#!/bin/sh
# SPDX-License-Identifier: GPL-3.0-or-later

# IMPORTANT!!
# DO NOT RUN THIS IN CRONJOB!

execute_subshell() {
	if [ $# -ne 1 ]; then
		echo "Usage:" "$0" "<function>"
	fi

	for script in /etc/layer3.d/*; do
		(
			# unset function to prevent executing parents shell function
			unset -f "$1"
			. "$script"

			if type "$1" | grep -q "function" ; then
				"$1"
			fi
		)

		if [ $? -ne 0 ]; then
			echo
			echo "Error when executing" "$1" "from" "$(basename "$script")"
			exit 1
		fi
	done
}

configure() {
	echo "This script might remove existing vlans, interfaces, addresses, etc."
	read -r -p "Do you really want to continue? (y/n) " response
	if ! ( [ "$response" == "y" ] || [ "$response" == "Y" ] ); then
		exit 1
	fi

	echo
	execute_subshell configure

	exit 0
}

reload_services() {
	execute_subshell reload
	reload_config
}

apply_changes() {
	execute_subshell apply
	reload_services
	exit 0
}

revert_changes() {
	execute_subshell revert
	exit 0
}

keep_changes() {
	if [ -f "/tmp/configure-layer3-pid" ]; then
		echo "Keep changes"
		kill -9 $(cat /tmp/configure-layer3-pid)
		rm /tmp/configure-layer3-pid
		# We need exit because trap in test_changes() will not stop
		# the script here and revert settings otherwise
		exit
	else
		echo "configure-layer3 -t is not running"
	fi
}

test_changes() {
	echo $$ > /tmp/configure-layer3-pid
	trap keep_changes SIGINT SIGTERM

	reload_services

	sleep 5

	echo "Configuration reloaded. Changes will be reverted in 200s."
	echo "Kill this script or use configure-layer3 -k to keep changes."

	sleep 200

	echo "Reverting changes.."
	# on revert we must delete the pid-file
	rm /tmp/configure-layer3-pid
	revert_changes
	reload_services
}


usage() {
	echo "Usage: $0 [OPTION]"
	echo
	echo "Options:"
	echo "	-c: configure. No commit, no restart!"
	echo "	-t: test changes. Restarts services, waits up to 200s for SIGINT"
	echo "	-k: keep changes from test mode"
	echo "	-a: apply changes"
	echo "	-r: revert changes"
}


if [ $# != 1 ]; then
	usage; exit 1
fi

case "$1" in
	-c) configure ;;
	-t) test_changes ;;
	-k) keep_changes ;;
	-a) apply_changes ;;
	-r) revert_changes ;;
	*) usage; exit 1 ;;
esac