From ce148271a3142f016b7b642b5d9777efa69f3bae Mon Sep 17 00:00:00 2001
From: Aurora Gaffney <aurora@blinklabs.io>
Date: Wed, 17 Jul 2024 21:02:01 -0500
Subject: [PATCH] feat: support for Conway redeemers and PlutusV3 TX witnesses
 (#672)

Fixes #671
---
 ledger/alonzo.go | 16 +++++++++++++-
 ledger/conway.go | 55 ++++++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 68 insertions(+), 3 deletions(-)

diff --git a/ledger/alonzo.go b/ledger/alonzo.go
index 0414d80b..ebef8a2a 100644
--- a/ledger/alonzo.go
+++ b/ledger/alonzo.go
@@ -253,11 +253,25 @@ func (o AlonzoTransactionOutput) Utxorpc() *utxorpc.TxOutput {
 	}
 }
 
+type AlonzoRedeemer struct {
+	cbor.StructAsArray
+	Tag     uint8
+	Index   uint32
+	Data    cbor.RawMessage
+	ExUnits RedeemerExUnits
+}
+
+type RedeemerExUnits struct {
+	cbor.StructAsArray
+	Memory uint64
+	Steps  uint64
+}
+
 type AlonzoTransactionWitnessSet struct {
 	ShelleyTransactionWitnessSet
 	PlutusScripts []cbor.RawMessage `cbor:"3,keyasint,omitempty"`
 	PlutusData    []cbor.RawMessage `cbor:"4,keyasint,omitempty"`
-	Redeemers     []cbor.RawMessage `cbor:"5,keyasint,omitempty"`
+	Redeemers     []AlonzoRedeemer  `cbor:"5,keyasint,omitempty"`
 }
 
 func (t *AlonzoTransactionWitnessSet) UnmarshalCBOR(cborData []byte) error {
diff --git a/ledger/conway.go b/ledger/conway.go
index cddba314..8dd9ea49 100644
--- a/ledger/conway.go
+++ b/ledger/conway.go
@@ -38,7 +38,7 @@ type ConwayBlock struct {
 	cbor.DecodeStoreCbor
 	Header                 *ConwayBlockHeader
 	TransactionBodies      []ConwayTransactionBody
-	TransactionWitnessSets []BabbageTransactionWitnessSet
+	TransactionWitnessSets []ConwayTransactionWitnessSet
 	TransactionMetadataSet map[uint]*cbor.LazyValue
 	InvalidTransactions    []uint
 }
@@ -119,6 +119,57 @@ func (h *ConwayBlockHeader) Era() Era {
 	return eras[EraIdConway]
 }
 
+type ConwayRedeemerKey struct {
+	cbor.StructAsArray
+	Tag   uint8
+	Index uint32
+}
+
+type ConwayRedeemerValue struct {
+	cbor.StructAsArray
+	Data    cbor.RawMessage
+	ExUnits RedeemerExUnits
+}
+
+type ConwayRedeemers struct {
+	Redeemers map[ConwayRedeemerKey]ConwayRedeemerValue
+	legacy    bool
+}
+
+func (r *ConwayRedeemers) UnmarshalCBOR(cborData []byte) error {
+	// Try to parse as legacy redeemer first
+	var tmpRedeemers []AlonzoRedeemer
+	if _, err := cbor.Decode(cborData, &tmpRedeemers); err == nil {
+		// Copy data from legacy redeemer type
+		for _, redeemer := range tmpRedeemers {
+			tmpKey := ConwayRedeemerKey{
+				Tag:   redeemer.Tag,
+				Index: redeemer.Index,
+			}
+			tmpVal := ConwayRedeemerValue{
+				Data:    redeemer.Data,
+				ExUnits: redeemer.ExUnits,
+			}
+			r.Redeemers[tmpKey] = tmpVal
+		}
+		r.legacy = true
+	} else {
+		_, err := cbor.Decode(cborData, &(r.Redeemers))
+		return err
+	}
+	return nil
+}
+
+type ConwayTransactionWitnessSet struct {
+	BabbageTransactionWitnessSet
+	Redeemers       ConwayRedeemers   `cbor:"5,keyasint,omitempty"`
+	PlutusV3Scripts []cbor.RawMessage `cbor:"7,keyasint,omitempty"`
+}
+
+func (t *ConwayTransactionWitnessSet) UnmarshalCBOR(cborData []byte) error {
+	return t.UnmarshalCbor(cborData, t)
+}
+
 type ConwayTransactionBody struct {
 	BabbageTransactionBody
 	TxVotingProcedures     VotingProcedures    `cbor:"19,keyasint,omitempty"`
@@ -336,7 +387,7 @@ type ConwayTransaction struct {
 	cbor.StructAsArray
 	cbor.DecodeStoreCbor
 	Body       ConwayTransactionBody
-	WitnessSet BabbageTransactionWitnessSet
+	WitnessSet ConwayTransactionWitnessSet
 	IsTxValid  bool
 	TxMetadata *cbor.LazyValue
 }