// TODO: Move this back to scheduler as a helper function that takes a Store,
// rather than a method of StoreToServiceLister.
func (s *StoreToServiceLister) GetPodServices(pod *api.Pod) (services []api.Service, err error) {
	var selector labels.Selector
	var service api.Service

	for _, m := range s.Store.List() {
		service = *m.(*api.Service)
		// consider only services that are in the same namespace as the pod
		if service.Namespace != pod.Namespace {
			continue
		}
		if service.Spec.Selector == nil {
			// services with nil selectors match nothing, not everything.
			continue
		}
		selector = labels.Set(service.Spec.Selector).AsSelector()
		if selector.Matches(labels.Set(pod.Labels)) {
			services = append(services, service)
		}
	}
	if len(services) == 0 {
		err = fmt.Errorf("Could not find service for pod %s in namespace %s with labels: %v", pod.Name, pod.Namespace, pod.Labels)
	}

	return
}

// WatchControllers begins watching for new, changed, or deleted controllers.
func (r *Registry) WatchControllers(ctx api.Context, label labels.Selector, field fields.Selector, resourceVersion string) (watch.Interface, error) {
	if !field.Empty() {
		return nil, fmt.Errorf("field selectors are not supported on replication controllers")
	}
	version, err := tools.ParseWatchResourceVersion(resourceVersion, "replicationControllers")
	if err != nil {
		return nil, err
	}
	key := makeControllerListKey(ctx)
	return r.WatchList(key, version, func(obj runtime.Object) bool {
		controller, ok := obj.(*api.ReplicationController)
		if !ok {
			// Must be an error: return true to propagate to upper level.
			return true
		}
		match := label.Matches(labels.Set(controller.Labels))
		if match {
			pods, err := r.pods.ListPods(ctx, labels.Set(controller.Spec.Selector).AsSelector())
			if err != nil {
				glog.Warningf("Error listing pods: %v", err)
				// No object that's useable so drop it on the floor
				return false
			}
			if pods == nil {
				glog.Warningf("Pods list is nil.  This should never happen...")
				// No object that's useable so drop it on the floor
				return false
			}
			controller.Status.Replicas = len(pods.Items)
		}
		return match
	})
}

// GetPodControllers returns a list of controllers managing a pod. Returns an error only if no matching controllers are found.
func (s *StoreToControllerLister) GetPodControllers(pod *api.Pod) (controllers []api.ReplicationController, err error) {
	var selector labels.Selector
	var rc api.ReplicationController

	if len(pod.Labels) == 0 {
		err = fmt.Errorf("No controllers found for pod %v because it has no labels", pod.Name)
		return
	}

	for _, m := range s.Store.List() {
		rc = *m.(*api.ReplicationController)
		if rc.Namespace != pod.Namespace {
			continue
		}
		labelSet := labels.Set(rc.Spec.Selector)
		selector = labels.Set(rc.Spec.Selector).AsSelector()

		// If an rc with a nil or empty selector creeps in, it should match nothing, not everything.
		if labelSet.AsSelector().Empty() || !selector.Matches(labels.Set(pod.Labels)) {
			continue
		}
		controllers = append(controllers, rc)
	}
	if len(controllers) == 0 {
		err = fmt.Errorf("Could not find controllers for pod %s in namespace %s with labels: %v", pod.Name, pod.Namespace, pod.Labels)
	}
	return
}

func MappingTypeForPod(pod *api.Pod) HostPortMappingType {
	filter := map[string]string{
		PortMappingLabelKey: string(HostPortMappingFixed),
	}
	selector := labels.Set(filter).AsSelector()
	if selector.Matches(labels.Set(pod.Labels)) {
		return HostPortMappingFixed
	}
	return HostPortMappingWildcard
}

func verifyExpectedRcsExistAndGetExpectedPods(c *client.Client) ([]string, error) {
	expectedPods := []string{}
	// Iterate over the labels that identify the replication controllers that we
	// want to check. The rcLabels contains the value values for the k8s-app key
	// that identify the replication controllers that we want to check. Using a label
	// rather than an explicit name is preferred because the names will typically have
	// a version suffix e.g. heapster-monitoring-v1 and this will change after a rolling
	// update e.g. to heapster-monitoring-v2. By using a label query we can check for the
	// situaiton when a heapster-monitoring-v1 and heapster-monitoring-v2 replication controller
	// is running (which would be an error except during a rolling update).
	for _, rcLabel := range rcLabels {
		rcList, err := c.ReplicationControllers(api.NamespaceDefault).List(labels.Set{"k8s-app": rcLabel}.AsSelector())
		if err != nil {
			return nil, err
		}
		if len(rcList.Items) != 1 {
			return nil, fmt.Errorf("expected to find one replica for RC with label %s but got %d",
				rcLabel, len(rcList.Items))
		}
		for _, rc := range rcList.Items {
			podList, err := c.Pods(api.NamespaceDefault).List(labels.Set(rc.Spec.Selector).AsSelector(), fields.Everything())
			if err != nil {
				return nil, err
			}
			for _, pod := range podList.Items {
				expectedPods = append(expectedPods, string(pod.UID))
			}
		}
	}
	return expectedPods, nil
}

// TODO Move to labels package.
func formatLabels(labelMap map[string]string) string {
	l := labels.Set(labelMap).String()
	if l == "" {
		l = "<none>"
	}
	return l
}

func (d *PodDescriber) Describe(namespace, name string) (string, error) {
	rc := d.ReplicationControllers(namespace)
	pc := d.Pods(namespace)

	pod, err := pc.Get(name)
	if err != nil {
		eventsInterface := d.Events(namespace)
		events, err2 := eventsInterface.List(
			labels.Everything(),
			eventsInterface.GetFieldSelector(&name, &namespace, nil, nil))
		if err2 == nil && len(events.Items) > 0 {
			return tabbedString(func(out io.Writer) error {
				fmt.Fprintf(out, "Pod '%v': error '%v', but found events.\n", name, err)
				DescribeEvents(events, out)
				return nil
			})
		}
		return "", err
	}

	var events *api.EventList
	if ref, err := api.GetReference(pod); err != nil {
		glog.Errorf("Unable to construct reference to '%#v': %v", pod, err)
	} else {
		ref.Kind = ""
		events, _ = d.Events(namespace).Search(ref)
	}

	rcs, err := getReplicationControllersForLabels(rc, labels.Set(pod.Labels))
	if err != nil {
		return "", err
	}

	return describePod(pod, rcs, events)
}

// CalculateNodeLabelPriority checks whether a particular label exists on a minion or not, regardless of its value.
// If presence is true, prioritizes minions that have the specified label, regardless of value.
// If presence is false, prioritizes minions that do not have the specified label.
func (n *NodeLabelPrioritizer) CalculateNodeLabelPriority(pod *api.Pod, podLister algorithm.PodLister, minionLister algorithm.MinionLister) (algorithm.HostPriorityList, error) {
	var score int
	minions, err := minionLister.List()
	if err != nil {
		return nil, err
	}

	labeledMinions := map[string]bool{}
	for _, minion := range minions.Items {
		exists := labels.Set(minion.Labels).Has(n.label)
		labeledMinions[minion.Name] = (exists && n.presence) || (!exists && !n.presence)
	}

	result := []algorithm.HostPriority{}
	//score int - scale of 0-10
	// 0 being the lowest priority and 10 being the highest
	for minionName, success := range labeledMinions {
		if success {
			score = 10
		} else {
			score = 0
		}
		result = append(result, algorithm.HostPriority{Host: minionName, Score: score})
	}
	return result, nil
}

func PodMatchesNodeLabels(pod *api.Pod, node *api.Node) bool {
	if len(pod.Spec.NodeSelector) == 0 {
		return true
	}
	selector := labels.SelectorFromSet(pod.Spec.NodeSelector)
	return selector.Matches(labels.Set(node.Labels))
}

// List returns []*api.Pod matching a query.
func (f FakePodLister) List(s labels.Selector) (selected []*api.Pod, err error) {
	for _, pod := range f {
		if s.Matches(labels.Set(pod.Labels)) {
			selected = append(selected, pod)
		}
	}
	return selected, nil
}

// MatchPodTemplate returns a generic matcher for a given label and field selector.
func MatchPodTemplate(label labels.Selector, field fields.Selector) generic.Matcher {
	return generic.MatcherFunc(func(obj runtime.Object) (bool, error) {
		podObj, ok := obj.(*api.PodTemplate)
		if !ok {
			return false, fmt.Errorf("not a pod template")
		}
		return label.Matches(labels.Set(podObj.Labels)), nil
	})
}

// Matcher returns a generic matcher for a given label and field selector.
func Matcher(label labels.Selector, field fields.Selector) generic.Matcher {
	return generic.MatcherFunc(func(obj runtime.Object) (bool, error) {
		sa, ok := obj.(*api.Secret)
		if !ok {
			return false, fmt.Errorf("not a secret")
		}
		fields := SelectableFields(sa)
		return label.Matches(labels.Set(sa.Labels)) && field.Matches(fields), nil
	})
}

// MatchPersistentVolume returns a generic matcher for a given label and field selector.
func MatchPersistentVolumes(label labels.Selector, field fields.Selector) generic.Matcher {
	return generic.MatcherFunc(func(obj runtime.Object) (bool, error) {
		persistentvolumeObj, ok := obj.(*api.PersistentVolume)
		if !ok {
			return false, fmt.Errorf("not a persistentvolume")
		}
		fields := PersistentVolumeToSelectableFields(persistentvolumeObj)
		return label.Matches(labels.Set(persistentvolumeObj.Labels)) && field.Matches(fields), nil
	})
}

// MatchNamespace returns a generic matcher for a given label and field selector.
func MatchNamespace(label labels.Selector, field fields.Selector) generic.Matcher {
	return generic.MatcherFunc(func(obj runtime.Object) (bool, error) {
		namespaceObj, ok := obj.(*api.Namespace)
		if !ok {
			return false, fmt.Errorf("not a namespace")
		}
		fields := NamespaceToSelectableFields(namespaceObj)
		return label.Matches(labels.Set(namespaceObj.Labels)) && field.Matches(fields), nil
	})
}

// GetPodServices gets the services that have the selector that match the labels on the given pod
func (f FakeServiceLister) GetPodServices(pod *api.Pod) (services []api.Service, err error) {
	var selector labels.Selector

	for _, service := range f {
		// consider only services that are in the same namespace as the pod
		if service.Namespace != pod.Namespace {
			continue
		}
		selector = labels.Set(service.Spec.Selector).AsSelector()
		if selector.Matches(labels.Set(pod.Labels)) {
			services = append(services, service)
		}
	}
	if len(services) == 0 {
		err = fmt.Errorf("Could not find service for pod %s in namespace %s with labels: %v", pod.Name, pod.Namespace, pod.Labels)
	}

	return
}

// MatchResourceQuota returns a generic matcher for a given label and field selector.
func MatchResourceQuota(label labels.Selector, field fields.Selector) generic.Matcher {
	return generic.MatcherFunc(func(obj runtime.Object) (bool, error) {
		resourcequotaObj, ok := obj.(*api.ResourceQuota)
		if !ok {
			return false, fmt.Errorf("not a resourcequota")
		}
		fields := ResourceQuotaToSelectableFields(resourcequotaObj)
		return label.Matches(labels.Set(resourcequotaObj.Labels)) && field.Matches(fields), nil
	})
}

// Please note that selector is filtering among the pods that have gotten into
// the store; there may have been some filtering that already happened before
// that.
func (s storePodsNamespacer) List(selector labels.Selector) (pods api.PodList, err error) {
	list := api.PodList{}
	for _, m := range s.store.List() {
		pod := m.(*api.Pod)
		if s.namespace == api.NamespaceAll || s.namespace == pod.Namespace {
			if selector.Matches(labels.Set(pod.Labels)) {
				list.Items = append(list.Items, *pod)
			}
		}
	}
	return list, nil
}

// syncReplicationController will sync the rc with the given key if it has had its expectations fulfilled, meaning
// it did not expect to see any more of its pods created or deleted. This function is not meant to be invoked
// concurrently with the same key.
func (rm *ReplicationManager) syncReplicationController(key string) error {
	startTime := time.Now()
	defer func() {
		glog.V(4).Infof("Finished syncing controller %q (%v)", key, time.Now().Sub(startTime))
	}()

	obj, exists, err := rm.controllerStore.Store.GetByKey(key)
	if !exists {
		glog.Infof("Replication Controller has been deleted %v", key)
		rm.expectations.DeleteExpectations(key)
		return nil
	}
	if err != nil {
		glog.Infof("Unable to retrieve rc %v from store: %v", key, err)
		rm.queue.Add(key)
		return err
	}
	controller := *obj.(*api.ReplicationController)
	if !rm.podStoreSynced() {
		// Sleep so we give the pod reflector goroutine a chance to run.
		time.Sleep(PodStoreSyncedPollPeriod)
		glog.Infof("Waiting for pods controller to sync, requeuing rc %v", controller.Name)
		rm.enqueueController(&controller)
		return nil
	}

	// Check the expectations of the rc before counting active pods, otherwise a new pod can sneak in
	// and update the expectations after we've retrieved active pods from the store. If a new pod enters
	// the store after we've checked the expectation, the rc sync is just deferred till the next relist.
	rcNeedsSync := rm.expectations.SatisfiedExpectations(&controller)
	podList, err := rm.podStore.Pods(controller.Namespace).List(labels.Set(controller.Spec.Selector).AsSelector())
	if err != nil {
		glog.Errorf("Error getting pods for rc %q: %v", key, err)
		rm.queue.Add(key)
		return err
	}

	// TODO: Do this in a single pass, or use an index.
	filteredPods := filterActivePods(podList.Items)
	if rcNeedsSync {
		rm.manageReplicas(filteredPods, &controller)
	}

	// Always updates status as pods come up or die.
	if err := updateReplicaCount(rm.qingClient.ReplicationControllers(controller.Namespace), controller, len(filteredPods)); err != nil {
		// Multiple things could lead to this update failing. Requeuing the controller ensures
		// we retry with some fairness.
		glog.V(2).Infof("Failed to update replica count for controller %v, requeuing", controller.Name)
		rm.enqueueController(&controller)
	}
	return nil
}

// MatchNode returns a generic matcher for a given label and field selector.
func MatchNode(label labels.Selector, field fields.Selector) generic.Matcher {
	return &generic.SelectionPredicate{
		Label: label,
		Field: field,
		GetAttrs: func(obj runtime.Object) (labels.Set, fields.Set, error) {
			nodeObj, ok := obj.(*api.Node)
			if !ok {
				return nil, nil, fmt.Errorf("not a node")
			}
			return labels.Set(nodeObj.ObjectMeta.Labels), NodeToSelectableFields(nodeObj), nil
		},
	}
}

// Scales RC to a random size within [0.5*size, 1.5*size] and lists all the pods afterwards.
// Scaling happens always based on original size, not the current size.
func scaleRC(wg *sync.WaitGroup, config *RCConfig) {
	defer GinkgoRecover()
	defer wg.Done()
	resizingTime := 3 * time.Minute

	sleepUpTo(resizingTime)
	newSize := uint(rand.Intn(config.Replicas) + config.Replicas/2)
	expectNoError(ScaleRC(config.Client, config.Namespace, config.Name, newSize),
		fmt.Sprintf("scaling rc %s for the first time", config.Name))
	selector := labels.SelectorFromSet(labels.Set(map[string]string{"name": config.Name}))
	_, err := config.Client.Pods(config.Namespace).List(selector, fields.Everything())
	expectNoError(err, fmt.Sprintf("listing pods from rc %v", config.Name))
}