#!/bin/sh -e

# call rsnapshot daily/weekly/monthly regularly
# this should be called from cron very often (several times a day) to not miss
# a cycle when the machine is powered down for extended times.
#
# Author: Martin Pitt <martin@piware.de>
# License: Public Domain

backupdir=`grep ^snapshot_root ~/.rsnapshotrc | awk '{print $2}'`

now=`date +%s`

get_age() {
    if [ -e $backupdir/$1 ]; then
        age=$(($now - `stat -c %Y $backupdir/$1`))
    else
        unset age
    fi
}

# abort if last backup was less than a day ago
get_age daily.0
[ -n "$age" ] && [ $age -lt 86300 ] && exit 0

print '------------1---------------'
# monthly backup if last monthly is older than a month (if it doesn't exist,
# check oldest weekly)
get_age monthly.0
[ -n "$age" ] || get_age weekly.3
[ -n "$age" ] && [ $age -ge 2591900 ] && mode=monthly

# weekly backup if last weekly is older than a week (if it doesn't exist,
# check oldest daily)
get_age weekly.0
[ -n "$age" ] || get_age daily.6
[ -n "$age" ] && [ $age -ge 604700 ] && mode=weekly

# default to daily
[ -n "$mode" ] || mode=daily

# call rsnapshot
echo mode: $mode
rsnapshot -c ~/.rsnapshotrc $mode