support partially finalized psbts

src/main/java/com/sparrowwallet/drongo/psbt/PSBT.java

@@ -253,8 +253,10 @@ public class PSBT {
             }
         }
 
+        if(log.isDebugEnabled()) {
             log.debug("Calculated fee at " + getFee());
         }
+    }
 
     private void parseGlobalEntries(List<PSBTEntry> globalEntries) throws PSBTParseException {
         PSBTEntry duplicate = findDuplicateKey(globalEntries);
@@ -395,12 +397,12 @@ public class PSBT {
 
     public boolean isFinalized() {
         for(PSBTInput psbtInput : getPsbtInputs()) {
-            if(psbtInput.getFinalScriptSig() != null || psbtInput.getFinalScriptWitness() != null) {
+            if(!psbtInput.isFinalized()) {
-                return true;
+                return false;
             }
         }
 
-        return false;
+        return true;
     }
 
     private List<PSBTEntry> getGlobalEntries() {
@@ -499,9 +501,6 @@ public class PSBT {
     public Transaction extractTransaction() {
         boolean hasWitness = false;
         for(PSBTInput psbtInput : getPsbtInputs()) {
-            if(psbtInput.getFinalScriptSig() == null) {
-                return null;
-            }
             if(psbtInput.getFinalScriptWitness() != null) {
                 hasWitness = true;
             }
@@ -516,7 +515,7 @@ public class PSBT {
         for(int i = 0; i < finalTransaction.getInputs().size(); i++) {
             TransactionInput txInput = finalTransaction.getInputs().get(i);
             PSBTInput psbtInput = getPsbtInputs().get(i);
-            txInput.setScriptBytes(psbtInput.getFinalScriptSig().getProgram());
+            txInput.setScriptBytes(psbtInput.getFinalScriptSig() == null ? new byte[0] : psbtInput.getFinalScriptSig().getProgram());
 
             if(hasWitness) {
                 if(psbtInput.getFinalScriptWitness() != null) {
@@ -530,6 +529,27 @@ public class PSBT {
         return finalTransaction;
     }
 
+    public PSBT getPublicCopy() {
+        try {
+            PSBT publicCopy = new PSBT(serialize());
+            publicCopy.extendedPublicKeys.clear();
+            for(PSBTInput psbtInput : publicCopy.getPsbtInputs()) {
+                psbtInput.clearPrivateFields();
+            }
+            for(PSBTOutput psbtOutput : publicCopy.getPsbtOutputs()) {
+                psbtOutput.getDerivedPublicKeys().clear();
+                psbtOutput.getProprietary().clear();
+            }
+            if(publicCopy.isFinalized()) {
+                publicCopy.transaction = publicCopy.extractTransaction();
+            }
+
+            return publicCopy;
+        } catch(PSBTParseException e) {
+            throw new IllegalStateException("Could not parse PSBT", e);
+        }
+    }
+
     public List<PSBTInput> getPsbtInputs() {
         return psbtInputs;
     }

src/main/java/com/sparrowwallet/drongo/psbt/PSBTInput.java

@@ -386,7 +386,7 @@ public class PSBTInput {
                 return false;
             }
         } else {
-            return getFinalScriptSig() != null;
+            return isFinalized();
         }
     }
 
@@ -525,12 +525,20 @@ public class PSBTInput {
         return signingScript;
     }
 
+    public boolean isFinalized() {
+        return getFinalScriptSig() != null || getFinalScriptWitness() != null;
+    }
+
+    public TransactionInput getInput() {
+        return transaction.getInputs().get(index);
+    }
+
     public TransactionOutput getUtxo() {
         int vout = (int)transaction.getInputs().get(index).getOutpoint().getIndex();
         return getWitnessUtxo() != null ? getWitnessUtxo() : (getNonWitnessUtxo() != null ?  getNonWitnessUtxo().getOutputs().get(vout) : null);
     }
 
-    public void clearFinalised() {
+    public void clearPrivateFields() {
         partialSignatures.clear();
         sigHash = null;
         redeemScript = null;

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

@@ -713,6 +713,10 @@ public class Wallet {
             TransactionInput txInput = psbt.getTransaction().getInputs().get(i);
             PSBTInput psbtInput = psbt.getPsbtInputs().get(i);
 
+            if(psbtInput.isFinalized()) {
+                continue;
+            }
+
             WalletNode signingNode = signingNodes.get(psbtInput);
 
             //Transaction parent on PSBT utxo might be null in a witness tx, so get utxo tx hash and utxo index from PSBT tx input
@@ -760,7 +764,7 @@ public class Wallet {
 
                 psbtInput.setFinalScriptSig(finalizedTxInput.getScriptSig());
                 psbtInput.setFinalScriptWitness(finalizedTxInput.getWitness());
-                psbtInput.clearFinalised();
+                psbtInput.clearPrivateFields();
             }
         }
     }