# unmount_on_exit
#
unmount_on_exit() {

	trap - INT TERM EXIT
	local stacktrace="$(get_extension_hook_stracktrace "${BASH_SOURCE[*]}" "${BASH_LINENO[*]}")"
	display_alert "unmount_on_exit() called!" "$stacktrace" "err"
	if [[ "${ERROR_DEBUG_SHELL}" == "yes" ]]; then
		ERROR_DEBUG_SHELL=no # dont do it twice
		display_alert "MOUNT" "${MOUNT}" "err"
		display_alert "SDCARD" "${SDCARD}" "err"
		display_alert "ERROR_DEBUG_SHELL=yes, starting a shell." "ERROR_DEBUG_SHELL" "err"
		bash < /dev/tty || true
	fi

	umount_chroot "${SDCARD}/"
	mountpoint -q "${SRC}"/cache/toolchain && umount -l "${SRC}"/cache/toolchain
	mountpoint -q "${SRC}"/cache/rootfs && umount -l "${SRC}"/cache/rootfs
	umount -l "${SDCARD}"/tmp > /dev/null 2>&1
	umount -l "${SDCARD}" > /dev/null 2>&1
	umount -l "${MOUNT}"/boot > /dev/null 2>&1
	umount -l "${MOUNT}" > /dev/null 2>&1
	[[ $CRYPTROOT_ENABLE == yes ]] && cryptsetup luksClose "${ROOT_MAPPER}"
	losetup -d "${LOOP}" > /dev/null 2>&1
	rm -rf --one-file-system "${SDCARD}"
	exit_with_error "debootstrap-ng was interrupted" || true # don't trigger again

}

# debootstrap_ng
#
debootstrap_ng() {
	display_alert "Checking for rootfs cache" "$(echo "${BRANCH} ${BOARD} ${RELEASE} ${DESKTOP_APPGROUPS_SELECTED} ${DESKTOP_ENVIRONMENT} ${BUILD_MINIMAL}" | tr -s " ")" "info"

	[[ $ROOTFS_TYPE != ext4 ]] && display_alert "Assuming $BOARD $BRANCH kernel supports $ROOTFS_TYPE" "" "wrn"

	# trap to unmount stuff in case of error/manual interruption
	trap unmount_on_exit INT TERM EXIT

	# stage: clean and create directories
	rm -rf $SDCARD $MOUNT
	mkdir -p $SDCARD $MOUNT $DEST/images $SRC/cache/rootfs

	# bind mount rootfs if defined
	if [[ -d "${ARMBIAN_CACHE_ROOTFS_PATH}" ]]; then
		mountpoint -q "${SRC}"/cache/rootfs && umount -l "${SRC}"/cache/toolchain
		mount --bind "${ARMBIAN_CACHE_ROOTFS_PATH}" "${SRC}"/cache/rootfs
	fi

	# stage: verify tmpfs configuration and mount
	# CLI needs ~1.5GiB, desktop - ~3.5GiB
	# calculate and set tmpfs mount to use 9/10 of available RAM+SWAP
	local phymem=$(((($(awk '/MemTotal/ {print $2}' /proc/meminfo) + $(awk '/SwapTotal/ {print $2}' /proc/meminfo))) / 1024 * 9 / 10)) # MiB
	if [[ $BUILD_DESKTOP == yes ]]; then local tmpfs_max_size=3500; else local tmpfs_max_size=1500; fi                                 # MiB
	if [[ $FORCE_USE_RAMDISK == no ]]; then
		local use_tmpfs=no
	elif [[ $FORCE_USE_RAMDISK == yes || $phymem -gt $tmpfs_max_size ]]; then
		local use_tmpfs=yes
	fi
	[[ -n $FORCE_TMPFS_SIZE ]] && phymem=$FORCE_TMPFS_SIZE

	[[ $use_tmpfs == yes ]] && mount -t tmpfs -o size=${phymem}M tmpfs $SDCARD

	# stage: prepare basic rootfs: unpack cache or create from scratch
	create_rootfs_cache

	call_extension_method "pre_install_distribution_specific" "config_pre_install_distribution_specific" << 'PRE_INSTALL_DISTRIBUTION_SPECIFIC'
*give config a chance to act before install_distribution_specific*
Called after `create_rootfs_cache` (_prepare basic rootfs: unpack cache or create from scratch_) but before `install_distribution_specific` (_install distribution and board specific applications_).
PRE_INSTALL_DISTRIBUTION_SPECIFIC

	# stage: install kernel and u-boot packages
	# install distribution and board specific applications

	install_distribution_specific
	install_common

	# install locally built packages
	[[ $EXTERNAL_NEW == compile ]] && chroot_installpackages_local

	# install from apt.armbian.com
	[[ $EXTERNAL_NEW == prebuilt ]] && chroot_installpackages "yes"

	# stage: user customization script
	# NOTE: installing too many packages may fill tmpfs mount
	customize_image

	# remove packages that are no longer needed. Since we have intrudoced uninstall feature, we might want to clean things that are no longer needed
	display_alert "No longer needed packages" "purge" "info"
	chroot $SDCARD /bin/bash -c "apt-get autoremove -y" > /dev/null 2>&1

	# create list of all installed packages for debug purposes
	chroot $SDCARD /bin/bash -c "dpkg -l | grep ^ii | awk '{ print \$2\",\"\$3 }'" > $DEST/${LOG_SUBPATH}/installed-packages-${RELEASE}$([[ ${BUILD_MINIMAL} == yes ]] &&
		echo "-minimal")$([[ ${BUILD_DESKTOP} == yes ]] && echo "-desktop").list 2>&1

	# clean up / prepare for making the image
	umount_chroot "$SDCARD"
	post_debootstrap_tweaks

	if [[ $ROOTFS_TYPE == fel ]]; then
		FEL_ROOTFS=$SDCARD/
		display_alert "Starting FEL boot" "$BOARD" "info"
		start_fel_boot
	else
		prepare_partitions
		create_image
	fi

	# stage: unmount tmpfs
	umount $SDCARD 2>&1
	if [[ $use_tmpfs = yes ]]; then
		while grep -qs "$SDCARD" /proc/mounts; do
			umount $SDCARD
			sleep 5
		done
	fi
	rm -rf $SDCARD

	# remove exit trap
	trap - INT TERM EXIT
}