// This is the main method implementing EDS.
// It replaces InstancesByPort in model - instead of iterating over all endpoints it uses
// the hostname-keyed map. And it avoids the conversion from Endpoint to ServiceEntry to envoy
// on each step: instead the conversion happens once, when an endpoint is first discovered.
//
// Note: the difference with `EDSUpdate` is that it only update the cache rather than requesting a push

// BuildClientConfig builds a client rest config from a kubeconfig filepath and context.
// It overrides the current context with the one provided (empty to use default).
//
// This is a modified version of k8s.io/client-go/tools/clientcmd/BuildConfigFromFlags with the
// difference that it loads default configs if not running in-cluster.
func BuildClientConfig(kubeconfig, context string) (*rest.Config, error) {

// result is used to contain the result of goroutines and is sent through a channel.
type result struct {
	update []byte
	err    error
}

// update adds a sorted list of keys and their values to the trie.
// It returns the root of the updated tree.
func (s *smt) update(root []byte, keys, values, batch [][]byte, iBatch, height int, shortcut, store bool, ch chan<- result) {
	if height == 0 {
		if bytes.Equal(values[0], defaultLeaf) {

	log := repairLog.WithLabels("pod", pod.Namespace+"/"+pod.Name)
	key := types.NamespacedName{Name: pod.Name, Namespace: pod.Namespace}
	// We will get an event every time the pod changes. The repair is not instantaneous, though -- it will only recover
	// once the pod restarts (in CrashLoopBackoff), which can take some time.
	// We don't want to constantly try to apply the iptables rules, which is unneeded and will fail.

  // When a driver is initialized on a node, it provides the same topology keys
  // along with values. Kubelet will expose these topology keys as labels
  // on its own node object.
  // When Kubernetes does topology aware provisioning, it can use this list to
  // determine which labels it should retrieve from the node object and pass
  // back to the driver.
  // It is possible for different nodes to use different topology keys.

// Debouncing and push request happens in a separate thread, it uses locks
// and we want to avoid complications, ConfigUpdate may already hold other locks.
// handleUpdates processes events from pushChannel
// It ensures that at minimum minQuiet time has elapsed since the last event before processing it.
// It also ensures that at most maxDelay is elapsed between receiving an event and processing it.

) krt.TransformationSingle[*v1.Pod, model.WorkloadInfo] {
	return func(ctx krt.HandlerContext, p *v1.Pod) *model.WorkloadInfo {
		// Pod Is Pending but have a pod IP should be a valid workload, we should build it ,
		// Such as the pod have initContainer which is initialing.
		// See https://github.com/istio/istio/issues/48854
		if (!IsPodRunning(p) && !IsPodPending(p)) || p.Spec.HostNetwork {
			return nil
		}

			return !removedVirtualHosts.Contains(virtualHost.Name)
		})
	}
}

// patchVirtualHost patches passed in virtual host if it is MERGE operation.
// The return value indicates whether the virtual host has been removed for REMOVE operations.
func patchVirtualHost(patchContext networking.EnvoyFilter_PatchContext,

)

var errNotFound = errors.New("item not found")

// EncodeIngressRuleName encodes an ingress rule name for a given ingress resource name,
// as well as the position of the rule and path specified within it, counting from 1.
// ruleNum == pathNum == 0 indicates the default backend specified for an ingress.
func EncodeIngressRuleName(ingressName string, ruleNum, pathNum int) string {

	return extractCertExpiryTimestamp("CA cert", b.GetCertChainPem())
}

// TimeBeforeCertExpires returns the time duration before the cert gets expired.
// It returns an error if it failed to extract the cert expiration timestamp.
// The returned time duration could be a negative value indicating the cert has already been expired.