#!/usr/bin/perl
#
# Created by Brandon Gillespie
# Additional work by Vang (Dale Mayberry)
#
# if (fork()) { exit(); }
#
## This creates a FIFO list of backups based off your configuration,
## it can do regular, weekly and monthly backups, with the intervals
## and depth of the FIFO list defined by you.

# Setup:
# Create a directory called "dbbin" off of your would directory. Put this
# script in the directory and make it executable. Add the file
# "timestamps" to the "logs" directory. Put four "0" (zeros) in the file,
# one per line.
#
# check the following variables and make sure they are appropriate to
# your system.

$base = "~/cold";
$logs = "${base}/logs";
$bdir = "${base}/backups";

# change these if you dont want to daily/weekly/monthly backups

$do_monthly = 1;
$do_weekly = 1;
$do_daily = 1;

# shift the FIFO list every hour, backups before the hour is up will
# simply update the most recent backup, they will not shift the list

$regular_interval = 3600;
$daily_interval = 86400;
$weekly_interval = 604800;
$monthly_interval = 2629728;

# how many increments do you want to keep in the various backups?

$regular_FIFO = 23;
$daily_FIFO = 6;
$weekly_FIFO = 4;
$monthly_FIFO = 12;

##
## you shouldn't have to change anything beyond here
##

## figure out the last time we did stuff
open(TMP, "$logs/timestamps") || exit;
$last  = <TMP>;
$last  = int($last);
$daily = <TMP>;
$daily = int($daily);
$week  = <TMP>;
$week  = int($week);
$month = <TMP>;
$month = int($month);
close(TMP);

## setup some basic vars
($l_sec,$l_min,$l_hour,$l_mday,$l_mon,$l_year,$l_wday,$l_yday) = localtime();
($time) = time();

@days = ("Sun","Mon","Tue","Wed","Thu","Fri","Sat");
@months = ("Jan","Feb","Mar","Apr","May","Jun",
           "Jul","Aug","Sep","Oct","Nov","Dec");

$day = "$l_mday$months[$l_mon]$l_year";

## zip up the current backup
rename("binary.bak", "binary-${day}");
system("tar", "-cf", "binary-${day}.tar", "binary-${day}");
system("gzip", "-9f", "binary-${day}.tar");
system("rm", "-rf", "binary-${day}"); 

## regular FIFO shuffle, give it 100 seconds leeway
if (($last + $regular_interval) <= ($time + 100)) {
    &backup($regular_FIFO, "");
    $last = $time;
}

## daily FIFO shuffle, give it 100 seconds leeway
if ($do_daily && (($daily + $daily_interval) <= ($time + 700))) {
    &backup($daily_FIFO, "DAILY");
    $daily = $time;
}

## weekly FIFO shuffle, give it 100 seconds leeway per day (700 total)
if ($do_weekly && (($week + $weekly_interval) <= ($time + 700))) {
    &backup($weekly_FIFO, "WEEKLY");
    $week = $time;
}

## monthly FIFO shuffle, give it 700 seconds leeway
if ($do_monthly && (($month + $monthly_interval) <= ($time + 700))) {
    &backup($monthly_FIFO, "MONTHLY");
    $month = $time;
}

## write out the new timestamp
if (open(TMP, ">$logs/timestamps")) {
    print TMP <<END;
$last
$daily
$week
$month
END
    close(TMP);
}

sub backup {
    ($top, $suffix) = @_;

    for $x (0 .. ($top - 1)) {
        $b = $top - $x;
        $a = $b - 1;
        rename("${bdir}/binary-${a}${suffix}.tar.gz",
               "${bdir}/binary-${b}${suffix}.tar.gz");
    }
    system("/bin/cp",
           "binary-${day}.tar.gz",
           "${bdir}/binary-1${suffix}.tar.gz");
}