#!/bin/bash

set -e
[ -n "$DEBUG" ] && set -x

print_gateway_uri=
print_time_diff=
print_json=
while getopts djuh opt; do
	case "$opt" in
	d) print_time_diff=1 ;;
	j) print_json=1 ;;
	u) print_gateway_uri=1 ;;
	h | ?)
		printf "usage: hspl [options]\n"
		printf "\n"
		printf "supported hotspot vendors:\n"
		printf "    hotsplots.de (Espresso House Berlin)\n"
		printf "    pbspot (CoffeeFellows Berlin)\n"
		printf "\n"
		printf "options:\n"
		printf "  -d   print time until expiry in seconds\n"
		printf "  -j   output json\n"
		printf "  -u   print gateway address\n"
		printf "\n"
		exit 2
		;;
	esac
done
shift $((OPTIND - 1))

if=wlan0

gateway=$(ip route show dev "$if" | awk '/default via/{print $3}')

if [ -n "$print_gateway_uri" ]; then
	echo "$gateway"
	exit 0
fi

html=$(curl -Ls --interface "$if" "$gateway")

t=
tx=
rx=
vendor=

# hotspot vendor implementations go here:

if grep -q pbspot <<<"$html"; then
	vendor=pbspot
	t=$(grep -i 'expires' <<<"$html" | awk -F 'td>' '{print $4}' | tr -d '</' | tr -d ':' | sed -e 's,s, seconds,' -e 's,m, minutes,')
	tx=$(grep -i 'transmitted' <<<"$html" | awk -F 'td>' '{print $4}' | tr -d '</')
	rx=$(grep -i 'received' <<<"$html" | awk -F 'td>' '{print $4}' | tr -d '</')
fi

if grep -q hotsplots <<<"$html"; then
	vendor=hotsplots
	html=$(sed 's,\/tr>,\/tr>\n,g' <<<"$html")
	t=$(grep -i 'verbleibende zeit' <<<"$html" | awk -F 'td>' '{print $3}' | tr -d '</' | sed -e 's,&nbsp,,' -e 's,h, hours,' -e 's,min, minutes,' -e 's,sec, seconds,')
	tx=$(grep -i 'übertragene daten' <<<"$html" | awk -F 'td>' '{print $3}' | tr -d '</' | sed -e 's,&nbsp,,' -e 's, (.*),,')
	rx="-"
fi

# end of hotspot vendor implementations

# no hotspot or unimplemented vendor
if [ -z "$t" ]; then
	exit 1
fi

expiry_time=$(date --date "now + $t" +%s)
remaining=$(((expiry_time - $(date +%s))))

if [ -n "$print_time_diff" ]; then
	echo "$remaining"
	exit 0
fi

# format remaining time like: 5h30m or 10s
remaining=$(awk '{
	s=$0
	h=(s/60/60);
	if(h>1){ printf "%dh", h }
	m=(s/60%60)
	if(m>1){ printf "%dm", m }
	if(h<1 && m<1){ printf "%ds", $0 }
}' <<<"$remaining")

if [ -n "$print_json" ]; then
	jq -n --args '{
		remaining:$ARGS.positional[0],
		tx:$ARGS.positional[1],
		rx:$ARGS.positional[2],
		t:$ARGS.positional[3],
		vendor:$ARGS.positional[4]
	}' "$remaining" "$tx" "$rx" "$t" "$vendor"
else
	echo "$remaining"
	echo "TX:" "$tx"
	echo "RX:" "$rx"
fi