#!/bin/bash

BACKUP_DIR=/var/tmp/targetdir
if ! [ -d "${BACKUP_DIR}" ]; then
	echo "${BACKUP_DIR} does not exist, please adjust the script or create the directory"
	exit 1
fi

argv0="$0"

stop_services() {
	for service in slapd univention-directory-listener univention-s4-connector samba-ad-dc; do
		invoke-rc.d "$service" stop
	done
}

start_services() {
	local rc

	for service in slapd univention-directory-listener samba-ad-dc univention-s4-connector; do
		invoke-rc.d "$service" start
		rc=$?
		if [ "$rc" != 0 ]; then
			return "$rc"
		fi
	done
}

usage() {
	echo "$0 [backup|restore <backup-archive>|stopservices|startservices]"
}

backup() {
	stop_services
	local TIMESTAMP
	local FATTR_FILE

	TIMESTAMP=`date +%d%m%y%H%M%S`
	FATTR_FILE="${BACKUP_DIR}/samba_sysvol.fattr"
	getfattr -R -d -m - /var/lib/samba/sysvol > "$FATTR_FILE"
	tar cjf "${BACKUP_DIR}/samba_${TIMESTAMP}.tar.bz2" \
		--exclude /var/lib/samba/private/smbd.tmp \
		--exclude /var/lib/samba/private/ldapi \
		--exclude /var/lib/samba/private/ldap_priv/ldapi \
		--exclude /var/lib/samba/winbindd_privileged/pipe \
		--exclude /var/lib/samba/ntp_signd/socket \
		/etc/samba \
		/var/lib/samba \
		"$FATTR_FILE" \
		/var/lib/univention-connector/s4 \
		/etc/univention/connector/s4internal.sqlite # >/dev/null 2>&1
	rm "$FATTR_FILE"

	start_services
}

replace_invocationID() {
	local new_uuid
	local ldif
	local account_dn
	local serverReference
	local ntds_settings_dn
	local REPLY

	new_uuid=$(python  -c 'import uuid; print uuid.uuid1()')
	if [ -z "$new_uuid" ]; then
		echo "ERROR: Generation of a new uuid failed"
		return 1
	fi


	eval "$(univention-config-registry shell)"
	ldif=$(ldbsearch -H var/lib/samba/private/sam.ldb samaccountname="$hostname\$"  serverReferenceBL)
	account_dn=$(echo "$ldif" | ldapsearch-wrapper | sed -n 's/^dn: //p')
	if [ -z "$account_dn" ]; then
		echo "ERROR: The server $hostname does not have an account in the restored var/lib/samba/private/sam.ldb"
		return 1
	fi

	serverReference=$(echo "$ldif" | ldapsearch-wrapper | sed -n 's/^serverReferenceBL: //p')
	if [ -z "$serverReference" ]; then
		echo "ERROR: The account for $hostname not have the attribute serverReferenceBL in the restored var/lib/samba/private/sam.ldb"
		return 1
	fi

	ldif=$(ldbsearch -H var/lib/samba/private/sam.ldb -b "$serverReference" objectClass=nTDSDSA invocationId)
	ntds_settings_dn=$(echo "$ldif" | ldapsearch-wrapper | sed -n 's/^dn: //p')
	
	if [ -z "$ntds_settings_dn" ]; then
		echo "ERROR: The server $hostname does not have an associated invocationId in the restored var/lib/samba/private/sam.ldb"
		return 1
	fi

	ldbmodify -H var/lib/samba/private/sam.ldb <<-%EOF
	dn: $ntds_settings_dn
	changetype: modify
	replace: invocationId
	invocationId: $new_uuid
	%EOF
}

restore() {
	local FATTR_FILE
	local REPLY
	local rc

	if ! [ -e "$1" ]; then
		echo "The file '$1' does not exist."
		return 1
	fi

	echo "This will overwrite the following files: (press return to see the list)"
	read
	tar tjvf "$1"
	echo
	read -p "Are you absolutely sure you want to procede? [y/N] "
	if [ "${REPLY^^}" != "Y" ]; then
		return 0
	fi

	stop_services

	FATTR_FILE="${BACKUP_DIR#/}/samba_sysvol.fattr"
	(
		cd /
		tar xjf "$1" >/dev/null 2>&1
		setfattr --restore="$FATTR_FILE"
		rm -f "$FATTR_FILE"

		read -p "Shall the SAM database invocationID be reset? [y/N] "
		if [ "${REPLY^^}" = "Y" ]; then
			replace_invocationID
			rc=$?
			if [ "$rc" != 0 ]; then
				echo "Changing the invocationID failed. Services have not been startet again yet, please check."
				echo "The services may be startet again by running '$argv0 startservices'".
				return "$rc"
			fi
		fi
	)

	read -p "Run ucr commit on the standard samba configuration files? [Y/n] "
	if [ "${REPLY^^}" != "N" ]; then
		univention-config-registry commit /etc/samba/smb.conf /etc/samba/base.conf
	fi

	read -p "Start the services again (Samba4, Univention S4 Connector, LDAP server, Univention Directory Listener ? [Y/n] "
	if [ "${REPLY^^}" != "N" ]; then
		start_services
		rc=$?
		if [ "$rc" != 0 ]; then
			return "$rc"
		fi
	fi
}

case "$1" in
	backup)
		backup
		exit $?
		;;
	restore)
		if [ -z "$2" ]; then
			usage
			exit 1
		fi
		restore "$2"
		exit $?
		;;
	startservices)
		start_services
		exit $?
		;;
	stopservices)
		stop_services
		exit $?
		;;
	*)
		usage
		;;
esac