#!/bin/bash

shopt -s extglob

declare -a batteries

status_by_charge() {
    capacity="$1"

    if [ "$capacity" -ge 95 ]; then
        echo ' '
    elif [ "$capacity" -ge 65 ]; then
        echo ' '
    elif [ "$capacity" -ge 50 ]; then
        echo ' '
    elif [ "$capacity" -gt 20 ]; then
        echo ' '
    fi
}

for battery_path in /sys/class/power_supply/!(AC*); do
	status="$(cat "${battery_path}/status")"
	capacity="$(cat "${battery_path}/capacity")"
        sep=$([ "$1" == "-s" ] && echo " ")

	case "${status}" in
		"Full") status_symbol=" " ;;
                "Discharging") status_symbol="$(status_by_charge "${capacity}")" ;;
		"Charging") status_symbol="󱐥 " ;;
		"Not charging") status_symbol="󱐤 " ;;
		"Unknown") status_symbol="󰒲 " ;;
		*) status_symbol="?? " ;;
	esac

        [ "$capacity" -eq 100 ] && status_symbol=" "
	[ "$status" = "Discharging" ] && [ "$capacity" -le 20 ] && { status_symbol="❗"; [ -n "$sep" ] && sep="" || sep=" "; }
	batteries+=("${status_symbol}${sep}${capacity}%")
done

echo "${batteries[@]}"