#!/usr/bin/python

# Bright would not allow us to add additional metrics to existing pdu entities (as you could with regular servers) so we create new standalone entities that we add via cmsh
# the /etc/hosts has the ip of pdu001 (we could use the device ip), our entity is ipower-pdu01, the targets dict provides the mapping so easysnmp knows what to target
#
# cmsh commands to add this monitoring script
#
# # Add standalone targets
# monitoring standalone
# add ipower-pdu1
# set type ipower-pdu
# commit
# exit
# add ipower-pdu2
# set type ipower-pdu
# commit
# exit
# add ipower-pdu3
# set type ipower-pdu
# commit
# exit
# add ipower-pdu4
# set type ipower-pdu
# commit
# exit
#
# # Create the collection, assign the monitoring script
# monitoring setup
# add collection ipower-pdu
# set script /cm/local/apps/cmd/scripts/powerscripts/ipower-pdu.py
# set format JSON
# set interval 1m
# commit
#
# # Create an execution filter to run the collection only on the active head node
# nodeexecutionfilters
# active
# commit
# exit
#
# # Check monitoring is being collected
# monitoring standalone
# list
#
# Name (key)               Type
# ------------------------ ------------------------
# ipower-pdu1              ipower-pdu
# ipower-pdu2              ipower-pdu
# ipower-pdu3              ipower-pdu
# ipower-pdu4              ipower-pdu
#
# use ipower-pdu1
# latestmetricdata
#
# Measurable   Parameter    Type         Value      Age        State      Info
# ------------ ------------ ------------ ---------- ---------- ---------- ----------
# IPK                       ipower-pdu   25.65 A    7.86s      filtered
# IRMS                      ipower-pdu   17.05 A    7.86s      filtered
# KW                        ipower-pdu   3.794 KW   7.86s      filtered
# VPK                       ipower-pdu   648.4 V    7.86s      filtered
# VRMS                      ipower-pdu   901 V      7.86s      filtered


import os
import sys
import json
from easysnmp import Session

def initialize(entity, meter_values):

    metric = []
    for i in meter_values:
        metric_name = i
        unit = meter_values[i]['unit']
        metric_class = meter_values[i]['class']
        entry = {"metric": metric_name, "entity": entity, "unit": unit, "class": metric_class}
        dict_copy = entry.copy()
        metric.append(dict_copy)

    return metric

def sample(entity, hostname, meter_values):
    
    # this only returns values which are set, snmpwalk will return zero values or no values at all (if powerbanks or phases arent in use the data is discarded and not returned it seems)
    # to force return of empty fields you may need to use get instead of get_bulk
    # get_bulk is like snmpwalk, get is equivalent to snmpget
    #
    # the endwith filter allows us to itterate over similarly named fields and aggregate them, for example you get multiple current readings for multiple phases that we want to aggregate for the pdu
    # however this also happens for voltage so you may get 230vX3 if all phases are in use

    session = Session(hostname=hostname, community='public', version=2, remote_port=161)
    system_items = session.get_bulk('PDUSNMP::pdu-Meters')
    for i in system_items:
        for j in meter_values:
            if i.oid.endswith(j):
                #print (i.oid + "." + i.oid_index + " = " + i.snmp_type + ": " + i.value)
                divide_value = int(meter_values[j]['divide'])
                meter_values[j]['value'] = float(meter_values[j]['value']) + (float(i.value) / divide_value)

    metric = []
    for i in meter_values:
        metric_name = i
        value = meter_values[i]['value']
        entry = {"metric": metric_name, "entity": entity, "value": value}
        dict_copy = entry.copy()
        metric.append(dict_copy)

    return metric

def main():
    # template for metric ititialization, also used for metric collection
    meter_values = {'VRMS': {'unit': 'V', 'class': "ipower-pdu", 'value': 0, 'divide': 10}, 'IRMS': {'unit': 'A', 'class': "ipower-pdu", 'value': 0, 'divide': 100}, 'KW': {'unit': 'KW', 'class': "ipower-pdu", 'value': 0, 'divide': 1000}, 'IPK': {'unit': 'A', 'class': "ipower-pdu", 'value': 0, 'divide': 100}, 'VPK': {'unit': 'V', 'class': "ipower-pdu", 'value': 0, 'divide': 10}}
    #targets = {'ocf-pdu1': '192.168.10.161'} # format = 'bright entity' : 'target address/hostname'
    targets = {'ipower-pdu1': 'pdu001', 'ipower-pdu2': 'pdu002', 'ipower-pdu3': 'pdu003', 'ipower-pdu4': 'pdu004'}
    data = []

    if len(sys.argv) > 1 and sys.argv[1] == "--initialize":
        for i in targets:
            entity = i
            entry = initialize(entity, meter_values)
            for j in entry:
                data.append(j)
    else:
        for i in targets:
            entity = i
            hostname = targets[i]
            entry = sample(entity, hostname, meter_values)
            for j in entry:
                data.append(j)

    print json.dumps(data, indent=4)

if __name__ == '__main__':
    main()