#!/bin/sh
# Silly speed test just by downloading a file directly to /dev/null
# Useful on routers which only have busybox installed.
# ↄ⃝🄯 B9 2016, 2018, 2023. Creative Commons Zero.

# NOTA BENE: cachefly has worked for over a decade, however they may
# be getting tired of scripts like this. Starting February 2023, their
# 100mb.test file is empty and the 50mb.test file holds 100MB.

dotest() {
    # $1 is which file to grab 200, 100, 50, 10, or 1 (megabytes).
    # $2 (optional) is how many megabytes that file actually is.
    filename=${1}
    megabytes=${2:-$1}

    wget=$(whichwget)

    bloburl=http://cachefly.cachefly.net/${filename}mb.test
    blobsize=$(($megabytes*1024*1024))

    if which time >/dev/null 2>/dev/null; then
	totaltime=$(dotime $wget "$bloburl" -O /dev/null)
    else
	start=$(date +%s)
	$wget "$bloburl" -O /dev/null 
	stop=$(date +%s)
	totaltime=$(( (stop-start) * 1000))
    fi 

    echo Total time was $totaltime milliseconds for $blobsize bytes

    if [ $totaltime -ne 0 ]; then
	bps=$(((1000*blobsize*8)/totaltime))
	echo $((bps/1024/1024)) Mbps
	echo $((bps/1024)) kbps
    else
	echo "Incalculable"
    fi
}

dotime() {
    # If we have the "time" program, use it for more precision
    # This is a wrapper since we want to return just
    # the number of milliseconds. Also, we handle different
    # formats for output from `time`. 
    output=$("time" "$@" 2>&1 | tee /dev/tty)

    if [ -z "$output" ]; then
	echo "Error: Is the time (`which time`) program broken?" >&2
	echo "Why was there no stderr?" >&2
	echo 0
	return
    fi

    # time's output usually looks like this:
    # Connecting to cachefly.cachefly.net (205.234.175.175:80)
    # null       100% |*******************************|  1024k  0:00:00 ETA
    # real    0m 0.22s
    # user    0m 0.00s
    # sys     0m 0.08s

    real=$(echo "$output" | grep ^real)

    # We expect real="real	0m 0.22s", but double check
    if [ "$real" ]; then
	# Yup, we got what we expected.
	set - $real
	min=$2			# 0m
	min=${min%m}		# 0
	sec=$3			# 0.22s
	sec=${sec%s}		# 0.22
    else
	# Oops. This must be one of those machines where `time` returns
	# 0.00user 0.00system 0:00.22elapsed 1%CPU (0avgtext+0avgdata 1284maxresident)k
	real=$(echo "$output" | grep elapsed)
	if [ -z "$real" ]; then
	    echo "Error: Unknown format from the 'time' program:" >&2
	    echo "$output" >&2
	    echo 0
	    return
	fi

	# ...tem 0:00.22elapsed 1%cpu...
	real=${real%%elapsed*}		# ...tem 0:00.22
	real=${real##* }		# 0:00.22
	min=${real%%:*}			# 0
	sec=${real##*:}			#   00.22
    fi

    # Now we've got min=0 and sec=0.22, get rid of the decimal point
    ms=${sec#*.}		# 22
    while [ ${#ms} -lt 3 ]; do	# 220
	ms=${ms}0
    done
    sec=${sec%.*}

    # Bourne arithmetic in $(...) treats leading 0 as octal!
    min=$(nooctal $min)
    sec=$(nooctal $sec)
    ms=$(nooctal $ms)

    echo "$min minutes, $sec seconds, $ms milliseconds" >&2

    # Now return the result as total number of milliseconds 
    echo $((min*60*1000 + sec*1000 + ms))
}

nooctal() {
    # Given a string in $1, print without leading zeros.
    # "008" --> "8"
    x=$1
    y=${x#0}
    while [ "$x" != "$y" ]; do
	x=$y
	y=${x#0}
    done

    if [ "$x" ]; then
	echo $x
    else
	echo 0
    fi
}

whichwget() {
    # On fancy machines, wget detects it is not on a tty and is too verbose.
    # On routers, wget doesn't understand the --progress flag.
    # Let's make everybody happy! :-)

    # Run a test and see how it dies. (255.255.255.255 always fails).

    wget --bind-address=192.168.3.1 --progress=bar:force  -t 1 -T 0.1  255.255.255.255 >/dev/null  2>&1
    case $? in
	127) echo "Sorry this test requires wget (busybox or regular)." >&2
	     ;;
	4) # Yay! Fancy wget.
	    options="--quiet --show-progress --progress=bar:force --report-speed=bits"
	    ;;
	1) # Still Yay! Busybox wget or a veritable simulacrum.
	    ;;
	*) # Huh... um... yay?
	    echo Error: The shell or wget gave a mysterious error code. >&2
	    echo Error: This ought never happen. >&2
	    ;;
    esac
    echo wget $options
}



echo "======================================================================"
echo "ROUGH APPROXIMATION"
dotest 1
echo "======================================================================"
echo "DOING QUICK TEST"
dotest 10
echo "======================================================================"
echo "DOING NORMAL TEST"
#dotest 100			# cachefly's "100" file is empty as of Feb 2023
dotest 50 100			# cachefly's "50" file is 100MB as of June 2023
#echo "======================================================================"
#echo "EXHAUSTIVE TEST"
#dotest 200