From 23aebae40d29a3d8d671d05a3a194febb2635186 Mon Sep 17 00:00:00 2001
From: Aurora Gaffney <aurora@blinklabs.io>
Date: Tue, 31 Dec 2024 15:15:20 -0600
Subject: [PATCH] fix: custom CBOR marshaling for ShelleyGenesisConfig (#818)

---
 ledger/shelley/genesis.go      | 96 +++++++++++++++++++++++++++++++++-
 ledger/shelley/genesis_test.go | 10 ++--
 2 files changed, 100 insertions(+), 6 deletions(-)

diff --git a/ledger/shelley/genesis.go b/ledger/shelley/genesis.go
index e32b23c8..4c2a5de1 100644
--- a/ledger/shelley/genesis.go
+++ b/ledger/shelley/genesis.go
@@ -15,19 +15,22 @@
 package shelley
 
 import (
+	"encoding/hex"
 	"encoding/json"
 	"io"
 	"os"
 	"time"
 
+	"github.com/blinklabs-io/gouroboros/cbor"
 	"github.com/blinklabs-io/gouroboros/ledger/common"
 )
 
 type ShelleyGenesis struct {
+	cbor.StructAsArray
 	SystemStart        time.Time                    `json:"systemStart"`
 	NetworkMagic       uint32                       `json:"networkMagic"`
 	NetworkId          string                       `json:"networkid"`
-	ActiveSlotsCoeff   float32                      `json:"activeSlotsCoeff"`
+	ActiveSlotsCoeff   common.GenesisRat            `json:"activeSlotsCoeff"`
 	SecurityParam      int                          `json:"securityParam"`
 	EpochLength        int                          `json:"epochLength"`
 	SlotsPerKESPeriod  int                          `json:"slotsPerKESPeriod"`
@@ -36,12 +39,67 @@ type ShelleyGenesis struct {
 	UpdateQuorum       int                          `json:"updateQuorum"`
 	MaxLovelaceSupply  uint64                       `json:"maxLovelaceSupply"`
 	ProtocolParameters ShelleyGenesisProtocolParams `json:"protocolParams"`
-	GenDelegs          map[string]map[string]any    `json:"genDelegs"`
+	GenDelegs          map[string]map[string]string `json:"genDelegs"`
 	InitialFunds       map[string]any               `json:"initialFunds"`
 	Staking            any                          `json:"staking"`
 }
 
+func (g ShelleyGenesis) MarshalCBOR() ([]byte, error) {
+	genDelegs := map[cbor.ByteString][]cbor.ByteString{}
+	for k, v := range g.GenDelegs {
+		keyBytes, err := hex.DecodeString(k)
+		if err != nil {
+			return nil, err
+		}
+		vrfBytes, err := hex.DecodeString(v["vrf"])
+		if err != nil {
+			return nil, err
+		}
+		delegateBytes, err := hex.DecodeString(v["delegate"])
+		if err != nil {
+			return nil, err
+		}
+		genDelegs[cbor.NewByteString(keyBytes)] = []cbor.ByteString{
+			cbor.NewByteString(delegateBytes),
+			cbor.NewByteString(vrfBytes),
+		}
+	}
+	staking := []any{}
+	if g.Staking == nil {
+		staking = []any{
+			map[any]any{},
+			map[any]any{},
+		}
+	}
+	tmpData := []any{
+		[]any{
+			g.SystemStart.Year(),
+			g.SystemStart.YearDay(),
+			g.SystemStart.Nanosecond() * 1000,
+		},
+		g.NetworkMagic,
+		map[string]int{"Testnet": 0, "Mainnet": 1}[g.NetworkId],
+		[]any{
+			g.ActiveSlotsCoeff.Num().Int64(),
+			g.ActiveSlotsCoeff.Denom().Int64(),
+		},
+		g.SecurityParam,
+		g.EpochLength,
+		g.SlotsPerKESPeriod,
+		g.MaxKESEvolutions,
+		g.SlotLength * 1_000_000,
+		g.UpdateQuorum,
+		g.MaxLovelaceSupply,
+		g.ProtocolParameters,
+		genDelegs,
+		g.InitialFunds,
+		staking,
+	}
+	return cbor.Encode(tmpData)
+}
+
 type ShelleyGenesisProtocolParams struct {
+	cbor.StructAsArray
 	MinFeeA            uint
 	MinFeeB            uint
 	MaxBlockBodySize   uint
@@ -64,6 +122,40 @@ type ShelleyGenesisProtocolParams struct {
 	MinPoolCost  uint
 }
 
+func (p ShelleyGenesisProtocolParams) MarshalCBOR() ([]byte, error) {
+	tmpData := []any{
+		p.MinFeeA,
+		p.MinFeeB,
+		p.MaxBlockBodySize,
+		p.MaxTxSize,
+		p.MaxBlockHeaderSize,
+		p.KeyDeposit,
+		p.PoolDeposit,
+		p.MaxEpoch,
+		p.NOpt,
+		cbor.Rat{
+			Rat: p.A0.Rat,
+		},
+		cbor.Rat{
+			Rat: p.Rho.Rat,
+		},
+		cbor.Rat{
+			Rat: p.Tau.Rat,
+		},
+		cbor.Rat{
+			Rat: p.Decentralization.Rat,
+		},
+		[]any{
+			map[string]int{"NeutralNonce": 0}[p.ExtraEntropy["Tag"]],
+		},
+		p.ProtocolVersion.Major,
+		p.ProtocolVersion.Minor,
+		p.MinUtxoValue,
+		p.MinPoolCost,
+	}
+	return cbor.Encode(tmpData)
+}
+
 func NewShelleyGenesisFromReader(r io.Reader) (ShelleyGenesis, error) {
 	var ret ShelleyGenesis
 	dec := json.NewDecoder(r)
diff --git a/ledger/shelley/genesis_test.go b/ledger/shelley/genesis_test.go
index a55850ac..3669323c 100644
--- a/ledger/shelley/genesis_test.go
+++ b/ledger/shelley/genesis_test.go
@@ -107,9 +107,11 @@ var expectedGenesisObj = shelley.ShelleyGenesis{
 		0,
 		time.UTC,
 	),
-	NetworkMagic:      764824073,
-	NetworkId:         "Mainnet",
-	ActiveSlotsCoeff:  0.05,
+	NetworkMagic: 764824073,
+	NetworkId:    "Mainnet",
+	ActiveSlotsCoeff: common.GenesisRat{
+		Rat: big.NewRat(5, 100),
+	},
 	SecurityParam:     2160,
 	EpochLength:       432000,
 	SlotsPerKESPeriod: 129600,
@@ -144,7 +146,7 @@ var expectedGenesisObj = shelley.ShelleyGenesis{
 		MinUtxoValue: 1000000,
 		MinPoolCost:  340000000,
 	},
-	GenDelegs: map[string]map[string]any{
+	GenDelegs: map[string]map[string]string{
 		"162f94554ac8c225383a2248c245659eda870eaa82d0ef25fc7dcd82": {
 			"delegate": "4485708022839a7b9b8b639a939c85ec0ed6999b5b6dc651b03c43f6",
 			"vrf":      "aba81e764b71006c515986bf7b37a72fbb5554f78e6775f08e384dbd572a4b32",