stellar#4728: pr feedback, bring asset balance changes into InvokeFnO…

…p details, include event type in op details

protocols/horizon/operations/main.go

@@ -352,11 +352,13 @@ type LiquidityPoolWithdraw struct {
 // Parameters - array of tuples of each function input parameter value and it's data type
 // Function - name of contract function
 // Footprint - base64 encoded string of it's xdr serialization.
+// AssetBalanceChanges - array of asset balance changed records
 type InvokeHostFunction struct {
 	Base
-	Parameters []HostFunctionParameter `json:"parameters"`
-	Function   string                  `json:"function"`
-	Footprint  string                  `json:"footprint"`
+	Parameters          []HostFunctionParameter      `json:"parameters"`
+	Function            string                       `json:"function"`
+	Footprint           string                       `json:"footprint"`
+	AssetBalanceChanges []AssetContractBalanceChange `json:"asset_balance_changes"`
 }
 
 // InvokeHostFunction parameter model, intentionally simplified, Value
@@ -366,6 +368,22 @@ type HostFunctionParameter struct {
 	Type  string `json:"type"`
 }
 
+// Type - refers to the source SAC Event
+// 		it can only be one of 'transfer', 'mint', 'clawback' or 'burn'
+// From - this is classic account that asset was decremented
+// To - this is the classic account that asset was incremented, or if not applicable
+//		for asset contract event, it can be absent such as 'burn'
+// Amount - expressed as a signed decimal to 7 digits precision.
+// Asset - the classic asset expressed as issuer and code.
+// The event is captured at ingestion time from the contract events present in tx meta.
+type AssetContractBalanceChange struct {
+	base.Asset
+	Type   string `json:"type"`
+	From   string `json:"from"`
+	To     string `json:"to,omitempty"`
+	Amount string `json:"amount"`
+}
+
 // Operation interface contains methods implemented by the operation types
 type Operation interface {
 	GetBase() Base

services/horizon/internal/actions/operation_test.go

@@ -18,7 +18,7 @@ import (
 	"github.com/stellar/go/xdr"
 )
 
-func TestContractEventsInPaymentOperations(t *testing.T) {
+func TestInvokeHostFnDetailsInPaymentOperations(t *testing.T) {
 	tt := test.Start(t)
 	defer tt.Finish()
 	test.ResetHorizonDB(t, tt.HorizonDB)
@@ -63,7 +63,44 @@ func TestContractEventsInPaymentOperations(t *testing.T) {
 		[]byte(`{
 			"parameters": [],
 	        "function": "fn",
-	        "footprint": ""
+	        "footprint": "",
+			"asset_balance_changes": [
+                {
+					"asset_type": "credit_alphanum4",
+					"asset_code": "abc",
+					"asset_issuer": "123",
+					"from": "contract",
+					"to": "G_FOR_CLASSIC_ACCOUNT_ADDRESS1",
+					"amount": "3",
+					"type": "transfer"
+				},
+				{
+					"asset_type": "credit_alphanum4",
+					"asset_code": "abc",
+					"asset_issuer": "123",
+					"from": "G_FOR_CLASSIC_ACCOUNT_ADDRESS2",
+					"to": "G_FOR_CLASSIC_ACCOUNT_ADDRESS3",
+					"amount": "5",
+					"type": "clawback"
+				},
+				{
+					"asset_type": "credit_alphanum4",
+					"asset_code": "abc",
+					"asset_issuer": "123",
+					"from": "G_FOR_CLASSIC_ACCOUNT_ADDRESS2",
+					"amount": "6",
+					"type": "burn"
+				},
+				{
+					"asset_type": "credit_alphanum4",
+					"asset_code": "abc",
+					"asset_issuer": "123",
+					"from": "G_FOR_CLASSIC_ACCOUNT_ADDRESS2",
+					"to": "contract",
+					"amount": "10",
+					"type": "mint"
+				}
+			]
 		}`),
 		"GAUJETIZVEP2NRYLUESJ3LS66NVCEGMON4UDCBCSBEVPIID773P2W6AY",
 		null.String{},
@@ -81,6 +118,35 @@ func TestContractEventsInPaymentOperations(t *testing.T) {
 
 	op := records[0].(operations.InvokeHostFunction)
 	tt.Assert.Equal(op.Function, "fn")
+	tt.Assert.Equal(len(op.AssetBalanceChanges), 4)
+	tt.Assert.Equal(op.AssetBalanceChanges[0].From, "contract")
+	tt.Assert.Equal(op.AssetBalanceChanges[0].To, "G_FOR_CLASSIC_ACCOUNT_ADDRESS1")
+	tt.Assert.Equal(op.AssetBalanceChanges[0].Amount, "3")
+	tt.Assert.Equal(op.AssetBalanceChanges[0].Type, "transfer")
+	tt.Assert.Equal(op.AssetBalanceChanges[0].Asset.Type, "credit_alphanum4")
+	tt.Assert.Equal(op.AssetBalanceChanges[0].Asset.Code, "abc")
+	tt.Assert.Equal(op.AssetBalanceChanges[0].Asset.Issuer, "123")
+	tt.Assert.Equal(op.AssetBalanceChanges[1].From, "G_FOR_CLASSIC_ACCOUNT_ADDRESS2")
+	tt.Assert.Equal(op.AssetBalanceChanges[1].To, "G_FOR_CLASSIC_ACCOUNT_ADDRESS3")
+	tt.Assert.Equal(op.AssetBalanceChanges[1].Amount, "5")
+	tt.Assert.Equal(op.AssetBalanceChanges[1].Type, "clawback")
+	tt.Assert.Equal(op.AssetBalanceChanges[1].Asset.Type, "credit_alphanum4")
+	tt.Assert.Equal(op.AssetBalanceChanges[1].Asset.Code, "abc")
+	tt.Assert.Equal(op.AssetBalanceChanges[1].Asset.Issuer, "123")
+	tt.Assert.Equal(op.AssetBalanceChanges[2].From, "G_FOR_CLASSIC_ACCOUNT_ADDRESS2")
+	tt.Assert.Equal(op.AssetBalanceChanges[2].To, "")
+	tt.Assert.Equal(op.AssetBalanceChanges[2].Amount, "6")
+	tt.Assert.Equal(op.AssetBalanceChanges[2].Type, "burn")
+	tt.Assert.Equal(op.AssetBalanceChanges[2].Asset.Type, "credit_alphanum4")
+	tt.Assert.Equal(op.AssetBalanceChanges[2].Asset.Code, "abc")
+	tt.Assert.Equal(op.AssetBalanceChanges[2].Asset.Issuer, "123")
+	tt.Assert.Equal(op.AssetBalanceChanges[3].From, "G_FOR_CLASSIC_ACCOUNT_ADDRESS2")
+	tt.Assert.Equal(op.AssetBalanceChanges[3].To, "contract")
+	tt.Assert.Equal(op.AssetBalanceChanges[3].Amount, "10")
+	tt.Assert.Equal(op.AssetBalanceChanges[3].Type, "mint")
+	tt.Assert.Equal(op.AssetBalanceChanges[3].Asset.Type, "credit_alphanum4")
+	tt.Assert.Equal(op.AssetBalanceChanges[3].Asset.Code, "abc")
+	tt.Assert.Equal(op.AssetBalanceChanges[3].Asset.Issuer, "123")
 }
 
 func TestGetOperationsWithoutFilter(t *testing.T) {

services/horizon/internal/ingest/processors/operations_processor.go

@@ -707,7 +707,7 @@ func (operation *transactionOperationWrapper) Details() (map[string]interface{},
 }
 
 // Searches an operation for SAC events that are of a type which represent
-//    Asset balances changed between contracts and/or classic.
+//    Asset balances changed with at least one participant of the change referencing a classic account.
 //
 // SAC events have a one-to-one association to SAC contract fn invocations,
 //    i.e. invoke the 'mint' function, will trigger one Mint Event to be emitted capturing the fn args.
@@ -716,7 +716,6 @@ func (operation *transactionOperationWrapper) Details() (map[string]interface{},
 //     The 'amount' expressed as non-negative, the event type can provide the context of
 //     whether an amount was considered negative i.e. credit or debit to a balance.
 //
-//     The 'from' and 'to' attributes represent an account or a contract
 func (operation *transactionOperationWrapper) parseAssetBalanceChangesFromContractEvents() ([]map[string]interface{}, error) {
 	balanceChanges := []map[string]interface{}{}
 
@@ -728,22 +727,32 @@ func (operation *transactionOperationWrapper) parseAssetBalanceChangesFromContra
 	}
 
 	for _, contractEvent := range events {
-		// parse the xdr contract event to contractevents.StellarAssetContractEvent model
-		// has some convenience like to/from attributes are expressed in strkey format for contracts(C...) and accounts(G...)
+		// Parse the xdr contract event to contractevents.StellarAssetContractEvent model
+		// has some convenience like to/from attributes are expressed in strkey format for classic accounts(G...)
+		// For now, if the event refers to contract addresses only, then drop the event, don't
+		// include in the operation details, this may change if contract addresses become a recognized entity in horizon history model
 		if sacEvent, err := contractevents.NewStellarAssetContractEvent(&contractEvent, operation.networkPassphrase); err == nil {
 			switch sacEvent.GetType() {
 			case contractevents.EventTypeTransfer:
 				transferEvt := sacEvent.(contractevents.TransferEvent)
-				balanceChanges = append(balanceChanges, createSACBalanceChangeEntry(transferEvt.From, transferEvt.To, transferEvt.Amount, transferEvt.Asset))
+				if !contractevents.IsContractAddress(transferEvt.From) || !contractevents.IsContractAddress(transferEvt.To) {
+					balanceChanges = append(balanceChanges, createSACBalanceChangeEntry(transferEvt.From, transferEvt.To, transferEvt.Amount, transferEvt.Asset, "transfer"))
+				}
 			case contractevents.EventTypeMint:
 				mintEvt := sacEvent.(contractevents.MintEvent)
-				balanceChanges = append(balanceChanges, createSACBalanceChangeEntry(mintEvt.Admin, mintEvt.To, mintEvt.Amount, mintEvt.Asset))
+				if !contractevents.IsContractAddress(mintEvt.Admin) || !contractevents.IsContractAddress(mintEvt.To) {
+					balanceChanges = append(balanceChanges, createSACBalanceChangeEntry(mintEvt.Admin, mintEvt.To, mintEvt.Amount, mintEvt.Asset, "mint"))
+				}
 			case contractevents.EventTypeClawback:
 				clawbackEvt := sacEvent.(contractevents.ClawbackEvent)
-				balanceChanges = append(balanceChanges, createSACBalanceChangeEntry(clawbackEvt.From, clawbackEvt.Admin, clawbackEvt.Amount, clawbackEvt.Asset))
+				if !contractevents.IsContractAddress(clawbackEvt.From) || !contractevents.IsContractAddress(clawbackEvt.Admin) {
+					balanceChanges = append(balanceChanges, createSACBalanceChangeEntry(clawbackEvt.From, clawbackEvt.Admin, clawbackEvt.Amount, clawbackEvt.Asset, "clawback"))
+				}
 			case contractevents.EventTypeBurn:
 				burnEvt := sacEvent.(contractevents.BurnEvent)
-				balanceChanges = append(balanceChanges, createSACBalanceChangeEntry(burnEvt.From, "", burnEvt.Amount, burnEvt.Asset))
+				if !contractevents.IsContractAddress(burnEvt.From) {
+					balanceChanges = append(balanceChanges, createSACBalanceChangeEntry(burnEvt.From, "", burnEvt.Amount, burnEvt.Asset, "burn"))
+				}
 			}
 		}
 	}
@@ -755,15 +764,31 @@ func (operation *transactionOperationWrapper) parseAssetBalanceChangesFromContra
 // toAccount - strkey format of contract or address, or nillable
 // amountChanged - absolute value that asset balance changed
 // asset - the fully qualified issuer:code for asset that had balance change
+// changeType - the type of source sac event that triggered this change
 //
 // return - a balance changed record expressed as map of key/value's
-func createSACBalanceChangeEntry(fromAccount string, toAccount string, amountChanged xdr.Int128Parts, asset xdr.Asset) map[string]interface{} {
+func createSACBalanceChangeEntry(fromAccount string, toAccount string, amountChanged xdr.Int128Parts, asset xdr.Asset, changeType string) map[string]interface{} {
 	balanceChange := map[string]interface{}{}
 
-	balanceChange["from"] = fromAccount
+	if contractevents.IsContractAddress(fromAccount) {
+		// TODO, place the 'C...' contract address here, if/when horizon has facility for
+		// contract addresses
+		balanceChange["from"] = "contract"
+	} else {
+		balanceChange["from"] = fromAccount
+	}
+
 	if toAccount != "" {
-		balanceChange["to"] = toAccount
+		if contractevents.IsContractAddress(toAccount) {
+			// TODO, place the 'C...' contract address here, if/when horizon has facility for
+			// contract addresses
+			balanceChange["to"] = "contract"
+		} else {
+			balanceChange["to"] = toAccount
+		}
 	}
+
+	balanceChange["type"] = changeType
 	balanceChange["amount"] = stringifyAmount(amountChanged)
 	addAssetDetails(balanceChange, asset, "")
 	return balanceChange

support/contractevents/utils.go

@@ -38,6 +38,10 @@ func MustScAddressToString(address *xdr.ScAddress) string {
 	return result
 }
 
+func IsContractAddress(account string) bool {
+	return account[0] == 'C'
+}
+
 func parseAddress(val *xdr.ScVal) *xdr.ScAddress {
 	if val == nil {
 		return nil