// 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 replication controllers managing a pod. Returns an error only if no matching controllers are found.
func (s *StoreToReplicationControllerLister) 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
}

// 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
}

// ListPods returns []api.Pod matching a query.
func (f FakePodLister) ListPods(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
}

// WatchControllers begins watching for new, changed, or deleted controllers.
func (registry *EtcdRegistry) WatchControllers(label, field labels.Selector, resourceVersion uint64) (watch.Interface, error) {
	if !field.Empty() {
		return nil, fmt.Errorf("no field selector implemented for controllers")
	}
	return registry.helper.WatchList("/registry/controllers", resourceVersion, func(obj interface{}) bool {
		return label.Matches(labels.Set(obj.(*api.ReplicationController).Labels))
	})
}

// Watch begins watching for new, changed, or deleted ImageRepositories.
func (s *ImageRepositoryStorage) Watch(label, field labels.Selector, resourceVersion uint64) (watch.Interface, error) {
	return s.registry.WatchImageRepositories(resourceVersion, func(repo *api.ImageRepository) bool {
		fields := labels.Set{
			"ID": repo.ID,
			"DockerImageRepository": repo.DockerImageRepository,
		}
		return label.Matches(labels.Set(repo.Labels)) && field.Matches(fields)
	})
}

// SelectorParam adds the given selector as a query parameter with the name paramName.
func (r *Request) SelectorParam(paramName string, s labels.Selector) *Request {
	if r.err != nil {
		return r
	}
	if s.Empty() {
		return r
	}
	return r.setParam(paramName, s.String())
}

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

// TODO Get rid of the selector because that is confusing because the user might not realize that there has already been
// some selection at the caching stage.  Also, consistency will facilitate code generation.  However, the pkg/client
// is inconsistent too.
func (s *StoreToPodLister) List(selector labels.Selector) (pods []api.Pod, err error) {
	for _, m := range s.Store.List() {
		pod := m.(*api.Pod)
		if selector.Matches(labels.Set(pod.Labels)) {
			pods = append(pods, *pod)
		}
	}
	return pods, nil
}

func (registry *MemoryRegistry) ListPods(selector labels.Selector) ([]api.Pod, error) {
	result := []api.Pod{}
	for _, value := range registry.podData {
		if selector.Matches(labels.Set(value.Labels)) {
			result = append(result, value)
		}
	}
	return result, nil
}

// LabelsSelectorParam adds the given selector as a query parameter
func (r *Request) LabelsSelectorParam(s labels.Selector) *Request {
	if r.err != nil {
		return r
	}
	if s.Empty() {
		return r
	}
	return r.setParam(api.LabelSelectorQueryParam(r.apiVersion), s.String())
}

// 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
	})
}

// Matchtoken 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) {
		clientObj, ok := obj.(*api.OAuthClientAuthorization)
		if !ok {
			return false, fmt.Errorf("not a client authorization")
		}
		fields := SelectableFields(clientObj)
		return label.Matches(labels.Set(clientObj.Labels)) && field.Matches(fields), nil
	})
}

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

// Matchtoken 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) {
		tokenObj, ok := obj.(*api.OAuthAccessToken)
		if !ok {
			return false, fmt.Errorf("not a token")
		}
		fields := SelectableFields(tokenObj)
		return label.Matches(labels.Set(tokenObj.Labels)) && field.Matches(fields), 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.ServiceAccount)
		if !ok {
			return false, fmt.Errorf("not a serviceaccount")
		}
		fields := SelectableFields(sa)
		return label.Matches(labels.Set(sa.Labels)) && field.Matches(fields), nil
	})
}

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

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

// 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
	})
}