feat(invocation): provide New constructor and encoding to wire-format

token/invocation/options.go

@@ -0,0 +1,134 @@
+package invocation
+
+import (
+	"time"
+
+	"github.com/ipfs/go-cid"
+	"github.com/ipld/go-ipld-prime/datamodel"
+	"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
+
+// WithArgument adds a key/value pair to the Token's Arguments field.
+func WithArgument(key string, val datamodel.Node) Option {
+	return func(t *Token) error {
+		t.arguments[key] = val
+
+		return nil
+	}
+}
+
+// WithArguments sets the Token's Arguments field to the provided map.
+//
+// Note that this will overwrite any existing Arguments whether provided
+// by a previous call to this function or by one or more calls to
+// WithArgument.
+func WithArguments(args map[string]datamodel.Node) Option {
+	return func(t *Token) error {
+		t.arguments = args
+
+		return nil
+	}
+}
+
+// WithAudience sets the Token's audience to the provided did.DID.
+//
+// If the provided did.DID is the same as the Token's subject, the
+// audience is not set.
+func WithAudience(aud did.DID) Option {
+	return func(t *Token) error {
+		if t.subject.String() != aud.String() {
+			t.audience = aud
+		}
+
+		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)
+	}
+}
+
+// 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 require.
+func WithNonce(nonce []byte) Option {
+	return func(t *Token) error {
+		t.nonce = nonce
+
+		return nil
+	}
+}
+
+// WithEmptyNonce sets the Token's nonce to an empty byte slice as
+// suggested by the UCAN spec for invocation tokens that represent
+// idem
+func WithEmptyNonce() Option {
+	return func(t *Token) error {
+		t.nonce = []byte{}
+
+		return nil
+	}
+}
+
+// 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 {
+		t.expiration = &exp
+
+		return nil
+	}
+}
+
+// WithExpirationIn set's the Token's optional "expiration" field to
+// Now() plus the given duration.
+func WithExpirationIn(exp time.Duration) Option {
+	return func(t *Token) error {
+		expTime := time.Now().Add(exp)
+		t.expiration = &expTime
+
+		return nil
+	}
+}
+
+// WithInvokedAt sets the Token's invokedAt field to the provided
+// time.Time.
+func WithInvokedAt(iat time.Time) Option {
+	return func(t *Token) error {
+		t.invokedAt = &iat
+
+		return nil
+	}
+}
+
+// WithInvokedAtIn sets the Token's invokedAt field to Now() plus the
+// given duration.
+func WithInvokedAtIn(after time.Duration) Option {
+	return func(t *Token) error {
+		iat := time.Now().Add(after)
+		t.invokedAt = &iat
+
+		return nil
+	}
+}
+
+// WithCause sets the Token's cause field to the provided cid.Cid.
+func WithCause(cause *cid.Cid) Option {
+	return func(t *Token) error {
+		t.cause = cause
+
+		return nil
+	}
+}