#!/usr/bin/env bash
# 2018 Luke Shumaker
declare -r NAME=osi-run
declare -r VERSION=20180812

set -euE
source "${BASH_SOURCE[0]%/*}/lib/osi.sh"

main() {

	local arg_mode=outside
	local arg_mountpoint=
	local arg_image=
	local arg_qemu=(
		qemu-system-x86_64
		-machine accel=kvm
		-m 512
	)

	local args
	if ! args="$(getopt -n "${0##*/}" -o hV -l inside:,help,version -- "$@")"; then
		arg_mode=error
	else
		eval "args=($args)"
		set -- "${args[@]}"
		while true; do
			case "$1" in
				--inside) shift; arg_mode=inside; arg_mountpoint=$1; shift;;
				-V|--version) shift; arg_mode=version;;
				-h|--help) shift; arg_mode=usage;;
				--) shift; break;;
				*) error 1 'Internal error.  The programmer writing this tool screwed up.';;
			esac
		done
		case "$arg_mode" in
			outside|inside)
				if (( $# != 1 )); then
					if (( $# == 0 )); then
						error 0 "Expected 1 positional argument, got none"
					else
						error 0 "Expected 1 positional argument, got %d: %s" "$#" "${@@Q}"
					fi
					arg_mode=error
				else
					arg_image=$1
				fi
				;;
		esac
	fi
	case "$arg_mode" in
		error) print "Try '%q --help' for more information" "${0##*/}" >&2; return 2;;
		version)
			print "%s (notsystemd) %s" "$NAME" "$VERSION"
			return 0
			;;
		usage)
			print 'Usage: %s [OPTIONS] FILENAME.img < SCRIPT.sh' "${0##*/}"
			print 'Operating System Image: Run Script'
			echo
			print 'OPTIONS:'
			# --inside is internal-only; undocumented
			print '  -h, --help     display this help'
			print '  -V, --version  output version information'
			return 0
			;;

		# main code starts here
		#
		# We get a little tricky with umount/mount, instead of
		# just calling osi-mount twice, because
		#  - want to escalate privileges *only once*
		#  - we want osi-mount to be the *only* command we
		#    escalate privileges for
		outside)
			arg_mountpoint=$(mktemp -dt -- "${0##*/}.XXXXXXXXXX")
			trap "rmdir -- ${arg_mountpoint@Q}" EXIT
			sudo -- ./osi-mount "$arg_image" "$arg_mountpoint" "${BASH_SOURCE[0]}" --inside="$arg_mountpoint" "${args[@]}"
			;;
		inside) # just keep reading...
			needs_sudo
			install -Dm755 /dev/stdin "$arg_mountpoint/etc/osi-run"
			umount "$arg_mountpoint"
			sudo -u "#${SUDO_UID}" -- "${qemu[@]}" -drive media=disk,format=raw,if=virtio,file="$arg_image"
			mount "$arg_image" "$arg_mountpoint"
			cat "$arg_mountpoint/var/log/osi-run.out"
			return "$(cat "$arg_mountpoint/var/log/osi-run.status")"
			;;

		*) error 1 'Internal error.  The programmer writing this tool screwed up.';;
	esac
}

main "$@"