feat: changes to support cost models while updating Alonzon protocols

Signed-off-by: Jenita <[email protected]>

Author: Jenita

ledger/alonzo/pparams.go

@@ -16,6 +16,7 @@ package alonzo
 
 import (
 	"math"
+	"sort"
 
 	"github.com/blinklabs-io/gouroboros/cbor"
 	"github.com/blinklabs-io/gouroboros/ledger/common"
@@ -94,9 +95,38 @@ func (p *AlonzoProtocolParameters) UpdateFromGenesis(genesis *AlonzoGenesis) {
 			StepPrice: &cbor.Rat{Rat: genesis.ExecutionPrices.Steps.Rat},
 		}
 	}
-	// TODO: cost models (#852)
-	// We have 150+ string values to map to array indexes
-	//	CostModels           map[string]map[string]int
+
+	// Process cost models
+	if genesis.CostModels != nil {
+		p.CostModels = make(map[uint][]int64)
+		for lang, model := range genesis.CostModels {
+			var langKey uint
+			switch lang {
+			case "plutus:v1":
+				langKey = 0
+			case "plutus:v2":
+				langKey = 1
+			default:
+				// Skip unknown language
+				continue
+			}
+
+			// Get sorted keys to determine indexes
+			keys := make([]string, 0, len(model))
+			for k := range model {
+				keys = append(keys, k)
+			}
+			sort.Strings(keys)
+
+			// Create slice with values in alphabetical order
+			costs := make([]int64, len(keys))
+			for i, key := range keys {
+				costs[i] = int64(model[key])
+			}
+
+			p.CostModels[langKey] = costs
+		}
+	}
 }
 
 type AlonzoProtocolParameterUpdate struct {

ledger/alonzo/pparams_test.go

@@ -163,6 +163,64 @@ func TestAlonzoProtocolParamsUpdateFromGenesis(t *testing.T) {
 				AdaPerUtxoByte: 34482 / 8,
 			},
 		},
+		{
+			startParams: alonzo.AlonzoProtocolParameters{},
+			genesisJson: `{
+				"lovelacePerUTxOWord": 34482,
+				"costModels": {
+					"plutus:v1": {
+						"addInteger-cpu-arguments-intercept": 10,
+						"subtractInteger-cpu-arguments-intercept": 30,
+						"multiplyInteger-cpu-arguments-intercept": 20
+					},
+					"plutus:v2": {
+						"appendByteString-cpu-arguments-slope": 5,
+						"consByteString-cpu-arguments-intercept": 2
+					},
+					"plutus:v3": {
+						"unknown-op": 999
+					}
+				}
+			}`,
+			expectedParams: alonzo.AlonzoProtocolParameters{
+				AdaPerUtxoByte: 34482 / 8,
+				CostModels: map[uint][]int64{
+					0: {
+						10, // addInteger-cpu-arguments-intercept
+						20, // multiplyInteger-cpu-arguments-intercept
+						30, // subtractInteger-cpu-arguments-intercept
+					},
+					1: {
+						5, // appendByteString-cpu-arguments-slope
+						2, // consByteString-cpu-arguments-intercept
+					},
+				},
+			},
+		},
+		{
+			//out of order keys
+			startParams: alonzo.AlonzoProtocolParameters{},
+			genesisJson: `{
+				"lovelacePerUTxOWord": 34482,
+				"costModels": {
+					"plutus:v1": {
+						"zzz": 3,
+						"aaa": 1,
+						"mmm": 2
+					}
+				}
+			}`,
+			expectedParams: alonzo.AlonzoProtocolParameters{
+				AdaPerUtxoByte: 34482 / 8,
+				CostModels: map[uint][]int64{
+					0: {
+						1, // "aaa"
+						2, // "mmm"
+						3, // "zzz"
+					},
+				},
+			},
+		},
 	}
 	for _, testDef := range testDefs {
 		tmpGenesis, err := alonzo.NewAlonzoGenesisFromReader(