Use watched scripts to pick up broadcast of staged txs

Since the multisig escrow outputs of the deposit & warning txs do not
belong to the user, bitcoinj won't pick up any txs spending them unless
a corresponding watched script (the ScriptPubKey) is added to the
wallet. To this end, provide a trade task to add watched scripts for
those three outputs, which runs just before the client or the peer might
broadcast the deposit tx. Also remove them upon withdrawal of funds at
the end of the trade (closed normally or through a dispute).

We need to add watched scripts for the deposit tx output and both the
user's and the peer's warning tx outputs, so that the peer's warning,
redirect and claim txs are all picked up, regardless of any message sent
to the client.

TODO: Possibly find a way to clear out old watched scripts from failed
 trades, as they will otherwise remain in the user's wallet permanently,
 creating a growing burden for the wallet. Also, we should possibly re-
 add all the watched scripts if the wallet is restored from seed.

core/src/main/java/bisq/core/trade/TradeManager.java

@@ -92,6 +92,7 @@
 import org.bitcoinj.core.InsufficientMoneyException;
 import org.bitcoinj.core.Transaction;
 import org.bitcoinj.core.TransactionConfidence;
+import org.bitcoinj.script.Script;
 
 import javax.inject.Inject;
 import javax.inject.Named;
@@ -723,6 +724,11 @@ public void onTradeCompleted(Trade trade) {
 
         // TODO The address entry should have been removed already. Check and if its the case remove that.
         btcWalletService.resetAddressEntriesForPendingTrade(trade.getId());
+        // FIXME: If the trade fails, any watched scripts will remain in the wallet permanently, which is not ideal.
+        List<Script> watchedScripts = trade.getWatchedScripts(btcWalletService);
+        if (!watchedScripts.isEmpty()) {
+            btcWalletService.getWallet().removeWatchedScripts(watchedScripts);
+        }
         requestPersistence();
     }
 

core/src/main/java/bisq/core/trade/model/bisq_v1/Trade.java

@@ -49,6 +49,8 @@
 import org.bitcoinj.core.Coin;
 import org.bitcoinj.core.Transaction;
 import org.bitcoinj.core.TransactionConfidence;
+import org.bitcoinj.core.TransactionOutput;
+import org.bitcoinj.script.Script;
 
 import com.google.common.util.concurrent.FutureCallback;
 import com.google.common.util.concurrent.Futures;
@@ -65,6 +67,7 @@
 import javafx.collections.ObservableList;
 
 import java.util.Date;
+import java.util.List;
 import java.util.Optional;
 import java.util.stream.Collectors;
 
@@ -707,6 +710,29 @@ public Transaction getClaimTx(BtcWalletService btcWalletService) {
         return signedClaimTx != null ? btcWalletService.getTxFromSerializedTx(signedClaimTx) : null;
     }
 
+    public List<Script> getWatchedScripts(BtcWalletService btcWalletService) {
+        if (!hasV5Protocol()) {
+            return List.of();
+        }
+        Transaction depositTx = btcWalletService.getTxFromSerializedTx(processModel.getPreparedDepositTx());
+        TransactionOutput depositTxOutput = depositTx.getOutput(0);
+        Script depositScriptPubKey = depositTxOutput.getScriptPubKey();
+
+        Transaction warningTx = btcWalletService.getTxFromSerializedTx(processModel.getFinalizedWarningTx());
+        TransactionOutput warningTxOutput = warningTx.getOutput(0);
+        Script warningScriptPubKey = warningTxOutput.getScriptPubKey();
+
+        if (processModel.getTradePeer().getFinalizedWarningTx() == null) {
+            log.warn("Missing peer's finalized warning tx. Cannot find watched script for its escrow output.");
+            return List.of(depositScriptPubKey, warningScriptPubKey);
+        }
+        Transaction peersWarningTx = btcWalletService.getTxFromSerializedTx(processModel.getTradePeer().getFinalizedWarningTx());
+        TransactionOutput peersWarningTxOutput = peersWarningTx.getOutput(0);
+        Script peersWarningScriptPubKey = peersWarningTxOutput.getScriptPubKey();
+
+        return List.of(depositScriptPubKey, warningScriptPubKey, peersWarningScriptPubKey);
+    }
+
     public void addAndPersistChatMessage(ChatMessage chatMessage) {
         if (!chatMessages.contains(chatMessage)) {
             chatMessages.add(chatMessage);

core/src/main/java/bisq/core/trade/protocol/bisq_v5/BaseSellerProtocol_v5.java

@@ -37,6 +37,7 @@
 import bisq.core.trade.protocol.bisq_v1.tasks.seller.SellerSendPayoutTxPublishedMessage;
 import bisq.core.trade.protocol.bisq_v1.tasks.seller.SellerSignAndFinalizePayoutTx;
 import bisq.core.trade.protocol.bisq_v5.messages.PreparedTxBuyerSignaturesMessage;
+import bisq.core.trade.protocol.bisq_v5.tasks.AddWatchedScriptsToWallet;
 import bisq.core.trade.protocol.bisq_v5.tasks.seller.SellerProcessPreparedTxBuyerSignaturesMessage;
 import bisq.core.trade.protocol.bisq_v5.tasks.seller.SellerSendsDepositTxAndSellerPaymentAccountMessage;
 
@@ -82,6 +83,7 @@ protected void handle(PreparedTxBuyerSignaturesMessage message, NodeAddress peer
                 .with(message)
                 .from(peer))
                 .setup(tasks(SellerProcessPreparedTxBuyerSignaturesMessage.class,
+                        AddWatchedScriptsToWallet.class,
                         SellerSendsDepositTxAndSellerPaymentAccountMessage.class,
                         SellerPublishesDepositTx.class,
                         SellerPublishesTradeStatistics.class))

core/src/main/java/bisq/core/trade/protocol/bisq_v5/BuyerAsMakerProtocol_v5.java

@@ -36,6 +36,7 @@
 import bisq.core.trade.protocol.bisq_v1.tasks.maker.MakerVerifyTakerFeePayment;
 import bisq.core.trade.protocol.bisq_v5.messages.DepositTxAndSellerPaymentAccountMessage;
 import bisq.core.trade.protocol.bisq_v5.messages.PreparedTxBuyerSignaturesRequest;
+import bisq.core.trade.protocol.bisq_v5.tasks.AddWatchedScriptsToWallet;
 import bisq.core.trade.protocol.bisq_v5.tasks.CreateFeeBumpAddressEntries;
 import bisq.core.trade.protocol.bisq_v5.tasks.CreateRedirectTxs;
 import bisq.core.trade.protocol.bisq_v5.tasks.CreateWarningTxs;
@@ -143,6 +144,7 @@ protected void handle(PreparedTxBuyerSignaturesRequest message, NodeAddress peer
                         FinalizeWarningTxs.class,
                         FinalizeRedirectTxs.class,
                         MakerRemovesOpenOffer.class,
+                        AddWatchedScriptsToWallet.class,
                         BuyerSendsPreparedTxBuyerSignaturesMessage.class)
                         .withTimeout(120))
                 .executeTasks();

core/src/main/java/bisq/core/trade/protocol/bisq_v5/BuyerAsTakerProtocol_v5.java

@@ -36,6 +36,7 @@
 import bisq.core.trade.protocol.bisq_v1.tasks.taker.TakerVerifyMakerFeePayment;
 import bisq.core.trade.protocol.bisq_v5.messages.DepositTxAndSellerPaymentAccountMessage;
 import bisq.core.trade.protocol.bisq_v5.messages.InputsForDepositTxResponse_v5;
+import bisq.core.trade.protocol.bisq_v5.tasks.AddWatchedScriptsToWallet;
 import bisq.core.trade.protocol.bisq_v5.tasks.CreateFeeBumpAddressEntries;
 import bisq.core.trade.protocol.bisq_v5.tasks.CreateRedirectTxs;
 import bisq.core.trade.protocol.bisq_v5.tasks.CreateWarningTxs;
@@ -135,6 +136,7 @@ private void handle(InputsForDepositTxResponse_v5 message, NodeAddress peer) {
                         TakerVerifyAndSignContract.class,
                         TakerPublishFeeTx.class,
                         BuyerAsTakerSignsDepositTx.class,
+                        AddWatchedScriptsToWallet.class,
                         BuyerSetupDepositTxListener.class,
                         BuyerSendsPreparedTxBuyerSignaturesMessage.class)
                         .withTimeout(120))

core/src/main/java/bisq/core/trade/protocol/bisq_v5/SellerAsMakerProtocol_v5.java

@@ -38,6 +38,7 @@
 import bisq.core.trade.protocol.bisq_v1.tasks.seller.SellerPublishesTradeStatistics;
 import bisq.core.trade.protocol.bisq_v1.tasks.seller_as_maker.SellerAsMakerCreatesUnsignedDepositTx;
 import bisq.core.trade.protocol.bisq_v5.messages.PreparedTxBuyerSignaturesMessage;
+import bisq.core.trade.protocol.bisq_v5.tasks.AddWatchedScriptsToWallet;
 import bisq.core.trade.protocol.bisq_v5.tasks.CreateFeeBumpAddressEntries;
 import bisq.core.trade.protocol.bisq_v5.tasks.CreateRedirectTxs;
 import bisq.core.trade.protocol.bisq_v5.tasks.CreateWarningTxs;
@@ -150,6 +151,7 @@ protected void handle(PreparedTxBuyerSignaturesMessage message, NodeAddress peer
                         FinalizeWarningTxs.class,
                         FinalizeRedirectTxs.class,
                         MakerRemovesOpenOffer.class,
+                        AddWatchedScriptsToWallet.class,
                         SellerSendsDepositTxAndSellerPaymentAccountMessage.class,
                         SellerPublishesDepositTx.class,
                         SellerPublishesTradeStatistics.class))

core/src/main/java/bisq/core/trade/protocol/bisq_v5/tasks/AddWatchedScriptsToWallet.java

@@ -0,0 +1,59 @@
+/*
+ * This file is part of Bisq.
+ *
+ * Bisq is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * Bisq is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with Bisq. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package bisq.core.trade.protocol.bisq_v5.tasks;
+
+import bisq.core.btc.wallet.BtcWalletService;
+import bisq.core.trade.model.bisq_v1.Trade;
+import bisq.core.trade.protocol.bisq_v1.tasks.TradeTask;
+
+import bisq.common.taskrunner.TaskRunner;
+
+import org.bitcoinj.core.Transaction;
+import org.bitcoinj.core.TransactionOutput;
+import org.bitcoinj.script.Script;
+
+import java.util.List;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class AddWatchedScriptsToWallet extends TradeTask {
+    public AddWatchedScriptsToWallet(TaskRunner<Trade> taskHandler, Trade trade) {
+        super(taskHandler, trade);
+    }
+
+    @Override
+    protected void run() {
+        try {
+            runInterceptHook();
+
+            BtcWalletService btcWalletService = processModel.getBtcWalletService();
+
+            long creationTimeSeconds = System.currentTimeMillis() / 1000;
+            List<Script> watchedScripts = trade.getWatchedScripts(btcWalletService);
+            watchedScripts.forEach(script -> script.setCreationTimeSeconds(creationTimeSeconds));
+
+            // TODO: Possibly find a way to re-add watched scripts in the event that the wallet is restored from seed.
+            btcWalletService.getWallet().addWatchedScripts(watchedScripts);
+
+            complete();
+        } catch (Throwable t) {
+            failed(t);
+        }
+    }
+}