#!/bin/sh

src=zhome/bjc
dst=babar/bjc

host=ditto.local

first=`ssh $host zfs list -Hd1 -t snap -o name -s creation $dst | cut -d@ -f2 | tail -1`
last=`zfs list -Hd1 -t snap -o name -s creation $src | cut -d@ -f2 | tail -1`

if [ $first != $last ]; then
    echo "Sending $src from $first to $last"
    zfs send -I $src@$first $src@$last | ssh $host zfs recv $dst
    if [ $? -ne 0 ]; then
        echo "Couldn't send snapshot stream" 1>&2
        exit 1
    fi
else
    echo "Skipping snapshot replication: $host:$dst@$last already exists."
fi

echo "Verifying final snapshot is $dst@$last"
verify=`ssh $host zfs list -Hd1 -t snap -o name $dst | grep $last`
if [ x"$verify" == x ]; then
    echo "Last snapshot not sent on $host:$dst" 1>&2
    exit 2
fi

echo "Removing local snapshots up to $src@$last"
for ds in `zfs list -Hd1 -t snap -o name -s creation $src | cut -d@ -f2`; do
    if [ $ds == $last ]; then
        break
    fi
    sudo zfs destroy $src@$ds
done

echo "Finished. Last snapshot sent: $src@$last"