#!/bin/bash

sleeptime=60

BatteryAlert(){
percentage=$(pmset -g batt | egrep "([0-9]+\%).*" -o | cut -f1 -d';' | sed 's/%//' | bc)
alertlevel=10

if [ "$percentage" -le "$alertlevel" ]
then
	if [ ! -f "./batteryalert_lock" ]
	then
	/usr/bin/osascript <<-EOF
    	tell application "System Events"
       		activate
        	display dialog "Your battery is at $percentage%. It is recommended you plug into a power outlet, or shut down!"
    	end tell
	EOF

	touch ./batteryalert_lock
	fi

	echo "Battery life is at $percentage%. Battery is running low."

elif [ "$percentage" -gt "$alertlevel" ]
then
	echo "Battery life is at $percentage%. No need to worry... yet."

	if [ -f "./batteryalert_lock" ]
	then
	rm ./batteryalert_lock
	fi

else
	echo "Error"
	# Do nothing
fi
}

while (true)
do
	BatteryAlert;
	sleep $sleeptime;
done