From 6722d9d691265fba19aa4c0d90ed63b3ace4b594 Mon Sep 17 00:00:00 2001
From: Alva Swanson <alvasw@protonmail.com>
Date: Thu, 7 Nov 2024 20:50:31 +0000
Subject: [PATCH] BsqWalletV2: Implement send BSQ

The sendBsq method creates a BSQ transaction, signs the BSQ inputs, and
adds the requires BTC mining fees to the transcation.
---
 .../bisq/core/btc/wallet/BsqWalletV2.java     | 68 +++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 core/src/main/java/bisq/core/btc/wallet/BsqWalletV2.java

diff --git a/core/src/main/java/bisq/core/btc/wallet/BsqWalletV2.java b/core/src/main/java/bisq/core/btc/wallet/BsqWalletV2.java
new file mode 100644
index 0000000000..cd573859e4
--- /dev/null
+++ b/core/src/main/java/bisq/core/btc/wallet/BsqWalletV2.java
@@ -0,0 +1,68 @@
+package bisq.core.btc.wallet;
+
+import bisq.core.btc.exceptions.BsqChangeBelowDustException;
+
+import org.bitcoinj.core.Address;
+import org.bitcoinj.core.Coin;
+import org.bitcoinj.core.InsufficientMoneyException;
+import org.bitcoinj.core.NetworkParameters;
+import org.bitcoinj.core.PeerGroup;
+import org.bitcoinj.core.Transaction;
+import org.bitcoinj.core.TransactionBroadcast;
+import org.bitcoinj.wallet.CoinSelection;
+import org.bitcoinj.wallet.Wallet;
+
+import lombok.extern.slf4j.Slf4j;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+@Slf4j
+public class BsqWalletV2 {
+    private final NetworkParameters networkParams;
+    private final PeerGroup peerGroup;
+
+    private final BtcWalletV2 btcWallet;
+    private final Wallet bsqWallet;
+    private final BsqCoinSelector bsqCoinSelector;
+
+    public BsqWalletV2(NetworkParameters networkParams,
+                       PeerGroup peerGroup,
+                       BtcWalletV2 btcWallet,
+                       Wallet bsqWallet,
+                       BsqCoinSelector bsqCoinSelector) {
+        this.networkParams = networkParams;
+        this.peerGroup = peerGroup;
+        this.btcWallet = btcWallet;
+        this.bsqWallet = bsqWallet;
+        this.bsqCoinSelector = bsqCoinSelector;
+    }
+
+    public TransactionBroadcast sendBsq(Address receiverAddress,
+                                        Coin receiverAmount,
+                                        Coin txFee) throws InsufficientMoneyException, BsqChangeBelowDustException {
+        checkArgument(Restrictions.isAboveDust(receiverAmount),
+                "The amount is too low (dust limit).");
+
+        Transaction bsqTx = new Transaction(networkParams);
+        bsqTx.addOutput(receiverAmount, receiverAddress);
+
+        CoinSelection selection = bsqCoinSelector.select(receiverAmount, bsqWallet.calculateAllSpendCandidates());
+        selection.gathered.forEach(bsqTx::addInput);
+
+        Coin change = bsqCoinSelector.getChange(receiverAmount, selection);
+        if (Restrictions.isAboveDust(change)) {
+            Address changeAddress = bsqWallet.freshReceiveAddress();
+            bsqTx.addOutput(change, changeAddress);
+        } else if (!change.isZero()) {
+            String msg = "BSQ change output is below dust limit. outputValue=" + change.value / 100 + " BSQ";
+            log.warn(msg);
+            throw new BsqChangeBelowDustException(msg, change);
+        }
+
+        BisqTransactionSigner.sign(bsqWallet, bsqTx, 0);
+        bsqCoinSelector.setUtxoCandidates(null);   // We reuse the selectors. Reset the transactionOutputCandidates field
+
+        Transaction finalTx = btcWallet.addMiningFeesToBsqTx(bsqTx, txFee);
+        return peerGroup.broadcastTransaction(finalTx);
+    }
+}