#!/bin/sh

LOCK=/var/lock/rmtbackup.sh
DATE=`date '+%Y%m%d-%H%M'`
REMOTEHOST=toriyu10
POOL=tank

if [ -f $LOCK ]; then
	echo "lock file is exist"
	exit
fi
touch $LOCK

backup_zfs()
{
	(df ; zfs list -t filesystem) | ssh -c blowfish $REMOTEHOST "cat >/$POOL/df.txt"
	echo "Creat snapshot $DATE"
	zfs snapshot -r $POOL@$DATE
	if [ $? -ne 0 ]; then
		zfs destroy -r $POOL@$DATE
		zfs snapshot -r $POOL@$DATE
		if [ $? -ne 0 ]; then
			echo "Error: Snapshot cannot created."
			rm $LOCK
			exit
		fi
	fi

	FS=`zfs list -t filesystem -o name -H -r $POOL | grep '/' `
	for i in $FS
	do
		echo "Sending $i"
		TARGET=/tmp/rmtbackup.sh_target
		REMOTE=/tmp/rmtbackup.sh_remote
		zfs list -t snapshot -Ho name -s creation | grep "$i@" >$TARGET
		ssh $REMOTEHOST "zfs list -t snapshot -Ho name -s creation | grep $i@" >$REMOTE
		err=1
		#for j in `comm -1 -2 $TARGET $REMOTE|tail -r`
		COMM=`/usr/local/bin/ruby -e "print File.readlines('$TARGET') & File.readlines('$REMOTE')"|tail -r`
		for j in $COMM
		do
			echo "Rollback $j"
			ssh $REMOTEHOST "zfs rollback -R $j"
			if [ $? -ne 0 ]; then
				continue  # rollback出来なければ別のスナップショットを試す
			fi

			first=1
			for k in `sed -e "1,/${j#*/}/d" $TARGET`	# $jより新しいスナップショット
			do
				if [ $first -eq 1 ]; then
					echo "incremental backup from $j to $k"
					zfs send -i $j $k  | ssh -c blowfish $REMOTEHOST "zfs receive -dF $POOL"
					if [ $? -eq 0 ]; then
						err=0
					fi
					first=0
				else
					echo "incremental backup from $prev to $k"
					zfs send -i $prev $k  | ssh -c blowfish $REMOTEHOST "zfs receive -dF $POOL"
					if [ $? -eq 0 ]; then
						err=0
					fi
				fi
				prev=$k

			done
			if [ $err -eq 0 ]; then
				break
			fi

		done

		if [ $err -eq 1 ]; then
			# フルバックアップ
			echo "incremental backup failed. trying full backup"
#			echo "destroy $i"
#			ssh $REMOTEHOST "zfs destroy -r $i" 2>/dev/null
			first=1
			for j in `cat $TARGET`
			do
				if [ $first -eq 1 ]; then
					first=0
					echo "send $j"
					zfs send $j | ssh -c blowfish $REMOTEHOST "zfs receive -d $POOL"
				else
					echo "send $j from $prev"
					zfs send -i $prev $j | ssh -c blowfish $REMOTEHOST "zfs receive -dF $POOL"
				fi
				prev=$j
			done
		fi
		
	done
}

date
zfs list -t filesystem -r $POOL

ping -c 1 $REMOTEHOST
if [ $? -eq 0 ]; then

	backup_zfs

	echo "done"
	ssh $REMOTEHOST "zpool list"

fi
date

rm $LOCK