From 7e4b9f1cbc27c9fbf5438c65479c0cde7f47ec2d Mon Sep 17 00:00:00 2001
From: Aurora Gaffney <aurora@blinklabs.io>
Date: Sun, 6 Oct 2024 18:52:17 -0500
Subject: [PATCH] feat: Mary protocol parameter updates

* update protocol parameter set from protocol param update spec

Fixes #743
---
 ledger/mary/mary.go         |  8 ----
 ledger/mary/pparams.go      | 31 ++++++++++++++
 ledger/mary/pparams_test.go | 85 +++++++++++++++++++++++++++++++++++++
 3 files changed, 116 insertions(+), 8 deletions(-)
 create mode 100644 ledger/mary/pparams.go
 create mode 100644 ledger/mary/pparams_test.go

diff --git a/ledger/mary/mary.go b/ledger/mary/mary.go
index 2708a0c7..7d2ced51 100644
--- a/ledger/mary/mary.go
+++ b/ledger/mary/mary.go
@@ -399,14 +399,6 @@ func (v *MaryTransactionOutputValue) MarshalCBOR() ([]byte, error) {
 	}
 }
 
-type MaryProtocolParameters struct {
-	allegra.AllegraProtocolParameters
-}
-
-type MaryProtocolParameterUpdate struct {
-	allegra.AllegraProtocolParameterUpdate
-}
-
 func NewMaryBlockFromCbor(data []byte) (*MaryBlock, error) {
 	var maryBlock MaryBlock
 	if _, err := cbor.Decode(data, &maryBlock); err != nil {
diff --git a/ledger/mary/pparams.go b/ledger/mary/pparams.go
new file mode 100644
index 00000000..595019f9
--- /dev/null
+++ b/ledger/mary/pparams.go
@@ -0,0 +1,31 @@
+// Copyright 2024 Blink Labs Software
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mary
+
+import "github.com/blinklabs-io/gouroboros/ledger/allegra"
+
+type MaryProtocolParameters struct {
+	allegra.AllegraProtocolParameters
+}
+
+func (p *MaryProtocolParameters) Update(paramUpdate *MaryProtocolParameterUpdate) {
+	p.AllegraProtocolParameters.Update(
+		&paramUpdate.AllegraProtocolParameterUpdate,
+	)
+}
+
+type MaryProtocolParameterUpdate struct {
+	allegra.AllegraProtocolParameterUpdate
+}
diff --git a/ledger/mary/pparams_test.go b/ledger/mary/pparams_test.go
new file mode 100644
index 00000000..2dacbbaf
--- /dev/null
+++ b/ledger/mary/pparams_test.go
@@ -0,0 +1,85 @@
+// Copyright 2024 Blink Labs Software
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mary_test
+
+import (
+	"encoding/hex"
+	"math/big"
+	"reflect"
+	"testing"
+
+	"github.com/blinklabs-io/gouroboros/cbor"
+	"github.com/blinklabs-io/gouroboros/ledger/allegra"
+	"github.com/blinklabs-io/gouroboros/ledger/mary"
+	"github.com/blinklabs-io/gouroboros/ledger/shelley"
+)
+
+func TestMaryProtocolParamsUpdate(t *testing.T) {
+	testDefs := []struct {
+		startParams    mary.MaryProtocolParameters
+		updateCbor     string
+		expectedParams mary.MaryProtocolParameters
+	}{
+		{
+			startParams: mary.MaryProtocolParameters{
+				AllegraProtocolParameters: allegra.AllegraProtocolParameters{
+					ShelleyProtocolParameters: shelley.ShelleyProtocolParameters{
+						Decentralization: &cbor.Rat{Rat: new(big.Rat).SetInt64(1)},
+					},
+				},
+			},
+			updateCbor: "a10cd81e82090a",
+			expectedParams: mary.MaryProtocolParameters{
+				AllegraProtocolParameters: allegra.AllegraProtocolParameters{
+					ShelleyProtocolParameters: shelley.ShelleyProtocolParameters{
+						Decentralization: &cbor.Rat{Rat: big.NewRat(9, 10)},
+					},
+				},
+			},
+		},
+		{
+			startParams: mary.MaryProtocolParameters{
+				AllegraProtocolParameters: allegra.AllegraProtocolParameters{
+					ShelleyProtocolParameters: shelley.ShelleyProtocolParameters{
+						ProtocolMajor: 4,
+					},
+				},
+			},
+			updateCbor: "a10e820500",
+			expectedParams: mary.MaryProtocolParameters{
+				AllegraProtocolParameters: allegra.AllegraProtocolParameters{
+					ShelleyProtocolParameters: shelley.ShelleyProtocolParameters{
+						ProtocolMajor: 5,
+					},
+				},
+			},
+		},
+	}
+	for _, testDef := range testDefs {
+		cborBytes, err := hex.DecodeString(testDef.updateCbor)
+		if err != nil {
+			t.Fatalf("unexpected error: %s", err)
+		}
+		var tmpUpdate mary.MaryProtocolParameterUpdate
+		if _, err := cbor.Decode(cborBytes, &tmpUpdate); err != nil {
+			t.Fatalf("unexpected error: %s", err)
+		}
+		tmpParams := testDef.startParams
+		tmpParams.Update(&tmpUpdate)
+		if !reflect.DeepEqual(tmpParams, testDef.expectedParams) {
+			t.Fatalf("did not get expected params:\n     got: %#v\n  wanted: %#v", tmpParams, testDef.expectedParams)
+		}
+	}
+}