fix high stonewall fee issue, add support for generalized transaction diagram

src/main/java/com/sparrowwallet/drongo/protocol/Script.java

@@ -165,6 +165,14 @@ public class Script {
         throw new ProtocolException("Script not a standard form that contains a single hash");
     }
 
+    public Address getToAddress() {
+        try {
+            return getToAddresses()[0];
+        } catch(Exception e) {
+            return null;
+        }
+    }
+
     /**
      * Gets the destination address from this script, if it's in the required form.
      */

src/main/java/com/sparrowwallet/drongo/wallet/Payment.java

@@ -7,13 +7,18 @@ public class Payment {
     private String label;
     private long amount;
     private boolean sendMax;
-    private Type type = Type.DEFAULT;
+    private Type type;
 
     public Payment(Address address, String label, long amount, boolean sendMax) {
+        this(address, label, amount, sendMax, Type.DEFAULT);
+    }
+
+    public Payment(Address address, String label, long amount, boolean sendMax, Type type) {
         this.address = address;
         this.label = label;
         this.amount = amount;
         this.sendMax = sendMax;
+        this.type = type;
     }
 
     public Address getAddress() {

src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java

@@ -518,6 +518,10 @@ public class Wallet extends Persistable implements Comparable<Wallet> {
         return getWalletTxos().keySet().stream().anyMatch(ref -> ref.getHash().equals(txInput.getOutpoint().getHash()) && ref.getIndex() == txInput.getOutpoint().getIndex());
     }
 
+    public boolean isWalletTxo(TransactionOutput txOutput) {
+        return getWalletTxos().keySet().stream().anyMatch(ref -> ref.getHash().equals(txOutput.getHash()) && ref.getIndex() == txOutput.getIndex());
+    }
+
     public boolean isWalletTxo(BlockTransactionHashIndex txo) {
         return getWalletTxos().containsKey(txo);
     }
@@ -771,7 +775,7 @@ public class Wallet extends Persistable implements Comparable<Wallet> {
             List<Long> setChangeAmts = getSetChangeAmounts(selectedUtxoSets, totalPaymentAmount, noChangeFeeRequiredAmt);
             double noChangeFeeRate = (fee == null ? feeRate : noChangeFeeRequiredAmt / transaction.getVirtualSize());
             long costOfChangeAmt = getCostOfChange(noChangeFeeRate, longTermFeeRate);
-            if(setChangeAmts.stream().allMatch(amt -> amt > costOfChangeAmt)) {
+            if(setChangeAmts.stream().allMatch(amt -> amt > costOfChangeAmt) || (numSets > 1 && differenceAmt / transaction.getVirtualSize() > noChangeFeeRate * 2)) {
                 //Change output is required, determine new fee once change output has been added
                 WalletNode changeNode = getFreshNode(KeyPurpose.CHANGE);
                 while(txExcludedChangeNodes.contains(changeNode)) {
@@ -796,7 +800,7 @@ public class Wallet extends Persistable implements Comparable<Wallet> {
 
                 if(setChangeAmts.stream().anyMatch(amt -> amt < costOfChangeAmt)) {
                     //The new fee has meant that one of the change outputs is now dust. We pay too high a fee without change, but change is dust when added.
-                    if(numSets > 1) {
+                    if(numSets > 1 && differenceAmt / transaction.getVirtualSize() < noChangeFeeRate * 2) {
                         //Maximize privacy. Pay a higher fee to keep multiple output sets.
                         return new WalletTransaction(this, transaction, utxoSelectors, selectedUtxos, txPayments, differenceAmt);
                     } else {

src/main/java/com/sparrowwallet/drongo/wallet/WalletTransaction.java

@@ -1,6 +1,7 @@
 package com.sparrowwallet.drongo.wallet;
 
 import com.sparrowwallet.drongo.address.Address;
+import com.sparrowwallet.drongo.protocol.Sha256Hash;
 import com.sparrowwallet.drongo.protocol.Transaction;
 import com.sparrowwallet.drongo.psbt.PSBT;
 
@@ -21,12 +22,17 @@ public class WalletTransaction {
     private final List<Payment> payments;
     private final Map<WalletNode, Long> changeMap;
     private final long fee;
+    private final Map<Sha256Hash, BlockTransaction> inputTransactions;
 
     public WalletTransaction(Wallet wallet, Transaction transaction, List<UtxoSelector> utxoSelectors, Map<BlockTransactionHashIndex, WalletNode> selectedUtxos, List<Payment> payments, long fee) {
         this(wallet, transaction, utxoSelectors, selectedUtxos, payments, Collections.emptyMap(), fee);
     }
 
     public WalletTransaction(Wallet wallet, Transaction transaction, List<UtxoSelector> utxoSelectors, Map<BlockTransactionHashIndex, WalletNode> selectedUtxos, List<Payment> payments, Map<WalletNode, Long> changeMap, long fee) {
+        this(wallet, transaction, utxoSelectors, selectedUtxos, payments, changeMap, fee, Collections.emptyMap());
+    }
+
+    public WalletTransaction(Wallet wallet, Transaction transaction, List<UtxoSelector> utxoSelectors, Map<BlockTransactionHashIndex, WalletNode> selectedUtxos, List<Payment> payments, Map<WalletNode, Long> changeMap, long fee, Map<Sha256Hash, BlockTransaction> inputTransactions) {
         this.wallet = wallet;
         this.transaction = transaction;
         this.utxoSelectors = utxoSelectors;
@@ -34,6 +40,7 @@ public class WalletTransaction {
         this.payments = payments;
         this.changeMap = changeMap;
         this.fee = fee;
+        this.inputTransactions = inputTransactions;
     }
 
     public PSBT createPSBT() {
@@ -80,12 +87,16 @@ public class WalletTransaction {
         return selectedUtxos.keySet().stream().mapToLong(BlockTransactionHashIndex::getValue).sum();
     }
 
+    public Map<Sha256Hash, BlockTransaction> getInputTransactions() {
+        return inputTransactions;
+    }
+
     /**
      * Fee percentage matches the Coldcard implementation of total fee as a percentage of total value out
      * @return the fee percentage
      */
     public double getFeePercentage() {
-        return (double)getFee() / (getTotal() - getFee());
+        return getFee() == 0 ? 0 : (double)getFee() / (getTotal() - getFee());
     }
 
     public boolean isCoinControlUsed() {
@@ -97,11 +108,19 @@ public class WalletTransaction {
     }
 
     public boolean isPremixSend(Payment payment) {
-        return isWalletSend(getWallet().getChildWallet(StandardAccount.WHIRLPOOL_PREMIX), payment);
+        return isWalletSend(StandardAccount.WHIRLPOOL_PREMIX, payment);
     }
 
     public boolean isBadbankSend(Payment payment) {
-        return isWalletSend(getWallet().getChildWallet(StandardAccount.WHIRLPOOL_BADBANK), payment);
+        return isWalletSend(StandardAccount.WHIRLPOOL_BADBANK, payment);
+    }
+
+    private boolean isWalletSend(StandardAccount childAccount, Payment payment) {
+        if(getWallet() != null) {
+            return isWalletSend(getWallet().getChildWallet(childAccount), payment);
+        }
+
+        return false;
     }
 
     public boolean isWalletSend(Wallet wallet, Payment payment) {