#! /bin/bash

# Readme and manual on
# http://www.dei.unipd.it/~sbologna/pages/linuxbackup.html  [ENGLISH]
# http://www.dei.unipd.it/~sbologna/ita/pages/linuxbackup.html [ITALIAN]
#

# Run a backup script every sunday or if a Sunday has passed without backup.
# Every month it also run the monthly backup.

a_week=7
a_month=31

timestamp_file_weekly=/home/saverio/.backup_timestamp_weekly
log_file=/home/saverio/.backup.log

date_now=`date "+%Y%m%d"`
day_of_week=`date "+%u"`
time_now=`date "+%s"`

date >> $log_file

if [ -e $timestamp_file_weekly ]; then
    date_of_backup=`stat --format=%y $timestamp_file_weekly | tr -d - | awk '{print $1}'`
    time_of_backup=`stat --format=%Y $timestamp_file_weekly`
    echo last weekly backup $date_of_backup >> $log_file
    if (( $day_of_week % 7 >= $time_now / 86400 - $time_of_backup / 86400 )); then
        echo "no Sunday is passed without doing a backup, doing nothing" >> $log_file
        exit 0;
    fi
    echo "a Sunday is passed without doing a backup!" >> $log_file
    if (( $date_now - $date_of_backup >= $a_month )); then
        echo "a new month started: time to do a monthly backup" >> $log_file
        /usr/bin/rsnapshot monthly && echo "monthly backup: DONE!" >> $log_file
    fi
fi

echo "let's do a weekly backup" >> $log_file
date > /home/saverio/.today
/usr/bin/rsnapshot weekly && touch $timestamp_file_weekly && echo "weekly backup: DONE!" >> $log_file