feat(ledger): Deposit should be collected when pool is retired and re-registered #640 (#1172)

* feat(ledger): Used current PoolState for deposit checks and dropped PoolRegistration

Signed-off-by: Akhil Repala <arepala@blinklabs.io>

* feat(ledger): Added clear definition of PoolCurrentState in PoolState

Signed-off-by: Akhil Repala <arepala@blinklabs.io>

* feat(ledger): Correctly formatted the ledger/common/state.go file

Signed-off-by: Akhil Repala <arepala@blinklabs.io>

---------

Signed-off-by: Akhil Repala <arepala@blinklabs.io>
Signed-off-by: Akhil <145306795+arepala-uml@users.noreply.github.com>

Author: arepala-uml

internal/test/ledger/ledger.go

@@ -63,20 +63,17 @@ func (ls MockLedgerState) StakeRegistration(
 	return ret, nil
 }
 
-func (ls MockLedgerState) PoolRegistration(
+func (ls MockLedgerState) PoolCurrentState(
 	poolKeyHash []byte,
-) ([]common.PoolRegistrationCertificate, error) {
-	ret := []common.PoolRegistrationCertificate{}
+) (*common.PoolRegistrationCertificate, *uint64, error) {
 	for _, cert := range ls.MockPoolRegistration {
-		if string(
-			common.Blake2b224(cert.Operator).Bytes(),
-		) == string(
-			poolKeyHash,
-		) {
-			ret = append(ret, cert)
+		if string(common.Blake2b224(cert.Operator).Bytes()) == string(poolKeyHash) {
+			// pretend latest registration is current; no retirement support in mock
+			c := cert
+			return &c, nil, nil
 		}
 	}
-	return ret, nil
+	return nil, nil, nil
 }
 
 func (ls MockLedgerState) SlotToTime(slot uint64) (time.Time, error) {

ledger/alonzo/rules.go

@@ -289,11 +289,11 @@ func UtxoValidateValueNotConservedUtxo(
 	for _, cert := range tx.Certificates() {
 		switch tmpCert := cert.(type) {
 		case *common.PoolRegistrationCertificate:
-			certs, err := ls.PoolRegistration(common.Blake2b224(tmpCert.Operator).Bytes())
+			reg, _, err := ls.PoolCurrentState(common.Blake2b224(tmpCert.Operator).Bytes())
 			if err != nil {
 				return err
 			}
-			if len(certs) == 0 {
+			if reg == nil {
 				producedValue += uint64(tmpPparams.PoolDeposit)
 			}
 		case *common.StakeRegistrationCertificate:

ledger/babbage/rules.go

@@ -275,11 +275,11 @@ func UtxoValidateValueNotConservedUtxo(
 	for _, cert := range tx.Certificates() {
 		switch tmpCert := cert.(type) {
 		case *common.PoolRegistrationCertificate:
-			certs, err := ls.PoolRegistration(common.Blake2b224(tmpCert.Operator).Bytes())
+			reg, _, err := ls.PoolCurrentState(common.Blake2b224(tmpCert.Operator).Bytes())
 			if err != nil {
 				return err
 			}
-			if len(certs) == 0 {
+			if reg == nil {
 				producedValue += uint64(tmpPparams.PoolDeposit)
 			}
 		case *common.StakeRegistrationCertificate:

ledger/common/state.go

@@ -28,14 +28,22 @@ type UtxoState interface {
 // CertState defines the interface for querying the certificate state
 type CertState interface {
 	StakeRegistration([]byte) ([]StakeRegistrationCertificate, error)
-	PoolRegistration([]byte) ([]PoolRegistrationCertificate, error)
+}
+
+// PoolState defines the interface for querying the current pool state
+type PoolState interface {
+	// PoolCurrentState returns the latest active registration certificate for the given pool key hash.
+	// It also returns the epoch of a pending retirement certificate, if one exists.
+	// If the pool is not registered, the registration certificate will be nil.
+	PoolCurrentState([]byte) (*PoolRegistrationCertificate, *uint64, error)
 }
 
 // LedgerState defines the interface for querying the ledger
 type LedgerState interface {
 	UtxoState
 	CertState
 	SlotState
+	PoolState
 	NetworkId() uint
 }
 

ledger/conway/rules.go

@@ -272,11 +272,11 @@ func UtxoValidateValueNotConservedUtxo(
 	for _, cert := range tx.Certificates() {
 		switch tmpCert := cert.(type) {
 		case *common.PoolRegistrationCertificate:
-			certs, err := ls.PoolRegistration(common.Blake2b224(tmpCert.Operator).Bytes())
+			reg, _, err := ls.PoolCurrentState(common.Blake2b224(tmpCert.Operator).Bytes())
 			if err != nil {
 				return err
 			}
-			if len(certs) == 0 {
+			if reg == nil {
 				producedValue += uint64(tmpPparams.PoolDeposit)
 			}
 		case *common.RegistrationCertificate:

ledger/shelley/rules.go

@@ -196,11 +196,11 @@ func UtxoValidateValueNotConservedUtxo(
 	for _, cert := range tx.Certificates() {
 		switch tmpCert := cert.(type) {
 		case *common.PoolRegistrationCertificate:
-			certs, err := ls.PoolRegistration(common.Blake2b224(tmpCert.Operator).Bytes())
+			reg, _, err := ls.PoolCurrentState(common.Blake2b224(tmpCert.Operator).Bytes())
 			if err != nil {
 				return err
 			}
-			if len(certs) == 0 {
+			if reg == nil {
 				producedValue += uint64(tmpPparams.PoolDeposit)
 			}
 		case *common.StakeRegistrationCertificate: