// NewSourceAPIserver creates config source that watches for changes to the services and endpoints.
func NewSourceAPI(c *client.Client, period time.Duration, servicesChan chan<- ServiceUpdate, endpointsChan chan<- EndpointsUpdate) {
	servicesLW := cache.NewListWatchFromClient(c, "services", api.NamespaceAll, fields.Everything())
	endpointsLW := cache.NewListWatchFromClient(c, "endpoints", api.NamespaceAll, fields.Everything())

	newServicesSourceApiFromLW(servicesLW, period, servicesChan)
	newEndpointsSourceApiFromLW(endpointsLW, period, endpointsChan)
}

// NewClient returns a usable Client. Don't forget to Stop it.
func NewClient(addr string, resyncPeriod time.Duration) (Client, error) {
	c, err := unversioned.New(&unversioned.Config{Host: addr})
	if err != nil {
		return nil, err
	}

	podListWatch := cache.NewListWatchFromClient(c, "pods", api.NamespaceAll, fields.Everything())
	podStore := cache.NewStore(cache.MetaNamespaceKeyFunc)
	podReflector := cache.NewReflector(podListWatch, &api.Pod{}, podStore, resyncPeriod)

	serviceListWatch := cache.NewListWatchFromClient(c, "services", api.NamespaceAll, fields.Everything())
	serviceStore := cache.NewStore(cache.MetaNamespaceKeyFunc)
	serviceReflector := cache.NewReflector(serviceListWatch, &api.Service{}, serviceStore, resyncPeriod)

	quit := make(chan struct{})
	podReflector.RunUntil(quit)
	serviceReflector.RunUntil(quit)

	return &client{
		quit:             quit,
		client:           c,
		podReflector:     podReflector,
		podStore:         &cache.StoreToPodLister{Store: podStore},
		serviceReflector: serviceReflector,
		serviceStore:     &cache.StoreToServiceLister{Store: serviceStore},
	}, nil
}

// newIPVSController creates a new controller from the given config.
func newIPVSController(kubeClient *unversioned.Client, namespace string, useUnicast bool, password string) *ipvsControllerController {
	ipvsc := ipvsControllerController{
		client:            kubeClient,
		queue:             workqueue.New(),
		reloadRateLimiter: util.NewTokenBucketRateLimiter(reloadQPS, int(reloadQPS)),
		reloadLock:        &sync.Mutex{},
	}

	clusterNodes := getClusterNodesIP(kubeClient)

	nodeInfo, err := getNodeInfo(clusterNodes)
	if err != nil {
		glog.Fatalf("Error getting local IP from nodes in the cluster: %v", err)
	}

	neighbors := getNodeNeighbors(nodeInfo, clusterNodes)

	ipvsc.keepalived = &keepalived{
		iface:      nodeInfo.iface,
		ip:         nodeInfo.ip,
		netmask:    nodeInfo.netmask,
		nodes:      clusterNodes,
		neighbors:  neighbors,
		priority:   getNodePriority(nodeInfo.ip, clusterNodes),
		useUnicast: useUnicast,
		password:   password,
	}

	enqueue := func(obj interface{}) {
		key, err := keyFunc(obj)
		if err != nil {
			glog.Infof("Couldn't get key for object %+v: %v", obj, err)
			return
		}

		ipvsc.queue.Add(key)
	}

	eventHandlers := framework.ResourceEventHandlerFuncs{
		AddFunc:    enqueue,
		DeleteFunc: enqueue,
		UpdateFunc: func(old, cur interface{}) {
			if !reflect.DeepEqual(old, cur) {
				enqueue(cur)
			}
		},
	}

	ipvsc.svcLister.Store, ipvsc.svcController = framework.NewInformer(
		cache.NewListWatchFromClient(
			ipvsc.client, "services", namespace, fields.Everything()),
		&api.Service{}, resyncPeriod, eventHandlers)

	ipvsc.epLister.Store, ipvsc.epController = framework.NewInformer(
		cache.NewListWatchFromClient(
			ipvsc.client, "endpoints", namespace, fields.Everything()),
		&api.Endpoints{}, resyncPeriod, eventHandlers)

	return &ipvsc
}

// NewSourceAPI creates config source that watches for changes to the services and endpoints.
func NewSourceAPI(c cache.Getter, period time.Duration, servicesChan chan<- ServiceUpdate, endpointsChan chan<- EndpointsUpdate) {
	servicesLW := cache.NewListWatchFromClient(c, "services", api.NamespaceAll, fields.Everything())
	cache.NewReflector(servicesLW, &api.Service{}, NewServiceStore(nil, servicesChan), period).Run()

	endpointsLW := cache.NewListWatchFromClient(c, "endpoints", api.NamespaceAll, fields.Everything())
	cache.NewReflector(endpointsLW, &api.Endpoints{}, NewEndpointsStore(nil, endpointsChan), period).Run()
}

// newLoadBalancerController creates a new controller from the given config.
func newLoadBalancerController(cfg *loadBalancerConfig, kubeClient *unversioned.Client, namespace string) *loadBalancerController {

	lbc := loadBalancerController{
		cfg:    cfg,
		client: kubeClient,
		queue:  workqueue.New(),
		reloadRateLimiter: util.NewTokenBucketRateLimiter(
			reloadQPS, int(reloadQPS)),
		targetService:   *targetService,
		forwardServices: *forwardServices,
		httpPort:        *httpPort,
		tcpServices:     map[string]int{},
	}

	for _, service := range strings.Split(*tcpServices, ",") {
		portSplit := strings.Split(service, ":")
		if len(portSplit) != 2 {
			glog.Errorf("Ignoring misconfigured TCP service %v", service)
			continue
		}
		if port, err := strconv.Atoi(portSplit[1]); err != nil {
			glog.Errorf("Ignoring misconfigured TCP service %v: %v", service, err)
			continue
		} else {
			lbc.tcpServices[portSplit[0]] = port
		}
	}
	enqueue := func(obj interface{}) {
		key, err := keyFunc(obj)
		if err != nil {
			glog.Infof("Couldn't get key for object %+v: %v", obj, err)
			return
		}
		lbc.queue.Add(key)
	}
	eventHandlers := framework.ResourceEventHandlerFuncs{
		AddFunc:    enqueue,
		DeleteFunc: enqueue,
		UpdateFunc: func(old, cur interface{}) {
			if !reflect.DeepEqual(old, cur) {
				enqueue(cur)
			}
		},
	}

	lbc.svcLister.Store, lbc.svcController = framework.NewInformer(
		cache.NewListWatchFromClient(
			lbc.client, "services", namespace, fields.Everything()),
		&api.Service{}, resyncPeriod, eventHandlers)

	lbc.epLister.Store, lbc.epController = framework.NewInformer(
		cache.NewListWatchFromClient(
			lbc.client, "endpoints", namespace, fields.Everything()),
		&api.Endpoints{}, resyncPeriod, eventHandlers)

	return &lbc
}

// newIPVSController creates a new controller from the given config.
func newIPVSController(kubeClient *unversioned.Client, namespace string, useUnicast bool, configMapName string) *ipvsControllerController {
	ipvsc := ipvsControllerController{
		client:            kubeClient,
		reloadRateLimiter: util.NewTokenBucketRateLimiter(reloadQPS, int(reloadQPS)),
		ruCfg:             []vip{},
		configMapName:     configMapName,
	}

	clusterNodes := getClusterNodesIP(kubeClient)

	nodeInfo, err := getNodeInfo(clusterNodes)
	if err != nil {
		glog.Fatalf("Error getting local IP from nodes in the cluster: %v", err)
	}

	neighbors := getNodeNeighbors(nodeInfo, clusterNodes)

	execer := exec.New()
	dbus := utildbus.New()
	iptInterface := utiliptables.New(execer, dbus, utiliptables.ProtocolIpv4)

	ipvsc.keepalived = &keepalived{
		iface:      nodeInfo.iface,
		ip:         nodeInfo.ip,
		netmask:    nodeInfo.netmask,
		nodes:      clusterNodes,
		neighbors:  neighbors,
		priority:   getNodePriority(nodeInfo.ip, clusterNodes),
		useUnicast: useUnicast,
		ipt:        iptInterface,
	}

	err = ipvsc.keepalived.loadTemplate()
	if err != nil {
		glog.Fatalf("Error loading keepalived template: %v", err)
	}

	eventHandlers := framework.ResourceEventHandlerFuncs{}

	ipvsc.svcLister.Store, ipvsc.svcController = framework.NewInformer(
		cache.NewListWatchFromClient(
			ipvsc.client, "services", namespace, fields.Everything()),
		&api.Service{}, resyncPeriod, eventHandlers)

	ipvsc.epLister.Store, ipvsc.epController = framework.NewInformer(
		cache.NewListWatchFromClient(
			ipvsc.client, "endpoints", namespace, fields.Everything()),
		&api.Endpoints{}, resyncPeriod, eventHandlers)

	return &ipvsc
}

func newPodsApi(client *kclient.Client) podsApi {
	// Extend the selector to include specific nodes to monitor
	// or provide an API to update the nodes to monitor.
	selector, err := kSelector.ParseSelector("spec.nodeName!=")
	if err != nil {
		panic(err)
	}

	lw := kcache.NewListWatchFromClient(client, "pods", kapi.NamespaceAll, selector)
	podLister := &kcache.StoreToPodLister{Store: kcache.NewStore(kcache.MetaNamespaceKeyFunc)}
	// Watch and cache all running pods.
	reflector := kcache.NewReflector(lw, &kapi.Pod{}, podLister.Store, 0)
	stopChan := make(chan struct{})
	reflector.RunUntil(stopChan)
	nStore, nController := kframework.NewInformer(
		createNamespaceLW(client),
		&kapi.Namespace{},
		resyncPeriod,
		kframework.ResourceEventHandlerFuncs{})
	go nController.Run(util.NeverStop)

	podsApi := &realPodsApi{
		client:         client,
		podLister:      podLister,
		stopChan:       stopChan,
		reflector:      reflector,
		namespaceStore: nStore,
	}

	return podsApi
}

func NewKubeletProvider(uri *url.URL) (MetricsSourceProvider, error) {
	// create clients
	kubeConfig, kubeletConfig, err := GetKubeConfigs(uri)
	if err != nil {
		return nil, err
	}
	kubeClient := kube_client.NewOrDie(kubeConfig)
	kubeletClient, err := NewKubeletClient(kubeletConfig)
	if err != nil {
		return nil, err
	}

	// Get nodes to test if the client is configured well. Watch gives less error information.
	if _, err := kubeClient.Nodes().List(kube_api.ListOptions{
		LabelSelector: labels.Everything(),
		FieldSelector: fields.Everything()}); err != nil {
		glog.Errorf("Failed to load nodes: %v", err)
	}

	// watch nodes
	lw := cache.NewListWatchFromClient(kubeClient, "nodes", kube_api.NamespaceAll, fields.Everything())
	nodeLister := &cache.StoreToNodeLister{Store: cache.NewStore(cache.MetaNamespaceKeyFunc)}
	reflector := cache.NewReflector(lw, &kube_api.Node{}, nodeLister.Store, time.Hour)
	reflector.Run()

	return &kubeletProvider{
		nodeLister:    nodeLister,
		reflector:     reflector,
		kubeletClient: kubeletClient,
	}, nil
}

// Run event queue for the given resource
func (registry *Registry) RunEventQueue(resourceName ResourceName) *oscache.EventQueue {
	var client cache.Getter
	var expectedType interface{}

	switch resourceName {
	case HostSubnets:
		expectedType = &osapi.HostSubnet{}
		client = registry.oClient
	case NetNamespaces:
		expectedType = &osapi.NetNamespace{}
		client = registry.oClient
	case Nodes:
		expectedType = &kapi.Node{}
		client = registry.kClient
	case Namespaces:
		expectedType = &kapi.Namespace{}
		client = registry.kClient
	case Services:
		expectedType = &kapi.Service{}
		client = registry.kClient
	case Pods:
		expectedType = &kapi.Pod{}
		client = registry.kClient
	default:
		log.Fatalf("Unknown resource %s during initialization of event queue", resourceName)
	}

	lw := cache.NewListWatchFromClient(client, strings.ToLower(string(resourceName)), kapi.NamespaceAll, fields.Everything())
	eventQueue := oscache.NewEventQueue(cache.MetaNamespaceKeyFunc)
	// Repopulate event queue every 30 mins
	// Existing items in the event queue will have watch.Modified event type
	cache.NewReflector(lw, expectedType, eventQueue, 30*time.Minute).Run()
	return eventQueue
}

func getNodeLister(kubeClient *kube_client.Client) (*cache.StoreToNodeLister, error) {
	lw := cache.NewListWatchFromClient(kubeClient, "nodes", kube_api.NamespaceAll, fields.Everything())
	nodeLister := &cache.StoreToNodeLister{Store: cache.NewStore(cache.MetaNamespaceKeyFunc)}
	reflector := cache.NewReflector(lw, &kube_api.Node{}, nodeLister.Store, time.Hour)
	reflector.Run()
	return nodeLister, nil
}

// Run event queue for the given resource
func (registry *Registry) runEventQueue(resourceName string) *oscache.EventQueue {
	var client cache.Getter
	var expectedType interface{}

	switch strings.ToLower(resourceName) {
	case "hostsubnets":
		expectedType = &osapi.HostSubnet{}
		client = registry.oClient
	case "netnamespaces":
		expectedType = &osapi.NetNamespace{}
		client = registry.oClient
	case "nodes":
		expectedType = &kapi.Node{}
		client = registry.kClient
	case "namespaces":
		expectedType = &kapi.Namespace{}
		client = registry.kClient
	case "services":
		expectedType = &kapi.Service{}
		client = registry.kClient
	case "pods":
		expectedType = &kapi.Pod{}
		client = registry.kClient
	default:
		log.Fatalf("Unknown resource %s during initialization of event queue", resourceName)
	}

	lw := cache.NewListWatchFromClient(client, strings.ToLower(resourceName), kapi.NamespaceAll, fields.Everything())
	eventQueue := oscache.NewEventQueue(cache.MetaNamespaceKeyFunc)
	cache.NewReflector(lw, expectedType, eventQueue, 0).Run()
	return eventQueue
}

func getPodLister(kubeClient *kube_client.Client) (*cache.StoreToPodLister, error) {
	lw := cache.NewListWatchFromClient(kubeClient, "pods", kube_api.NamespaceAll, fields.Everything())
	store := cache.NewIndexer(cache.MetaNamespaceKeyFunc, cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc})
	podLister := &cache.StoreToPodLister{Indexer: store}
	reflector := cache.NewReflector(lw, &kube_api.Pod{}, store, time.Hour)
	reflector.Run()
	return podLister, nil
}

// NewNodeLister builds a node lister.
func NewNodeLister(kubeClient client.Interface) *ReadyNodeLister {
	listWatcher := cache.NewListWatchFromClient(kubeClient.Core().RESTClient(), "nodes", apiv1.NamespaceAll, fields.Everything())
	nodeLister := &cache.StoreToNodeLister{Store: cache.NewStore(cache.MetaNamespaceKeyFunc)}
	reflector := cache.NewReflector(listWatcher, &apiv1.Node{}, nodeLister.Store, time.Hour)
	reflector.Run()
	return &ReadyNodeLister{
		nodeLister: nodeLister,
	}
}

// NewNodeLister builds a node lister.
func NewNodeLister(kubeClient *kube_client.Client) *ReadyNodeLister {
	listWatcher := cache.NewListWatchFromClient(kubeClient, "nodes", kube_api.NamespaceAll, fields.Everything())
	nodeLister := &cache.StoreToNodeLister{Store: cache.NewStore(cache.MetaNamespaceKeyFunc)}
	reflector := cache.NewReflector(listWatcher, &kube_api.Node{}, nodeLister.Store, time.Hour)
	reflector.Run()
	return &ReadyNodeLister{
		nodeLister: nodeLister,
	}
}

// newLoadBalancerController creates a new controller from the given config.
func newLoadBalancerController(cfg *loadBalancerConfig, kubeClient *unversioned.Client, namespace string, tcpServices map[string]int) *loadBalancerController {
	lbc := loadBalancerController{
		cfg:    cfg,
		client: kubeClient,
		queue:  workqueue.New(),
		reloadRateLimiter: util.NewTokenBucketRateLimiter(
			reloadQPS, int(reloadQPS)),
		targetService:   *targetService,
		forwardServices: *forwardServices,
		httpPort:        *httpPort,
		tcpServices:     tcpServices,
	}

	enqueue := func(obj interface{}) {
		key, err := keyFunc(obj)
		if err != nil {
			glog.Infof("Couldn't get key for object %+v: %v", obj, err)
			return
		}
		lbc.queue.Add(key)
	}
	eventHandlers := framework.ResourceEventHandlerFuncs{
		AddFunc:    enqueue,
		DeleteFunc: enqueue,
		UpdateFunc: func(old, cur interface{}) {
			if !reflect.DeepEqual(old, cur) {
				enqueue(cur)
			}
		},
	}

	lbc.svcLister.Store, lbc.svcController = framework.NewInformer(
		cache.NewListWatchFromClient(
			lbc.client, "services", namespace, fields.Everything()),
		&api.Service{}, resyncPeriod, eventHandlers)

	lbc.epLister.Store, lbc.epController = framework.NewInformer(
		cache.NewListWatchFromClient(
			lbc.client, "endpoints", namespace, fields.Everything()),
		&api.Endpoints{}, resyncPeriod, eventHandlers)

	return &lbc
}

// Run starts a background goroutine that watches for changes to services that
// have (or had) LoadBalancers=true and ensures that they have
// load balancers created and deleted appropriately.
// serviceSyncPeriod controls how often we check the cluster's services to
// ensure that the correct load balancers exist.
// nodeSyncPeriod controls how often we check the cluster's nodes to determine
// if load balancers need to be updated to point to a new set.
//
// It's an error to call Run() more than once for a given ServiceController
// object.
func (s *ServiceController) Run(workers int) {
	defer runtime.HandleCrash()
	go s.serviceController.Run(wait.NeverStop)
	for i := 0; i < workers; i++ {
		go wait.Until(s.worker, time.Second, wait.NeverStop)
	}
	nodeLW := cache.NewListWatchFromClient(s.kubeClient.Core().RESTClient(), "nodes", v1.NamespaceAll, fields.Everything())
	cache.NewReflector(nodeLW, &v1.Node{}, s.nodeLister.Store, 0).Run()
	go wait.Until(s.nodeSyncLoop, nodeSyncPeriod, wait.NeverStop)
}

// NewCachedServiceAccessor returns a service accessor that can answer queries about services.
// It uses a backing cache to make ClusterIP lookups efficient.
func NewCachedServiceAccessor(client cache.Getter, stopCh <-chan struct{}) ServiceAccessor {
	accessor, store := NewCachedServiceAccessorAndStore()
	lw := cache.NewListWatchFromClient(client, "services", api.NamespaceAll, fields.Everything())
	reflector := cache.NewReflector(lw, &api.Service{}, store, 30*time.Minute)
	if stopCh != nil {
		reflector.RunUntil(stopCh)
	} else {
		reflector.Run()
	}
	return accessor
}

// NewClient returns a usable Client. Don't forget to Stop it.
func NewClient(addr string, resyncPeriod time.Duration) (Client, error) {
	var config *unversioned.Config
	if addr != "" {
		config = &unversioned.Config{Host: addr}
	} else {
		// If no API server address was provided, assume we are running
		// inside a pod. Try to connect to the API server through its
		// Service environment variables, using the default Service
		// Account Token.
		var err error
		if config, err = unversioned.InClusterConfig(); err != nil {
			return nil, err
		}
	}

	c, err := unversioned.New(config)
	if err != nil {
		return nil, err
	}

	podListWatch := cache.NewListWatchFromClient(c, "pods", api.NamespaceAll, fields.Everything())
	podStore := cache.NewStore(cache.MetaNamespaceKeyFunc)
	podReflector := cache.NewReflector(podListWatch, &api.Pod{}, podStore, resyncPeriod)

	serviceListWatch := cache.NewListWatchFromClient(c, "services", api.NamespaceAll, fields.Everything())
	serviceStore := cache.NewStore(cache.MetaNamespaceKeyFunc)
	serviceReflector := cache.NewReflector(serviceListWatch, &api.Service{}, serviceStore, resyncPeriod)

	quit := make(chan struct{})
	runReflectorUntil(podReflector, resyncPeriod, quit)
	runReflectorUntil(serviceReflector, resyncPeriod, quit)

	return &client{
		quit:             quit,
		client:           c,
		podReflector:     podReflector,
		podStore:         &cache.StoreToPodLister{Store: podStore},
		serviceReflector: serviceReflector,
		serviceStore:     &cache.StoreToServiceLister{Store: serviceStore},
	}, nil
}

// Run event queue for the given resource. The 'process' function is called
// repeatedly with each available cache.Delta that describes state changes
// to an object. If the process function returns an error queued changes
// for that object are dropped but processing continues with the next available
// object's cache.Deltas.  The error is logged with call stack information.
func runEventQueueForResource(client kcache.Getter, resourceName ResourceName, expectedType interface{}, selector fields.Selector, process ProcessEventFunc) {
	rn := strings.ToLower(string(resourceName))
	lw := kcache.NewListWatchFromClient(client, rn, kapi.NamespaceAll, selector)
	eventQueue := NewEventQueue(kcache.MetaNamespaceKeyFunc)
	// Repopulate event queue every 30 mins
	// Existing items in the event queue will have watch.Modified event type
	kcache.NewReflector(lw, expectedType, eventQueue, 30*time.Minute).Run()

	// Run the queue
	for {
		eventQueue.Pop(process)
	}
}

// NewUnscheduledPodLister returns a lister providing pods that failed to be scheduled.
func NewUnscheduledPodLister(kubeClient *kube_client.Client) *UnscheduledPodLister {
	// watch unscheduled pods
	selector := fields.ParseSelectorOrDie("spec.nodeName==" + "" + ",status.phase!=" +
		string(kube_api.PodSucceeded) + ",status.phase!=" + string(kube_api.PodFailed))
	podListWatch := cache.NewListWatchFromClient(kubeClient, "pods", kube_api.NamespaceAll, selector)
	podLister := &cache.StoreToPodLister{Store: cache.NewStore(cache.MetaNamespaceKeyFunc)}
	podReflector := cache.NewReflector(podListWatch, &kube_api.Pod{}, podLister.Store, time.Hour)
	podReflector.Run()

	return &UnscheduledPodLister{
		podLister: podLister,
	}
}