#!/usr/bin/perl -w
# $Id: $
# Copyright (C) 2009 Jonas Genannt <jonas@brachium-system.net>
#
# Munin plugin for Arduino DS1820 Ethernet Sketch
#
# Copy to /usr/local/ create an link to /etc/munin/plugins/arduino_ds1820_192.168.1.3
# to fetch from 192.168.1.3 the DS1820.
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 3 of the License, or (at your option) any later version.
# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along with this program;
# if not, see <http://www.gnu.org/licenses/>.
#

use strict;
use Net::Telnet;
use Data::Dumper;

my $DEBUG=0;
sub get_temperatures ;

my $host;
if ( $0 =~m/ds1820_(.+)*$/) {
	$host = $1;
}
exit 2 unless defined $host;

print "[D] Host = $host\n" if ($DEBUG);
my %temperatures = get_temeratures();

if ($ARGV[0] and $ARGV[0] eq "config") {
	print "graph_args --base 1000 --vertical-label temperature\n";
	print "graph_category other\n";
	print "graph_scale no\n";
	print "graph_info Dallas DS1820 sensors via Arduino with Ethershield\n";
	print "graph_title temperature sensors\n";
	foreach (keys(%temperatures)) {
		my $desc = $ENV{$_} || $_;
		print $_ . ".label $desc\n" ;
	}
	exit;
}


foreach (keys(%temperatures)) {
print $_ . ".value " . $temperatures{$_} . "\n";
}

sub get_temeratures {
	my %ds1820;
	my $arduino = new Net::Telnet(Telnetmode => 0);
	$arduino->open($host);
	$arduino->print("\n");
	my @data = $arduino->getlines();
	$arduino->close;
	foreach my $line (@data) {
		chomp($line);
		my @values = split(/:/, $line);
		if (@values == 4) {
			$values[2]=~s/^\s+|\s+$//g;
			$values[3]=~s/^\s+|\s+$//g;
			if ($values[3]=~m/^([0-9\.]+)$/) {
				$ds1820{$values[2]} = $values[3];
			}
			else {
				$ds1820{$values[2]} = -1;
			}
			print "[D] SN: " . $values[2] . ": ". $values[3] ."\n" if($DEBUG);
		}
		else {
			print "[D] Could not parse line: $line\n" if ($DEBUG);
		}
	}
	return %ds1820;
}