#!/bin/bash

# This script increases/decreases brightness by a fixed increment specified in step.
# This script relies on the script notify-send-improved.

# i3-brightness-toggle - Increase and decrease brightness.
# Copyright (C) 2017 Fabrizio Romano Genovese <egonigredo@gmail.com>

# This copyrighted material is made available to anyone wishing to use,
# modify, copy, or redistribute it subject to the terms and conditions of
# the GNU General Public License v.2, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY expressed or implied, including the implied warranties of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
# Public License for more details.

# You should have received a copy of the
# GNU General Public License along with this program; if not, 
# see <http://www.gnu.org/licenses/>

# Put this file in /bin/ or in /usr/bin. Do not forget to give 
# sudo chmod +x i3-blur 
# to make it executable.

version=1.0
step=10

# Check if xbacklight  and notify-send-improved are installed
check_installed()
{
if [ ! -f /bin/notify-send-improved -a -f /bin/xbacklight ]; then
	echo "Notify-send-improved and/or xbacklight not present."
        echo "Please install them."     
        exit 2
fi
}

#Here we display the help messages and change the brightness using xbacklight
if [[ "$#" -ge 2 ]]; then
        echo "Usage: $0 {-v, --version | -h --help}"
        exit 2
elif [[ $# -le 1 ]]; then
	 case $1 in
		-v | --version) 
			echo "$0 - Version $version"
			exit 0
			;;
		-h | --help)
			echo "- v, --version		Display current version"
			echo "-h, --help		Display this message"
			echo "up			Increase brightness by $step%"
			echo "down			Decrease brightness by $step%"
			exit 0
			;;		
		"up")
			check_installed
			xbacklight -steps 1 -time 0 -inc $step
			;;
		"down")
			check_installed
                        xbacklight -steps 1 -time 0 -dec $step
			;;
		*)
                	echo "Usage: $0 {up|down| -v, --version | -h, --help}"
                	exit 2
	esac
fi

# Here we get the current brightness status from xbacklight
# awk is necessary because xbacklight is not precise and the 
# resulting brightness number is always slightly less than it should, 
# by ~0.05 usually. If we were to use cut instead of awk the result would 
# then be aesthetically unpleasant.

brightness=`xbacklight | awk '{printf("%d\n", $0+=$0<0?0:0.9)}'`

# Selects the right icon for the notification
# If the icon is not present it will not be displayed.

brightnessicon="/usr/share/icons/Adwaita/32x32/status/display-brightness-symbolic.symbolic.png"

# Here we read the notification id from a temporary file. 
# If the file doesn't exist, we initialize it the notification to 0
# Then we send the notification out and we reassign the notification 
# id to the current one using tee

#If the file exists, we just replace that notification id, that will 
# then stay the same and not increment.

if [ ! -f "/tmp/brightness_notification_id.dat" ]; then
		notification_id="0"
        		notification_id=$(notify-send-improved "Brightness Control" -i $muteicon --print-id -t 1000 "Brightness: $brightness" | tee /dev/tty)

else
		notification_id=`cat /tmp/volume_notification_id.dat`
	                notify-send-improved "Brightness Control" -i $brightnessicon --print-id --replace=$notification_id -t 1000 "Brightness: $brightness\%"

fi


# Here we write the notification id to a file. Next time we use this 
# script it will know if the notification has to be overwritten or not

echo "${notification_id}" > /tmp/brightness_notification_id.dat