tokens: expose Inspect and FindTag

tokens/inspect.go

@@ -1,90 +1,19 @@
 package tokens
 
-//
-// // EnvelopeInfo describes the fields of an Envelope enclosing a UCAN token.
-// type EnvelopeInfo struct {
-// 	Signature    []byte
-// 	Tag          string
-// 	VarsigHeader []byte
-// }
-//
-// // InspectEnvelope accepts arbitrary data and attempts to decode it as a
-// // UCAN token's Envelope.
-// func Inspect(data []byte) (EnvelopeInfo, error) {
-// 	undef := EnvelopeInfo{}
-//
-// 	node, err := decodeAny(data)
-// 	if err != nil {
-// 		return undef, err
-// 	}
-//
-// 	info, err := envelope.inspect(node)
-// 	if err != nil {
-// 		return undef, err
-// 	}
-//
-// 	iterator := info.SigPayloadNode.MapIterator()
-// 	foundVarsigHeader := false
-// 	foundTokenPayload := false
-// 	tag := ""
-// 	i := 0
-//
-// 	for !iterator.Done() {
-// 		k, _, err := iterator.Next()
-// 		if err != nil {
-// 			return undef, err
-// 		}
-//
-// 		key, err := k.AsString()
-// 		if err != nil {
-// 			return undef, err
-// 		}
-//
-// 		if key == envelope.VarsigHeaderKey {
-// 			foundVarsigHeader = true
-// 			i++
-//
-// 			continue
-// 		}
-//
-// 		if strings.HasPrefix(key, envelope.UCANTagPrefix) {
-// 			tag = key
-// 			foundTokenPayload = true
-// 			i++
-// 		}
-// 	}
-//
-// 	if i != 2 {
-// 		return undef, fmt.Errorf("expected two and only two fields in SigPayload: %d", i)
-// 	}
-//
-// 	if !foundVarsigHeader {
-// 		return undef, errors.New("failed to find VarsigHeader field")
-// 	}
-//
-// 	if !foundTokenPayload {
-// 		return undef, errors.New("failed to find TokenPayload field")
-// 	}
-//
-// 	return EnvelopeInfo{
-// 		Signature:    info.Signature,
-// 		Tag:          tag,
-// 		VarsigHeader: info.VarsigHeader,
-// 	}, nil
-// }
-//
-// func decodeAny(data []byte) (datamodel.Node, error) {
-// 	for _, decoder := range []codec.Decoder{
-// 		dagcbor.Decode,
-// 		dagjson.Decode,
-// 		cbor.Decode,
-// 		json.Decode,
-// 		raw.Decode,
-// 	} {
-// 		if node, err := ipld.Decode(data, decoder); err == nil {
-// 			return node, nil
-// 		}
-// 	}
-//
-// 	return nil, errors.New("failed to decode (any) the provided data")
-// }
+import (
+	"github.com/ipld/go-ipld-prime/datamodel"
+
+	"github.com/ucan-wg/go-ucan/tokens/internal/envelope"
+)
+
+type Info = envelope.Info
+
+// Inspect inspects the given token IPLD representation and extract some envelope facts.
+func Inspect(node datamodel.Node) (Info, error) {
+	return envelope.Inspect(node)
+}
+
+// FindTag inspect the given token IPLD representation and extract the token tag.
+func FindTag(node datamodel.Node) (string, error) {
+	return envelope.FindTag(node)
+}