#! /bin/sh
set -e

# adapted from '/etc/kernel/postinst.d/zz-update-grub and
# /usr/lib/kernel/install.d/90-loaderentry.install, see also
# https://kernel-team.pages.debian.net/kernel-handbook/ch-update-hooks.html


MOUNTROOT="${TMPDIR:-/var/tmp}/espmounts"

# - cleanup - gently delete all kernels not in kernel-keep-list

if command -V systemd-detect-virt >/dev/null 2>&1 &&
	systemd-detect-virt --quiet --container; then
	exit 0
fi

cleanup() {

	for mount in "${MOUNTROOT}"/* ; do
		if echo "${mount}" | grep -qE '[0-9a-fA-F]{4}-[0-9a-fA-F]{4}' && \
			mountpoint -q "${mount}"; then
			umount "${mount}"
		fi
	done

}

trap cleanup EXIT INT TERM QUIT

. /usr/share/pve-kernel-helper/scripts/functions

BOOT_KVERS="$(boot_kernel_list "$@")"

potential_esps(){
	lsblk --list -o PATH,UUID,FSTYPE,PARTTYPE,MOUNTPOINT |
	awk '$3 == "vfat" && $4 == "c12a7328-f81f-11d2-ba4b-00a0c93ec93b" && $5 == "" {print $1,$2}'
}

update_esps() {
	if [ ! -f "${ESP_LIST}" ]; then
	    warn "No ${ESP_LIST} found, skipping ESP sync."
	    exit 0
	fi
	if [ -f /etc/kernel/cmdline ]; then
		CMDLINE="$(cat /etc/kernel/cmdline)"
	else
		warn "No /etc/kernel/cmdline found - falling back to /proc/cmdline"
		CMDLINE="$(cat /proc/cmdline)"
	fi

	cat "${ESP_LIST}" | while IFS= read -r uuid; do
		if ! (echo "${uuid}" | grep -qE '[0-9a-fA-F]{4}-[0-9a-fA-F]{4}'); then
			warn "WARN: ${uuid} read from ${ESP_LIST} does not look like a VFAT-UUID - skipping"
			continue
		fi

		path="/dev/disk/by-uuid/$uuid"
		if [ ! -e "${path}" ]; then
			warn "WARN: ${path} does not exist - clean ${ESP_LIST}! - skipping"
			continue
		fi

		mountpoint="${MOUNTROOT}/${uuid}"
		mkdir -p "${mountpoint}"
		mount "${path}" "${mountpoint}" || \
			{ warn "mount of ${path} failed - skipping"; continue; }
		if [ ! -f "${mountpoint}/$PMX_LOADER_CONF" ]; then
			warn "${path} contains no loader.conf - skipping"
			continue
		fi
		if [ ! -d "${mountpoint}/$PMX_ESP_DIR" ]; then
			warn "${path}/$PMX_ESP_DIR does not exist- skipping"
			continue
		fi

		warn "Copying and configuring kernels on ${path}"
		copy_and_config_kernels "${mountpoint}"
		remove_old_kernels "${mountpoint}"

		umount "${mountpoint}" || \
			{ warn "umount of ${path} failed - failure"; exit 2; }

		rmdir "${mountpoint}"
	done

}

copy_and_config_kernels() {
	esp="$1"


	for kver in ${BOOT_KVERS}; do

		linux_image="/boot/vmlinuz-${kver}"
		initrd="/boot/initrd.img-${kver}"

		if [ ! -f "${linux_image}" ]; then
			warn "No linux-image ${linux_image} found - skipping"
			continue
		fi
		if [ ! -f "${initrd}" ]; then
			warn "No initrd-image ${initrd} found - skipping"
			continue
		fi

		warn "	Copying kernel and creating boot-entry for ${kver}"
		KERNEL_ESP_DIR="${PMX_ESP_DIR}/${kver}"
		KERNEL_LIVE_DIR="${esp}/${KERNEL_ESP_DIR}"
		mkdir -p "${KERNEL_LIVE_DIR}"
		cp -u --preserve=timestamps "${linux_image}" "${KERNEL_LIVE_DIR}/"
		cp -u --preserve=timestamps "${initrd}" "${KERNEL_LIVE_DIR}/"

		# create loader entry
		cat > "${esp}/loader/entries/proxmox-${kver}.conf" <<- EOF
			title    Proxmox
			version  ${kver}
			options   ${CMDLINE}
			linux    /${KERNEL_ESP_DIR}/vmlinuz-${kver}
			initrd   /${KERNEL_ESP_DIR}/initrd.img-${kver}
		EOF
	done

}

remove_old_kernels() {
	esp="$1"

	for kerneldir in "${esp}/${PMX_ESP_DIR}"/*; do
		if [ ! -d "${kerneldir}" ]; then
			warn "	${kerneldir} is not a directory - skipping"
			continue
		fi

		kver="$(echo "${kerneldir}" | sed -r "s#^${esp}/${PMX_ESP_DIR}/(.+)\$#\\1#")"

		echo "${BOOT_KVERS}" | grep -q "${kver}" && continue;
		warn "	Removing old version ${kver}"
		rm -rf "${kerneldir}"
		rm -f "${esp}/loader/entries/proxmox-${kver}.conf"
	done

}

set -- $DEB_MAINT_PARAMS
mode="${1#\'}"
mode="${mode%\'}"
case $0:$mode in
	# Only run on postinst configure and postrm remove, to avoid wasting
	# time by calling update-grub multiple times on upgrade and removal.
	# Also run if we have no DEB_MAINT_PARAMS, in order to work with old
	# kernel packages.
	*/postinst.d/*:|*/postinst.d/*:configure|*/postrm.d/*:|*/postrm.d/*:remove)
	update_esps
	;;
esac

exit 0