#!/bin/sh

# container-tools - Manage systemd-nspawn containers
# Copyright (C) 2014-2017 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

SOFTWARE="container-tools"
PROGRAM="container"

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

LC_ALL="C.UTF-8"

Usage ()
{
	echo "Usage: ${PROGRAM}-shell" >&2
	exit 1
}

Shell ()
{
	COMMAND="${1}"

	if [ -z "${COMMAND}" ]
	then
		return
	fi

	shift 1

	OPTIONS="${@}"

	case "${COMMAND}" in
		about)
			man ${PROGRAM} || true

			return
			;;

		logout|exit)
			exit 0
			;;

		help)
			case "${OPTIONS}" in
				"")
					echo
					echo "The following ${PROGRAM} commands are available:"
					echo

					cd "/usr/lib/${SOFTWARE}/${PROGRAM}"
					find . -type f -printf "  %f\n" | sort
					cd "${OLDPWD}"

					if [ -n "${CONTAINER_COMMANDS_ENABLE}" ]
					then
						echo
						echo "The following container commands are enabled for the current user:"
						echo "  ${CONTAINER_COMMANDS_ENABLE}"
					fi

					if [ -n "${CONTAINER_COMMANDS_DISABLE}" ]
					then
						echo
						echo "The following container commands are disabled for the current user:"
						echo "  ${CONTAINER_COMMANDS_DISABLE}"
					fi

					echo
					echo "Use 'help COMMAND' for more information."

					return
					;;

				*)
					man ${PROGRAM}-${1} || true

					return
					;;
			esac
			;;
	esac

	if [ ! -e "/usr/lib/${SOFTWARE}/${PROGRAM}/${COMMAND}" ]
	then
		echo "'${COMMAND}': no such ${PROGRAM} command" >&2
		return
	fi

	if [ -n "${CONTAINER_COMMANDS_ENABLE}" ]
	then
		COMMAND_ALLOWED=""

		for CONTAINER_COMMAND in ${CONTAINER_COMMANDS_ENABLE}
		do
			case "${CONTAINER_COMMAND}" in
				${COMMAND}|all|about|logout|exit|help)
						COMMAND_ALLOWED="true"
						;;
			esac
		done

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

			*)
				echo "'${COMMAND}': command not allowed for current user" >&2
				return
				;;
		esac
	fi

	if [ -n "${CONTAINER_COMMANDS_DISABLE}" ]
	then
		COMMAND_DISALLOWED=""

		for CONTAINER_COMMAND in ${CONTAINER_COMMANDS_DISABLE}
		do
			case "${CONTAINER_COMMAND}" in
				${COMMAND}|all|about|logout|exit|help)
						COMMAND_DISALLOWED="true"
						;;
			esac
		done

		case "${COMMAND_DISALLOWED}" in
			true)
				echo "'${COMMAND}': command not allowed for current user" >&2
				return
				;;
		esac
	fi

	echo
	sudo ${PROGRAM} ${COMMAND} ${OPTIONS} || true
}

trap 'echo' EXIT HUP INT QUIT TERM

echo "${SOFTWARE} $(${PROGRAM} version)"
echo "Type \"about\" or \"help\" for more information, \"logout\" to exit."

while true
do
	echo
	echo -n "${PROGRAM}: "
	read CMDLINE

	Shell ${CMDLINE}
done