#!/bin/sh

percentage="$(cat /sys/class/power_supply/BAT0/capacity)"
class=""
tooltip="$(upower -i /org/freedesktop/UPower/devices/battery_BAT0 | grep 'time to' | sed -E 's/^\s*//;s/\s+/ /g')"
[ "$percentage" -lt "30" ] && class="battery_low"
[ "$percentage" -lt "15" ] && class="battery_crit"
grep -qE '^Charging$' /sys/class/power_supply/BAT0/status && class="battery_charging"

printf "{\"text\": \"battery\", \"alt\": \"bat\", \"tooltip\": \"%s\", \"class\": \"%s\", \"percentage\": %s}" "$tooltip" "$class" "$percentage"