feat: helper function to convert MultiAsset to PlutusData

Fixes #1101

Signed-off-by: Aurora Gaffney <[email protected]>

Author: agaffney

ledger/common/common.go

@@ -15,9 +15,13 @@
 package common
 
 import (
+	"bytes"
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
+	"maps"
+	"math/big"
+	"slices"
 
 	"github.com/blinklabs-io/gouroboros/cbor"
 	"github.com/blinklabs-io/plutigo/pkg/data"
@@ -199,6 +203,38 @@ func (m MultiAsset[T]) MarshalJSON() ([]byte, error) {
 	return json.Marshal(&tmpAssets)
 }
 
+func (m *MultiAsset[T]) ToPlutusData() data.PlutusData {
+	tmpData := make([][2]data.PlutusData, 0, len(m.data))
+	// Sort policy IDs
+	policyKeys := slices.Collect(maps.Keys(m.data))
+	slices.SortFunc(policyKeys, func(a, b Blake2b224) int { return bytes.Compare(a.Bytes(), b.Bytes()) })
+	for _, policyId := range policyKeys {
+		policyData := m.data[policyId]
+		tmpPolicyData := make([][2]data.PlutusData, 0, len(policyData))
+		// Sort asset names
+		assetKeys := slices.Collect(maps.Keys(policyData))
+		slices.SortFunc(assetKeys, func(a, b cbor.ByteString) int { return bytes.Compare(a.Bytes(), b.Bytes()) })
+		for _, assetName := range assetKeys {
+			amount := policyData[assetName]
+			tmpPolicyData = append(
+				tmpPolicyData,
+				[2]data.PlutusData{
+					data.NewByteString(assetName.Bytes()),
+					data.NewInteger(big.NewInt(int64(amount))),
+				},
+			)
+		}
+		tmpData = append(
+			tmpData,
+			[2]data.PlutusData{
+				data.NewByteString(policyId.Bytes()),
+				data.NewMap(tmpPolicyData),
+			},
+		)
+	}
+	return data.NewMap(tmpData)
+}
+
 func (m *MultiAsset[T]) Policies() []Blake2b224 {
 	ret := []Blake2b224{}
 	for policyId := range m.data {

ledger/common/common_test.go

@@ -17,6 +17,7 @@ package common
 import (
 	"encoding/hex"
 	"encoding/json"
+	"math/big"
 	"reflect"
 	"testing"
 
@@ -128,6 +129,90 @@ func TestMultiAssetJson(t *testing.T) {
 	}
 }
 
+func TestMultiAssetToPlutusData(t *testing.T) {
+	testDefs := []struct {
+		multiAssetObj any
+		expectedData  data.PlutusData
+	}{
+		{
+			multiAssetObj: MultiAsset[MultiAssetTypeOutput]{
+				data: map[Blake2b224]map[cbor.ByteString]MultiAssetTypeOutput{
+					NewBlake2b224(test.DecodeHexString("29a8fb8318718bd756124f0c144f56d4b4579dc5edf2dd42d669ac61")): {
+						cbor.NewByteString(test.DecodeHexString("6675726e697368613239686e")): 123456,
+					},
+				},
+			},
+			expectedData: data.NewMap(
+				[][2]data.PlutusData{
+					{
+						data.NewByteString(test.DecodeHexString("29a8fb8318718bd756124f0c144f56d4b4579dc5edf2dd42d669ac61")),
+						data.NewMap(
+							[][2]data.PlutusData{
+								{
+									data.NewByteString(test.DecodeHexString("6675726e697368613239686e")),
+									data.NewInteger(big.NewInt(123456)),
+								},
+							},
+						),
+					},
+				},
+			),
+		},
+		{
+			multiAssetObj: MultiAsset[MultiAssetTypeOutput]{
+				data: map[Blake2b224]map[cbor.ByteString]MultiAssetTypeOutput{
+					NewBlake2b224(test.DecodeHexString("29a8fb8318718bd756124f0c144f56d4b4579dc5edf2dd42d669ac61")): {
+						cbor.NewByteString(test.DecodeHexString("6675726e697368613239686e")): 123456,
+					},
+					NewBlake2b224(test.DecodeHexString("eaf8042c1d8203b1c585822f54ec32c4c1bb4d3914603e2cca20bbd5")): {
+						cbor.NewByteString(test.DecodeHexString("426f7764757261436f6e63657074733638")): 234567,
+					},
+				},
+			},
+			expectedData: data.NewMap(
+				[][2]data.PlutusData{
+					{
+						data.NewByteString(test.DecodeHexString("29a8fb8318718bd756124f0c144f56d4b4579dc5edf2dd42d669ac61")),
+						data.NewMap(
+							[][2]data.PlutusData{
+								{
+									data.NewByteString(test.DecodeHexString("6675726e697368613239686e")),
+									data.NewInteger(big.NewInt(123456)),
+								},
+							},
+						),
+					},
+					{
+						data.NewByteString(test.DecodeHexString("eaf8042c1d8203b1c585822f54ec32c4c1bb4d3914603e2cca20bbd5")),
+						data.NewMap(
+							[][2]data.PlutusData{
+								{
+									data.NewByteString(test.DecodeHexString("426f7764757261436f6e63657074733638")),
+									data.NewInteger(big.NewInt(234567)),
+								},
+							},
+						),
+					},
+				},
+			),
+		},
+	}
+	for _, testDef := range testDefs {
+		var tmpData data.PlutusData
+		switch v := testDef.multiAssetObj.(type) {
+		case MultiAsset[MultiAssetTypeOutput]:
+			tmpData = v.ToPlutusData()
+		case MultiAsset[MultiAssetTypeMint]:
+			tmpData = v.ToPlutusData()
+		default:
+			t.Fatalf("test def multi-asset object was not expected type: %T", v)
+		}
+		if !reflect.DeepEqual(tmpData, testDef.expectedData) {
+			t.Fatalf("did not get expected PlutusData\n     got: %#v\n  wanted: %#v", tmpData, testDef.expectedData)
+		}
+	}
+}
+
 func TestMultiAssetCompare(t *testing.T) {
 	testDefs := []struct {
 		asset1         *MultiAsset[MultiAssetTypeOutput]