#!/usr/bin/env bash

if [ ! -d /sys/class/power_supply/BAT0 ]; then
    echo "<span color='gray'></span> No battery"
    exit
fi

current_now=$(cat /sys/class/power_supply/BAT0/current_now)
charge_now=$(cat /sys/class/power_supply/BAT0/charge_now)
charge_full=$(cat /sys/class/power_supply/BAT0/charge_full)
bat_status=$(cat /sys/class/power_supply/BAT0/status)
charge_percent=$(( (100*charge_now) / charge_full ))

if [ "$bat_status" = "Full" ]; then
    echo "<span color='gray'></span> Full" && exit
fi

if [ "$bat_status" = "Discharging" ]; then
    tot_minutes_remaining=$(( charge_now*60/current_now ))

    if [[ $charge_percent -lt 20 ]]; then
        icon=""
        color="#FF0000"
    elif [[ $charge_percent -lt 40 ]]; then
        icon=""
        color='gray' # ="#FFAE00"
    elif [[ $charge_percent -lt 60 ]]; then
        icon=""
        color='gray' # ="#FFF600"
    elif [[ $charge_percent -lt 80 ]]; then
        icon=""
        color='gray' # ="#A8FF00"
    else
        icon=""
        color='gray' # ="#00FF00"
    fi

elif [ "$bat_status" = "Charging" ]; then
    tot_minutes_remaining=$(( (charge_full-charge_now)*60/current_now ))

    icon=
    color="lightblue"
fi

time_remaining=$(printf "%02d:%02d" \
    $(( tot_minutes_remaining/60 )) \
    $(( tot_minutes_remaining - (tot_minutes_remaining/60)*60 )))

echo "<span color='$color'>$icon</span> $charge_percent% ($time_remaining)"