#!/usr/bin/env bash

# You can call this script like this:
# $ ./brightnessControl.sh up
# $ ./brightnessControl.sh down

# Script inspired by these wonderful people:
# https://github.com/dastorm/volume-notification-dunst/blob/master/volume.sh
# https://gist.github.com/sebastiencs/5d7227f388d93374cebdf72e783fbd6a

function get_brightness {
  brightnessctl -m | grep -o '[0-9]\+%' | head -c-2
}

function send_notification {
  icon="notification-display-brightness"
  brightness=$(get_brightness)
  # Make the bar with the special character ─ (it's not dash -)
  # https://en.wikipedia.org/wiki/Box-drawing_character
  bar=$(seq -s "━" 0 $((brightness / 2)) | sed 's/[0-9]//g')
  # Send the notification
  dunstify -i "$icon" -r 5555 -u normal "  $bar"
}

case $1 in
  up)
    # increase the backlight by 5%
    brightnessctl set +5%
    send_notification
    ;;
  down)
    if [[ $(get_brightness) -lt 5 ]]; then
        # avoid 0% brightness
        brightnessctl set 1%
    else
        # decrease the backlight by 5%
        brightnessctl set 5%-
    fi
    send_notification
    ;;
esac