#!/usr/bin/bash

if ! [[ $KERNEL_INSTALL_MACHINE_ID ]]; then
    exit 0
fi

[[ -f /etc/default/grub ]] && . /etc/default/grub
[[ -f /etc/os-release ]] && . /etc/os-release

COMMAND="$1"
KERNEL_VERSION="$2"
BOOT_DIR_ABS="$3"
KERNEL_IMAGE="$4"

KERNEL_DIR="${KERNEL_IMAGE%/*}"

MACHINE_ID=$KERNEL_INSTALL_MACHINE_ID

# If ${BOOT_DIR_ABS} exists, some other boot loader is active.
[[ -d "${BOOT_DIR_ABS}" ]] && exit 0

BLS_DIR="/boot/loader/entries"

mkbls() {
    local kernelver=$1 && shift
    local datetime=$1 && shift
    local kernelopts=$1 && shift

    local debugname=""
    local debugid=""
    local flavor=""

    if [[ "$kernelver" == *\+* ]] ; then
        local flavor=-"${kernelver##*+}"
        if [[ "${flavor}" == "-debug" ]]; then
            local debugname=" with debugging"
            local debugid="-debug"
        fi
    fi

    cat <<EOF
title ${NAME} (${kernelver}) ${VERSION}${debugname}
version ${kernelver}${debugid}
linux /vmlinuz-${kernelver}
initrd /initramfs-${kernelver}.img
options ${kernelopts}
grub_users \$grub_users
grub_arg --unrestricted
grub_class ${ID}
EOF
}

default_bls() {
    local saved_entry
    local saved_entry_file

    saved_entry=$(grub2-editenv - list | grep -oP '(?<=saved_entry=).*$')
    saved_entry_file=${BLS_DIR}/${saved_entry}.conf

    # If there is no "saved_entry", try to take the running kernel
    if [[ -z "$saved_entry" ]] || [[ ! -f "$saved_entry_file" ]]; then
        for bls_file in "$BLS_DIR"/*-"$(uname -r)".conf; do
            if [[ -f "$bls_file" ]]; then
                # Let's set this as default explicitly
                if [[ "$GRUB_UPDATE_DEFAULT_KERNEL" = "true" ]]; then
                    bls="${bls_file%.conf}"
                    bls="${bls##*/}"
                    grub2-editenv - set "saved_entry=${bls}"
                fi
                echo "$bls_file"
                return
            fi
        done
    else
        echo "$saved_entry_file"
    fi
}

[[ "$KERNEL_VERSION" == *\+* ]] && flavor=-"${KERNEL_VERSION##*+}"
case "$COMMAND" in
    add)
        if [[ "${KERNEL_DIR}" != "/boot" ]]; then
            # rename to match the name used in the pseudo-BLS snippet above
            rm -f "/boot/vmlinuz-${KERNEL_VERSION}"
            cp --preserve=timestamps -T "${KERNEL_IMAGE}" "/boot/vmlinuz-${KERNEL_VERSION}"
            command -v restorecon &>/dev/null && \
                restorecon -R "/boot/vmlinuz-${KERNEL_VERSION}"

            for i in \
                    "$KERNEL_DIR"/System.map \
                    "$KERNEL_DIR"/config \
                    "$KERNEL_DIR"/zImage.stub \
                    "$KERNEL_DIR"/dtb
            do
                [[ -e "$i" ]] || continue
                rm -f "/boot/${i##*/}-${KERNEL_VERSION}"
                cp --preserve=timestamps -T "$i" "/boot/${i##*/}-${KERNEL_VERSION}"
                command -v restorecon &>/dev/null && \
                    restorecon -R "/boot/${i##*/}-${KERNEL_VERSION}"
            done
            # hmac is .vmlinuz-<version>.hmac so needs a special treatment
            i="$KERNEL_DIR/.${KERNEL_IMAGE##*/}.hmac"
            if [[ -e "$i" ]]; then
                rm -f "/boot/.${KERNEL_IMAGE##*/}-${KERNEL_VERSION}.hmac"
                cp --preserve=timestamps "$i" "/boot/.${KERNEL_IMAGE##*/}-${KERNEL_VERSION}.hmac"
                command -v restorecon &>/dev/null && \
                    restorecon "/boot/.${KERNEL_IMAGE##*/}-${KERNEL_VERSION}.hmac"
            fi
            # OLD method using gzip'd file (will be deprecated and removed in the future)
            # symvers is symvers-<version>.gz symlink, needs a special treatment
            i="$KERNEL_DIR/symvers.gz"
            if [[ -e "$i" ]]; then
                rm -f "/boot/symvers-${KERNEL_VERSION}.gz"
                ln -s "$i" "/boot/symvers-${KERNEL_VERSION}.gz"
                command -v restorecon &>/dev/null && \
                    restorecon "/boot/symvers-${KERNEL_VERSION}.gz"
            fi
            # symvers is symvers-<version>.bz symlink, needs a special treatment
            i="$KERNEL_DIR/symvers.bz"
            if [[ -e "$i" ]]; then
                rm -f "/boot/symvers-${KERNEL_VERSION}.bz"
                ln -s "$i" "/boot/symvers-${KERNEL_VERSION}.bz"
                command -v restorecon &>/dev/null && \
                    restorecon "/boot/symvers-${KERNEL_VERSION}.bz"
            fi
        fi

        if [[ "x${GRUB_ENABLE_BLSCFG}" = "xtrue" ]] || [[ ! -f /sbin/new-kernel-pkg ]]; then
            if [[ -f /etc/kernel/cmdline ]]; then
                if [[ /etc/kernel/cmdline -ot /etc/default/grub ]]; then
                    # user modified /etc/default/grub manually; sync
                    grub2-mkconfig -o /etc/grub2.cfg
                fi
                read -r -d '' -a BOOT_OPTIONS < /etc/kernel/cmdline
            elif [[ -f /usr/lib/kernel/cmdline ]]; then
                read -r -d '' -a BOOT_OPTIONS < /usr/lib/kernel/cmdline
	    elif [ ! -z "$GRUB_CMDLINE_LINUX" ] || [ ! -z "$GRUB_CMDLINE_LINUX_DEFAULT" ]; then
                declare -a BOOT_OPTIONS

		# Grab the root device and "ro" option from the current command line
		# because doing otherwise is too hard
                read -r -d '' -a line < /proc/cmdline
                for i in "${line[@]}"; do
                    if [[ "${i#root=*}" != "$i" ]] ; then
			BOOT_OPTIONS+=("$i")
		    fi
		    if [ "$i" == "ro" ]; then
			BOOT_OPTIONS+=("$i")
		    fi
                done

		# Grab everything else from /etc/default/grub
		if  [ ! -z "$GRUB_CMDLINE_LINUX" ]; then
		    BOOT_OPTIONS+=("$GRUB_CMDLINE_LINUX")
		fi
		if  [ ! -z "$GRUB_CMDLINE_LINUX_DEFAULT" ]; then
		    BOOT_OPTIONS+=("$GRUB_CMDLINE_LINUX_DEFAULT")
		fi
	    else
                declare -a BOOT_OPTIONS

                read -r -d '' -a line < /proc/cmdline
                for i in "${line[@]}"; do
                    [[ "${i#initrd=*}" != "$i" ]] && continue
                    [[ "${i#BOOT_IMAGE=*}" != "$i" ]] && continue
                    BOOT_OPTIONS+=("$i")
                done
            fi

            eval "$(grub2-get-kernel-settings)" || true
            [[ -d "$BLS_DIR" ]] || mkdir -m 0700 -p "$BLS_DIR"
            BLS_ID="${MACHINE_ID}-${KERNEL_VERSION}"
            BLS_TARGET="${BLS_DIR}/${BLS_ID}.conf"
            mkbls "${KERNEL_VERSION}" \
		  "$(date -u +%Y%m%d%H%M%S -d "$(stat -c '%y' "${KERNEL_DIR}")")" \
                  "${BOOT_OPTIONS[*]}" >"${BLS_TARGET}"
            command -v restorecon &>/dev/null && restorecon -R "${BLS_TARGET}"

            LINUX="$(grep '^linux[ \t]' "${BLS_TARGET}" | sed -e 's,^linux[ \t]*,,')"
            INITRD="$(grep '^initrd[ \t]' "${BLS_TARGET}" | sed -e 's,^initrd[ \t]*,,')"
            if [[ "$(grub2-probe --device $(grub2-probe --target=device /) --target=fs)" == "btrfs" &&
		      "${SUSE_BTRFS_SNAPSHOT_BOOTING}" == "true" ]]; then
                LINUX_RELPATH="$(grub2-mkrelpath -r /boot${LINUX})"
            else
                LINUX_RELPATH="$(grub2-mkrelpath /boot${LINUX})"
            fi
            BOOTPREFIX="$(dirname ${LINUX_RELPATH})"
            ROOTPREFIX="$(dirname "/boot${LINUX}")"

            if [[ $LINUX != $LINUX_RELPATH ]]; then
                sed -i -e "s,^linux.*,linux ${BOOTPREFIX}${LINUX},g" "${BLS_TARGET}"
                sed -i -e "s,^initrd.*,initrd ${BOOTPREFIX}${INITRD},g" "${BLS_TARGET}"
            fi

            if [[ "$KERNEL_VERSION" == *\+* ]] && [ "x$GRUB_DEFAULT_TO_DEBUG" != "xtrue" ]; then
                GRUB_UPDATE_DEFAULT_KERNEL=false
            fi

            # Only update the default when making a minor kernel upgrade. This
            # is to prevent unpredictability when multiple namespaced kernel
            # packages are installed that each ship different major kernel
            # versions.
            #
            # E.g. if you have kernel-A.B.C installed, then update the default
            # when you install kernel-A.B.D. Do not update the default when
            # installing kernel-X.Y.Z (with A!=X or B!=Y).
            CUR_DEFAULT_BLS="$(default_bls)"
            if [[ -f "$CUR_DEFAULT_BLS" ]]; then
                CUR_DEFAULT_VERSION=$(grep -oP '(?<=version ).*' "$CUR_DEFAULT_BLS")
                CUR_MAJOR=$(cut -d. -f1-2 <<<"$CUR_DEFAULT_VERSION")
                NEW_MAJOR=$(cut -d. -f1-2 <<<"$KERNEL_VERSION")
                if [[ "$CUR_MAJOR" != "$NEW_MAJOR" ]]; then
                    GRUB_UPDATE_DEFAULT_KERNEL=false
                fi
            fi

            if [ "x$GRUB_UPDATE_DEFAULT_KERNEL" = "xtrue" ]; then
                NEWDEFAULT="${BLS_ID}"
            fi

            if [ "x$GRUB_LINUX_MAKE_DEBUG" = "xtrue" ]; then
                BLS_DEBUG="$(echo ${BLS_TARGET} | sed -e "s/${KERNEL_VERSION}/${KERNEL_VERSION}~debug/")"
                cp --preserve=timestamps -T  "${BLS_TARGET}" "${BLS_DEBUG}"
                TITLE="$(grep '^title[ \t]' "${BLS_DEBUG}" | sed -e 's/^title[ \t]*//')"
                OPTIONS="$(echo "${BOOT_OPTIONS[*]} ${GRUB_CMDLINE_LINUX_DEBUG}" | sed -e 's/\//\\\//g')"
                sed -i -e "s/^title.*/title ${TITLE}${GRUB_LINUX_DEBUG_TITLE_POSTFIX}/" "${BLS_DEBUG}"
                sed -i -e "s/^options.*/options ${OPTIONS}/" "${BLS_DEBUG}"
                if [ -n "$NEWDEFAULT" -a "x$GRUB_DEFAULT_TO_DEBUG" = "xtrue" ]; then
                    NEWDEFAULT="${BLS_DEBUG_ID}"
                fi
            fi
            if [ -n "$NEWDEFAULT" ]; then
                grub2-editenv - set "saved_entry=${NEWDEFAULT}"
            fi

            # this probably isn't the best place to do this, but it will do for now.
            if [ -e "${ROOTPREFIX}${INITRD}" -a -e "${ROOTPREFIX}${LINUX}" -a \
                 "${ROOTPREFIX}${INITRD}" -ot "${ROOTPREFIX}${LINUX}" -a \
                 -x /usr/lib/kernel/install.d/50-dracut.install ]; then
                rm -f "${ROOTPREFIX}${INITRD}"
            fi
            exit 0
        fi

        /sbin/new-kernel-pkg --package "kernel${flavor}" --install "$KERNEL_VERSION" || exit $?
        /sbin/new-kernel-pkg --package "kernel${flavor}" --mkinitrd --dracut --depmod --update "$KERNEL_VERSION" || exit $?
        /sbin/new-kernel-pkg --package "kernel${flavor}" --rpmposttrans "$KERNEL_VERSION" || exit $?
        # If grubby is used there's no need to run other installation plugins
        exit 77
        ;;
    remove)

        if [[ "x${GRUB_ENABLE_BLSCFG}" = "xtrue" ]] || [[ ! -f /sbin/new-kernel-pkg ]]; then
            BLS_TARGET="${BLS_DIR}/${MACHINE_ID}-${KERNEL_VERSION}.conf"
            BLS_DEBUG="$(echo ${BLS_TARGET} | sed -e "s/${KERNEL_VERSION}/${KERNEL_VERSION}~debug/")"
            rm -f "${BLS_TARGET}" "${BLS_DEBUG}"

            for i in vmlinuz System.map config zImage.stub dtb; do
                rm -rf "/boot/${i}-${KERNEL_VERSION}"
            done
            # hmac is .vmlinuz-<version>.hmac so needs a special treatment
            rm -f "/boot/.vmlinuz-${KERNEL_VERSION}.hmac"
            # symvers is symvers-<version>.gz symlink, needs a special treatment
            rm -f "/boot/symvers-${KERNEL_VERSION}.gz"

            exit 0
        fi

        /sbin/new-kernel-pkg --package "kernel${flavor+-$flavor}" --rminitrd --rmmoddep --remove "$KERNEL_VERSION" || exit $?
        # If grubby is used there's no need to run other installation plugins
        exit 77
        ;;
    *)
        ;;
esac