#!/bin/bash
#
# zipl-switch-to-blscfg - Switch zipl to use BootLoaderSpec configuration
#
# Copyright 2018 Red Hat, Inc.
#
# s390-tools is free software; you can redistribute it and/or modify
# it under the terms of the MIT license. See LICENSE for details.
#

readonly SCRIPTNAME="${0##*/}"

declare -A zipl_to_bls
zipl_to_bls["image"]="linux"
zipl_to_bls["ramdisk"]="initrd"
zipl_to_bls["parameters"]="options"

print_error() {
    echo "$1" >&2
    exit 1
}

function on_exit() {
    if ! rm -rf $TMP; then
        echo "Delete temporary files failed!" >&2
        exit 1
    fi
}

if ! TMP="$(mktemp -d)"; then
    print_error "Creating a temporary dir for config files failed!"
fi

trap 'on_exit' EXIT

print_version() {
    cat <<EOF
${SCRIPTNAME}: version %S390_TOOLS_VERSION%
Copyright Red Hat, Inc. 2018
EOF
}

print_usage()
{
    print_version

    cat <<EOF

Usage: ${SCRIPTNAME} [OPTIONS]

Switches the zipl boot-loader configuration to use BootLoaderSpec files.

Options:

	-h, --help		print this help and exit
	-v, --version      	print version information and exit
	--backup-suffix=SUFFIX  suffix used for backup files, defaults to .bak
	--bls-directory=DIR     path to generate BLS files, defaults to /boot/loader/entries
	--config-file=FILE      path to zipl configuration file, defaults to /etc/zipl.conf
	--ignore-default	ignore the default option from the zipl configuration file
	--use-version-name	use the section kernel version as the BLS file name

EOF
}

OPTS="$(getopt -o hv --long help,version,backup-suffix:,bls-directory:,config-file:,\
ignore-default,use-version-name -n \'$SCRIPTNAME\' -- "$@")"
eval set -- "$OPTS"

BACKUP_SUFFIX=.bak
BLS_DIR="/boot/loader/entries"
CMDLINE_LINUX_DEBUG=" systemd.log_level=debug systemd.log_target=kmsg"
LINUX_DEBUG_VERSION_POSTFIX="_with_debugging"
LINUX_DEBUG_TITLE_POSTFIX=" with debugging"
CONFIG="/etc/zipl.conf"

while [ ${#} -gt 0 ]; do
    case "$1" in
	--help|-h)
	    print_usage
	    exit 0
	    ;;
	--version|-v)
	    print_version
	    exit 0
	    ;;
	--backup-suffix)
	    BACKUP_SUFFIX=${2}
	    shift
	    ;;
	--bls-directory)
	    BLS_DIR=${2}
	    shift
	    ;;
	--config-file)
	    CONFIG=${2}
	    shift
	    ;;
	--ignore-default)
	    ignore_default=true
	    ;;
	--use-version-name)
	    version_name=true
	    ;;
	--)
	    shift
	    break
	    ;;
	*)
	    echo >&2
	    echo "${SCRIPTNAME}: invalid option \"${1}\"" >&2
	    echo "Try '${SCRIPTNAME} --help' for more information" >&2
	    echo >&2
	    exit 1
	    ;;
    esac
    shift
done

TMP_CONFIG="${TMP}/${CONFIG##*/}"

[[ -d "$BLS_DIR" ]] || mkdir -m 0700 -p "$BLS_DIR"

if [ -f /etc/machine-id ]; then
    read MACHINE_ID < /etc/machine-id
    MACHINE_ID=${MACHINE_ID}-
fi

count=0
OUTPUT=""
TARGET=""
while IFS='= ' read key val; do
    # for BLS the default kernel is always the latest one
    if [[ $key == \#* ]] || [[ $key == "default" && $ignore_default == true ]]; then
        continue
    fi

    # remove spaces
    key="$(echo $key | sed -e 's/^[ \t"]*//;s/[ \t"]*$//')"

    if [[ $key = \[*] ]]; then
        if [[ $key == "[defaultboot]" ]]; then
            OUTPUT=${TMP_CONFIG}
            echo $key >> ${OUTPUT}
        else
            key="${key%\]}"
            key="${key#\[}"
            section=$key
            OUTPUT=${BLS_DIR}/${MACHINE_ID}${section}.conf
            if [ -f "${OUTPUT}" ]; then
                print_error "BLS file ${OUTPUT} already exists"
            fi
            echo "title $section" >> ${OUTPUT}
        fi
    elif [[ $val ]]; then
        val="$(echo $val | sed -e 's/^[ \t"]*//;s/[ \t"]*$//')"
        if [[ $key == "target" ]]; then
            if [ -z ${TARGET} ]; then
                echo $key=$val >> ${TMP_CONFIG}
                TARGET=$val
            else if [ "${TARGET}" != "${val}" ]; then
                     print_error "BLS is only supported if all sections have the same target"
                 fi
            fi
        else
            if [ -n "${zipl_to_bls[$key]}" ]; then
		if [[ $key = "image" && $version_name == true ]]; then
                    if [[ $val = *"vmlinuz-"* ]]; then
                        version="${val##*/vmlinuz-}"
                    else
                        version="${val##*/}"
                    fi
                    echo "version $version" >> ${OUTPUT}
                    if [[ $version = *"rescue"* ]]; then
                        FILENAME=${BLS_DIR}/${MACHINE_ID}0-rescue.conf
                    else
                        FILENAME=${BLS_DIR}/${MACHINE_ID}${version}.conf
                    fi

                    if [[ ${OUTPUT} != ${FILENAME} ]]; then
			if [ -f "${FILENAME}" ]; then
			    print_error "BLS file ${FILENAME} already exists"
			fi
                        mv ${OUTPUT} ${FILENAME}
                        if [ ! $? -eq 0 ]; then
                            print_error "Creating BLS file ${FILENAME} failed"
                        fi
                        OUTPUT=${FILENAME}
                    fi
		elif [[ $key = "image" ]]; then
                    echo "version $section" >> ${OUTPUT}
		fi

                echo "${zipl_to_bls[$key]} ${val}" >> ${OUTPUT}
            else
                echo $key=$val >> ${TMP_CONFIG}
            fi
        fi
    fi
done < "${CONFIG}"

if [ -f "${CONFIG}${BACKUP_SUFFIX}" ]; then
    print_error "Backup file ${CONFIG}${BACKUP_SUFFIX} already exists"
fi

cp -af "${CONFIG}" "${CONFIG}${BACKUP_SUFFIX}"
mv "${TMP_CONFIG}" "${CONFIG}"

zipl > /dev/null
if [ ! $? -eq 0 ]; then
    mv "${CONFIG}${BACKUP_SUFFIX}" "${CONFIG}"
fi

exit 0