#!/usr/bin/env bash
#
# Stage4 addons setup script
#
###############################################################################
# Support stage4 addons residing under '/opt/openslx/addons'.
# This script will loop over all addons found, in the form of
# directories containing directory structures relative to '/'
#
# Additionally addons are expected to provide:
# * <addon_dir>/addon-required -> script to check whether the
#   addon should be installed (exit 0) or not (exit 1).
#
# * <addon_dir>/opt/openslx/etc/<addon_name>.whiteout -> list of files
#   that were removed during the addon installation and thus need to be
#   removed after the addon was installed.
#
# * <addon_dir>/opt/openslx/etc/<addon_name> ld.so.cache -> ld cache containing
#   the newly installed libraries. CAVE: multiple addons -> ld cache combination
#
### CURRENTLY NOT EXECUTED
# * <addon_dir>/addon-init -> script that will be automatically
#   be executed after the addon was installed.
#   NOTE: question remains if this should be done within stage3
#         or by chroot'ing into the stage4 before executing it.
### CURRENTLY NOT EXECUTED: Since whiteouts could be handled for _all_addons

type emergency_shell >/dev/null 2>&1 || . /lib/dracut-lib.sh

# Check if we even have any addons to process
if [ ! -d "$NEWROOT/opt/openslx/addons" ]; then
	info "No stage4 addons found."
	return 0
fi

setup_addons() {
	local ADDONS_DIR="$NEWROOT/opt/openslx/addons/"
	cd "$ADDONS_DIR" || return 1
	for ADDON in *; do
		if ! setup_addon "$ADDON"; then
			info "Failed to setup $ADDON"
		fi
	done
}

setup_addon() {
	[ -z "$1" -o ! -d "$ADDONS_DIR/$1" ] && return 1
	local ADDON="$1"
	cd "$ADDONS_DIR/$ADDON" || return 1

	if ! bash addon-required 2>&1 ; then
		info "'$ADDONS_DIR/$ADDON/addon-required' missing or returned non-zero, skipping..."
		return 1
	fi
	# purge addon-* files
	rm -f -- addon-*

	# move all the files over
	for entry in $(find * -not -type d 2>/dev/null); do
		mkdir -p "${NEWROOT}/${entry%/*}"
		mv -f -- "$entry" "${NEWROOT}/${entry}"
	done

	# post merge: remove files marked as whiteouts
	# (e.g. they were removed during the addon installation)
	for WHITEOUT in "$NEWROOT/opt/openslx/etc/"*.whiteout; do
		[ -e "$WHITEOUT" ] || continue
		while read line; do
			rm -f "${NEWROOT}/${line}"
		done < "$WHITEOUT"
	done
}

if ! setup_addons; then
	warn "Failed to fully setup some addons! They will likely malfunction..."
fi