From 5d14be5c9c8cfaaa0fbf9d362b6609873dce38e0 Mon Sep 17 00:00:00 2001
From: Craig Raw <craigraw@gmail.com>
Date: Tue, 7 Jul 2020 07:42:36 +0200
Subject: [PATCH] send all utxos support

---
 .../drongo/wallet/PresetUtxoSelector.java     | 25 +++++++++++++++++++
 .../sparrowwallet/drongo/wallet/Wallet.java   |  9 ++++++-
 2 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 src/main/java/com/sparrowwallet/drongo/wallet/PresetUtxoSelector.java

diff --git a/src/main/java/com/sparrowwallet/drongo/wallet/PresetUtxoSelector.java b/src/main/java/com/sparrowwallet/drongo/wallet/PresetUtxoSelector.java
new file mode 100644
index 0000000..82895df
--- /dev/null
+++ b/src/main/java/com/sparrowwallet/drongo/wallet/PresetUtxoSelector.java
@@ -0,0 +1,25 @@
+package com.sparrowwallet.drongo.wallet;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+public class PresetUtxoSelector implements UtxoSelector {
+    private final Collection<BlockTransactionHashIndex> presetUtxos;
+
+    public PresetUtxoSelector(Collection<BlockTransactionHashIndex> presetUtxos) {
+        this.presetUtxos = presetUtxos;
+    }
+
+    @Override
+    public Collection<BlockTransactionHashIndex> select(long targetValue, Collection<BlockTransactionHashIndex> candidates) {
+        List<BlockTransactionHashIndex> utxos = new ArrayList<>(presetUtxos);
+        utxos.retainAll(candidates);
+
+        return utxos;
+    }
+
+    public Collection<BlockTransactionHashIndex> getPresetUtxos() {
+        return presetUtxos;
+    }
+}
diff --git a/src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java b/src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java
index c2489e6..0cd9037 100644
--- a/src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java
+++ b/src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java
@@ -248,7 +248,7 @@ public class Wallet {
         }
     }
 
-    public WalletTransaction createWalletTransaction(List<UtxoSelector> utxoSelectors, Address recipientAddress, long recipientAmount, double feeRate, Long fee) throws InsufficientFundsException {
+    public WalletTransaction createWalletTransaction(List<UtxoSelector> utxoSelectors, Address recipientAddress, long recipientAmount, double feeRate, Long fee, boolean sendAll) throws InsufficientFundsException {
         long valueRequiredAmt = recipientAmount;
 
         while(true) {
@@ -281,6 +281,13 @@ public class Wallet {
             int noChangeVSize = transaction.getVirtualSize();
             long noChangeFeeRequiredAmt = (fee == null ? (long)(feeRate * noChangeVSize) : fee);
 
+            //If sending all selected utxos, set the recipient amount to equal to total of those utxos less the no change fee
+            long maxSendAmt = totalSelectedAmt - noChangeFeeRequiredAmt;
+            if(sendAll && recipientAmount != maxSendAmt) {
+                recipientAmount = maxSendAmt;
+                continue;
+            }
+
             //Calculate what is left over from selected utxos after paying recipient
             long differenceAmt = totalSelectedAmt - recipientAmount;