// If the image does not exist, it returns false and an optional error message, for debug purposes.
func Exists(image string) (bool, error) {
	ref, err := name.ParseReference(image)
	if err != nil {
		return false, fmt.Errorf("parsing reference %q: %w", image, err)
	}
	_, err = remote.Get(ref, remote.WithAuthFromKeychain(authn.DefaultKeychain))
	if err == nil {
		// image exists

			bases[keys[i]] = rbi
		}
		basesMu.Unlock()
	}()

	t0 := time.Now()
	for i, b := range keys {
		b, i := b, i
		go func() {
			defer wg.Done()
			ref, err := name.ParseReference(b.name)
			if err != nil {
				log.WithLabels("image", b).Warnf("base failed: %v", err)
				return
			}
			plat := v1.Platform{
				Architecture: b.arch,
				OS:           "linux",
			}

func (o *ImageFetcher) PrepareFetch(url string) (binaryFetcher func() ([]byte, error), actualDigest string, err error) {
	ref, err := name.ParseReference(url)
	if err != nil {
		err = fmt.Errorf("could not parse url in image reference: %v", err)
		return
	}
	wasmLog.Infof("fetching image %s from registry %s with tag %s", ref.Context().RepositoryStr(),

	convertedTag := tag
	if converted, found := h.tagMap[imageName+":"+tag]; found {
		convertedTag = converted
	}

	u := fmt.Sprintf("%v/%v:%v", *registry, imageName, convertedTag)
	ref, err := name.ParseReference(u)
	if err != nil {
		return "", fmt.Errorf("could not parse url in image reference: %v", err)
	}

	t := remote.DefaultTransport.(*http.Transport).Clone()

	}

	go func() {
		cache.purge()
	}()
	return cache
}

func moduleNameFromURL(fullURLStr string) string {
	if strings.HasPrefix(fullURLStr, ociURLPrefix) {
		if tag, err := name.ParseReference(fullURLStr[len(ociURLPrefix):]); err == nil {
			// remove tag or sha
			return ociURLPrefix + tag.Context().Name()
		}
	}
	return fullURLStr
}