/*
Copyright 2018 The Kubernetes Authors All rights reserved.

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 store

import (
	"context"
	"reflect"
	"sort"
	"strconv"
	"strings"

	"github.com/pkg/errors"
	"github.com/prometheus/client_golang/prometheus"
	admissionregistrationv1 "k8s.io/api/admissionregistration/v1"
	appsv1 "k8s.io/api/apps/v1"
	autoscaling "k8s.io/api/autoscaling/v2beta2"
	batchv1 "k8s.io/api/batch/v1"
	certv1 "k8s.io/api/certificates/v1"
	coordinationv1 "k8s.io/api/coordination/v1"
	v1 "k8s.io/api/core/v1"
	networkingv1 "k8s.io/api/networking/v1"
	policyv1 "k8s.io/api/policy/v1"
	storagev1 "k8s.io/api/storage/v1"
	vpaautoscaling "k8s.io/autoscaler/vertical-pod-autoscaler/pkg/apis/autoscaling.k8s.io/v1beta2"
	vpaclientset "k8s.io/autoscaler/vertical-pod-autoscaler/pkg/client/clientset/versioned"
	clientset "k8s.io/client-go/kubernetes"
	"k8s.io/client-go/tools/cache"
	"k8s.io/klog/v2"

	ksmtypes "k8s.io/kube-state-metrics/v2/pkg/builder/types"
	"k8s.io/kube-state-metrics/v2/pkg/customresource"
	generator "k8s.io/kube-state-metrics/v2/pkg/metric_generator"
	metricsstore "k8s.io/kube-state-metrics/v2/pkg/metrics_store"
	"k8s.io/kube-state-metrics/v2/pkg/options"
	"k8s.io/kube-state-metrics/v2/pkg/sharding"
	"k8s.io/kube-state-metrics/v2/pkg/watch"
)

// Make sure the internal Builder implements the public BuilderInterface.
// New Builder methods should be added to the public BuilderInterface.
var _ ksmtypes.BuilderInterface = &Builder{}

// Builder helps to build store. It follows the builder pattern
// (https://en.wikipedia.org/wiki/Builder_pattern).
type Builder struct {
	kubeClient                    clientset.Interface
	customResourceClients         map[string]interface{}
	vpaClient                     vpaclientset.Interface
	namespaces                    options.NamespaceList
	namespaceFilter               string
	ctx                           context.Context
	enabledResources              []string
	familyGeneratorFilter         generator.FamilyGeneratorFilter
	listWatchMetrics              *watch.ListWatchMetrics
	shardingMetrics               *sharding.Metrics
	shard                         int32
	totalShards                   int
	buildStoresFunc               ksmtypes.BuildStoresFunc
	buildCustomResourceStoresFunc ksmtypes.BuildCustomResourceStoresFunc
	allowAnnotationsList          map[string][]string
	allowLabelsList               map[string][]string
	useAPIServerCache             bool
}

// NewBuilder returns a new builder.
func NewBuilder() *Builder {
	b := &Builder{}
	return b
}

// WithMetrics sets the metrics property of a Builder.
func (b *Builder) WithMetrics(r prometheus.Registerer) {
	b.listWatchMetrics = watch.NewListWatchMetrics(r)
	b.shardingMetrics = sharding.NewShardingMetrics(r)
}

// WithEnabledResources sets the enabledResources property of a Builder.
func (b *Builder) WithEnabledResources(r []string) error {
	for _, col := range r {
		if !resourceExists(col) {
			return errors.Errorf("resource %s does not exist. Available resources: %s", col, strings.Join(availableResources(), ","))
		}
	}

	var copy []string
	copy = append(copy, r...)

	sort.Strings(copy)

	b.enabledResources = copy
	return nil
}

// WithNamespaces sets the namespaces property of a Builder.
func (b *Builder) WithNamespaces(n options.NamespaceList, nsFilter string) {
	b.namespaces = n
	b.namespaceFilter = nsFilter
}

// WithSharding sets the shard and totalShards property of a Builder.
func (b *Builder) WithSharding(shard int32, totalShards int) {
	b.shard = shard
	labels := map[string]string{sharding.LabelOrdinal: strconv.Itoa(int(shard))}
	b.shardingMetrics.Ordinal.Reset()
	b.shardingMetrics.Ordinal.With(labels).Set(float64(shard))
	b.totalShards = totalShards
	b.shardingMetrics.Total.Set(float64(totalShards))
}

// WithContext sets the ctx property of a Builder.
func (b *Builder) WithContext(ctx context.Context) {
	b.ctx = ctx
}

// WithKubeClient sets the kubeClient property of a Builder.
func (b *Builder) WithKubeClient(c clientset.Interface) {
	b.kubeClient = c
}

// WithVPAClient sets the vpaClient property of a Builder so that the verticalpodautoscaler collector can query VPA objects.
func (b *Builder) WithVPAClient(c vpaclientset.Interface) {
	b.vpaClient = c
}

// WithCustomResourceClients sets the customResourceClients property of a Builder.
func (b *Builder) WithCustomResourceClients(cs map[string]interface{}) {
	b.customResourceClients = cs
}

// WithUsingAPIServerCache configures whether using APIServer cache or not.
func (b *Builder) WithUsingAPIServerCache(u bool) {
	b.useAPIServerCache = u
}

// WithFamilyGeneratorFilter configures the family generator filter which decides which
// metrics are to be exposed by the store build by the Builder.
func (b *Builder) WithFamilyGeneratorFilter(l generator.FamilyGeneratorFilter) {
	b.familyGeneratorFilter = l
}

// WithGenerateStoresFunc configures a custom generate store function
func (b *Builder) WithGenerateStoresFunc(f ksmtypes.BuildStoresFunc) {
	b.buildStoresFunc = f
}

// WithGenerateCustomResourceStoresFunc configures a custom generate custom resource store function
func (b *Builder) WithGenerateCustomResourceStoresFunc(f ksmtypes.BuildCustomResourceStoresFunc) {
	b.buildCustomResourceStoresFunc = f
}

// DefaultGenerateStoresFunc returns default buildStores function
func (b *Builder) DefaultGenerateStoresFunc() ksmtypes.BuildStoresFunc {
	return b.buildStores
}

// DefaultGenerateCustomResourceStoresFunc returns default buildCustomResourceStores function
func (b *Builder) DefaultGenerateCustomResourceStoresFunc() ksmtypes.BuildCustomResourceStoresFunc {
	return b.buildCustomResourceStores
}

// WithCustomResourceStoreFactories returns configures a custom resource stores factory
func (b *Builder) WithCustomResourceStoreFactories(fs ...customresource.RegistryFactory) {
	for i := range fs {
		f := fs[i]
		if _, ok := availableStores[f.Name()]; ok {
			klog.Warningf("The internal resource store named %s already exists and is overridden by a custom resource store with the same name, please make sure it meets your expectation", f.Name())
		}
		availableStores[f.Name()] = func(b *Builder) []cache.Store {
			return b.buildCustomResourceStoresFunc(
				f.Name(),
				f.MetricFamilyGenerators(b.allowAnnotationsList[f.Name()], b.allowLabelsList[f.Name()]),
				f.ExpectedType(),
				f.ListWatch,
				b.useAPIServerCache,
			)
		}
	}
}

// WithAllowAnnotations configures which annotations can be returned for metrics
func (b *Builder) WithAllowAnnotations(annotations map[string][]string) {
	if len(annotations) > 0 {
		b.allowAnnotationsList = annotations
	}
}

// WithAllowLabels configures which labels can be returned for metrics
func (b *Builder) WithAllowLabels(labels map[string][]string) {
	if len(labels) > 0 {
		b.allowLabelsList = labels
	}
}

// Build initializes and registers all enabled stores.
// It returns metrics writers which can be used to write out
// metrics from the stores.
func (b *Builder) Build() []metricsstore.MetricsWriter {
	if b.familyGeneratorFilter == nil {
		panic("familyGeneratorFilter should not be nil")
	}

	var metricsWriters []metricsstore.MetricsWriter
	var activeStoreNames []string

	for _, c := range b.enabledResources {
		constructor, ok := availableStores[c]
		if ok {
			stores := cacheStoresToMetricStores(constructor(b))
			activeStoreNames = append(activeStoreNames, c)
			if len(stores) == 1 {
				metricsWriters = append(metricsWriters, stores[0])
			} else {
				metricsWriters = append(metricsWriters, metricsstore.NewMultiStoreMetricsWriter(stores))
			}
		}
	}

	klog.Infof("Active resources: %s", strings.Join(activeStoreNames, ","))

	return metricsWriters
}

// BuildStores initializes and registers all enabled stores.
// It returns metric stores which can be used to consume
// the generated metrics from the stores.
func (b *Builder) BuildStores() [][]cache.Store {
	if b.familyGeneratorFilter == nil {
		panic("familyGeneratorFilter should not be nil")
	}

	var allStores [][]cache.Store
	var activeStoreNames []string

	for _, c := range b.enabledResources {
		constructor, ok := availableStores[c]
		if ok {
			stores := constructor(b)
			activeStoreNames = append(activeStoreNames, c)
			allStores = append(allStores, stores)
		}
	}

	klog.Infof("Active resources: %s", strings.Join(activeStoreNames, ","))

	return allStores
}

var availableStores = map[string]func(f *Builder) []cache.Store{
	"certificatesigningrequests":      func(b *Builder) []cache.Store { return b.buildCsrStores() },
	"configmaps":                      func(b *Builder) []cache.Store { return b.buildConfigMapStores() },
	"cronjobs":                        func(b *Builder) []cache.Store { return b.buildCronJobStores() },
	"daemonsets":                      func(b *Builder) []cache.Store { return b.buildDaemonSetStores() },
	"deployments":                     func(b *Builder) []cache.Store { return b.buildDeploymentStores() },
	"endpoints":                       func(b *Builder) []cache.Store { return b.buildEndpointsStores() },
	"horizontalpodautoscalers":        func(b *Builder) []cache.Store { return b.buildHPAStores() },
	"ingresses":                       func(b *Builder) []cache.Store { return b.buildIngressStores() },
	"jobs":                            func(b *Builder) []cache.Store { return b.buildJobStores() },
	"leases":                          func(b *Builder) []cache.Store { return b.buildLeasesStores() },
	"limitranges":                     func(b *Builder) []cache.Store { return b.buildLimitRangeStores() },
	"mutatingwebhookconfigurations":   func(b *Builder) []cache.Store { return b.buildMutatingWebhookConfigurationStores() },
	"namespaces":                      func(b *Builder) []cache.Store { return b.buildNamespaceStores() },
	"networkpolicies":                 func(b *Builder) []cache.Store { return b.buildNetworkPolicyStores() },
	"nodes":                           func(b *Builder) []cache.Store { return b.buildNodeStores() },
	"persistentvolumeclaims":          func(b *Builder) []cache.Store { return b.buildPersistentVolumeClaimStores() },
	"persistentvolumes":               func(b *Builder) []cache.Store { return b.buildPersistentVolumeStores() },
	"poddisruptionbudgets":            func(b *Builder) []cache.Store { return b.buildPodDisruptionBudgetStores() },
	"pods":                            func(b *Builder) []cache.Store { return b.buildPodStores() },
	"replicasets":                     func(b *Builder) []cache.Store { return b.buildReplicaSetStores() },
	"replicationcontrollers":          func(b *Builder) []cache.Store { return b.buildReplicationControllerStores() },
	"resourcequotas":                  func(b *Builder) []cache.Store { return b.buildResourceQuotaStores() },
	"secrets":                         func(b *Builder) []cache.Store { return b.buildSecretStores() },
	"services":                        func(b *Builder) []cache.Store { return b.buildServiceStores() },
	"statefulsets":                    func(b *Builder) []cache.Store { return b.buildStatefulSetStores() },
	"storageclasses":                  func(b *Builder) []cache.Store { return b.buildStorageClassStores() },
	"validatingwebhookconfigurations": func(b *Builder) []cache.Store { return b.buildValidatingWebhookConfigurationStores() },
	"volumeattachments":               func(b *Builder) []cache.Store { return b.buildVolumeAttachmentStores() },
	"verticalpodautoscalers":          func(b *Builder) []cache.Store { return b.buildVPAStores() },
}

func resourceExists(name string) bool {
	_, ok := availableStores[name]
	return ok
}

func availableResources() []string {
	c := []string{}
	for name := range availableStores {
		c = append(c, name)
	}
	return c
}

func (b *Builder) buildConfigMapStores() []cache.Store {
	return b.buildStoresFunc(configMapMetricFamilies(b.allowAnnotationsList["configmaps"], b.allowLabelsList["configmaps"]), &v1.ConfigMap{}, createConfigMapListWatch, b.useAPIServerCache)
}

func (b *Builder) buildCronJobStores() []cache.Store {
	return b.buildStoresFunc(cronJobMetricFamilies(b.allowAnnotationsList["cronjobs"], b.allowLabelsList["cronjobs"]), &batchv1.CronJob{}, createCronJobListWatch, b.useAPIServerCache)
}

func (b *Builder) buildDaemonSetStores() []cache.Store {
	return b.buildStoresFunc(daemonSetMetricFamilies(b.allowAnnotationsList["daemonsets"], b.allowLabelsList["daemonsets"]), &appsv1.DaemonSet{}, createDaemonSetListWatch, b.useAPIServerCache)
}

func (b *Builder) buildDeploymentStores() []cache.Store {
	return b.buildStoresFunc(deploymentMetricFamilies(b.allowAnnotationsList["deployments"], b.allowLabelsList["deployments"]), &appsv1.Deployment{}, createDeploymentListWatch, b.useAPIServerCache)
}

func (b *Builder) buildEndpointsStores() []cache.Store {
	return b.buildStoresFunc(endpointMetricFamilies(b.allowAnnotationsList["endpoints"], b.allowLabelsList["endpoints"]), &v1.Endpoints{}, createEndpointsListWatch, b.useAPIServerCache)
}

func (b *Builder) buildHPAStores() []cache.Store {
	return b.buildStoresFunc(hpaMetricFamilies(b.allowAnnotationsList["horizontalpodautoscalers"], b.allowLabelsList["horizontalpodautoscalers"]), &autoscaling.HorizontalPodAutoscaler{}, createHPAListWatch, b.useAPIServerCache)
}

func (b *Builder) buildIngressStores() []cache.Store {
	return b.buildStoresFunc(ingressMetricFamilies(b.allowAnnotationsList["ingresses"], b.allowLabelsList["ingresses"]), &networkingv1.Ingress{}, createIngressListWatch, b.useAPIServerCache)
}

func (b *Builder) buildJobStores() []cache.Store {
	return b.buildStoresFunc(jobMetricFamilies(b.allowAnnotationsList["jobs"], b.allowLabelsList["jobs"]), &batchv1.Job{}, createJobListWatch, b.useAPIServerCache)
}

func (b *Builder) buildLimitRangeStores() []cache.Store {
	return b.buildStoresFunc(limitRangeMetricFamilies, &v1.LimitRange{}, createLimitRangeListWatch, b.useAPIServerCache)
}

func (b *Builder) buildMutatingWebhookConfigurationStores() []cache.Store {
	return b.buildStoresFunc(mutatingWebhookConfigurationMetricFamilies, &admissionregistrationv1.MutatingWebhookConfiguration{}, createMutatingWebhookConfigurationListWatch, b.useAPIServerCache)
}

func (b *Builder) buildNamespaceStores() []cache.Store {
	return b.buildStoresFunc(namespaceMetricFamilies(b.allowAnnotationsList["namespaces"], b.allowLabelsList["namespaces"]), &v1.Namespace{}, createNamespaceListWatch, b.useAPIServerCache)
}

func (b *Builder) buildNetworkPolicyStores() []cache.Store {
	return b.buildStoresFunc(networkPolicyMetricFamilies(b.allowAnnotationsList["networkpolicies"], b.allowLabelsList["networkpolicies"]), &networkingv1.NetworkPolicy{}, createNetworkPolicyListWatch, b.useAPIServerCache)
}

func (b *Builder) buildNodeStores() []cache.Store {
	return b.buildStoresFunc(nodeMetricFamilies(b.allowAnnotationsList["nodes"], b.allowLabelsList["nodes"]), &v1.Node{}, createNodeListWatch, b.useAPIServerCache)
}

func (b *Builder) buildPersistentVolumeClaimStores() []cache.Store {
	return b.buildStoresFunc(persistentVolumeClaimMetricFamilies(b.allowAnnotationsList["persistentvolumeclaims"], b.allowLabelsList["persistentvolumeclaims"]), &v1.PersistentVolumeClaim{}, createPersistentVolumeClaimListWatch, b.useAPIServerCache)
}

func (b *Builder) buildPersistentVolumeStores() []cache.Store {
	return b.buildStoresFunc(persistentVolumeMetricFamilies(b.allowAnnotationsList["persistentvolumes"], b.allowLabelsList["persistentvolumes"]), &v1.PersistentVolume{}, createPersistentVolumeListWatch, b.useAPIServerCache)
}

func (b *Builder) buildPodDisruptionBudgetStores() []cache.Store {
	return b.buildStoresFunc(podDisruptionBudgetMetricFamilies(b.allowAnnotationsList["poddisruptionbudgets"], b.allowLabelsList["poddisruptionbudgets"]), &policyv1.PodDisruptionBudget{}, createPodDisruptionBudgetListWatch, b.useAPIServerCache)
}

func (b *Builder) buildReplicaSetStores() []cache.Store {
	return b.buildStoresFunc(replicaSetMetricFamilies(b.allowAnnotationsList["replicasets"], b.allowLabelsList["replicasets"]), &appsv1.ReplicaSet{}, createReplicaSetListWatch, b.useAPIServerCache)
}

func (b *Builder) buildReplicationControllerStores() []cache.Store {
	return b.buildStoresFunc(replicationControllerMetricFamilies, &v1.ReplicationController{}, createReplicationControllerListWatch, b.useAPIServerCache)
}

func (b *Builder) buildResourceQuotaStores() []cache.Store {
	return b.buildStoresFunc(resourceQuotaMetricFamilies, &v1.ResourceQuota{}, createResourceQuotaListWatch, b.useAPIServerCache)
}

func (b *Builder) buildSecretStores() []cache.Store {
	return b.buildStoresFunc(secretMetricFamilies(b.allowAnnotationsList["secrets"], b.allowLabelsList["secrets"]), &v1.Secret{}, createSecretListWatch, b.useAPIServerCache)
}

func (b *Builder) buildServiceStores() []cache.Store {
	return b.buildStoresFunc(serviceMetricFamilies(b.allowAnnotationsList["services"], b.allowLabelsList["services"]), &v1.Service{}, createServiceListWatch, b.useAPIServerCache)
}

func (b *Builder) buildStatefulSetStores() []cache.Store {
	return b.buildStoresFunc(statefulSetMetricFamilies(b.allowAnnotationsList["statefulsets"], b.allowLabelsList["statefulsets"]), &appsv1.StatefulSet{}, createStatefulSetListWatch, b.useAPIServerCache)
}

func (b *Builder) buildStorageClassStores() []cache.Store {
	return b.buildStoresFunc(storageClassMetricFamilies(b.allowAnnotationsList["storageclasses"], b.allowLabelsList["storageclasses"]), &storagev1.StorageClass{}, createStorageClassListWatch, b.useAPIServerCache)
}

func (b *Builder) buildPodStores() []cache.Store {
	return b.buildStoresFunc(podMetricFamilies(b.allowAnnotationsList["pods"], b.allowLabelsList["pods"]), &v1.Pod{}, createPodListWatch, b.useAPIServerCache)
}

func (b *Builder) buildCsrStores() []cache.Store {
	return b.buildStoresFunc(csrMetricFamilies(b.allowAnnotationsList["certificatesigningrequests"], b.allowLabelsList["certificatesigningrequests"]), &certv1.CertificateSigningRequest{}, createCSRListWatch, b.useAPIServerCache)
}

func (b *Builder) buildValidatingWebhookConfigurationStores() []cache.Store {
	return b.buildStoresFunc(validatingWebhookConfigurationMetricFamilies, &admissionregistrationv1.ValidatingWebhookConfiguration{}, createValidatingWebhookConfigurationListWatch, b.useAPIServerCache)
}

func (b *Builder) buildVolumeAttachmentStores() []cache.Store {
	return b.buildStoresFunc(volumeAttachmentMetricFamilies, &storagev1.VolumeAttachment{}, createVolumeAttachmentListWatch, b.useAPIServerCache)
}

func (b *Builder) buildVPAStores() []cache.Store {
	return b.buildStoresFunc(vpaMetricFamilies(b.allowAnnotationsList["verticalpodautoscalers"], b.allowLabelsList["verticalpodautoscalers"]), &vpaautoscaling.VerticalPodAutoscaler{}, createVPAListWatchFunc(b.vpaClient), b.useAPIServerCache)
}

func (b *Builder) buildLeasesStores() []cache.Store {
	return b.buildStoresFunc(leaseMetricFamilies, &coordinationv1.Lease{}, createLeaseListWatch, b.useAPIServerCache)
}

func (b *Builder) buildStores(
	metricFamilies []generator.FamilyGenerator,
	expectedType interface{},
	listWatchFunc func(kubeClient clientset.Interface, ns string, fieldSelector string) cache.ListerWatcher,
	useAPIServerCache bool,
) []cache.Store {
	metricFamilies = generator.FilterFamilyGenerators(b.familyGeneratorFilter, metricFamilies)
	composedMetricGenFuncs := generator.ComposeMetricGenFuncs(metricFamilies)
	familyHeaders := generator.ExtractMetricFamilyHeaders(metricFamilies)

	if b.namespaces.IsAllNamespaces() {
		store := metricsstore.NewMetricsStore(
			familyHeaders,
			composedMetricGenFuncs,
		)
		listWatcher := listWatchFunc(b.kubeClient, v1.NamespaceAll, b.namespaceFilter)
		b.startReflector(expectedType, store, listWatcher, useAPIServerCache)
		return []cache.Store{store}
	}

	stores := make([]cache.Store, 0, len(b.namespaces))
	for _, ns := range b.namespaces {
		store := metricsstore.NewMetricsStore(
			familyHeaders,
			composedMetricGenFuncs,
		)
		listWatcher := listWatchFunc(b.kubeClient, ns, b.namespaceFilter)
		b.startReflector(expectedType, store, listWatcher, useAPIServerCache)
		stores = append(stores, store)
	}

	return stores
}

// TODO(Garrybest): Merge `buildStores` and `buildCustomResourceStores`
func (b *Builder) buildCustomResourceStores(resourceName string,
	metricFamilies []generator.FamilyGenerator,
	expectedType interface{},
	listWatchFunc func(customResourceClient interface{}, ns string, fieldSelector string) cache.ListerWatcher,
	useAPIServerCache bool,
) []cache.Store {
	metricFamilies = generator.FilterFamilyGenerators(b.familyGeneratorFilter, metricFamilies)
	composedMetricGenFuncs := generator.ComposeMetricGenFuncs(metricFamilies)
	familyHeaders := generator.ExtractMetricFamilyHeaders(metricFamilies)

	customResourceClient, ok := b.customResourceClients[resourceName]
	if !ok {
		klog.Warningf("Custom resource client %s does not exist", resourceName)
		return []cache.Store{}
	}

	if b.namespaces.IsAllNamespaces() {
		store := metricsstore.NewMetricsStore(
			familyHeaders,
			composedMetricGenFuncs,
		)
		listWatcher := listWatchFunc(customResourceClient, v1.NamespaceAll, b.namespaceFilter)
		b.startReflector(expectedType, store, listWatcher, useAPIServerCache)
		return []cache.Store{store}
	}

	stores := make([]cache.Store, 0, len(b.namespaces))
	for _, ns := range b.namespaces {
		store := metricsstore.NewMetricsStore(
			familyHeaders,
			composedMetricGenFuncs,
		)
		listWatcher := listWatchFunc(customResourceClient, ns, b.namespaceFilter)
		b.startReflector(expectedType, store, listWatcher, useAPIServerCache)
		stores = append(stores, store)
	}

	return stores
}

// startReflector starts a Kubernetes client-go reflector with the given
// listWatcher and registers it with the given store.
func (b *Builder) startReflector(
	expectedType interface{},
	store cache.Store,
	listWatcher cache.ListerWatcher,
	useAPIServerCache bool,
) {
	instrumentedListWatch := watch.NewInstrumentedListerWatcher(listWatcher, b.listWatchMetrics, reflect.TypeOf(expectedType).String(), useAPIServerCache)
	reflector := cache.NewReflector(sharding.NewShardedListWatch(b.shard, b.totalShards, instrumentedListWatch), expectedType, store, 0)
	go reflector.Run(b.ctx.Done())
}

// cacheStoresToMetricStores converts []cache.Store into []*metricsstore.MetricsStore
func cacheStoresToMetricStores(cStores []cache.Store) []*metricsstore.MetricsStore {
	mStores := make([]*metricsstore.MetricsStore, 0, len(cStores))
	for _, store := range cStores {
		mStores = append(mStores, store.(*metricsstore.MetricsStore))
	}

	return mStores
}