rename tokens to token

token/delegation/options.go

@@ -0,0 +1,72 @@
+package delegation
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/ucan-wg/go-ucan/did"
+)
+
+// Option is a type that allows optional fields to be set during the
+// creation of a Token.
+type Option func(*Token) error
+
+// WithExpiration set's the Token's optional "expiration" field to the
+// value of the provided time.Time.
+func WithExpiration(exp time.Time) Option {
+	return func(t *Token) error {
+		if exp.Before(time.Now()) {
+			return fmt.Errorf("a Token's expiration should be set to a time in the future: %s", exp.String())
+		}
+
+		t.expiration = &exp
+		return nil
+	}
+}
+
+// WithMeta adds a key/value pair in the "meta" field.
+//
+// WithMeta can be used multiple times in the same call.
+// Accepted types for the value are: bool, string, int, int32, int64, []byte,
+// and ipld.Node.
+func WithMeta(key string, val any) Option {
+	return func(t *Token) error {
+		return t.meta.Add(key, val)
+	}
+}
+
+// WithNotBefore set's the Token's optional "notBefore" field to the value
+// of the provided time.Time.
+func WithNotBefore(nbf time.Time) Option {
+	return func(t *Token) error {
+		if nbf.Before(time.Now()) {
+			return fmt.Errorf("a Token's \"not before\" field should be set to a time in the future: %s", nbf.String())
+		}
+
+		t.notBefore = &nbf
+		return nil
+	}
+}
+
+// WithSubject sets the Tokens's optional "subject" field to the value of
+// provided did.DID.
+//
+// This Option should only be used with the New constructor - since
+// Subject is a required parameter when creating a Token via the  Root
+// constructor, any value provided via this Option will be silently
+// overwritten.
+func WithSubject(sub did.DID) Option {
+	return func(t *Token) error {
+		t.subject = sub
+		return nil
+	}
+}
+
+// WithNonce sets the Token's nonce with the given value.
+// If this option is not used, a random 12-byte nonce is generated for this required field.
+func WithNonce(nonce []byte) Option {
+	return func(t *Token) error {
+		t.nonce = nonce
+		return nil
+	}
+}