#!/usr/bin/env bash
# battery_monitor
# Intended to be run via .xinitrc
# - Exit automatically if no battery (desktop)
# - When below 15%, warn user of low battery
# - When below 10%, suspend within 10 seconds if not charging
#
# Craig Jennings <c@cjennings.net>

# check if acpi is installed
if ! command -v acpi &> /dev/null; then
	echo "acpi is not installed. Cannot continue. Exiting...."
	exit 1
fi

# exit if a battery exists
if [ ! -d "/sys/class/power_supply/BAT0" ] && [ ! -d "/sys/class/power_supply/BAT1" ]; then
	echo "Acpi is installed but no battery detected. Assuming this is a desktop and exiting...."
	exit 1
fi

while true; do
	# Get the current battery percentage using acpi
	battery_percentage=$(acpi -b | awk -F ', ' '{print $2}' | tr -d '%')
	# battery_percentage=$(acpi -b | awk -F ', ' '{print $2}' | sed 's/%//')

	# When below 10%, suspend within 10 seconds if not charging
	if [ "$battery_percentage" -lt 11 ] && ! acpi -a | grep -q "on-line" ; then
		# Send a notification of sleeping in 10 seconds
        notify-send -u critical "Critical Battery" "Battery is at $battery_percentage%. System entering sleep in 30 seconds."

		# sleep for 10 seconds, then abort if charging
		sleep 30

		# Check if the system is charging (AC adapter connected)
		if acpi -a | grep -q "on-line"; then
			notify-send "Charging" "The system is now charging. No action taken."
		else
            notify-send -u critical "Critical Battery" "Putting the system to sleep."
			sudo systemctl suspend
		fi
	fi

	# When below 15%, warn user
	if [ "$battery_percentage" -lt 15 ] && ! acpi -a | grep -q "on-line" ; then
		# Send a notification using notify-send and dunst
        notify-send -u critical "Low Battery" "Battery is at $battery_percentage%. System will automatically sleep at 10%."
	fi

	# Sleep for 5 minutes before checking again
	sleep 300
done