#!/bin/bash

RES_OPENSLX=0
RES_SAT=0
case "$1" in
	both)
		RES_OPENSLX=1
		RES_SAT=1
		;;
	openslx)
		RES_OPENSLX=1
		;;
	sat)
		RES_SAT=1
		;;
	*)
		echo "Error: Restore mode must be one of both, openslx, sat"
		exit 1
		;;
esac

BACKUP="$1"
if [ -z "$BACKUP" ] || [ ! -f "$BACKUP" ]; then
	echo "Backup file not found: $BACKUP"
	exit 1
fi

if [ "$(whoami)" != "root" ]; then
	echo "Must be running as root!"
	exit 1
fi

DIR="/root/restore/$(date +%s)"

if [ -d "$DIR" ]; then
	echo "Restore already running!?"
	exit 1
fi

mkdir -p "$DIR"
if ! cd "$DIR"; then
	echo "Could not cd to $DIR"
	exit 1
fi

if ! tar --ignore-failed-read -x -f "$BACKUP"; then
	echo "Could not extract $BACKUP - make sure it's a valid .tar.gz / .tgz"
	exit 1
fi

if [ -f db.sql ]; then
	DB_OLD=1
elif [ -f openslx.sql ] || [ -f sat.sql ]; then
	DB_OLD=0
else
	echo "Error: database dump not found in backup - are you sure this is a valid backup?"
	exit 1
fi

if [ $RES_SAT -eq 1 -a $DB_OLD -eq 0 -a ! -f sat.sql ]; then
	echo "Error: this backup does not contain the DozMod database"
	echo "Error: cannot restore VM/lecture information"
	exit 1
fi
if [ $RES_OPENSLX -eq 1 -a $DB_OLD -eq 0 -a ! -f openslx.sql ]; then
	echo "Error: this backup does not contain the OpenSLX database"
	echo "Error: cannot restore satellite configuration"
	exit 1
fi

if [ $RES_OPENSLX -eq 1 -a ! -f files.tgz ]; then
	echo "Error: files.tgz not found in backup - are your sure this is a valid backup?"
	exit 1
fi

if [ $DB_OLD -eq 1 ]; then
	mysql --defaults-extra-file=/etc/mysql/debian.cnf --default-character-set=utf8 < db.sql
	RET=$?
else
	RET=0
	if [ $RES_SAT -eq 1 ]; then
		mysql --defaults-extra-file=/etc/mysql/debian.cnf --default-character-set=utf8 < sat.sql
		RET=$?
	fi
	if [ $RET -eq 0 -a $RES_OPENSLX -eq 1 ]; then
		mysql --defaults-extra-file=/etc/mysql/debian.cnf --default-character-set=utf8 < openslx.sql
		RET=$?
	fi
fi

if [ $RET -ne 0 ]; then
	echo "Error: Restoring database contents failed with exit code $RET"
	exit 1
fi

if [ $RES_OPENSLX -eq 1 ]; then
	# Since we came that far we'll delete some old configs (if existent)
	rm -rf /opt/ldadp/{configs,pid,logs}/* /opt/openslx/configs/* /srv/openslx/www/boot/default/config.tgz 2> /dev/null
	# Force triggering IP detection/setting, which should in turn regenerate ldadp configs and launch ldadp instances if applicable
	echo "UPDATE openslx.property SET value = 'invalid' WHERE name = 'server-ip' LIMIT 1" | mysql --defaults-extra-file=/etc/mysql/debian.cnf --default-character-set=utf8
	# Try to update the db (if required)
	curl -s 'http://localhost/slx-admin/api.php?do=update'

	tar --ignore-failed-read -x -f files.tgz -C /
	RET=$?
	if [ $RET -ne 0 ]; then
		echo "WARNING: Restoring filesystem contents failed with exit code $RET - backup might be incomplete!"
	fi
	# Make sure the directory tree is owned by taskmanager, as tar will create intermediate
	# directories as owned by root if they do not exist.
	chown -R taskmanager /srv/openslx/www/boot /opt/openslx/configs
fi

rm -rf -- "$DIR"
rm -f -- "$BACKUP"

echo "Success."

exit 0