internal/pkg/pmmgr/onu_metrics_manager.go

/*
 * Copyright 2021-present Open Networking Foundation

 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at

 * http://www.apache.org/licenses/LICENSE-2.0

 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

//Package pmmgr provides the utilities to manage onu metrics
package pmmgr

import (
	"context"
	"encoding/json"
	"fmt"
	"math"
	"sync"
	"time"

	"github.com/looplab/fsm"
	omci "github.com/opencord/omci-lib-go/v2"
	me "github.com/opencord/omci-lib-go/v2/generated"
	"github.com/opencord/voltha-lib-go/v7/pkg/db"
	"github.com/opencord/voltha-lib-go/v7/pkg/db/kvstore"
	"github.com/opencord/voltha-lib-go/v7/pkg/log"
	cmn "github.com/opencord/voltha-openonu-adapter-go/internal/pkg/common"
	"github.com/opencord/voltha-protos/v5/go/extension"
	"github.com/opencord/voltha-protos/v5/go/voltha"
)

// events of L2 PM FSM
const (
	L2PmEventInit     = "L2PmEventInit"
	L2PmEventTick     = "L2PmEventTick"
	L2PmEventSuccess  = "L2PmEventSuccess"
	L2PmEventFailure  = "L2PmEventFailure"
	L2PmEventAddMe    = "L2PmEventAddMe"
	L2PmEventDeleteMe = "L2PmEventDeleteMe"
	L2PmEventStop     = "L2PmEventStop"
)

// states of L2 PM FSM
const (
	L2PmStNull        = "L2PmStNull"
	L2PmStStarting    = "L2PmStStarting"
	L2PmStSyncTime    = "L2PmStSyncTime"
	L2PmStIdle        = "L2PmStIdle"
	L2PmStCreatePmMe  = "L2PmStCreatePm"
	L2PmStDeletePmMe  = "L2PmStDeletePmMe"
	L2PmStCollectData = "L2PmStCollectData"
)

// CL2PmFsmIdleState - TODO: add comment
const CL2PmFsmIdleState = L2PmStIdle

// general constants used for overall Metric Collection management
const (
	DefaultMetricCollectionFrequency = 15 * 60 // unit in seconds. This setting can be changed from voltha NBI PmConfig configuration
	GroupMetricEnabled               = true    // This is READONLY and cannot be changed from VOLTHA NBI
	DefaultFrequencyOverrideEnabled  = true    // This is READONLY and cannot be changed from VOLTHA NBI
	FrequencyGranularity             = 5       // The frequency (in seconds) has to be multiple of 5. This setting cannot changed later.
	MaxTimeForPmFsmShutDown          = 120     // in seconds
)

// constants for ethernet frame extended pm collection
const (
	ExtendedPmCreateAttempts            = 3
	UnsupportedCounterValue32bit uint64 = 4294967294
	UnsupportedCounterValue64bit uint64 = 18446744073709551614
)

// OpticalPowerGroupMetrics are supported optical pm names
var OpticalPowerGroupMetrics = map[string]voltha.PmConfig_PmType{
	"ani_g_instance_id":  voltha.PmConfig_CONTEXT,
	"transmit_power_dBm": voltha.PmConfig_GAUGE,
	"receive_power_dBm":  voltha.PmConfig_GAUGE,
}

// OpticalPowerGroupMetrics specific constants
const (
	OpticalPowerGroupMetricName                = "PON_Optical"
	OpticalPowerGroupMetricEnabled             = true   // This setting can be changed from voltha NBI PmConfig configuration
	OpticalPowerMetricGroupCollectionFrequency = 5 * 60 // unit in seconds. This setting can be changed from voltha NBI PmConfig configuration
)

// UniStatusGroupMetrics are supported UNI status names
var UniStatusGroupMetrics = map[string]voltha.PmConfig_PmType{
	"uni_port_no":       voltha.PmConfig_CONTEXT,
	"me_class_id":       voltha.PmConfig_CONTEXT,
	"entity_id":         voltha.PmConfig_CONTEXT,
	"configuration_ind": voltha.PmConfig_GAUGE,
	"oper_status":       voltha.PmConfig_GAUGE,
	"uni_admin_state":   voltha.PmConfig_GAUGE,
}

// UniStatusGroupMetrics specific constants
const (
	UniStatusGroupMetricName                = "UNI_Status"
	UniStatusGroupMetricEnabled             = true   // This setting can be changed from voltha NBI PmConfig configuration
	UniStatusMetricGroupCollectionFrequency = 5 * 60 // unit in seconds. This setting can be changed from voltha NBI PmConfig configuration
)

// *** Classical L2 PM Counters begin ***

// EthernetBridgeHistory are supported ethernet bridge history counters fetched from
// Ethernet Frame Performance Monitoring History Data Downstream and Ethernet Frame Performance Monitoring History Data Upstream MEs.
var EthernetBridgeHistory = map[string]voltha.PmConfig_PmType{
	"class_id":          voltha.PmConfig_CONTEXT,
	"entity_id":         voltha.PmConfig_CONTEXT,
	"interval_end_time": voltha.PmConfig_CONTEXT,
	"parent_class_id":   voltha.PmConfig_CONTEXT,
	"parent_entity_id":  voltha.PmConfig_CONTEXT,
	"upstream":          voltha.PmConfig_CONTEXT,

	"drop_events":         voltha.PmConfig_COUNTER,
	"octets":              voltha.PmConfig_COUNTER,
	"packets":             voltha.PmConfig_COUNTER,
	"broadcast_packets":   voltha.PmConfig_COUNTER,
	"multicast_packets":   voltha.PmConfig_COUNTER,
	"crc_errored_packets": voltha.PmConfig_COUNTER,
	"undersize_packets":   voltha.PmConfig_COUNTER,
	"oversize_packets":    voltha.PmConfig_COUNTER,
	"64_octets":           voltha.PmConfig_COUNTER,
	"65_to_127_octets":    voltha.PmConfig_COUNTER,
	"128_to_255_octets":   voltha.PmConfig_COUNTER,
	"256_to_511_octets":   voltha.PmConfig_COUNTER,
	"512_to_1023_octets":  voltha.PmConfig_COUNTER,
	"1024_to_1518_octets": voltha.PmConfig_COUNTER,
}

// EthernetUniHistory are supported ethernet uni history counters fetched from
// Ethernet Performance Monitoring History Data ME.
var EthernetUniHistory = map[string]voltha.PmConfig_PmType{
	"class_id":          voltha.PmConfig_CONTEXT,
	"entity_id":         voltha.PmConfig_CONTEXT,
	"interval_end_time": voltha.PmConfig_CONTEXT,

	"fcs_errors":                        voltha.PmConfig_COUNTER,
	"excessive_collision_counter":       voltha.PmConfig_COUNTER,
	"late_collision_counter":            voltha.PmConfig_COUNTER,
	"frames_too_long":                   voltha.PmConfig_COUNTER,
	"buffer_overflows_on_rx":            voltha.PmConfig_COUNTER,
	"buffer_overflows_on_tx":            voltha.PmConfig_COUNTER,
	"single_collision_frame_counter":    voltha.PmConfig_COUNTER,
	"multiple_collisions_frame_counter": voltha.PmConfig_COUNTER,
	"sqe_counter":                       voltha.PmConfig_COUNTER,
	"deferred_tx_counter":               voltha.PmConfig_COUNTER,
	"internal_mac_tx_error_counter":     voltha.PmConfig_COUNTER,
	"carrier_sense_error_counter":       voltha.PmConfig_COUNTER,
	"alignment_error_counter":           voltha.PmConfig_COUNTER,
	"internal_mac_rx_error_counter":     voltha.PmConfig_COUNTER,
}

// FecHistory is supported FEC Performance Monitoring History Data related metrics
var FecHistory = map[string]voltha.PmConfig_PmType{
	"class_id":          voltha.PmConfig_CONTEXT,
	"entity_id":         voltha.PmConfig_CONTEXT,
	"interval_end_time": voltha.PmConfig_CONTEXT,

	"corrected_bytes":          voltha.PmConfig_COUNTER,
	"corrected_code_words":     voltha.PmConfig_COUNTER,
	"uncorrectable_code_words": voltha.PmConfig_COUNTER,
	"total_code_words":         voltha.PmConfig_COUNTER,
	"fec_seconds":              voltha.PmConfig_COUNTER,
}

// GemPortHistory is supported GEM Port Network Ctp Performance Monitoring History Data
// related metrics
var GemPortHistory = map[string]voltha.PmConfig_PmType{
	"class_id":          voltha.PmConfig_CONTEXT,
	"entity_id":         voltha.PmConfig_CONTEXT,
	"interval_end_time": voltha.PmConfig_CONTEXT,

	"transmitted_gem_frames":    voltha.PmConfig_COUNTER,
	"received_gem_frames":       voltha.PmConfig_COUNTER,
	"received_payload_bytes":    voltha.PmConfig_COUNTER,
	"transmitted_payload_bytes": voltha.PmConfig_COUNTER,
	"encryption_key_errors":     voltha.PmConfig_COUNTER,
}

var maskToEthernetFrameExtendedPM32Bit = map[uint16][]string{
	0x3F00: {"drop_events", "octets", "frames", "broadcast_frames", "multicast_frames", "crc_errored_frames"},
	0x00FC: {"undersize_frames", "oversize_frames", "64_octets", "65_to_127_octets", "128_to_255_octets", "256_to_511_octets"},
	0x0003: {"512_to_1023_octets", "1024_to_1518_octets"},
}

var maskToEthernetFrameExtendedPM64Bit = map[uint16][]string{
	0x3800: {"drop_events", "octets", "frames"},
	0x0700: {"broadcast_frames", "multicast_frames", "crc_errored_frames"},
	0x00E0: {"undersize_frames", "oversize_frames", "64_octets"},
	0x001C: {"65_to_127_octets", "128_to_255_octets", "256_to_511_octets"},
	0x0003: {"512_to_1023_octets", "1024_to_1518_octets"},
}

// Constants specific for L2 PM collection
const (
	L2PmCollectionInterval = 15 * 60 // Unit in seconds. Do not change this as this fixed by OMCI specification for L2 PM counters
	SyncTimeRetryInterval  = 15      // Unit seconds
	L2PmCreateAttempts     = 3
	L2PmDeleteAttempts     = 3
	L2PmCollectAttempts    = 3
	// Per Table 11.2.9-1 – OMCI baseline message limitations in G.988 spec, the max GET Response
	// payload size is 25. We define 24 (one less) to allow for dynamic insertion of IntervalEndTime
	// attribute (1 byte) in L2 PM GET Requests.
	MaxBaselineL2PMGetPayLoadSize = 24
	// unused: MaxEthernetFrameExtPmPayloadSize = 25
	MaxExtendedL2PMGetPayLoadSize = omci.MaxExtendedLength - 17 - 1 - 4 // minus header, attribute IntervalEndTime and MIC
)

// EthernetUniHistoryName specific constants
const (
	EthernetBridgeHistoryName      = "Ethernet_Bridge_Port_History"
	EthernetBridgeHistoryEnabled   = true // This setting can be changed from voltha NBI PmConfig configuration
	EthernetBridgeHistoryFrequency = L2PmCollectionInterval
)

// EthernetBridgeHistory specific constants
const (
	EthernetUniHistoryName      = "Ethernet_UNI_History"
	EthernetUniHistoryEnabled   = true // This setting can be changed from voltha NBI PmConfig configuration
	EthernetUniHistoryFrequency = L2PmCollectionInterval
)

// FecHistory specific constants
const (
	FecHistoryName      = "FEC_History"
	FecHistoryEnabled   = true // This setting can be changed from voltha NBI PmConfig configuration
	FecHistoryFrequency = L2PmCollectionInterval
)

// GemPortHistory specific constants
const (
	GemPortHistoryName      = "GEM_Port_History"
	GemPortHistoryEnabled   = true // This setting can be changed from voltha NBI PmConfig configuration
	GemPortHistoryFrequency = L2PmCollectionInterval
)

// CPmKvStorePrefixBase - kv store base path of ONU specific PM data
const CPmKvStorePrefixBase = cmn.CBasePathOnuKVStore + "/pm-data" // <some-base-path>/openonu/pm-data

// KV Store related constants
const (
	cPmKvStorePrefix    = CPmKvStorePrefixBase + "/%s" // <some-base-path>/openonu/pm-data/<onu-device-id>
	cPmAdd              = "add"
	cPmAdded            = "added"
	cPmRemove           = "remove"
	cPmRemoved          = "removed"
	cExtPmKvStorePrefix = "%s/omci_me" //<some-base-path>/omci_me/<onu_vendor>/<onu_equipment_id>/<onu_sw_version>
)

// Defines the type for generic metric population function
type groupMetricPopulateFunc func(context.Context, me.ClassID, uint16, me.AttributeValueMap, me.AttributeValueMap, map[string]float32, *int) error

// *** Classical L2 PM Counters end   ***

type pmMEData struct {
	InstancesActive   []uint16 `json:"instances_active"`    // list of active ME instance IDs for the group
	InstancesToDelete []uint16 `json:"instances_to_delete"` // list of ME instance IDs marked for deletion for the group
	InstancesToAdd    []uint16 `json:"instances_to_add"`    // list of ME instance IDs marked for addition for the group
}

type groupMetric struct {
	groupName              string
	Enabled                bool
	Frequency              uint32 // valid only if FrequencyOverride is enabled.
	metricMap              map[string]voltha.PmConfig_PmType
	NextCollectionInterval time.Time // valid only if FrequencyOverride is enabled.
	IsL2PMCounter          bool      // true for only L2 PM counters
	collectAttempts        uint32    // number of attempts to collect L2 PM data
	pmMEData               *pmMEData
}

type standaloneMetric struct {
	metricName             string
	Enabled                bool
	Frequency              uint32    // valid only if FrequencyOverride is enabled.
	NextCollectionInterval time.Time // valid only if FrequencyOverride is enabled.
}

// OnuMetricsManager - TODO: add comment
type OnuMetricsManager struct {
	deviceID        string
	pDeviceHandler  cmn.IdeviceHandler
	pOnuDeviceEntry cmn.IonuDeviceEntry
	PAdaptFsm       *cmn.AdapterFsm

	opticalMetricsChan             chan me.AttributeValueMap
	uniStatusMetricsChan           chan me.AttributeValueMap
	l2PmChan                       chan me.AttributeValueMap
	extendedPmMeChan               chan me.AttributeValueMap
	syncTimeResponseChan           chan bool       // true is success, false is fail
	l2PmCreateOrDeleteResponseChan chan bool       // true is success, false is fail
	extendedPMMeResponseChan       chan me.Results // true is sucesss, false is fail

	activeL2Pms  []string // list of active l2 pm MEs created on the ONU.
	l2PmToDelete []string // list of L2 PMs to delete
	l2PmToAdd    []string // list of L2 PM to add

	GroupMetricMap      map[string]*groupMetric
	StandaloneMetricMap map[string]*standaloneMetric

	StopProcessingOmciResponses chan bool
	omciProcessingActive        bool

	StopTicks            chan bool
	tickGenerationActive bool

	deviceDeletionInProgress  bool
	GarbageCollectionComplete chan bool

	NextGlobalMetricCollectionTime time.Time // valid only if pmConfig.FreqOverride is set to false.

	OnuMetricsManagerLock sync.RWMutex

	pmKvStore *db.Backend

	supportedEthernetFrameExtendedPMClass         me.ClassID
	ethernetFrameExtendedPmUpStreamMEByEntityID   map[uint16]*me.ManagedEntity
	ethernetFrameExtendedPmDownStreamMEByEntityID map[uint16]*me.ManagedEntity
	extPmKvStore                                  *db.Backend
	onuEthernetFrameExtendedPmLock                sync.RWMutex
	isDeviceReadyToCollectExtendedPmStats         bool
	isEthernetFrameExtendedPmOperationOngoing     bool
	isExtendedOmci                                bool
	maxL2PMGetPayLoadSize                         int
}

// NewOnuMetricsManager returns a new instance of the NewOnuMetricsManager
// The metrics manager module is responsible for configuration and management of individual and group metrics.
// Currently all the metrics are managed as a group which fall into two categories - L2 PM and "all others"
// The L2 PM counters have a fixed 15min interval for PM collection while all other group counters have
// the collection interval configurable.
// The global PM config is part of the voltha.Device struct and is backed up on KV store (by rw-core).
// This module also implements resiliency for L2 PM ME instances that are active/pending-delete/pending-add.
func NewOnuMetricsManager(ctx context.Context, dh cmn.IdeviceHandler, onuDev cmn.IonuDeviceEntry) *OnuMetricsManager {

	var metricsManager OnuMetricsManager
	metricsManager.deviceID = dh.GetDeviceID()
	logger.Debugw(ctx, "init-OnuMetricsManager", log.Fields{"device-id": metricsManager.deviceID})
	metricsManager.pDeviceHandler = dh
	metricsManager.pOnuDeviceEntry = onuDev

	commMetricsChan := make(chan cmn.Message)
	metricsManager.opticalMetricsChan = make(chan me.AttributeValueMap)
	metricsManager.uniStatusMetricsChan = make(chan me.AttributeValueMap)
	metricsManager.l2PmChan = make(chan me.AttributeValueMap)
	metricsManager.extendedPmMeChan = make(chan me.AttributeValueMap)

	metricsManager.syncTimeResponseChan = make(chan bool)
	metricsManager.l2PmCreateOrDeleteResponseChan = make(chan bool)
	metricsManager.extendedPMMeResponseChan = make(chan me.Results)

	metricsManager.StopProcessingOmciResponses = make(chan bool)
	metricsManager.StopTicks = make(chan bool)

	metricsManager.GroupMetricMap = make(map[string]*groupMetric)
	metricsManager.StandaloneMetricMap = make(map[string]*standaloneMetric)

	metricsManager.ethernetFrameExtendedPmUpStreamMEByEntityID = make(map[uint16]*me.ManagedEntity)
	metricsManager.ethernetFrameExtendedPmDownStreamMEByEntityID = make(map[uint16]*me.ManagedEntity)

	// make this a buffered channel so that the sender is not blocked for any reason if there is no listener
	metricsManager.GarbageCollectionComplete = make(chan bool, 1)

	if dh.GetPmConfigs() == nil { // dh.GetPmConfigs() is NOT nil if adapter comes back from a restart. We should NOT go back to defaults in this case
		metricsManager.initializeAllGroupMetrics()
	}

	metricsManager.populateLocalGroupMetricData(ctx)

	if err := metricsManager.initializeL2PmFsm(ctx, commMetricsChan); err != nil {
		return nil
	}

	// initialize the next metric collection intervals.
	metricsManager.InitializeMetricCollectionTime(ctx)

	baseKvStorePath := fmt.Sprintf(cPmKvStorePrefix, dh.GetBackendPathPrefix(), metricsManager.deviceID)
	metricsManager.pmKvStore = dh.SetBackend(ctx, baseKvStorePath)
	if metricsManager.pmKvStore == nil {
		logger.Errorw(ctx, "Can't initialize pmKvStore - no backend connection to PM module",
			log.Fields{"device-id": metricsManager.deviceID, "service": baseKvStorePath})
		return nil
	}
	// restore data from KV store
	if err := metricsManager.restorePmData(ctx); err != nil {
		logger.Errorw(ctx, "error restoring pm data", log.Fields{"device-id": metricsManager.deviceID, "err": err})
		// we continue given that it does not effect the actual services for the ONU,
		// but there may be some negative effect on PM collection (there may be some mismatch in
		// the actual PM config and what is present on the device).
	}

	baseExtPmKvStorePath := fmt.Sprintf(cExtPmKvStorePrefix, dh.GetBackendPathPrefix())
	metricsManager.extPmKvStore = dh.SetBackend(ctx, baseExtPmKvStorePath)
	if metricsManager.extPmKvStore == nil {
		logger.Errorw(ctx, "Can't initialize extPmKvStore - no backend connection to PM module",
			log.Fields{"device-id": metricsManager.deviceID, "service": baseExtPmKvStorePath})
		return nil
	}

	logger.Info(ctx, "init-OnuMetricsManager completed", log.Fields{"device-id": metricsManager.deviceID})
	return &metricsManager
}

// InitializeMetricCollectionTime - TODO: add comment
func (mm *OnuMetricsManager) InitializeMetricCollectionTime(ctx context.Context) {
	if mm.pDeviceHandler.GetPmConfigs().FreqOverride {
		// If mm.pDeviceHandler.GetPmConfigs().FreqOverride is set to true, then group/standalone metric specific interval applies
		mm.OnuMetricsManagerLock.Lock()
		defer mm.OnuMetricsManagerLock.Unlock()
		for _, v := range mm.GroupMetricMap {
			if v.Enabled && !v.IsL2PMCounter { // L2 PM counter collection is managed in a L2PmFsm
				v.NextCollectionInterval = time.Now().Add(time.Duration(v.Frequency) * time.Second)
			}
		}

		for _, v := range mm.StandaloneMetricMap {
			if v.Enabled {
				v.NextCollectionInterval = time.Now().Add(time.Duration(v.Frequency) * time.Second)
			}
		}
	} else {
		// If mm.pDeviceHandler.GetPmConfigs().FreqOverride is set to false, then overall metric specific interval applies
		mm.NextGlobalMetricCollectionTime = time.Now().Add(time.Duration(mm.pDeviceHandler.GetPmConfigs().DefaultFreq) * time.Second)
	}
	logger.Infow(ctx, "initialized standalone group/metric collection time", log.Fields{"device-id": mm.deviceID})
}

// UpdateDefaultFrequency - TODO: add comment
func (mm *OnuMetricsManager) UpdateDefaultFrequency(ctx context.Context, pmConfigs *voltha.PmConfigs) error {
	// Verify that the configured DefaultFrequency is > 0 and is a multiple of FrequencyGranularity
	if pmConfigs.DefaultFreq == 0 || (pmConfigs.DefaultFreq > 0 && pmConfigs.DefaultFreq%FrequencyGranularity != 0) {
		logger.Errorf(ctx, "frequency-%u-should-be-a-multiple-of-%u", pmConfigs.DefaultFreq, FrequencyGranularity)
		return fmt.Errorf("frequency-%d-should-be-a-multiple-of-%d", pmConfigs.DefaultFreq, FrequencyGranularity)
	}
	mm.pDeviceHandler.GetPmConfigs().DefaultFreq = pmConfigs.DefaultFreq
	// re-set the NextGlobalMetricCollectionTime based on the new DefaultFreq
	mm.NextGlobalMetricCollectionTime = time.Now().Add(time.Duration(mm.pDeviceHandler.GetPmConfigs().DefaultFreq) * time.Second)
	logger.Debugw(ctx, "frequency-updated--new-frequency", log.Fields{"device-id": mm.deviceID, "frequency": mm.pDeviceHandler.GetPmConfigs().DefaultFreq})
	return nil
}

// UpdateGroupFreq - TODO: add comment
func (mm *OnuMetricsManager) UpdateGroupFreq(ctx context.Context, aGroupName string, pmConfigs *voltha.PmConfigs) error {
	var newGroupFreq uint32
	found := false
	groupSliceIdx := 0
	var group *voltha.PmGroupConfig
	for groupSliceIdx, group = range pmConfigs.Groups {
		if group.GroupName == aGroupName {
			// freq 0 is not allowed and it should be multiple of FrequencyGranularity
			if group.GroupFreq == 0 || (group.GroupFreq > 0 && group.GroupFreq%FrequencyGranularity != 0) {
				logger.Errorf(ctx, "frequency-%u-should-be-a-multiple-of-%u", group.GroupFreq, FrequencyGranularity)
				return fmt.Errorf("frequency-%d-should-be-a-multiple-of-%d", group.GroupFreq, FrequencyGranularity)
			}
			newGroupFreq = group.GroupFreq
			found = true
			break
		}
	}
	// if not found update group freq and next collection interval for the group
	if !found {
		logger.Errorw(ctx, "group name not found", log.Fields{"device-id": mm.deviceID, "groupName": aGroupName})
		return fmt.Errorf("group-name-not-found-%v", aGroupName)
	}

	updated := false
	mm.OnuMetricsManagerLock.Lock()
	defer mm.OnuMetricsManagerLock.Unlock()
	for k, v := range mm.GroupMetricMap {
		if k == aGroupName && !v.IsL2PMCounter { // We cannot allow the L2 PM counter frequency to be updated. It is 15min fixed by OMCI spec
			v.Frequency = newGroupFreq
			// update internal pm config
			mm.pDeviceHandler.GetPmConfigs().Groups[groupSliceIdx].GroupFreq = newGroupFreq
			// Also updated the next group metric collection time from now
			v.NextCollectionInterval = time.Now().Add(time.Duration(newGroupFreq) * time.Second)
			updated = true
			logger.Infow(ctx, "group frequency updated", log.Fields{"device-id": mm.deviceID, "newGroupFreq": newGroupFreq, "groupName": aGroupName})
			break
		}
	}
	if !updated {
		logger.Errorw(ctx, "group frequency not updated", log.Fields{"device-id": mm.deviceID, "newGroupFreq": newGroupFreq, "groupName": aGroupName})
		return fmt.Errorf("internal-error-during-group-freq-update--groupname-%s-freq-%d", aGroupName, newGroupFreq)
	}
	return nil
}

// UpdateMetricFreq - TODO: add comment
func (mm *OnuMetricsManager) UpdateMetricFreq(ctx context.Context, aMetricName string, pmConfigs *voltha.PmConfigs) error {
	var newMetricFreq uint32
	found := false
	metricSliceIdx := 0
	var metric *voltha.PmConfig
	for metricSliceIdx, metric = range pmConfigs.Metrics {
		if metric.Name == aMetricName {
			// freq 0 is not allowed and it should be multiple of FrequencyGranularity
			if metric.SampleFreq == 0 || (metric.SampleFreq > 0 && metric.SampleFreq%FrequencyGranularity != 0) {
				logger.Errorf(ctx, "frequency-%u-should-be-a-multiple-of-%u", metric.SampleFreq, FrequencyGranularity)
				return fmt.Errorf("frequency-%d-should-be-a-multiple-of-%d", metric.SampleFreq, FrequencyGranularity)
			}
			newMetricFreq = metric.SampleFreq
			found = true
			break
		}
	}
	if !found {
		logger.Errorw(ctx, "metric name not found", log.Fields{"device-id": mm.deviceID, "metricName": aMetricName})
		return fmt.Errorf("metric-name-not-found-%v", aMetricName)
	}

	updated := false
	mm.OnuMetricsManagerLock.Lock()
	defer mm.OnuMetricsManagerLock.Unlock()
	for k, v := range mm.GroupMetricMap {
		if k == aMetricName {
			v.Frequency = newMetricFreq
			// update internal pm config
			mm.pDeviceHandler.GetPmConfigs().Metrics[metricSliceIdx].SampleFreq = newMetricFreq
			// Also updated the next standalone metric collection time from now
			v.NextCollectionInterval = time.Now().Add(time.Duration(newMetricFreq) * time.Second)
			updated = true
			logger.Infow(ctx, "metric frequency updated", log.Fields{"device-id": mm.deviceID, "newMetricFreq": newMetricFreq, "aMetricName": aMetricName})
			break
		}
	}
	if !updated {
		logger.Errorw(ctx, "metric frequency not updated", log.Fields{"device-id": mm.deviceID, "newMetricFreq": newMetricFreq, "aMetricName": aMetricName})
		return fmt.Errorf("internal-error-during-standalone-metric-update--matricnane-%s-freq-%d", aMetricName, newMetricFreq)
	}
	return nil
}

// UpdateGroupSupport - TODO: add comment
func (mm *OnuMetricsManager) UpdateGroupSupport(ctx context.Context, aGroupName string, pmConfigs *voltha.PmConfigs) error {
	groupSliceIdx := 0
	var group *voltha.PmGroupConfig

	for groupSliceIdx, group = range pmConfigs.Groups {
		if group.GroupName == aGroupName {
			break
		}
	}
	if group == nil {
		logger.Errorw(ctx, "group metric not found", log.Fields{"device-id": mm.deviceID, "groupName": aGroupName})
		return fmt.Errorf("group-not-found--groupName-%s", aGroupName)
	}

	updated := false
	mm.OnuMetricsManagerLock.Lock()
	defer mm.OnuMetricsManagerLock.Unlock()
	for k, v := range mm.GroupMetricMap {
		if k == aGroupName && v.Enabled != group.Enabled {
			mm.pDeviceHandler.GetPmConfigs().Groups[groupSliceIdx].Enabled = group.Enabled
			v.Enabled = group.Enabled
			if group.Enabled {
				if v.IsL2PMCounter {
					// If it is a L2 PM counter we need to mark the PM to be added
					mm.l2PmToAdd = mm.appendIfMissingString(mm.l2PmToAdd, v.groupName)
					// If the group support flag toggles too soon, we need to delete the group name from l2PmToDelete slice
					mm.l2PmToDelete = mm.removeIfFoundString(mm.l2PmToDelete, v.groupName)

					// The GemPortHistory group requires some special handling as the instance IDs are not pre-defined
					// unlike other L2 PM counters. We need to fetch the active gemport instance IDs in the system to
					// take further action
					if v.groupName == GemPortHistoryName {
						mm.updateGemPortNTPInstanceToAddForPerfMonitoring(ctx)
					}
				} else if mm.pDeviceHandler.GetPmConfigs().FreqOverride { // otherwise just update the next collection interval
					v.NextCollectionInterval = time.Now().Add(time.Duration(v.Frequency) * time.Second)
				}
			} else { // group counter is disabled
				if v.IsL2PMCounter {
					// If it is a L2 PM counter we need to mark the PM to be deleted
					mm.l2PmToDelete = mm.appendIfMissingString(mm.l2PmToDelete, v.groupName)
					// If the group support flag toggles too soon, we need to delete the group name from l2PmToAdd slice
					mm.l2PmToAdd = mm.removeIfFoundString(mm.l2PmToAdd, v.groupName)

					// The GemPortHistory group requires some special handling as the instance IDs are not pre-defined
					// unlike other L2 PM counters. We need to fetch the active gemport instance IDs in the system to
					// take further action
					if v.groupName == GemPortHistoryName {
						mm.updateGemPortNTPInstanceToDeleteForPerfMonitoring(ctx)
					}
				}
			}
			updated = true
			if v.IsL2PMCounter {
				logger.Infow(ctx, "l2 pm group metric support updated",
					log.Fields{"device-id": mm.deviceID, "groupName": aGroupName, "enabled": group.Enabled, "l2PmToAdd": mm.l2PmToAdd, "l2PmToDelete": mm.l2PmToDelete})
			} else {
				logger.Infow(ctx, "group metric support updated", log.Fields{"device-id": mm.deviceID, "groupName": aGroupName, "enabled": group.Enabled})
			}
			break
		}
	}

	if !updated {
		logger.Errorw(ctx, "group metric support not updated", log.Fields{"device-id": mm.deviceID, "groupName": aGroupName})
		return fmt.Errorf("internal-error-during-group-support-update--groupName-%s", aGroupName)
	}
	return nil
}

// UpdateMetricSupport - TODO: add comment
func (mm *OnuMetricsManager) UpdateMetricSupport(ctx context.Context, aMetricName string, pmConfigs *voltha.PmConfigs) error {
	metricSliceIdx := 0
	var metric *voltha.PmConfig

	for metricSliceIdx, metric = range pmConfigs.Metrics {
		if metric.Name == aMetricName {
			break
		}
	}

	if metric == nil {
		logger.Errorw(ctx, "standalone metric not found", log.Fields{"device-id": mm.deviceID, "metricName": aMetricName})
		return fmt.Errorf("metric-not-found--metricname-%s", aMetricName)
	}

	updated := false
	mm.OnuMetricsManagerLock.Lock()
	defer mm.OnuMetricsManagerLock.Unlock()
	for k, v := range mm.StandaloneMetricMap {
		if k == aMetricName && v.Enabled != metric.Enabled {
			mm.pDeviceHandler.GetPmConfigs().Metrics[metricSliceIdx].Enabled = metric.Enabled
			v.Enabled = metric.Enabled
			// If the standalone metric is now enabled and frequency override is enabled, set the next metric collection time
			if metric.Enabled && mm.pDeviceHandler.GetPmConfigs().FreqOverride {
				v.NextCollectionInterval = time.Now().Add(time.Duration(v.Frequency) * time.Second)
			}
			updated = true
			logger.Infow(ctx, "standalone metric support updated", log.Fields{"device-id": mm.deviceID, "metricName": aMetricName, "enabled": metric.Enabled})
			break
		}
	}
	if !updated {
		logger.Errorw(ctx, "standalone metric support not updated", log.Fields{"device-id": mm.deviceID, "metricName": aMetricName})
		return fmt.Errorf("internal-error-during-standalone-support-update--metricname-%s", aMetricName)
	}
	return nil
}

// CollectAllGroupAndStandaloneMetrics - TODO: add comment
func (mm *OnuMetricsManager) CollectAllGroupAndStandaloneMetrics(ctx context.Context) {
	if mm.pDeviceHandler.GetPmConfigs().Grouped { // metrics are managed as a group.
		go mm.collectAllGroupMetrics(ctx)
	} else {
		go mm.collectAllStandaloneMetrics(ctx)
	}
}

func (mm *OnuMetricsManager) collectAllGroupMetrics(ctx context.Context) {
	go func() {
		logger.Debug(ctx, "startCollector before collecting optical metrics")
		metricInfo, err := mm.collectOpticalMetrics(ctx)
		if err != nil {
			logger.Errorw(ctx, "collectOpticalMetrics failed",
				log.Fields{"device-id": mm.deviceID, "Error": err})
			return
		}
		if metricInfo != nil {
			mm.publishMetrics(ctx, metricInfo)
		}
	}()

	go func() {
		logger.Debug(ctx, "startCollector before collecting uni metrics")
		metricInfo, err := mm.collectUniStatusMetrics(ctx)
		if err != nil {
			logger.Errorw(ctx, "collectOpticalMetrics failed",
				log.Fields{"device-id": mm.deviceID, "Error": err})
			return
		}
		if metricInfo != nil {
			mm.publishMetrics(ctx, metricInfo)
		}
	}()

	// Add more here
}

func (mm *OnuMetricsManager) collectAllStandaloneMetrics(ctx context.Context) {
	// None exists as of now, add when available here
}

// CollectGroupMetric - TODO: add comment
func (mm *OnuMetricsManager) CollectGroupMetric(ctx context.Context, groupName string) {
	switch groupName {
	case OpticalPowerGroupMetricName:
		go func() {
			if mi, _ := mm.collectOpticalMetrics(ctx); mi != nil {
				mm.publishMetrics(ctx, mi)
			}
		}()
	case UniStatusGroupMetricName:
		go func() {
			if mi, _ := mm.collectUniStatusMetrics(ctx); mi != nil {
				mm.publishMetrics(ctx, mi)
			}
		}()
	default:
		logger.Errorw(ctx, "unhandled group metric name", log.Fields{"device-id": mm.deviceID, "groupName": groupName})
	}
}

// CollectStandaloneMetric - TODO: add comment
func (mm *OnuMetricsManager) CollectStandaloneMetric(ctx context.Context, metricName string) {
	switch metricName {
	// None exist as of now, add when available
	default:
		logger.Errorw(ctx, "unhandled standalone metric name", log.Fields{"device-id": mm.deviceID, "metricName": metricName})
	}
}

// collectOpticalMetrics collects groups metrics related to optical power from ani-g ME.
func (mm *OnuMetricsManager) collectOpticalMetrics(ctx context.Context) ([]*voltha.MetricInformation, error) {
	logger.Debugw(ctx, "collectOpticalMetrics", log.Fields{"device-id": mm.deviceID})

	mm.OnuMetricsManagerLock.RLock()
	if !mm.GroupMetricMap[OpticalPowerGroupMetricName].Enabled {
		mm.OnuMetricsManagerLock.RUnlock()
		logger.Debugw(ctx, "optical power group metric is not enabled", log.Fields{"device-id": mm.deviceID})
		return nil, nil
	}
	mm.OnuMetricsManagerLock.RUnlock()

	var metricInfoSlice []*voltha.MetricInformation
	metricsContext := make(map[string]string)
	metricsContext["onuID"] = fmt.Sprintf("%d", mm.pDeviceHandler.GetProxyAddress().OnuId)
	metricsContext["intfID"] = fmt.Sprintf("%d", mm.pDeviceHandler.GetProxyAddress().ChannelId)
	metricsContext["devicetype"] = mm.pDeviceHandler.GetDeviceType()

	raisedTs := time.Now().Unix()
	mmd := voltha.MetricMetaData{
		Title:           OpticalPowerGroupMetricName,
		Ts:              float64(raisedTs),
		Context:         metricsContext,
		DeviceId:        mm.deviceID,
		LogicalDeviceId: mm.pDeviceHandler.GetLogicalDeviceID(),
		SerialNo:        mm.pDeviceHandler.GetDevice().SerialNumber,
	}

	// get the ANI-G instance IDs
	anigInstKeys := mm.pOnuDeviceEntry.GetOnuDB().GetSortedInstKeys(ctx, me.AniGClassID)
loop:
	for _, anigInstID := range anigInstKeys {
		var meAttributes me.AttributeValueMap
		opticalMetrics := make(map[string]float32)
		// Get the ANI-G instance optical power attributes
		requestedAttributes := me.AttributeValueMap{me.AniG_OpticalSignalLevel: 0, me.AniG_TransmitOpticalLevel: 0}
		meInstance, err := mm.pOnuDeviceEntry.GetDevOmciCC().SendGetMe(ctx, me.AniGClassID, anigInstID, requestedAttributes,
			mm.pDeviceHandler.GetOmciTimeout(), true, mm.PAdaptFsm.CommChan, mm.isExtendedOmci)
		if err != nil {
			logger.Errorw(ctx, "GetMe failed, failure PM FSM!", log.Fields{"device-id": mm.deviceID})
			_ = mm.PAdaptFsm.PFsm.Event(L2PmEventFailure)
			return nil, err
		}

		if meInstance != nil {
			select {
			case meAttributes = <-mm.opticalMetricsChan:
				logger.Debugw(ctx, "received optical metrics", log.Fields{"device-id": mm.deviceID})
			case <-time.After(mm.pOnuDeviceEntry.GetDevOmciCC().GetMaxOmciTimeoutWithRetries() * time.Second):
				logger.Errorw(ctx, "timeout waiting for omci-get response for optical metrics", log.Fields{"device-id": mm.deviceID})
				// The metrics will be empty in this case
				break loop
			}
			// Populate metric only if it was enabled.
			for k := range OpticalPowerGroupMetrics {
				switch k {
				case "ani_g_instance_id":
					if val, ok := meAttributes[me.ManagedEntityID]; ok && val != nil {
						opticalMetrics[k] = float32(val.(uint16))
					}
				case "transmit_power_dBm":
					if val, ok := meAttributes[me.AniG_TransmitOpticalLevel]; ok && val != nil {
						opticalMetrics[k] = float32(math.Round((float64(cmn.TwosComplementToSignedInt16(val.(uint16)))/500.0)*10) / 10) // convert to dBm rounded of to single decimal place
					}
				case "receive_power_dBm":
					if val, ok := meAttributes[me.AniG_OpticalSignalLevel]; ok && val != nil {
						opticalMetrics[k] = float32(math.Round((float64(cmn.TwosComplementToSignedInt16(val.(uint16)))/500.0)*10) / 10) // convert to dBm rounded of to single decimal place
					}
				default:
					// do nothing
				}
			}
		}
		// create slice of metrics given that there could be more than one ANI-G instance and
		// optical metrics are collected per ANI-G instance
		metricInfo := voltha.MetricInformation{Metadata: &mmd, Metrics: opticalMetrics}
		metricInfoSlice = append(metricInfoSlice, &metricInfo)
	}

	return metricInfoSlice, nil
}

// collectUniStatusMetrics collects UNI status group metric from various MEs (uni-g, pptp and veip).
// nolint: gocyclo
func (mm *OnuMetricsManager) collectUniStatusMetrics(ctx context.Context) ([]*voltha.MetricInformation, error) {
	logger.Debugw(ctx, "collectUniStatusMetrics", log.Fields{"device-id": mm.deviceID})
	mm.OnuMetricsManagerLock.RLock()
	if !mm.GroupMetricMap[UniStatusGroupMetricName].Enabled {
		mm.OnuMetricsManagerLock.RUnlock()
		logger.Debugw(ctx, "uni status group metric is not enabled", log.Fields{"device-id": mm.deviceID})
		return nil, nil
	}
	mm.OnuMetricsManagerLock.RUnlock()

	var metricInfoSlice []*voltha.MetricInformation
	metricsContext := make(map[string]string)
	metricsContext["onuID"] = fmt.Sprintf("%d", mm.pDeviceHandler.GetDevice().ProxyAddress.OnuId)
	metricsContext["intfID"] = fmt.Sprintf("%d", mm.pDeviceHandler.GetDevice().ProxyAddress.ChannelId)
	metricsContext["devicetype"] = mm.pDeviceHandler.GetDeviceType()

	raisedTs := time.Now().Unix()
	mmd := voltha.MetricMetaData{
		Title:           UniStatusGroupMetricName,
		Ts:              float64(raisedTs),
		Context:         metricsContext,
		DeviceId:        mm.deviceID,
		LogicalDeviceId: mm.pDeviceHandler.GetLogicalDeviceID(),
		SerialNo:        mm.pDeviceHandler.GetDevice().SerialNumber,
	}

	// get the UNI-G instance IDs
	unigInstKeys := mm.pOnuDeviceEntry.GetOnuDB().GetSortedInstKeys(ctx, me.UniGClassID)
loop1:
	for _, unigInstID := range unigInstKeys {
		// TODO: Include additional information in the voltha.MetricMetaData - like portno, uni-id, instance-id
		// to uniquely identify this ME instance and also to correlate the ME instance to physical instance
		unigMetrics := make(map[string]float32)
		var meAttributes me.AttributeValueMap
		// Get the UNI-G instance optical power attributes
		requestedAttributes := me.AttributeValueMap{me.UniG_AdministrativeState: 0}
		meInstance, err := mm.pOnuDeviceEntry.GetDevOmciCC().SendGetMe(ctx, me.UniGClassID, unigInstID, requestedAttributes,
			mm.pDeviceHandler.GetOmciTimeout(), true, mm.PAdaptFsm.CommChan, mm.isExtendedOmci)
		if err != nil {
			logger.Errorw(ctx, "UNI-G failed, failure PM FSM!", log.Fields{"device-id": mm.deviceID})
			_ = mm.PAdaptFsm.PFsm.Event(L2PmEventFailure)
			return nil, err
		}
		if meInstance != nil {
			// Wait for metrics or timeout
			select {
			case meAttributes = <-mm.uniStatusMetricsChan:
				logger.Debugw(ctx, "received uni-g metrics", log.Fields{"device-id": mm.deviceID})
			case <-time.After(mm.pOnuDeviceEntry.GetDevOmciCC().GetMaxOmciTimeoutWithRetries() * time.Second):
				logger.Errorw(ctx, "timeout waiting for omci-get response for uni status", log.Fields{"device-id": mm.deviceID})
				// The metrics could be empty in this case
				break loop1
			}
			// Populate metric only if it was enabled.
			for k := range UniStatusGroupMetrics {
				switch k {
				case "uni_admin_state":
					if val, ok := meAttributes[me.UniG_AdministrativeState]; ok && val != nil {
						unigMetrics[k] = float32(val.(byte))
					}
				default:
					// do nothing
				}
			}
			if val, ok := meAttributes[me.ManagedEntityID]; ok && val != nil {
				entityID := val.(uint16)
				unigMetrics["entity_id"] = float32(entityID)
				// TODO: Rlock needed for reading uniEntityMap? May not be needed given uniEntityMap is populated setup at initial ONU bring up
				for _, uni := range *mm.pDeviceHandler.GetUniEntityMap() {
					if uni.EntityID == entityID {
						unigMetrics["uni_port_no"] = float32(uni.PortNo)
						break
					}
				}
			}
			unigMetrics["me_class_id"] = float32(me.UniGClassID)

			// create slice of metrics given that there could be more than one UNI-G instance
			metricInfo := voltha.MetricInformation{Metadata: &mmd, Metrics: unigMetrics}
			metricInfoSlice = append(metricInfoSlice, &metricInfo)
		}
	}

	// get the PPTP instance IDs
	pptpInstKeys := mm.pOnuDeviceEntry.GetOnuDB().GetSortedInstKeys(ctx, me.PhysicalPathTerminationPointEthernetUniClassID)
loop2:
	for _, pptpInstID := range pptpInstKeys {
		// TODO: Include additional information in the voltha.MetricMetaData - like portno, uni-id, instance-id
		// to uniquely identify this ME instance and also to correlate the ME instance to physical instance
		var meAttributes me.AttributeValueMap
		pptpMetrics := make(map[string]float32)

		requestedAttributes := me.AttributeValueMap{
			me.PhysicalPathTerminationPointEthernetUni_ConfigurationInd:    0,
			me.PhysicalPathTerminationPointEthernetUni_OperationalState:    0,
			me.PhysicalPathTerminationPointEthernetUni_AdministrativeState: 0}
		meInstance, err := mm.pOnuDeviceEntry.GetDevOmciCC().SendGetMe(ctx, me.PhysicalPathTerminationPointEthernetUniClassID,
			pptpInstID, requestedAttributes, mm.pDeviceHandler.GetOmciTimeout(), true, mm.PAdaptFsm.CommChan, mm.isExtendedOmci)
		if err != nil {
			logger.Errorw(ctx, "GetMe failed, failure PM FSM!", log.Fields{"device-id": mm.deviceID})
			_ = mm.PAdaptFsm.PFsm.Event(L2PmEventFailure)
			return nil, err
		}
		if meInstance != nil {
			// Wait for metrics or timeout
			select {
			case meAttributes = <-mm.uniStatusMetricsChan:
				logger.Debugw(ctx, "received pptp metrics", log.Fields{"device-id": mm.deviceID})
			case <-time.After(mm.pOnuDeviceEntry.GetDevOmciCC().GetMaxOmciTimeoutWithRetries() * time.Second):
				logger.Errorw(ctx, "timeout waiting for omci-get response for uni status", log.Fields{"device-id": mm.deviceID})
				// The metrics could be empty in this case
				break loop2
			}

			// Populate metric only if it was enabled.
			for k := range UniStatusGroupMetrics {
				switch k {
				case "configuration_ind":
					if val, ok := meAttributes[me.PhysicalPathTerminationPointEthernetUni_ConfigurationInd]; ok && val != nil {
						pptpMetrics[k] = float32(val.(byte))
					}
				case "oper_status":
					if val, ok := meAttributes[me.PhysicalPathTerminationPointEthernetUni_OperationalState]; ok && val != nil {
						pptpMetrics[k] = float32(val.(byte))
					}
				case "uni_admin_state":
					if val, ok := meAttributes[me.PhysicalPathTerminationPointEthernetUni_AdministrativeState]; ok && val != nil {
						pptpMetrics[k] = float32(val.(byte))
					}
				default:
					// do nothing
				}
			}
		}
		if val, ok := meAttributes[me.ManagedEntityID]; ok && val != nil {
			entityID := val.(uint16)
			pptpMetrics["entity_id"] = float32(entityID)
			// TODO: Rlock needed for reading uniEntityMap? May not be needed given uniEntityMap is populated setup at initial ONU bring up
			for _, uni := range *mm.pDeviceHandler.GetUniEntityMap() {
				if uni.EntityID == entityID {
					pptpMetrics["uni_port_no"] = float32(uni.PortNo)
					break
				}
			}
		}
		pptpMetrics["me_class_id"] = float32(me.PhysicalPathTerminationPointEthernetUniClassID)

		// create slice of metrics given that there could be more than one PPTP instance and
		metricInfo := voltha.MetricInformation{Metadata: &mmd, Metrics: pptpMetrics}
		metricInfoSlice = append(metricInfoSlice, &metricInfo)
	}

	// get the VEIP instance IDs
	veipInstKeys := mm.pOnuDeviceEntry.GetOnuDB().GetSortedInstKeys(ctx, me.VirtualEthernetInterfacePointClassID)
loop3:
	for _, veipInstID := range veipInstKeys {
		// TODO: Include additional information in the voltha.MetricMetaData - like portno, uni-id, instance-id
		// to uniquely identify this ME instance and also to correlate the ME instance to physical instance
		var meAttributes me.AttributeValueMap
		veipMetrics := make(map[string]float32)

		requestedAttributes := me.AttributeValueMap{me.VirtualEthernetInterfacePoint_OperationalState: 0,
			me.VirtualEthernetInterfacePoint_AdministrativeState: 0}
		meInstance, err := mm.pOnuDeviceEntry.GetDevOmciCC().SendGetMe(ctx, me.VirtualEthernetInterfacePointClassID, veipInstID, requestedAttributes,
			mm.pDeviceHandler.GetOmciTimeout(), true, mm.PAdaptFsm.CommChan, mm.isExtendedOmci)
		if err != nil {
			logger.Errorw(ctx, "GetMe failed, failure PM FSM!", log.Fields{"device-id": mm.deviceID})
			_ = mm.PAdaptFsm.PFsm.Event(L2PmEventFailure)
			return nil, err
		}
		if meInstance != nil {
			// Wait for metrics or timeout
			select {
			case meAttributes = <-mm.uniStatusMetricsChan:
				logger.Debugw(ctx, "received veip metrics", log.Fields{"device-id": mm.deviceID})
			case <-time.After(mm.pOnuDeviceEntry.GetDevOmciCC().GetMaxOmciTimeoutWithRetries() * time.Second):
				logger.Errorw(ctx, "timeout waiting for omci-get response for uni status", log.Fields{"device-id": mm.deviceID})
				// The metrics could be empty in this case
				break loop3
			}

			// Populate metric only if it was enabled.
			for k := range UniStatusGroupMetrics {
				switch k {
				case "oper_status":
					if val, ok := meAttributes[me.VirtualEthernetInterfacePoint_OperationalState]; ok && val != nil {
						veipMetrics[k] = float32(val.(byte))
					}
				case "uni_admin_state":
					if val, ok := meAttributes[me.VirtualEthernetInterfacePoint_AdministrativeState]; ok && val != nil {
						veipMetrics[k] = float32(val.(byte))
					}
				default:
					// do nothing
				}
			}
		}

		if val, ok := meAttributes[me.ManagedEntityID]; ok && val != nil {
			entityID := val.(uint16)
			veipMetrics["entity_id"] = float32(entityID)
			// TODO: Rlock needed for reading uniEntityMap? May not be needed given uniEntityMap is populated setup at initial ONU bring up
			for _, uni := range *mm.pDeviceHandler.GetUniEntityMap() {
				if uni.EntityID == entityID {
					veipMetrics["uni_port_no"] = float32(uni.PortNo)
					break
				}
			}
		}
		veipMetrics["me_class_id"] = float32(me.VirtualEthernetInterfacePointClassID)

		// create slice of metrics given that there could be more than one VEIP instance
		metricInfo := voltha.MetricInformation{Metadata: &mmd, Metrics: veipMetrics}
		metricInfoSlice = append(metricInfoSlice, &metricInfo)
	}

	return metricInfoSlice, nil
}

// publishMetrics publishes the metrics on kafka
func (mm *OnuMetricsManager) publishMetrics(ctx context.Context, metricInfo []*voltha.MetricInformation) {
	var ke voltha.KpiEvent2
	ts := time.Now().Unix()
	ke.SliceData = metricInfo
	ke.Type = voltha.KpiEventType_slice
	ke.Ts = float64(ts)

	if err := mm.pDeviceHandler.GetEventProxy().SendKpiEvent(ctx, "STATS_PUBLISH_EVENT", &ke, voltha.EventCategory_EQUIPMENT, voltha.EventSubCategory_ONU, ts); err != nil {
		logger.Errorw(ctx, "failed-to-send-pon-stats", log.Fields{"device-id": mm.deviceID, "err": err})
	}
}

// ProcessOmciMessages - TODO: add comment
func (mm *OnuMetricsManager) ProcessOmciMessages(ctx context.Context, waitForOmciProcessor *sync.WaitGroup) {
	logger.Infow(ctx, "Start routine to process OMCI-GET messages for device-id", log.Fields{"device-id": mm.deviceID})
	// Flush metric collection channels to be safe.
	// It is possible that there is stale data on this channel if the ProcessOmciMessages routine
	// is stopped right after issuing a OMCI-GET request and started again.
	// The ProcessOmciMessages routine will get stopped if startCollector routine (in device_handler.go)
	// is stopped - as a result of ONU going down.
	mm.flushMetricCollectionChannels(ctx)
	// when instantiating mm it was too early, but now we can check for ONU's extended OMCI support
	mm.isExtendedOmci = mm.pOnuDeviceEntry.GetPersIsExtOmciSupported()
	if mm.isExtendedOmci {
		mm.maxL2PMGetPayLoadSize = MaxExtendedL2PMGetPayLoadSize
	} else {
		mm.maxL2PMGetPayLoadSize = MaxBaselineL2PMGetPayLoadSize
	}
	mm.updateOmciProcessingStatus(true)
	waitForOmciProcessor.Done()
	for {
		select {
		case <-mm.StopProcessingOmciResponses: // stop this routine
			logger.Infow(ctx, "Stop routine to process OMCI-GET messages for device-id", log.Fields{"device-id": mm.deviceID})
			mm.updateOmciProcessingStatus(false)
			return
		case message, ok := <-mm.PAdaptFsm.CommChan:
			if !ok {
				logger.Errorw(ctx, "Message couldn't be read from channel", log.Fields{"device-id": mm.deviceID})
				continue
			}
			logger.Debugw(ctx, "Received message on ONU metrics channel", log.Fields{"device-id": mm.deviceID})

			switch message.Type {
			case cmn.OMCI:
				msg, _ := message.Data.(cmn.OmciMessage)
				mm.handleOmciMessage(ctx, msg)
			default:
				logger.Warn(ctx, "Unknown message type received", log.Fields{"device-id": mm.deviceID, "message.Type": message.Type})
			}
		}
	}
}

func (mm *OnuMetricsManager) handleOmciMessage(ctx context.Context, msg cmn.OmciMessage) {
	logger.Debugw(ctx, "omci Msg", log.Fields{"device-id": mm.deviceID,
		"msgType": msg.OmciMsg.MessageType, "msg": msg})
	switch msg.OmciMsg.MessageType {
	case omci.GetResponseType:
		//TODO: error handling
		_ = mm.handleOmciGetResponseMessage(ctx, msg)
	case omci.SynchronizeTimeResponseType:
		_ = mm.handleOmciSynchronizeTimeResponseMessage(ctx, msg)
	case omci.CreateResponseType:
		_ = mm.handleOmciCreateResponseMessage(ctx, msg)
	case omci.DeleteResponseType:
		_ = mm.handleOmciDeleteResponseMessage(ctx, msg)
	case omci.GetCurrentDataResponseType:
		_ = mm.handleOmciGetCurrentDataResponseMessage(ctx, msg)
	case omci.SetResponseType:
		_ = mm.handleOmciSetResponseMessage(ctx, msg)
	default:
		logger.Warnw(ctx, "Unknown Message Type", log.Fields{"device-id": mm.deviceID, "msgType": msg.OmciMsg.MessageType})

	}
}

func (mm *OnuMetricsManager) handleOmciGetResponseMessage(ctx context.Context, msg cmn.OmciMessage) error {
	msgLayer := (*msg.OmciPacket).Layer(omci.LayerTypeGetResponse)
	if msgLayer == nil {
		logger.Errorw(ctx, "omci Msg layer could not be detected for GetResponse - handling stopped", log.Fields{"device-id": mm.deviceID})
		return fmt.Errorf("omci Msg layer could not be detected for GetResponse - handling stopped: %s", mm.deviceID)
	}
	msgObj, msgOk := msgLayer.(*omci.GetResponse)
	if !msgOk {
		logger.Errorw(ctx, "omci Msg layer could not be assigned for GetResponse - handling stopped", log.Fields{"device-id": mm.deviceID})
		return fmt.Errorf("omci Msg layer could not be assigned for GetResponse - handling stopped: %s", mm.deviceID)
	}
	logger.Debugw(ctx, "OMCI GetResponse Data", log.Fields{"device-id": mm.deviceID, "data-fields": msgObj, "result": msgObj.Result})
	if msgObj.Result == me.Success {
		meAttributes := msgObj.Attributes
		switch msgObj.EntityClass {
		case me.AniGClassID:
			mm.opticalMetricsChan <- meAttributes
			return nil
		case me.UniGClassID:
			mm.uniStatusMetricsChan <- meAttributes
			return nil
		case me.PhysicalPathTerminationPointEthernetUniClassID:
			mm.uniStatusMetricsChan <- meAttributes
			return nil
		case me.VirtualEthernetInterfacePointClassID:
			mm.uniStatusMetricsChan <- meAttributes
			return nil
		case me.EthernetFramePerformanceMonitoringHistoryDataUpstreamClassID,
			me.EthernetFramePerformanceMonitoringHistoryDataDownstreamClassID,
			me.EthernetPerformanceMonitoringHistoryDataClassID,
			me.FecPerformanceMonitoringHistoryDataClassID,
			me.GemPortNetworkCtpPerformanceMonitoringHistoryDataClassID:
			mm.l2PmChan <- meAttributes
			return nil
		case me.EthernetFrameExtendedPmClassID,
			me.EthernetFrameExtendedPm64BitClassID:
			mm.extendedPmMeChan <- meAttributes
			return nil
		default:
			logger.Errorw(ctx, "unhandled omci get response message",
				log.Fields{"device-id": mm.deviceID, "class-id": msgObj.EntityClass})
		}
	} else {
		meAttributes := msgObj.Attributes
		switch msgObj.EntityClass {
		case me.EthernetFrameExtendedPmClassID,
			me.EthernetFrameExtendedPm64BitClassID:
			// not all counters may be supported in which case we have seen some ONUs throwing
			// AttributeFailure error code, while correctly populating other counters it supports
			mm.extendedPmMeChan <- meAttributes
			return nil
		default:
			logger.Errorw(ctx, "unhandled omci get response message",
				log.Fields{"device-id": mm.deviceID, "class-id": msgObj.EntityClass})
		}
	}
	return fmt.Errorf("unhandled-omci-get-response-message")
}

func (mm *OnuMetricsManager) handleOmciGetCurrentDataResponseMessage(ctx context.Context, msg cmn.OmciMessage) error {
	msgLayer := (*msg.OmciPacket).Layer(omci.LayerTypeGetCurrentDataResponse)
	if msgLayer == nil {
		logger.Errorw(ctx, "omci Msg layer could not be detected for GetCurrentDataResponse - handling stopped", log.Fields{"device-id": mm.deviceID})
		return fmt.Errorf("omci Msg layer could not be detected for GetCurrentDataResponse - handling stopped: %s", mm.deviceID)
	}
	msgObj, msgOk := msgLayer.(*omci.GetCurrentDataResponse)
	if !msgOk {
		logger.Errorw(ctx, "omci Msg layer could not be assigned for GetCurrentDataResponse - handling stopped", log.Fields{"device-id": mm.deviceID})
		return fmt.Errorf("omci Msg layer could not be assigned for GetCurrentDataResponse - handling stopped: %s", mm.deviceID)
	}
	logger.Debugw(ctx, "OMCI GetCurrentDataResponse Data", log.Fields{"device-id": mm.deviceID, "data-fields": msgObj, "result": msgObj.Result})
	if msgObj.Result == me.Success {
		meAttributes := msgObj.Attributes
		switch msgObj.EntityClass {
		case me.EthernetFrameExtendedPmClassID,
			me.EthernetFrameExtendedPm64BitClassID:
			mm.extendedPmMeChan <- meAttributes
			return nil
		default:
			logger.Errorw(ctx, "unhandled omci get current data response message",
				log.Fields{"device-id": mm.deviceID, "class-id": msgObj.EntityClass})
		}
	} else {
		meAttributes := msgObj.Attributes
		switch msgObj.EntityClass {
		case me.EthernetFrameExtendedPmClassID,
			me.EthernetFrameExtendedPm64BitClassID:
			// not all counters may be supported in which case we have seen some ONUs throwing
			// AttributeFailure error code, while correctly populating other counters it supports
			mm.extendedPmMeChan <- meAttributes
			return nil
		default:
			logger.Errorw(ctx, "unhandled omci get current data response message",
				log.Fields{"device-id": mm.deviceID, "class-id": msgObj.EntityClass})
		}
	}
	return fmt.Errorf("unhandled-omci-get-current-data-response-message")
}

func (mm *OnuMetricsManager) handleOmciSynchronizeTimeResponseMessage(ctx context.Context, msg cmn.OmciMessage) error {
	msgLayer := (*msg.OmciPacket).Layer(omci.LayerTypeSynchronizeTimeResponse)
	if msgLayer == nil {
		logger.Errorw(ctx, "omci Msg layer could not be detected for synchronize time response - handling stopped", log.Fields{"device-id": mm.deviceID})
		return fmt.Errorf("omci Msg layer could not be detected for synchronize time response - handling stopped: %s", mm.deviceID)
	}
	msgObj, msgOk := msgLayer.(*omci.SynchronizeTimeResponse)
	if !msgOk {
		logger.Errorw(ctx, "omci Msg layer could not be assigned for synchronize time response - handling stopped", log.Fields{"device-id": mm.deviceID})
		return fmt.Errorf("omci Msg layer could not be assigned for synchronize time response - handling stopped: %s", mm.deviceID)
	}
	logger.Debugw(ctx, "OMCI synchronize time response Data", log.Fields{"device-id": mm.deviceID, "data-fields": msgObj})
	if msgObj.Result == me.Success {
		switch msgObj.EntityClass {
		case me.OnuGClassID:
			logger.Infow(ctx, "omci synchronize time success", log.Fields{"device-id": mm.deviceID})
			mm.syncTimeResponseChan <- true
			return nil
		default:
			logger.Errorw(ctx, "unhandled omci message",
				log.Fields{"device-id": mm.deviceID, "class-id": msgObj.EntityClass})
		}
	}
	mm.syncTimeResponseChan <- false
	logger.Errorf(ctx, "unhandled-omci-synchronize-time-response-message--error-code-%v", msgObj.Result)
	return fmt.Errorf("unhandled-omci-synchronize-time-response-message--error-code-%v", msgObj.Result)
}

func (mm *OnuMetricsManager) handleOmciSetResponseMessage(ctx context.Context, msg cmn.OmciMessage) error {
	msgLayer := (*msg.OmciPacket).Layer(omci.LayerTypeSetResponse)
	if msgLayer == nil {
		logger.Errorw(ctx, "omci Msg layer could not be detected for SetResponse - handling stopped", log.Fields{"device-id": mm.deviceID})
		return fmt.Errorf("omci Msg layer could not be detected for SetResponse - handling stopped: %s", mm.deviceID)
	}
	msgObj, msgOk := msgLayer.(*omci.SetResponse)
	if !msgOk {
		logger.Errorw(ctx, "omci Msg layer could not be assigned for SetResponse - handling stopped", log.Fields{"device-id": mm.deviceID})
		return fmt.Errorf("omci Msg layer could not be assigned for SetResponse - handling stopped: %s", mm.deviceID)
	}
	logger.Debugw(ctx, "OMCI SetResponse Data", log.Fields{"device-id": mm.deviceID, "data-fields": msgObj, "result": msgObj.Result})
	switch msgObj.EntityClass {
	case me.EthernetFrameExtendedPmClassID,
		me.EthernetFrameExtendedPm64BitClassID:
		mm.extendedPMMeResponseChan <- msgObj.Result
		return nil
	default:
		logger.Errorw(ctx, "unhandled omci set response message",
			log.Fields{"device-id": mm.deviceID, "class-id": msgObj.EntityClass})
	}
	return fmt.Errorf("unhandled-omci-set-response-message-%v", mm.deviceID)
}

// flushMetricCollectionChannels flushes all metric collection channels for any stale OMCI responses
func (mm *OnuMetricsManager) flushMetricCollectionChannels(ctx context.Context) {
	// flush commMetricsChan
	select {
	case <-mm.PAdaptFsm.CommChan:
		logger.Debug(ctx, "flushed common metrics channel")
	default:
	}

	// flush opticalMetricsChan
	select {
	case <-mm.opticalMetricsChan:
		logger.Debug(ctx, "flushed optical metrics channel")
	default:
	}

	// flush uniStatusMetricsChan
	select {
	case <-mm.uniStatusMetricsChan:
		logger.Debug(ctx, "flushed uni status metrics channel")
	default:
	}

	// flush syncTimeResponseChan
	select {
	case <-mm.syncTimeResponseChan:
		logger.Debug(ctx, "flushed sync time response channel")
	default:
	}

	// flush l2PmChan
	select {
	case <-mm.l2PmChan:
		logger.Debug(ctx, "flushed L2 PM collection channel")
	default:
	}

	// flush StopTicks
	select {
	case <-mm.StopTicks:
		logger.Debug(ctx, "flushed StopTicks channel")
	default:
	}

}

// ** L2 PM FSM Handlers start **

func (mm *OnuMetricsManager) l2PMFsmStarting(ctx context.Context, e *fsm.Event) {
	if mm.GetdeviceDeletionInProgress() {
		logger.Infow(ctx, "device already deleted, return", log.Fields{"curr-state": mm.PAdaptFsm.PFsm.Current, "deviceID": mm.deviceID})
		return
	}

	// Loop through all the group metrics
	// If it is a L2 PM Interval metric and it is enabled, then if it is not in the
	// list of active L2 PM list then mark it for creation
	// It it is a L2 PM Interval metric and it is disabled, then if it is in the
	// list of active L2 PM list then mark it for deletion
	mm.OnuMetricsManagerLock.Lock()
	for n, g := range mm.GroupMetricMap {
		if g.IsL2PMCounter { // it is a l2 pm counter
			if g.Enabled { // metric enabled.
				found := false
			inner1:
				for _, v := range mm.activeL2Pms {
					if v == n {
						found = true // metric already present in active l2 pm list
						break inner1
					}
				}
				if !found { // metric not in active l2 pm list. Mark this to be added later
					mm.l2PmToAdd = mm.appendIfMissingString(mm.l2PmToAdd, n)
				}
			} else { // metric not enabled.
				found := false
			inner2:
				for _, v := range mm.activeL2Pms {
					if v == n {
						found = true // metric is found in active l2 pm list
						break inner2
					}
				}
				if found { // metric is found in active l2 pm list. Mark this to be deleted later
					mm.l2PmToDelete = mm.appendIfMissingString(mm.l2PmToDelete, n)
				}
			}
		}
	}
	mm.OnuMetricsManagerLock.Unlock()
	logger.Debugw(ctx, "pms to add and delete",
		log.Fields{"device-id": mm.deviceID, "pms-to-add": mm.l2PmToAdd, "pms-to-delete": mm.l2PmToDelete})
	go func() {
		// push a tick event to move to next state
		if err := mm.PAdaptFsm.PFsm.Event(L2PmEventTick); err != nil {
			logger.Errorw(ctx, "error calling event", log.Fields{"device-id": mm.deviceID, "err": err})
		}
	}()
}

func (mm *OnuMetricsManager) l2PMFsmSyncTime(ctx context.Context, e *fsm.Event) {
	if mm.GetdeviceDeletionInProgress() {
		logger.Infow(ctx, "device already deleted, return", log.Fields{"curr-state": mm.PAdaptFsm.PFsm.Current, "deviceID": mm.deviceID})
		return
	}
	// Sync time with the ONU to establish 15min boundary for PM collection.
	if err := mm.syncTime(ctx); err != nil {
		// device could be deleted while waiting on sync time response
		if mm.GetdeviceDeletionInProgress() {
			logger.Infow(ctx, "device already deleted, return", log.Fields{"curr-state": mm.PAdaptFsm.PFsm.Current, "deviceID": mm.deviceID})
			return
		}
		go func() {
			time.Sleep(SyncTimeRetryInterval * time.Second) // retry to sync time after this timeout
			// This will result in FSM attempting to sync time again
			if err := mm.PAdaptFsm.PFsm.Event(L2PmEventFailure); err != nil {
				logger.Errorw(ctx, "error calling event", log.Fields{"device-id": mm.deviceID, "err": err})
			}
		}()
	}
	// Initiate a tick generation routine every L2PmCollectionInterval
	go mm.generateTicks(ctx)

	go func() {
		if err := mm.PAdaptFsm.PFsm.Event(L2PmEventSuccess); err != nil {
			logger.Errorw(ctx, "error calling event", log.Fields{"device-id": mm.deviceID, "err": err})
		}
	}()
}

func (mm *OnuMetricsManager) l2PMFsmNull(ctx context.Context, e *fsm.Event) {
	// We need to reset the local data so that the L2 PM MEs are re-provisioned once the ONU is back up based on the latest PM CONFIG
	mm.OnuMetricsManagerLock.Lock()
	mm.activeL2Pms = nil
	mm.l2PmToAdd = nil
	mm.l2PmToDelete = nil
	mm.OnuMetricsManagerLock.Unlock()
	// If the FSM was stopped, then clear PM data from KV store
	// The FSM is stopped when ONU goes down. It is time to clear its data from store
	if e.Event == L2PmEventStop {
		_ = mm.clearPmGroupData(ctx) // ignore error
	}

	if mm.GetdeviceDeletionInProgress() {
		mm.pDeviceHandler = nil
		mm.pOnuDeviceEntry = nil
		mm.GarbageCollectionComplete <- true
	}
}
func (mm *OnuMetricsManager) l2PMFsmIdle(ctx context.Context, e *fsm.Event) {
	logger.Debugw(ctx, "Enter state idle", log.Fields{"device-id": mm.deviceID})
	if mm.GetdeviceDeletionInProgress() {
		logger.Infow(ctx, "device already deleted, return", log.Fields{"curr-state": mm.PAdaptFsm.PFsm.Current, "deviceID": mm.deviceID})
		return
	}

	mm.OnuMetricsManagerLock.RLock()
	numOfPmToDelete := len(mm.l2PmToDelete)
	numOfPmToAdd := len(mm.l2PmToAdd)
	mm.OnuMetricsManagerLock.RUnlock()

	if numOfPmToDelete > 0 {
		logger.Debugw(ctx, "state idle - pms to delete", log.Fields{"device-id": mm.deviceID, "pms-to-delete": numOfPmToDelete})
		go func() {
			if err := mm.PAdaptFsm.PFsm.Event(L2PmEventDeleteMe); err != nil {
				logger.Errorw(ctx, "error calling event", log.Fields{"device-id": mm.deviceID, "err": err})
			}
		}()
	} else if numOfPmToAdd > 0 {
		logger.Debugw(ctx, "state idle - pms to add", log.Fields{"device-id": mm.deviceID, "pms-to-add": numOfPmToAdd})
		go func() {
			if err := mm.PAdaptFsm.PFsm.Event(L2PmEventAddMe); err != nil {
				logger.Errorw(ctx, "error calling event", log.Fields{"device-id": mm.deviceID, "err": err})
			}
		}()
	}
}

func (mm *OnuMetricsManager) l2PmFsmCollectData(ctx context.Context, e *fsm.Event) {
	logger.Debugw(ctx, "state collect data", log.Fields{"device-id": mm.deviceID})
	if mm.GetdeviceDeletionInProgress() {
		logger.Infow(ctx, "device already deleted, return", log.Fields{"curr-state": mm.PAdaptFsm.PFsm.Current, "deviceID": mm.deviceID})
		return
	}
	// Copy the activeL2Pms for which we want to collect the metrics since activeL2Pms can change dynamically
	mm.OnuMetricsManagerLock.RLock()
	copyOfActiveL2Pms := make([]string, len(mm.activeL2Pms))
	_ = copy(copyOfActiveL2Pms, mm.activeL2Pms)
	mm.OnuMetricsManagerLock.RUnlock()

	for _, n := range copyOfActiveL2Pms {
		var metricInfoSlice []*voltha.MetricInformation

		// mm.GroupMetricMap[n].pmMEData.InstancesActive could dynamically change, so make a copy
		mm.OnuMetricsManagerLock.RLock()
		copyOfEntityIDs := make([]uint16, len(mm.GroupMetricMap[n].pmMEData.InstancesActive))
		_ = copy(copyOfEntityIDs, mm.GroupMetricMap[n].pmMEData.InstancesActive)
		mm.OnuMetricsManagerLock.RUnlock()

		switch n {
		case EthernetBridgeHistoryName:
			logger.Debugw(ctx, "state collect data - collecting data for EthernetFramePerformanceMonitoringHistoryData ME", log.Fields{"device-id": mm.deviceID})
			for _, entityID := range copyOfEntityIDs {
				if metricInfo := mm.collectEthernetFramePerformanceMonitoringHistoryData(ctx, true, entityID); metricInfo != nil { // upstream
					metricInfoSlice = append(metricInfoSlice, metricInfo)
				}
				if metricInfo := mm.collectEthernetFramePerformanceMonitoringHistoryData(ctx, false, entityID); metricInfo != nil { // downstream
					metricInfoSlice = append(metricInfoSlice, metricInfo)
				}
			}
		case EthernetUniHistoryName:
			logger.Debugw(ctx, "state collect data - collecting data for EthernetPerformanceMonitoringHistoryData ME", log.Fields{"device-id": mm.deviceID})
			for _, entityID := range copyOfEntityIDs {
				if metricInfo := mm.collectEthernetUniHistoryData(ctx, entityID); metricInfo != nil { // upstream
					metricInfoSlice = append(metricInfoSlice, metricInfo)
				}
			}

		case FecHistoryName:
			for _, entityID := range copyOfEntityIDs {
				if metricInfo := mm.collectFecHistoryData(ctx, entityID); metricInfo != nil { // upstream
					metricInfoSlice = append(metricInfoSlice, metricInfo)
				}
			}
		case GemPortHistoryName:
			for _, entityID := range copyOfEntityIDs {
				if metricInfo := mm.collectGemHistoryData(ctx, entityID); metricInfo != nil { // upstream
					metricInfoSlice = append(metricInfoSlice, metricInfo)
				}
			}

		default:
			logger.Errorw(ctx, "unsupported l2 pm", log.Fields{"device-id": mm.deviceID, "name": n})
		}
		mm.handleMetricsPublish(ctx, n, metricInfoSlice)
	}
	// Does not matter we send success or failure here.
	// Those PMs that we failed to collect data will be attempted to collect again in the next PM collection cycle (assuming
	// we have not exceed max attempts to collect the PM data)
	go func() {
		if err := mm.PAdaptFsm.PFsm.Event(L2PmEventSuccess); err != nil {
			logger.Errorw(ctx, "error calling event", log.Fields{"device-id": mm.deviceID, "err": err})
		}
	}()
}

// nolint: gocyclo
func (mm *OnuMetricsManager) l2PmFsmCreatePM(ctx context.Context, e *fsm.Event) error {
	if mm.GetdeviceDeletionInProgress() {
		logger.Infow(ctx, "device already deleted, return", log.Fields{"curr-state": mm.PAdaptFsm.PFsm.Current, "deviceID": mm.deviceID})
		return nil
	}
	// Copy the l2PmToAdd for which we want to collect the metrics since l2PmToAdd can change dynamically
	mm.OnuMetricsManagerLock.RLock()
	copyOfL2PmToAdd := make([]string, len(mm.l2PmToAdd))
	_ = copy(copyOfL2PmToAdd, mm.l2PmToAdd)
	mm.OnuMetricsManagerLock.RUnlock()

	logger.Debugw(ctx, "state create pm - start", log.Fields{"device-id": mm.deviceID, "pms-to-add": copyOfL2PmToAdd})
	for _, n := range copyOfL2PmToAdd {
		resp := false
		atLeastOneSuccess := false // flag indicates if at least one ME instance of the PM was successfully created.
		cnt := 0
		switch n {
		case EthernetBridgeHistoryName:
			// Create ME twice, one for each direction. Boolean true is used to indicate upstream and false for downstream.
			for _, direction := range []bool{true, false} {
				for _, uniPort := range *mm.pDeviceHandler.GetUniEntityMap() {
					// Attach the EthernetFramePerformanceMonitoringHistoryData ME to MacBridgePortConfigData on the UNI port
					entityID := cmn.MacBridgePortAniBaseEID + uniPort.EntityID
					_ = mm.updatePmData(ctx, n, entityID, cPmAdd) // TODO: ignore error for now
				inner1:
					// retry L2PmCreateAttempts times to create the instance of PM
					for cnt = 0; cnt < L2PmCreateAttempts; cnt++ {
						_, err := mm.pOnuDeviceEntry.GetDevOmciCC().SendCreateOrDeleteEthernetPerformanceMonitoringHistoryME(
							ctx, mm.pDeviceHandler.GetOmciTimeout(), true, direction, true, mm.PAdaptFsm.CommChan, entityID)
						if err != nil {
							logger.Errorw(ctx, "EthernetPerformanceMonitoringHistoryME create or delete failed, failure PM FSM!",
								log.Fields{"device-id": mm.deviceID})
							pPMFsm := mm.PAdaptFsm
							if pPMFsm != nil {
								go func(p_pmFsm *cmn.AdapterFsm) {
									_ = p_pmFsm.PFsm.Event(L2PmEventFailure)
								}(pPMFsm)
							}
							return fmt.Errorf(fmt.Sprintf("CreateOrDeleteEthernetPerformanceMonitoringHistoryMe-failed-%s-%s",
								mm.deviceID, err))
						}
						if resp = mm.waitForResponseOrTimeout(ctx, true, entityID, "EthernetFramePerformanceMonitoringHistoryData"); resp {
							atLeastOneSuccess = true
							_ = mm.updatePmData(ctx, n, entityID, cPmAdded) // TODO: ignore error for now
							break inner1
						}
						if mm.GetdeviceDeletionInProgress() {
							logger.Debugw(ctx, "device deleted, no more pm processing", log.Fields{"deviceID": mm.deviceID})
							return nil
						}
					}
					if cnt == L2PmCreateAttempts { // if we reached max attempts just give up hope on this given instance of the PM ME
						_ = mm.updatePmData(ctx, n, entityID, cPmRemoved) // TODO: ignore error for now
					}
				}
			}
		case EthernetUniHistoryName:
			for _, uniPort := range *mm.pDeviceHandler.GetUniEntityMap() {
				if uniPort.PortType == cmn.UniPPTP { // This metric is only applicable for PPTP Uni Type
					// Attach the EthernetPerformanceMonitoringHistoryData ME to PPTP port instance
					entityID := uniPort.EntityID
					_ = mm.updatePmData(ctx, n, entityID, cPmAdd) // TODO: ignore error for now
				inner2:
					// retry L2PmCreateAttempts times to create the instance of PM
					for cnt = 0; cnt < L2PmCreateAttempts; cnt++ {
						_, err := mm.pOnuDeviceEntry.GetDevOmciCC().SendCreateOrDeleteEthernetUniHistoryME(
							ctx, mm.pDeviceHandler.GetOmciTimeout(), true, true, mm.PAdaptFsm.CommChan, entityID)
						if err != nil {
							logger.Errorw(ctx, "CreateOrDeleteEthernetUNIHistoryME failed, failure PM FSM!",
								log.Fields{"device-id": mm.deviceID})
							_ = mm.PAdaptFsm.PFsm.Event(L2PmEventFailure)
							return fmt.Errorf(fmt.Sprintf("CreateOrDeleteEthernetUniHistoryMe-failed-%s-%s",
								mm.deviceID, err))
						}
						if resp = mm.waitForResponseOrTimeout(ctx, true, entityID, "EthernetPerformanceMonitoringHistoryData"); resp {
							atLeastOneSuccess = true
							_ = mm.updatePmData(ctx, n, entityID, cPmAdded) // TODO: ignore error for now
							break inner2
						}
						if mm.GetdeviceDeletionInProgress() {
							logger.Debugw(ctx, "device deleted, no more pm processing", log.Fields{"deviceID": mm.deviceID})
							return nil
						}
					}
					if cnt == L2PmCreateAttempts { // if we reached max attempts just give up hope on this given instance of the PM ME
						_ = mm.updatePmData(ctx, n, entityID, cPmRemoved) // TODO: ignore error for now
					}
				}
			}
		case FecHistoryName:
			for _, anigInstID := range mm.pOnuDeviceEntry.GetOnuDB().GetSortedInstKeys(ctx, me.AniGClassID) {
				// Attach the FecPerformanceMonitoringHistoryData ME to the ANI-G ME instance
				_, err := mm.pOnuDeviceEntry.GetDevOmciCC().SendCreateOrDeleteFecHistoryME(
					ctx, mm.pDeviceHandler.GetOmciTimeout(), true, true, mm.PAdaptFsm.CommChan, anigInstID)
				if err != nil {
					logger.Errorw(ctx, "CreateOrDeleteFecHistoryME failed, failure PM FSM!",
						log.Fields{"device-id": mm.deviceID})
					_ = mm.PAdaptFsm.PFsm.Event(L2PmEventFailure)
					return fmt.Errorf(fmt.Sprintf("CreateOrDeleteFecHistoryMe-failed-%s-%s",
						mm.deviceID, err))
				}
				_ = mm.updatePmData(ctx, n, anigInstID, cPmAdd) // TODO: ignore error for now
			inner3:
				// retry L2PmCreateAttempts times to create the instance of PM
				for cnt = 0; cnt < L2PmCreateAttempts; cnt++ {
					if resp = mm.waitForResponseOrTimeout(ctx, true, anigInstID, "FecPerformanceMonitoringHistoryData"); resp {
						atLeastOneSuccess = true
						_ = mm.updatePmData(ctx, n, anigInstID, cPmAdded) // TODO: ignore error for now
						break inner3
					}
					if mm.GetdeviceDeletionInProgress() {
						logger.Debugw(ctx, "device deleted, no more pm processing", log.Fields{"deviceID": mm.deviceID})
						return nil
					}
				}
				if cnt == L2PmCreateAttempts { // if we reached max attempts just give up hope on this given instance of the PM ME
					_ = mm.updatePmData(ctx, n, anigInstID, cPmRemoved) // TODO: ignore error for now
				}
			}
		case GemPortHistoryName:

			mm.OnuMetricsManagerLock.RLock()
			copyOfGemPortInstIDsToAdd := make([]uint16, len(mm.GroupMetricMap[GemPortHistoryName].pmMEData.InstancesToAdd))
			_ = copy(copyOfGemPortInstIDsToAdd, mm.GroupMetricMap[GemPortHistoryName].pmMEData.InstancesToAdd)
			mm.OnuMetricsManagerLock.RUnlock()

			if len(copyOfGemPortInstIDsToAdd) == 0 {
				// If there are no gemport history MEs to be created, just skip further processing
				// Otherwise down below (after 'switch' case handling) we assume the ME creation failed because resp and atLeastOneSuccess flag are false.
				// Normally there are no GemPortHistory MEs to create at start up. They come in only after provisioning service on the ONU.
				mm.OnuMetricsManagerLock.Lock()
				mm.l2PmToAdd = mm.removeIfFoundString(mm.l2PmToAdd, n)
				mm.OnuMetricsManagerLock.Unlock()
				continue
			}

			for _, v := range copyOfGemPortInstIDsToAdd {
				_, err := mm.pOnuDeviceEntry.GetDevOmciCC().SendCreateOrDeleteGemPortHistoryME(
					ctx, mm.pDeviceHandler.GetOmciTimeout(), true, true, mm.PAdaptFsm.CommChan, v)
				if err != nil {
					logger.Errorw(ctx, "CreateOrDeleteGemPortHistoryME failed, failure PM FSM!",
						log.Fields{"device-id": mm.deviceID})
					_ = mm.PAdaptFsm.PFsm.Event(L2PmEventFailure)
					return fmt.Errorf(fmt.Sprintf("CreateOrDeleteGemPortHistoryMe-failed-%s-%s",
						mm.deviceID, err))
				}
				_ = mm.updatePmData(ctx, n, v, cPmAdd) // TODO: ignore error for now
			inner4:
				// retry L2PmCreateAttempts times to create the instance of PM
				for cnt = 0; cnt < L2PmCreateAttempts; cnt++ {
					if resp = mm.waitForResponseOrTimeout(ctx, true, v, "GemPortNetworkCtpPerformanceMonitoringHistoryData"); resp {
						atLeastOneSuccess = true
						_ = mm.updatePmData(ctx, n, v, cPmAdded) // TODO: ignore error for now
						break inner4
					}
					if mm.GetdeviceDeletionInProgress() {
						logger.Debugw(ctx, "device deleted, no more pm processing", log.Fields{"deviceID": mm.deviceID})
						return nil
					}
				}
				if cnt == L2PmCreateAttempts { // if we reached max attempts just give up hope on this given instance of the PM ME
					_ = mm.updatePmData(ctx, n, v, cPmRemoved) // TODO: ignore error for now
				}
			}

		default:
			logger.Errorw(ctx, "unsupported l2 pm", log.Fields{"device-id": mm.deviceID, "name": n})
		}
		// On success of at least one instance of the PM for a given ME, update the local list maintained for active PMs and PMs to add
		if atLeastOneSuccess {
			mm.OnuMetricsManagerLock.Lock()
			mm.activeL2Pms = mm.appendIfMissingString(mm.activeL2Pms, n)
			// gem ports can be added dynamically for perf monitoring. We want to clear the GemPortHistoryName from mm.l2PmToAdd
			// only if no more new gem port instances created.
			if n != GemPortHistoryName || (n == GemPortHistoryName && len(mm.GroupMetricMap[GemPortHistoryName].pmMEData.InstancesToAdd) == 0) {
				mm.l2PmToAdd = mm.removeIfFoundString(mm.l2PmToAdd, n)
			}
			logger.Debugw(ctx, "success-resp", log.Fields{"pm-name": n, "active-l2-pms": mm.activeL2Pms, "pms-to-add": mm.l2PmToAdd})
			mm.OnuMetricsManagerLock.Unlock()
		} else {
			// If we are here then no instance of the PM of the given ME were created successfully, so locally disable the PM
			// and also remove it from l2PmToAdd slice so that we do not try to create the PM ME anymore
			mm.OnuMetricsManagerLock.Lock()
			logger.Debugw(ctx, "exceeded-max-add-retry-attempts--disabling-group", log.Fields{"groupName": n})
			mm.GroupMetricMap[n].Enabled = false
			mm.l2PmToAdd = mm.removeIfFoundString(mm.l2PmToAdd, n)

			logger.Warnw(ctx, "state create pm - failed to create pm",
				log.Fields{"device-id": mm.deviceID, "metricName": n,
					"active-l2-pms": mm.activeL2Pms, "pms-to-add": mm.l2PmToAdd})
			mm.OnuMetricsManagerLock.Unlock()
		}
	}
	mm.OnuMetricsManagerLock.RLock()
	logger.Debugw(ctx, "state create pm - done", log.Fields{"device-id": mm.deviceID, "active-l2-pms": mm.activeL2Pms, "pms-to-add": mm.l2PmToAdd})
	mm.OnuMetricsManagerLock.RUnlock()
	// Does not matter we send success or failure here.
	// Those PMs that we failed to create will be attempted to create again in the next PM creation cycle (assuming
	// we have not exceed max attempts to create the PM ME)
	go func() {
		if err := mm.PAdaptFsm.PFsm.Event(L2PmEventSuccess); err != nil {
			logger.Errorw(ctx, "error calling event", log.Fields{"device-id": mm.deviceID, "err": err})
		}
	}()
	return nil
}

// nolint: gocyclo
func (mm *OnuMetricsManager) l2PmFsmDeletePM(ctx context.Context, e *fsm.Event) error {
	if mm.GetdeviceDeletionInProgress() {
		logger.Infow(ctx, "device already deleted, return", log.Fields{"curr-state": mm.PAdaptFsm.PFsm.Current, "deviceID": mm.deviceID})
		return nil
	}
	// Copy the l2PmToDelete for which we want to collect the metrics since l2PmToDelete can change dynamically
	mm.OnuMetricsManagerLock.RLock()
	copyOfL2PmToDelete := make([]string, len(mm.l2PmToDelete))
	_ = copy(copyOfL2PmToDelete, mm.l2PmToDelete)
	mm.OnuMetricsManagerLock.RUnlock()

	logger.Debugw(ctx, "state delete pm", log.Fields{"device-id": mm.deviceID, "pms-to-delete": copyOfL2PmToDelete})
	for _, n := range copyOfL2PmToDelete {
		resp := false
		cnt := 0
		atLeastOneDeleteFailure := false

		// mm.GroupMetricMap[n].pmMEData.InstancesActive could dynamically change, so make a copy
		mm.OnuMetricsManagerLock.RLock()
		copyOfEntityIDs := make([]uint16, len(mm.GroupMetricMap[n].pmMEData.InstancesActive))
		_ = copy(copyOfEntityIDs, mm.GroupMetricMap[n].pmMEData.InstancesActive)
		mm.OnuMetricsManagerLock.RUnlock()

		if len(copyOfEntityIDs) == 0 {
			// if there are no enityIDs to remove for the PM ME just clear the PM name entry from cache and continue
			mm.OnuMetricsManagerLock.Lock()
			mm.activeL2Pms = mm.removeIfFoundString(mm.activeL2Pms, n)
			mm.l2PmToDelete = mm.removeIfFoundString(mm.l2PmToDelete, n)
			logger.Debugw(ctx, "success-resp", log.Fields{"pm-name": n, "active-l2-pms": mm.activeL2Pms, "pms-to-delete": mm.l2PmToDelete})
			mm.OnuMetricsManagerLock.Unlock()
			continue
		}
		logger.Debugw(ctx, "entities to delete", log.Fields{"device-id": mm.deviceID, "metricName": n, "entityIDs": copyOfEntityIDs})
		switch n {
		case EthernetBridgeHistoryName:
			// Create ME twice, one for each direction. Boolean true is used to indicate upstream and false for downstream.
			for _, direction := range []bool{true, false} {
				for _, entityID := range copyOfEntityIDs {
				inner1:
					// retry L2PmDeleteAttempts times to delete the instance of PM
					for cnt = 0; cnt < L2PmDeleteAttempts; cnt++ {
						_, err := mm.pOnuDeviceEntry.GetDevOmciCC().SendCreateOrDeleteEthernetPerformanceMonitoringHistoryME(
							ctx, mm.pDeviceHandler.GetOmciTimeout(), true, direction, false, mm.PAdaptFsm.CommChan, entityID)
						if err != nil {
							logger.Errorw(ctx, "CreateOrDeleteEthernetPerformanceMonitoringHistoryME failed, failure PM FSM!",
								log.Fields{"device-id": mm.deviceID})
							pPMFsm := mm.PAdaptFsm
							if pPMFsm != nil {
								go func(p_pmFsm *cmn.AdapterFsm) {
									_ = mm.PAdaptFsm.PFsm.Event(L2PmEventFailure)
								}(pPMFsm)
							}
							return fmt.Errorf(fmt.Sprintf("CreateOrDeleteEthernetPerformanceMonitoringHistoryMe-failed-%s-%s",
								mm.deviceID, err))
						}
						_ = mm.updatePmData(ctx, n, entityID, cPmRemove) // TODO: ignore error for now
						if resp = mm.waitForResponseOrTimeout(ctx, false, entityID, "EthernetFramePerformanceMonitoringHistoryData"); !resp {
							if mm.GetdeviceDeletionInProgress() {
								logger.Debugw(ctx, "device deleted, no more pm processing", log.Fields{"deviceID": mm.deviceID})
								return nil
							}
							atLeastOneDeleteFailure = true
						} else {
							_ = mm.updatePmData(ctx, n, entityID, cPmRemoved) // TODO: ignore error for now
							break inner1
						}
					}
					if cnt == L2PmDeleteAttempts { // if we reached max attempts just give up hope on this given instance of the PM ME
						_ = mm.updatePmData(ctx, n, entityID, cPmRemoved) // TODO: ignore error for now
					}
				}
			}
		case EthernetUniHistoryName:
			for _, entityID := range copyOfEntityIDs {
			inner2:
				// retry L2PmDeleteAttempts times to delete the instance of PM
				for cnt = 0; cnt < L2PmDeleteAttempts; cnt++ {
					_, err := mm.pOnuDeviceEntry.GetDevOmciCC().SendCreateOrDeleteEthernetUniHistoryME(
						ctx, mm.pDeviceHandler.GetOmciTimeout(), true, false, mm.PAdaptFsm.CommChan, entityID)
					if err != nil {
						logger.Errorw(ctx, "CreateOrDeleteEthernetUniHistoryME failed, failure PM FSM!",
							log.Fields{"device-id": mm.deviceID})
						pmFsm := mm.PAdaptFsm
						if pmFsm != nil {
							go func(p_pmFsm *cmn.AdapterFsm) {
								_ = p_pmFsm.PFsm.Event(L2PmEventFailure)
							}(pmFsm)
							return err
						}
						return fmt.Errorf(fmt.Sprintf("CreateOrDeleteEthernetUniHistoryMe-failed-%s-%s",
							mm.deviceID, err))
					}
					if resp = mm.waitForResponseOrTimeout(ctx, false, entityID, "EthernetPerformanceMonitoringHistoryData"); !resp {
						if mm.GetdeviceDeletionInProgress() {
							logger.Debugw(ctx, "device deleted, no more pm processing", log.Fields{"deviceID": mm.deviceID})
							return nil
						}
						atLeastOneDeleteFailure = true
					} else {
						_ = mm.updatePmData(ctx, n, entityID, cPmRemoved) // TODO: ignore error for now
						break inner2
					}
				}
				if cnt == L2PmDeleteAttempts { // if we reached max attempts just give up hope on this given instance of the PM ME
					_ = mm.updatePmData(ctx, n, entityID, cPmRemoved) // TODO: ignore error for now
				}
			}
		case FecHistoryName:
			for _, entityID := range copyOfEntityIDs {
			inner3:
				// retry L2PmDeleteAttempts times to delete the instance of PM
				for cnt = 0; cnt < L2PmDeleteAttempts; cnt++ {
					_, err := mm.pOnuDeviceEntry.GetDevOmciCC().SendCreateOrDeleteFecHistoryME(
						ctx, mm.pDeviceHandler.GetOmciTimeout(), true, false, mm.PAdaptFsm.CommChan, entityID)
					if err != nil {
						logger.Errorw(ctx, "CreateOrDeleteFecHistoryME failed, failure PM FSM!",
							log.Fields{"device-id": mm.deviceID})
						_ = mm.PAdaptFsm.PFsm.Event(L2PmEventFailure)
						return fmt.Errorf(fmt.Sprintf("CreateOrDeleteFecHistoryMe-failed-%s-%s",
							mm.deviceID, err))
					}
					if resp := mm.waitForResponseOrTimeout(ctx, false, entityID, "FecPerformanceMonitoringHistoryData"); !resp {
						if mm.GetdeviceDeletionInProgress() {
							logger.Debugw(ctx, "device deleted, no more pm processing", log.Fields{"deviceID": mm.deviceID})
							return nil
						}
						atLeastOneDeleteFailure = true
					} else {
						_ = mm.updatePmData(ctx, n, entityID, cPmRemoved) // TODO: ignore error for now
						break inner3
					}
				}
				if cnt == L2PmDeleteAttempts { // if we reached max attempts just give up hope on this given instance of the PM ME
					_ = mm.updatePmData(ctx, n, entityID, cPmRemoved) // TODO: ignore error for now
				}
			}
		case GemPortHistoryName:
			for _, entityID := range copyOfEntityIDs {
			inner4:
				// retry L2PmDeleteAttempts times to delete the instance of PM
				for cnt = 0; cnt < L2PmDeleteAttempts; cnt++ {
					_, err := mm.pOnuDeviceEntry.GetDevOmciCC().SendCreateOrDeleteGemPortHistoryME(
						ctx, mm.pDeviceHandler.GetOmciTimeout(), true, false, mm.PAdaptFsm.CommChan, entityID)
					if err != nil {
						logger.Errorw(ctx, "CreateOrDeleteGemPortHistoryME failed, failure PM FSM!",
							log.Fields{"device-id": mm.deviceID})
						_ = mm.PAdaptFsm.PFsm.Event(L2PmEventFailure)
						return fmt.Errorf(fmt.Sprintf("CreateOrDeleteGemPortHistoryMe-failed-%s-%s",
							mm.deviceID, err))
					}
					if resp = mm.waitForResponseOrTimeout(ctx, false, entityID, "GemPortNetworkCtpPerformanceMonitoringHistoryData"); !resp {
						if mm.GetdeviceDeletionInProgress() {
							logger.Debugw(ctx, "device deleted, no more pm processing", log.Fields{"deviceID": mm.deviceID})
							return nil
						}
						atLeastOneDeleteFailure = true
					} else {
						_ = mm.updatePmData(ctx, n, entityID, cPmRemoved) // TODO: ignore error for now
						break inner4
					}
				}
				if cnt == L2PmDeleteAttempts { // if we reached max attempts just give up hope on this given instance of the PM ME
					_ = mm.updatePmData(ctx, n, entityID, cPmRemoved) // TODO: ignore error for now
				}
			}
		default:
			logger.Errorw(ctx, "unsupported l2 pm", log.Fields{"device-id": mm.deviceID, "name": n})
		}
		// If we could not completely clean up the PM ME then just give up.
		if atLeastOneDeleteFailure {
			logger.Warnw(ctx, "state delete pm - failed to delete at least one instance of the PM ME",
				log.Fields{"device-id": mm.deviceID, "metricName": n,
					"active-l2-pms": mm.activeL2Pms, "pms-to-delete": mm.l2PmToDelete})
			mm.OnuMetricsManagerLock.Lock()
			logger.Debugw(ctx, "exceeded-max-delete-retry-attempts--disabling-group", log.Fields{"groupName": n})
			mm.activeL2Pms = mm.removeIfFoundString(mm.activeL2Pms, n)
			mm.l2PmToDelete = mm.removeIfFoundString(mm.l2PmToDelete, n)
			mm.GroupMetricMap[n].Enabled = false
			mm.OnuMetricsManagerLock.Unlock()
		} else { // success case
			mm.OnuMetricsManagerLock.Lock()
			mm.activeL2Pms = mm.removeIfFoundString(mm.activeL2Pms, n)
			// gem ports can be deleted dynamically from perf monitoring. We want to clear the GemPortHistoryName from mm.l2PmToDelete
			// only if no more new gem port instances removed.
			if n != GemPortHistoryName || (n == GemPortHistoryName && len(mm.GroupMetricMap[GemPortHistoryName].pmMEData.InstancesToDelete) == 0) {
				mm.l2PmToDelete = mm.removeIfFoundString(mm.l2PmToDelete, n)
			}
			logger.Debugw(ctx, "success-resp", log.Fields{"pm-name": n, "active-l2-pms": mm.activeL2Pms, "pms-to-delete": mm.l2PmToDelete})
			mm.OnuMetricsManagerLock.Unlock()
		}
	}
	mm.OnuMetricsManagerLock.RLock()
	logger.Debugw(ctx, "state delete pm - done", log.Fields{"device-id": mm.deviceID, "active-l2-pms": mm.activeL2Pms, "pms-to-delete": mm.l2PmToDelete})
	mm.OnuMetricsManagerLock.RUnlock()
	// Does not matter we send success or failure here.
	// Those PMs that we failed to delete will be attempted to create again in the next PM collection cycle
	go func() {
		if err := mm.PAdaptFsm.PFsm.Event(L2PmEventSuccess); err != nil {
			logger.Errorw(ctx, "error calling event", log.Fields{"device-id": mm.deviceID, "err": err})
		}
	}()
	return nil
}

// ** L2 PM FSM Handlers end **

// syncTime synchronizes time with the ONU to establish a 15 min boundary for PM collection and reporting.
func (mm *OnuMetricsManager) syncTime(ctx context.Context) error {
	if mm.GetdeviceDeletionInProgress() {
		logger.Infow(ctx, "device already deleted, return", log.Fields{"curr-state": mm.PAdaptFsm.PFsm.Current, "deviceID": mm.deviceID})
		return nil
	}

	if !mm.GetOmciProcessingStatus() {
		logger.Errorw(ctx, "not sending sync time, because the omci resp processor is shutdown due to device down/delete", log.Fields{"device-id": mm.deviceID})
		return fmt.Errorf("omci-resp-processor-not-running")
	}

	if err := mm.pOnuDeviceEntry.GetDevOmciCC().SendSyncTime(ctx, mm.pDeviceHandler.GetOmciTimeout(), true, mm.PAdaptFsm.CommChan); err != nil {
		logger.Errorw(ctx, "cannot send sync time request", log.Fields{"device-id": mm.deviceID})
		return err
	}

	select {
	case <-time.After(mm.pOnuDeviceEntry.GetDevOmciCC().GetMaxOmciTimeoutWithRetries() * time.Second):
		logger.Errorw(ctx, "timed out waiting for sync time response from onu", log.Fields{"device-id": mm.deviceID})
		return fmt.Errorf("timed-out-waiting-for-sync-time-response-%v", mm.deviceID)
	case syncTimeRes := <-mm.syncTimeResponseChan:
		if !syncTimeRes {
			return fmt.Errorf("failed-to-sync-time-%v", mm.deviceID)
		}
		logger.Infow(ctx, "sync time success", log.Fields{"device-id": mm.deviceID})
		return nil
	}
}

func (mm *OnuMetricsManager) collectEthernetFramePerformanceMonitoringHistoryData(ctx context.Context, upstream bool, entityID uint16) *voltha.MetricInformation {
	var mEnt *me.ManagedEntity</