#!/usr/bin/python
# -*- coding: utf-8 -*-

# Copyright (C) 2014 Johann Schmitz <johann@j-schmitz.net>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU Library General Public License as published by
# the Free Software Foundation; version 2 only
#
# 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 Library General Public License for more details.
#
# You should have received a copy of the GNU Library General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
#

"""
=head1 NAME

snmp__synology_ - Health and system status monitoring plugin for Synology NAS systems

=head1 CONFIGURATION

Make sure your Synology device is accessible via SNMP (e.g. via snmpwalk) and the munin-node
has been configured correctly.

=head1 MAGIC MARKERS

	#%# family=snmpauto
	#%# capabilities=snmpconf

=head1 VERSION

0.0.1

=head1 BUGS

Open a ticket at https://github.com/ercpe/contrib if you find one.

=head1 AUTHOR

Johann Schmitz <johann@j-schmitz.net>

=head1 LICENSE

GPLv2

=cut
"""

import re
import sys
import os
import logging

from pysnmp.entity.rfc3413.oneliner import cmdgen

disktable_id = '1.3.6.1.4.1.6574.2.1.1.2'
disktable_model = '1.3.6.1.4.1.6574.2.1.1.3'
disktable_temp = '1.3.6.1.4.1.6574.2.1.1.6'
sys_temperature = '1.3.6.1.4.1.6574.1.2.0'

class SynologySNMPClient(object):
	def __init__(self, host, port, community):
		self.hostname = host
		self.transport = cmdgen.UdpTransportTarget((host, int(port)))
		self.auth = cmdgen.CommunityData('test-agent', community)
		self.gen = cmdgen.CommandGenerator()

	def _get_disks(self):
		disk_table = '1.3.6.1.4.1.6574.2.1'
		errorIndication, errorStatus, errorIndex, varBindTable = self.gen.bulkCmd(
			self.auth,
			self.transport,
			0, 24,
			disk_table)

		if errorIndication:
			logging.error("SNMP bulkCmd for devices failed: %s, %s, %s" % (errorIndication, errorStatus, errorIndex))
			return

		devices = {}
		for row in varBindTable:
			for oid, value in row:
				oid = str(oid)
				if not oid.startswith(disk_table):
					continue

				disk_id = oid[oid.rindex('.')+1:]

				values = devices.get(disk_id, [None, None, None])
				if oid.startswith(disktable_id):
					values[0] = str(value).strip()
				if oid.startswith(disktable_model):
					values[1] = str(value).strip()
				if oid.startswith(disktable_temp):
					values[2] = int(value)
				devices[disk_id] = values

		for x in sorted(devices.keys()):
			yield tuple([x] + devices[x])

	def _get_sys_temperature(self):
		errorIndication, errorStatus, errorIndex, varBindTable = self.gen.getCmd(
			self.auth,
			self.transport,
			sys_temperature)

		if errorIndication:
			logging.error("SNMP getCmd for %s failed: %s, %s, %s" % (sys_temperature, errorIndication, errorStatus, errorIndex))
			return None

		return int(varBindTable[0][1])

	def print_config(self):
		print """multigraph synology_hdd_temperatures
host_name {hostname}
graph_title HDD temperatures on {hostname}
graph_vlabel Temperature in °C
graph_args --base 1000
graph_category system
graph_info HDD temperatures on {hostname}""".format(hostname=self.hostname)

		for id, name, model, temp in self._get_disks():
			print """disk{disk_id}.info Temperature of {name} ({model})
disk{disk_id}.label {name} ({model})
disk{disk_id}.type GAUGE
disk{disk_id}.min 0""".format(disk_id=id, name=name, model=model)


		print """multigraph synology_sys_temperature
host_name {hostname}
graph_title System temperatures of {hostname}
graph_vlabel Temperature in °C
graph_args --base 1000
graph_category system
graph_info System temperature of {hostname}
sys_temp.info System temperature
sys_temp.label Temperature
sys_temp.type GAUGE
sys_temp.min 0
""".format(hostname=self.hostname)

	def execute(self):
		print """multigraph synology_hdd_temperatures"""
		for id, name, model, temp in self._get_disks():
			print """disk{disk_id}.value {temp}""".format(disk_id=id, temp=temp)

		print """multigraph synology_sys_temperature"""
		print "sys_temp.value {temp}".format(temp=self._get_sys_temperature())


host = None
port = os.getenv('port', 161)
community = os.getenv('community', None)
debug = bool(os.getenv('MUNIN_DEBUG', os.getenv('DEBUG', 0)))

if debug:
	logging.basicConfig(level=logging.DEBUG, format='%(asctime)s %(levelname)-7s %(message)s')

try:
	match = re.search("^(?:|.*\/)snmp_([^_]+)_synology$", sys.argv[0])
	host = match.group(1)
	match = re.search("^([^:]+):(\d+)$", host)
	if match is not None:
		host = match.group(1)
		port = match.group(2)
except Exception as ex:
	logging.error("Caught exception: %s" % ex)


if "snmpconf" in sys.argv[1:]:
	print "require 1.3.6.1.4.1.6574.2.1.1"
	sys.exit(0)
else:
	if not (host and port and community):
		print "# Bad configuration. Cannot run with Host=%s, port=%s and community=%s" % (host, port, community)
		sys.exit(1)

	c = SynologySNMPClient(host, port, community)

	if "config" in sys.argv[1:]:
		c.print_config()
	else:
		c.execute()