/*	$OpenBSD: progressmeter.c,v 1.4 2019/05/14 18:51:07 deraadt Exp $ */

/*
 * Copyright (c) 2015 Sunil Nimmagadda <sunil@openbsd.org>
 * 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 <sys/types.h>
#include <sys/ioctl.h>

#include <err.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "ftp.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 */

time_t	monotime(void);

/* formats and inserts the specified size into the given buffer */
static void format_size(char *, int, off_t);
static void format_rate(char *, int, off_t);

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

/* updates the progressmeter to reflect the current state of the transfer */
void refresh_progress_meter(void);

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

static const char *title;	/* short title for the start of progress bar */
static time_t start;		/* start progress */
static time_t last_update;	/* last progress update */
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 off_t offset;		/* initial offset from start_pos */
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 const char *filename;	/* To be displayed in non-verbose mode */
/* units for format_size */
static const char unit[] = " KMGT";

time_t
monotime(void)
{
	struct timespec ts;

	if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0)
		err(1, "monotime");

	return ts.tv_sec;
}

static void
format_rate(char *buf, int size, off_t bytes)
{
	int i;

	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, size, "%3lld.%1lld%c%s",
	    (long long) (bytes + 5) / 100,
	    (long long) (bytes + 5) / 10 % 10,
	    unit[i],
	    "B");
}

static void
format_size(char *buf, int size, off_t bytes)
{
	int i;

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

void
refresh_progress_meter(void)
{
	char buf[MAX_WINSIZE + 1];
	const char *dot = "";
	time_t now;
	off_t transferred, bytes_left;
	double elapsed;
	int len, cur_speed, hours, minutes, seconds, barlength, i;
	int percent, overhead = 30;

	transferred = *counter - (cur_pos ? cur_pos : start_pos);
	cur_pos = *counter;
	now = monotime();
	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;

	buf[0] = '\0';
	/* title */
	if (!verbose && title != NULL) {
		len = strlen(title);
		if (len < 7)
			len = 7;
		else if (len > 12) {
			len = 12;
			dot = "...";
			overhead += 3;
		}
		snprintf(buf, sizeof buf, "\r%-*.*s%s ", len, len, title, dot);
		overhead += len + 1;
	} else
		snprintf(buf, sizeof buf, "\r");

	if (end_pos == 0 || cur_pos == end_pos)
		percent = 100;
	else
		percent = ((float)cur_pos / end_pos) * 100;

	/* filename and percent */
	if (!verbose && filename != NULL) {
		len = strlen(filename);
		if (len < 12)
			len = 12;
		else if (len > 25) {
			len = 22;
			dot = "...";
			overhead += 3;
		}
		snprintf(buf + strlen(buf), sizeof buf - strlen(buf),
		    "%-*.*s%s %3d%% ", len, len, filename, dot, percent);
		overhead += len + 1;
	} else
		snprintf(buf, sizeof buf, "\r%3d%% ", percent);

	/* bar */
	barlength = win_size - overhead;
	if (barlength > 0) {
		i = barlength * percent / 100;
		snprintf(buf + strlen(buf), sizeof buf - strlen(buf),
		    "|%.*s%*s| ", i,
		    "*******************************************************"
		    "*******************************************************"
		    "*******************************************************"
		    "*******************************************************"
		    "*******************************************************"
		    "*******************************************************"
		    "*******************************************************",
		    barlength - i, "");

	}

	/* amount transferred */
	format_size(buf + strlen(buf), win_size - strlen(buf), cur_pos);
	strlcat(buf, " ", win_size);

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

	if (stalled >= STALL_TIME)
		strlcat(buf, "- stalled -", win_size);
	else if (bytes_per_second == 0 && bytes_left)
		strlcat(buf, "  --:-- ETA", win_size);
	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)
			snprintf(buf + strlen(buf), win_size - strlen(buf),
			    "%d:%02d:%02d", hours, minutes, seconds);
		else
			snprintf(buf + strlen(buf), win_size - strlen(buf),
			    "  %02d:%02d", minutes, seconds);

		if (bytes_left > 0)
			strlcat(buf, " ETA", win_size);
		else
			strlcat(buf, "    ", win_size);
	}

	fwrite(buf, strlen(buf), 1, stderr);
	last_update = now;
}

static void
update_progress_meter(int ignore)
{
	int save_errno;

	save_errno = errno;

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

	refresh_progress_meter();

	signal(SIGALRM, update_progress_meter);
	alarm(UPDATE_INTERVAL);
	errno = save_errno;
}

void
start_progress_meter(const char *fn, const char *t, off_t filesize, off_t *ctr)
{
	start = last_update = monotime();
	start_pos = *ctr;
	offset = *ctr;
	cur_pos = 0;
	end_pos = 0;
	counter = ctr;
	stalled = 0;
	bytes_per_second = 0;
	filename = fn;
	title = t;

	/*
	 * Suppress progressmeter if filesize isn't known when
	 * Content-Length header has bogus values.
	 */
	if (filesize <= 0)
		return;

	end_pos = filesize;
	setscreensize();
	refresh_progress_meter();

	signal(SIGALRM, update_progress_meter);
	signal(SIGWINCH, sig_winch);
	alarm(UPDATE_INTERVAL);
}

void
stop_progress_meter(void)
{
	char	rate_str[32];
	double	elapsed;

	alarm(0);

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

	if (end_pos)
		fprintf(stderr, "\n");

	if (!verbose)
		return;

	elapsed = monotime() - start;
	if (end_pos == 0) {
		if (elapsed != 0)
			bytes_per_second = *counter / elapsed;
		else
			bytes_per_second = *counter;
	}

	format_rate(rate_str, sizeof rate_str, bytes_per_second);
	log_info("%lld bytes received in %.2f seconds (%s/s)\n",
	    (end_pos) ? cur_pos - offset : *counter, elapsed, rate_str);
}

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 */
}