 10) + 1)

static const char *
format_rate(off_t bytes)
{
        int i;
        static char buf[STRING_SIZE(bytes) * 2 + 16];

        bytes *= 100;
        for (i = 0; bytes >= 100*1000 && unit[i] != 'T'; i++)
                bytes = (bytes + 512) / 1024;
        if (i == 0) {
                i++;
                bytes = (bytes + 512) / 1024;
        }
        snprintf(buf, sizeof(buf), "%3lld.%1lld%c%s",
            (long long) (bytes + 5) / 100,
            (long long) (bytes + 5) / 10 % 10,
            unit[i],
            i ? "B" : " ");
        return buf;
}

static const char *
format_size(off_t bytes)
{
        int i;
        static char buf[STRING_SIZE(bytes) + 16];

        for (i = 0; bytes >= 10000 && unit[i] != 'T'; i++)
                bytes = (bytes + 512) / 1024;
        snprintf(buf, sizeof(buf), "%4lld%c%s",
            (long long) bytes,
            unit[i],
            i ? "B" : " ");
        return buf;
}

void
refresh_progress_meter(int force_update)
{
        char *buf = NULL, *obuf = NULL;
        off_t transferred;
        double elapsed, now;
        int percent;
        off_t bytes_left;
        int cur_speed;
        int hours, minutes, seconds;
        int file_len, cols;

        if ((!force_update && !alarm_fired && !win_resized) || !can_output())
                return;
        alarm_fired = 0;

        if (win_resized) {
                setscreensize();
                win_resized = 0;
        }

        transferred = *counter - (cur_pos ? cur_pos : start_pos);
        cur_pos = *counter;
        now = monotime_double();
        bytes_left = end_pos - cur_pos;

        if (bytes_left > 0)
                elapsed = now - last_update;
        else {
                elapsed = now - start;
                /* Calculate true total speed when done */
                transferred = end_pos - start_pos;
                bytes_per_second = 0;
        }

        /* calculate speed */
        if (elapsed != 0)
                cur_speed = (transferred / elapsed);
        else
                cur_speed = transferred;

#define AGE_FACTOR 0.9
        if (bytes_per_second != 0) {
                bytes_per_second = (bytes_per_second * AGE_FACTOR) +
                    (cur_speed * (1.0 - AGE_FACTOR));
        } else
                bytes_per_second = cur_speed;

        last_update = now;

        /* Don't bother if we can't even display the completion percentage */
        if (win_size < 4)
                return;

        /* filename */
        file_len = cols = win_size - 36;
        if (file_len > 0) {
                asmprintf(&buf, INT_MAX, &cols, "%-*s", file_len, file);
                /* If we used fewer columns than expected then pad */
                if (cols < file_len)
                        xextendf(&buf, NULL, "%*s", file_len - cols, "");
        }
        /* percent of transfer done */
        if (end_pos == 0 || cur_pos == end_pos)
                percent = 100;
        else
                percent = ((float)cur_pos / end_pos) * 100;

        /* percent / amount transferred / bandwidth usage */
        xextendf(&buf, NULL, " %3d%% %s %s/s ", percent, format_size(cur_pos),
            format_rate((off_t)bytes_per_second));

        /* ETA */
        if (!transferred)
                stalled += elapsed;
        else
                stalled = 0;

        if (stalled >= STALL_TIME)
                xextendf(&buf, NULL, "- stalled -");
        else if (bytes_per_second == 0 && bytes_left)
                xextendf(&buf, NULL, "  --:-- ETA");
        else {
                if (bytes_left > 0)
                        seconds = bytes_left / bytes_per_second;
                else
                        seconds = elapsed;

                hours = seconds / 3600;
                seconds -= hours * 3600;
                minutes = seconds / 60;
                seconds -= minutes * 60;

                if (hours != 0) {
                        xextendf(&buf, NULL, "%d:%02d:%02d",
                            hours, minutes, seconds);
                } else
                        xextendf(&buf, NULL, "  %02d:%02d", minutes, seconds);

                if (bytes_left > 0)
                        xextendf(&buf, NULL, " ETA");
                else
                        xextendf(&buf, NULL, "    ");
        }

        /* Finally, truncate string at window width */
        cols = win_size - 1;
        asmprintf(&obuf, INT_MAX, &cols, " %s", buf);
        if (obuf != NULL) {
                *obuf = '\r'; /* must insert as asmprintf() would escape it */
                atomicio(vwrite, STDOUT_FILENO, obuf, strlen(obuf));
        }
        free(buf);
        free(obuf);
}

static void
sig_alarm(int ignore)
{
        alarm_fired = 1;
        alarm(UPDATE_INTERVAL);
}

void
start_progress_meter(const char *f, off_t filesize, off_t *ctr)
{
        start = last_update = monotime_double();
        file = f;
        start_pos = *ctr;
        end_pos = filesize;
        cur_pos = 0;
        counter = ctr;
        stalled = 0;
        bytes_per_second = 0;

        setscreensize();
        refresh_progress_meter(1);

        ssh_signal(SIGALRM, sig_alarm);
        ssh_signal(SIGWINCH, sig_winch);
        alarm(UPDATE_INTERVAL);
}

void
stop_progress_meter(void)
{
        alarm(0);

        if (!can_output())
                return;

        /* Ensure we complete the progress */
        if (cur_pos != end_pos)
                refresh_progress_meter(1);

        atomicio(vwrite, STDOUT_FILENO, "\n", 1);
}

static void
sig_winch(int sig)
{
        win_resized = 1;
}

static void
setscreensize(void)
{
        struct winsize winsize;

        if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &winsize) != -1 &&
            winsize.ws_col != 0) {
                if (winsize.ws_col > MAX_WINSIZE)
                        win_size = MAX_WINSIZE;
                else
                        win_size = winsize.ws_col;
        } else
                win_size = DEFAULT_WINSIZE;
        win_size += 1;                                  /* trailing \0 */
}