/*

 * 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, "%lld.%02lld %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);

	}

	if (progressmeter)

		write(STDERR_FILENO, buf, strlen(buf));

	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;

	if (progressmeter)

		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 (progressmeter && end_pos)

		write(STDERR_FILENO, "\n", 1);

	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 byte%s received in %.2f seconds (%s/s)\n",

	    (end_pos) ? cur_pos - offset : *counter,

	    *counter != 1 ? "s" : "",  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 */

}