#!/bin/sh

# container-tools - Manage systemd-nspawn containers
# Copyright (C) 2014-2016 Daniel Baumann <daniel.baumann@open-infrastructure.net>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty 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/>.

set -e

COMMAND="$(basename ${0})"

CONFIG="/etc/container-tools/config"
MACHINES="/var/lib/machines"

Parameters ()
{
	LONG_OPTIONS="force,new:,old:,"
	OPTIONS="f,n:,o:,"

	PARAMETERS="$(getopt --longoptions ${LONG_OPTIONS} --name=${COMMAND} --options ${OPTIONS} --shell sh -- ${@})"

	if [ "${?}" != "0" ]
	then
		echo "'${COMMAND}': getopt exit" >&2
		exit 1
	fi

	eval set -- "${PARAMETERS}"

	while true
	do
		case "${1}" in
			-f|--force)
				FORCE="true"
				shift 1
				;;

			-n|--new)
				NEW="${2}"
				shift 2
				;;

			-o|--old)
				OLD="${2}"
				shift 2
				;;

			--)
				shift 1
				break
				;;

			*)
				echo "'${COMMAND}': getopt error" >&2
				exit 1
				;;
		esac
	done
}

Usage ()
{
	echo "Usage: container ${COMMAND} [-f|--force] -n|--new NAME -o|--old NAME" >&2
	exit 1
}

Parameters "${@}"

if [ -z "${OLD}" ] || [ -z "${NEW}" ]
then
	Usage
fi

if [ ! -e "${MACHINES}/${OLD}" ]
then
	echo "'${OLD}': no such container" >&2
	exit 1
fi

if [ ! -e "${MACHINES}/${NEW}" ]
then
	echo "'${NEW}': container already exists" >&2
	exit 1
fi

STATE="$(machinectl show ${OLD} 2>&1 | awk -F= '/^State=/ { print $2 }')"

case "${STATE}" in
	running)
		echo "'${OLD}': container is started" >&2
		exit 1
		;;
esac

case "${FORCE}" in
	true)
		;;

	*)
		if container list --other | grep -qs "^${OLD}$"
		then
			echo -n "'${OLD}': rename remote container to '${NEW}' [y|N]? "
			read FORCE

			FORCE="$(echo ${FORCE} | tr [A-Z] [a-z])"

			case "${FORCE}" in
				y|yes)
					;;

				*)
					exit 1
					;;
			esac
		fi
		;;
esac

# Run
mv "${CONFIG}/${OLD}.conf" "${CONFIG}/${NEW}.conf"
mv "${MACHINES}/${OLD}" "${MACHINES}/${NEW}"

# Renaming bind mounts
BIND="$(awk -F= '/^bind=/ { print $2 }' ${CONFIG}/${NAME}.conf)"

if [ -n "${BIND}" ]
then
	BINDS="$(echo ${BIND} | sed -e 's|;| |g')"

	for BIND in ${BINDS}
	do
		SOURCE_OLD="$(echo ${BIND} | awk -F: '{ print $1 }')"
		SOURCE_NEW="$(echo ${SOURCE_OLD} | sed -e "s|${OLD}|${NEW}|g")"

		if [ "${SOURCE_OLD}" != "${SOURCE_NEW}" ]
		then
			mv "${SOURCE_OLD}" "${SOURCE_NEW}"
		fi

		TARGET_OLD="$(echo ${BIND} | awk -F: '{ print $2 }')"
		TARGET_NEW="$(echo ${TARGET_OLD} | sed -e "s|${OLD}|${NEW}|g")"

		if [ "${TARGET_OLD}" != "${TARGET_NEW}" ]
		then
			mv "${MACHINES}/${NEW}/${TARGET_OLD}" "${MACHINES}/${NEW}/${TARGET_NEW}"
		fi
	done
fi

# Updating configuration file
sed -i -e "s|${OLD}|${NEW}|g" "${CONFIG}/${NEW}.conf"