"k8s.io/apimachinery/pkg/watch"
)

type decoratedWatcher struct {
	w         watch.Interface
	decorator func(runtime.Object)
	cancel    context.CancelFunc
	resultCh  chan watch.Event
}

func newDecoratedWatcher(ctx context.Context, w watch.Interface, decorator func(runtime.Object)) *decoratedWatcher {
	ctx, cancel := context.WithCancel(ctx)
	d := &decoratedWatcher{
		w:         w,
		decorator: decorator,
		cancel:    cancel,

	decorator := func(obj runtime.Object) {
		if pod, ok := obj.(*example.Pod); ok {
			pod.Annotations = map[string]string{"decorated": "true"}
		}
	}
	ctx, cancel := context.WithCancel(context.Background())
	dw := newDecoratedWatcher(ctx, w, decorator)
	defer dw.Stop()

	go func() {
		w.Error(&metav1.Status{Status: "Failure"})
		w.Add(&example.Pod{ObjectMeta: metav1.ObjectMeta{Name: "foo"}})
		w.Error(&metav1.Status{Status: "Failure"})

		// optimization is skipped
	}

	w, err := e.Storage.Watch(ctx, key, storageOpts)
	if err != nil {
		return nil, err
	}
	if e.Decorator != nil {
		return newDecoratedWatcher(ctx, w, e.Decorator), nil
	}
	return w, nil
}

// calculateTTL is a helper for retrieving the updated TTL for an object or
// returning an error if the TTL cannot be calculated. The defaultTTL is