#!/usr/bin/env bash
battery_charge() {
  if [[ -r /sys/class/power_supply/BAT0/uevent ]]; then
    cat /sys/class/power_supply/BAT0/uevent | awk '
      /CHARGE_NOW/   { split($0, a, "="); curr = a[2]; n++ }
      /CHARGE_FULL=/ { split($0, a, "="); full = a[2]; n++ }

      END { if (n == 2) printf "%.1f", curr / full * 100 }
    '
  fi
}

display_brightness() {
  if command -v ddcutil &>/dev/null; then
    ddcutil getvcp 10 | awk '
        match($0, /[0-9]+,/) { printf "%s", substr($0, RSTART, RLENGTH - 1) }'
  else
    light -G | awk '{ split($0, a, "."); printf "%s", a[1] }'
  fi
}

get_volume() {
  pactl get-sink-volume @DEFAULT_SINK@ | awk '
    match($0, /[0-9]+%/) { printf "%s", substr($0, RSTART, RLENGTH - 1) }'
}

remaining_ram() {
  awk '
  /MemTotal:/     { memtotal   = $2 / 1024**2 }
  /MemAvailable:/ { mavailable = $2 / 1024**2 }

  END {
    used = memtotal - mavailable
    printf "%0.1fG / %.1fG", used, memtotal
  }
' /proc/meminfo
}

ramu="$(remaining_ram)"
brightness="$(display_brightness)"
volume="$(get_volume)"
charge="$(battery_charge)"
time="$(date +'%d %a %l:%M %p' | awk '{ gsub(/ +/, " "); print }')"

output=''

[[ -z "$brightness" ]] || output+="${brightness}cd | "
[[ -z "$volume" ]] || output+="${volume}dB | "
[[ -z "$charge" ]] || output+="[${charge}%] | "
[[ -z "$ramu" ]] || output+="${ramu} | "
[[ -z "$time" ]] || output+="$time"

printf "%s" "$output"