#!/bin/bash


# Check for pause time.
pause_time=0

if [[ "$1" ]]; then
	if   [[ $1 =~ ^([0-9]+):([0-9]+):([0-9]+)$ ]]; then
		pause_time=$(((${BASH_REMATCH[1]}*60*60) + (${BASH_REMATCH[2]}*60) + (${BASH_REMATCH[3]})))
	elif [[ $1 =~ ^([0-9]+):([0-9]+)$ ]]; then
		pause_time=$(((${BASH_REMATCH[1]}*60) + (${BASH_REMATCH[2]})))
	elif [[ $1 =~ ^([0-9]+)$ ]]; then
		pause_time=$1
	else
		echo "Bad pause time: $1" >&2
		exit 1
	fi
fi


# Get national debt.
function get_debt()
{
	local t=$(wget --quiet http://brillig.com/debt_clock -O - | grep debtiv.gif)

	t=$(sed -e 's/.*ALT="\$//' -e 's/".*//' -e 's/[ ,]//g' <<<$t)
	echo $t
}

# Print time item.
# Pass time value and one of 'hour', 'minute', 'ssecond'.
function fmt_time()
{
	local t=$1
	local p=$2
	if [[ $t -gt 0 ]]; then
		if [[ $t -eq 1 ]]; then
			printf '%d %s' $t $p
		else
			printf '%d %ss' $t $p
		fi
	fi
}

# Print the elapsed time between the first and second argument.
# Times given in seconds.
# Earliest time is first arugment.
function elapsed_time()
{
	local st=$1
	local et=$2
	local dt=$((et - st))
	local ds=$((dt % 60))
	local dm=$(((dt / 60) % 60))
	local dh=$((dt / 3600))
	
	echo $(fmt_time $dh 'hour') $(fmt_time $dm 'minute') $(fmt_time $ds 'second')
}


######################################################################

stime=$(date +%s)
sdebt=$(get_debt)

if [[ $pause_time -gt 0 ]]; then sleep $pause_time; fi

etime=$(date +%s)
edebt=$(get_debt)

t=$(elapsed_time $stime $etime)
d=$(bc <<<"scale=2; $edebt - $sdebt")

printf "During the last %s the US National Debt has increased by %s\n" "$t" "$d"


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