# -*- ruby -*-

# vim: set noet nosta sw=4 ts=4 :

require 'arborist/monitor/snmp/ups' unless defined?( Arborist::Monitor::SNMP::UPS )

# Checks for UPS battery health.

#

# Checks the available battery percentage, if the UPS is on battery,

# and the temperature of the battery.

#

class Arborist::Monitor::SNMP::UPS::Battery

	include Arborist::Monitor::SNMP

	extend Configurability, Loggability

	log_to :arborist_snmp

	# OIDS for discovering ups status.

	#

	OIDS = {

		battery_status:        '.1.3.6.1.2.1.33.1.2.1.0', # 1 - unk, 2 - normal, 3 - low, 4 - depleted

		seconds_on_battery:    '.1.3.6.1.2.1.33.1.2.2.0',

		est_minutes_remaining: '.1.3.6.1.2.1.33.1.2.3.0',

		est_charge_remaining:  '.1.3.6.1.2.1.33.1.2.4.0', # in percent

		battery_voltage:       '.1.3.6.1.2.1.33.1.2.5.0', # in 0.1v DC

		battery_current:       '.1.3.6.1.2.1.33.1.2.6.0', # in 0.1a DC

		battery_temperature:   '.1.3.6.1.2.1.33.1.2.7.0'  # in Celcius

	}

	# Human-readable translations for battery status OID.

	#

	BATTERY_STATUS = {

		1 => "Battery status is Unknown.",

		2 => "Battery is OK.",

		3 => "Battery is Low.",

		4 => "Battery is Depleted."

	}

	# Global defaults for instances of this monitor

	#

	configurability( 'arborist.snmp.ups.battery' ) do

		# What battery percentage qualifies as a warning

		setting :capacity_warn_at, default: 60

		# What battery temperature qualifies as a warning, in C

		setting :temperature_warn_at, default: 50

	end

	### Return the properties used by this monitor.

	###

	def self::node_properties

		return USED_PROPERTIES

	end

	### Class #run creates a new instance and immediately runs it.

	###

	def self::run( nodes )

		return new.run( nodes )

	end

	### Perform the monitoring checks.

	###

	def run( nodes )

		super do |host, snmp|

			self.check_battery( host, snmp )

		end

	end

	#########

	protected

	#########

	### Query SNMP and format information into a hash.

	###

	def format_battery( snmp )

		info = {}

		# basic info that's always available

		info[ :status ] = snmp.get( oid: OIDS[:battery_status] )

		info[ :capacity ] = snmp.get( oid: OIDS[:est_charge_remaining] ) rescue nil

		info[ :temperature ] = snmp.get( oid: OIDS[:battery_temperature] ) rescue nil

		info[ :minutes_remaining ]  = snmp.get( oid: OIDS[:est_minutes_remaining] ) rescue nil

		# don't report voltage if the UPS doesn't

		voltage = snmp.get( oid: OIDS[:battery_voltage] ) rescue nil

		info[ :voltage ] = voltage / 10 if voltage

		# don't report current if the UPS doesn't

		current = snmp.get( oid: OIDS[:battery_current] ) rescue nil

		info[ :current ] = current/10 if current

		# see if we are on battery

		info[ :seconds_on_battery ] = snmp.get( oid: OIDS[:seconds_on_battery] ) rescue 0

		info[ :in_use ] = ( info[ :seconds_on_battery ] != 0 )

		return { battery: info.compact }

	end

	### Parse SNMP-provided information and alert based on thresholds.

	###

	def check_battery( host, snmp )

		info = self.format_battery( snmp )

		config    = identifiers[ host ].last || {}

		cap_warn  = config[ 'capacity_warn_at' ] || self.class.capacity_warn_at

		temp_warn = config[ 'temperature_warn_at' ] || self.class.temperature_warn_at

		in_use      = info.dig( :battery, :in_use )

		status      = info.dig( :battery, :status )

		capacity    = info.dig( :battery, :capacity )

		temperature = info.dig( :battery, :temperature )

		warnings	= []

		if in_use

			mins = info.dig( :battery, :minutes_remaining ) || "(unknown)"

			warnings << "UPS on battery - %s minute(s) remaning." % [ mins ]

		end

		warnings << BATTERY_STATUS[ status ] if status != 2

		warnings << "Battery remaining capacity %0.1f%% less than %0.1f percent" %

			[ capacity, cap_warn ] if capacity && capacity <= cap_warn

		warnings << "Battery temperature %dC greater than %dC" %

			[ temperature, temp_warn ] if temperature && temperature >= temp_warn

		info[ :warning ] = warnings.join( "\n" ) unless warnings.empty?

		self.results[ host ] = info

	end

end # class Arborist::Monitor::UPS::Battery