#! /usr/bin/env perl

use warnings;
use strict;

# Part of backupServer package. This module creates a copy of the current directory
# using zfs snapshot
# allows multiple copies of a directory tree to exist without using a lot of disk space
# third parameter is the root path of the backups (ie, /srv)
# third and fourth parameters are the client name and server name
# last parameter is the configuration directory (again, not used)
# Example call:
# version_zfs /srv DailyData strax.dailydata.net /usr/local/etc/rsbackup
# First verifies all required parameters entered, and the source directory exists
# then determines the zfs dataset name (from the path), and concatenates the date/time

my $rootDir = shift;   # root of all backups
my $client = shift;    # client name (subdirectory of $rootdir)
my $server = shift;    # server name (subdirectory of rootdir/client and a zfs dataset)

sub dateTimeStamp {
   use POSIX qw(strftime);
   my $format = shift;
   return strftime $format, localtime();
}

# following command accepts path, and returns tab separated list, the first
# value being the zfs name mounted there
my $GETZFSFROMPATH = 'zfs list -H ';

my @error;
push @error, '$rootDir unset' unless $rootDir;
push @error, '$client unset' unless $client;
push @error, '$server unset' unless $server;
die "Invalid Call: " . join( "\n\t", @error ) . "\n" if @error;

my $sourceDir = "$rootDir/$client/$server";

die "Source directory $sourceDir does not exist" unless -d $sourceDir;

my ($zfsName) = split( "\t", `$GETZFSFROMPATH $sourceDir` );
$zfsName .= '@' . &dateTimeStamp( '%Y%m%d_%H%M%S' );
chomp $zfsName;

print "Creating Linked Backup of source tree at " . &dateTimeStamp( '%F %T') . "\n";
print qx/zfs snapshot -r $zfsName/;
#print "zfs snapshot -r $zfsName\n";
print "  Complete at " . &dateTimeStamp( '%F %T') . "\n";

1;