// NewStorageCodec assembles a storage codec for the provided storage media type, the provided serializer, and the requested
// storage and memory versions.
func NewStorageCodec(storageMediaType string, ns runtime.StorageSerializer, storageVersion, memoryVersion unversioned.GroupVersion, config storagebackend.Config) (runtime.Codec, error) {
	mediaType, _, err := mime.ParseMediaType(storageMediaType)
	if err != nil {
		return nil, fmt.Errorf("%q is not a valid mime-type", storageMediaType)
	}
	serializer, ok := runtime.SerializerInfoForMediaType(ns.SupportedMediaTypes(), mediaType)
	if !ok {
		return nil, fmt.Errorf("unable to find serializer for %q", storageMediaType)
	}

	s := serializer.Serializer

	// etcd2 only supports string data - we must wrap any result before returning
	// TODO: storagebackend should return a boolean indicating whether it supports binary data
	if !serializer.EncodesAsText && (config.Type == storagebackend.StorageTypeUnset || config.Type == storagebackend.StorageTypeETCD2) {
		glog.V(4).Infof("Wrapping the underlying binary storage serializer with a base64 encoding for etcd2")
		s = runtime.NewBase64Serializer(s)
	}

	encoder := ns.EncoderForVersion(
		s,
		runtime.NewMultiGroupVersioner(
			storageVersion,
			unversioned.GroupKind{Group: storageVersion.Group},
			unversioned.GroupKind{Group: memoryVersion.Group},
		),
	)

	ds := recognizer.NewDecoder(s, ns.UniversalDeserializer())
	decoder := ns.DecoderToVersion(
		ds,
		runtime.NewMultiGroupVersioner(
			memoryVersion,
			unversioned.GroupKind{Group: memoryVersion.Group},
			unversioned.GroupKind{Group: storageVersion.Group},
		),
	)

	return runtime.NewCodec(encoder, decoder), nil
}