#!/bin/bash

# $0 [--decrypt <pass>] <backup_file> [openslx] [dozmod]

TMDIR="/opt/taskmanager"

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

RES_OPENSLX=0
RES_SAT=0
decrypt=
mode=
while [ $# -gt 0 ]; do
	case "$1" in
		openslx)
			RES_OPENSLX=1
			echo "Restoring system config"
			;;
		dozmod)
			RES_SAT=1
			echo "Restoring VM and lecture db"
			;;
		--decrypt)
			decrypt="$2"
			echo "Expecting AES encrypted archive"
			shift
			;;
		--restore)
			mode="restore"
			;;
		--test)
			mode="test"
			;;
		*)
			echo "Error: Restore mode params must be one of openslx, dozmod (Got $1)"
			exit 1
			;;
	esac
	shift
done

decryptor() {
	if ! openssl enc -d -aes-256-cbc -pbkdf2 -pass "env:$decrypt" -in "$1" -out "$2" \
			&& ! openssl enc -d -aes-256-cbc -pass "env:$decrypt" -in "$1" -out "$2"; then
		echo "- - - - - - - - - - - - - - - - -"
		echo "- Could not decrypt backup"
		echo "- Wrong password?"
		echo "- - - - - - - - - - - - - - - - -"
		rm -f -- "$2"
		exit 1
	fi
}

if [ -z "$mode" ]; then
	echo "No mode given"
	exit 1
elif [ "$mode" = "test" ]; then
	# test
	if [ -n "$decrypt" ]; then
		out="/tmp/bwlp-test-${RANDOM}-$$.tgz"
		decryptor "$BACKUP" "$out"
		echo "- Decrypted backup successfully"
		rm -f -- "$BACKUP"
		BACKUP="$out"
	fi
	num=$( tar tf "$BACKUP" | grep -c -x -F -e "files.tgz" -e "sat.sql" -e "openslx.sql" -e "db.sql" )
	rm -f -- "$BACKUP"
	if (( num < 2 )); then
		echo "- - -"
		echo "- This does not look like a .tar.gz containing a Satellite Server backup"
		exit 1
	fi
	exit 0
	# End test
fi

[ "$RES_OPENSLX$RES_SAT" = "00" ] && exit 1

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

slxsql() {
	mysql --defaults-extra-file=/etc/mysql/debian.cnf --default-character-set=utf8mb4 "$@"
}

slxsqldump() {
	mysqldump --defaults-extra-file=/etc/mysql/debian.cnf --default-character-set=utf8mb4 "$@"
}

cleanup_hook() {
	rm -rf -- "$DIR"
	rm -f -- "$BACKUP"
}

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

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

trap cleanup_hook EXIT

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

# Decrypt
if [ -n "$decrypt" ]; then
	out="${BACKUP%.aes}"
	[ "$out" = "$BACKUP" ] && out="${BACKUP}.tgz"
	decryptor "$BACKUP" "$out"
	rm -f -- "$BACKUP"
	BACKUP="$out"
fi

if ! tar --ignore-failed-read -x -f "$BACKUP"; then
	echo "Could not extract $BACKUP - make sure it's a valid .tar.gz[.aes] / .tgz[.aes]"
	echo "And that you provide the password in case of .aes"
	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 == 1 && DB_OLD == 0 )) && ! [ -f sat.sql ]; then
	echo "Error: this backup does not contain the dmsd database"
	echo "Error: cannot restore VM/lecture information"
	exit 1
fi
if (( RES_OPENSLX == 1 && DB_OLD == 0 )) && ! [ -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 == 1 )) && ! [ -f files.tgz ]; then
	echo "Error: files.tgz not found in backup - are your sure this is a valid backup?"
	exit 1
fi

echo "-- Restoring Database"
if (( DB_OLD == 1 )); then
	echo "--- Importing legacy database dump"
	# Restoring from dozmod v1.0 db
	slxsql < db.sql
	RET=$?
	if (( RES_SAT == 1 )); then
		echo "--- Trying to convert dozmod data (this might not work too well...)"
		slxsql < "${TMDIR}/data/dozmod-upgrade.sql"
	else
		echo "DROP DATABASE bwLehrpool" | slxsql
	fi
else
	# Restoring from v1.1+ db
	RET=0
	if (( RES_SAT == 1 )); then
		echo "--- Importing dozmod database (vms/lectures meta data)"
		slxsql < sat.sql
		RET=$?
	fi
	if (( RET == 0 && RES_OPENSLX == 1 )); then
		echo "--- Importing system configuration"
		# Backup and restore minilinux metadata -- doesn't make sense to import this from the backup
		mtmp="$( mktemp )"
		slxsqldump --add-locks openslx minilinux_source minilinux_branch minilinux_version > "${mtmp}" 2> /dev/null
		mlret=$?
		slxsql < openslx.sql
		RET=$?
		if (( mlret == 0 )); then
			slxsql --database=openslx -e "DROP TABLE IF EXISTS minilinux_version, minilinux_branch, minilinux_source"
			slxsql --database=openslx < "${mtmp}"
		fi
		rm -f -- "$mtmp"
	fi
fi

if (( RET != 0 )); then
	echo "Error: Restoring database contents failed with exit code $RET"
	exit 1
fi

if (( RES_OPENSLX == 1 )); then
	echo "-- Restoring system files"
	# 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
	slxsql -e "UPDATE openslx.property SET value = 'invalid' WHERE name = 'server-ip' LIMIT 1"

	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

	# Try to update the db (if required)
	(
		cd /srv/openslx/www/slx-admin && ./install-all
	)

	# legacy config.tgz symlink -> db entry
	if [ -L "/srv/openslx/www/boot/default/config.tgz" ]; then
		CONFTGZ=$( readlink /srv/openslx/www/boot/default/config.tgz | sed "s/\\\\/\\\\\\\\/g;s/'/\\\'/g" )
		echo "Config.tgz links to '$CONFTGZ'"
		slxsql -e "INSERT IGNORE INTO openslx.configtgz_location (locationid, configid) SELECT 0, configid FROM openslx.configtgz WHERE filepath = '$CONFTGZ' LIMIT 1" \
			|| echo "Could not convert default config.tgz setting - do so manually"
		rm -f -- /srv/openslx/www/boot/default/config.tgz
	fi

	sleep 0.5
	for i in 1 1 1 1 1 2 2 3 4 END; do
		CB=$( sudo -u www-data -n php /srv/openslx/www/slx-admin/api.php cb )
		[ "$CB" != "True" ] && break
		[ "$i" = "END" ] && break
		sleep $i
	done

fi

# Sync redirect flag file with setting stored in DB
/opt/taskmanager/scripts/install-https --redirect --redirect-only

# Run all post-restore scripts
for i in /opt/openslx/restore.d/*/init.sh; do
	[ -x "$i" ] || continue
	"$i" || echo "ERROR running post-restore script $i: $?"
done


echo "Success."

exit 0