gui: Menu action for exporting a watchonly wallet

diff --git a/src/interfaces/wallet.h b/src/interfaces/wallet.h
index 326361aa..f080f070 100644
--- a/src/interfaces/wallet.h
+++ b/src/interfaces/wallet.h
@@ -302,6 +302,9 @@ public:
 
     //! Return pointer to internal wallet class, useful for testing.
     virtual wallet::CWallet* wallet() { return nullptr; }
+
+    //! Export a watchonly wallet file. See CWallet::ExportWatchOnlyWallet
+    virtual util::Result<std::string> exportWatchOnlyWallet(const fs::path& destination) = 0;
 };
 
 //! Wallet chain client that in addition to having chain client methods for
diff --git a/src/qt/bitcoingui.cpp b/src/qt/bitcoingui.cpp
index 5f169a95..98d9d21b 100644
--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -377,6 +377,10 @@ void BitcoinGUI::createActions()
     m_mask_values_action->setStatusTip(tr("Mask the values in the Overview tab"));
     m_mask_values_action->setCheckable(true);
 
+    m_export_watchonly_action = new QAction(tr("Export watch-only wallet"), this);
+    m_export_watchonly_action->setEnabled(false);
+    m_export_watchonly_action->setStatusTip(tr("Export a watch-only version of the current wallet that can be restored onto another node."));
+
     connect(quitAction, &QAction::triggered, this, &BitcoinGUI::quitRequested);
     connect(aboutAction, &QAction::triggered, this, &BitcoinGUI::aboutClicked);
     connect(aboutQtAction, &QAction::triggered, qApp, QApplication::aboutQt);
@@ -524,6 +528,18 @@ void BitcoinGUI::createActions()
         });
         connect(m_mask_values_action, &QAction::toggled, this, &BitcoinGUI::setPrivacy);
         connect(m_mask_values_action, &QAction::toggled, this, &BitcoinGUI::enableHistoryAction);
+        GUIUtil::ExceptionSafeConnect(m_export_watchonly_action, &QAction::triggered, [this](bool) {
+            QString destination = GUIUtil::getSaveFileName(this, tr("Save Watch-only Wallet Export"), QString(), QString(), nullptr);
+            if (destination.isEmpty()) return;
+            WalletModel* model = walletFrame->currentWalletModel();
+            if (!Assume(model)) return;
+            util::Result<std::string> export_res = model->wallet().exportWatchOnlyWallet(GUIUtil::QStringToPath(destination));
+            if (export_res) {
+                QMessageBox::information(nullptr, tr("Export Successful"), tr("The wallet has been exported to ") + QString::fromStdString(*export_res));
+            } else {
+                QMessageBox::critical(nullptr, tr("Export Error"), QString::fromStdString(util::ErrorString(export_res).translated));
+            }
+        });
     }
 #endif // ENABLE_WALLET
 
@@ -547,6 +563,7 @@ void BitcoinGUI::createMenuBar()
         file->addSeparator();
         file->addAction(backupWalletAction);
         file->addAction(m_restore_wallet_action);
+        file->addAction(m_export_watchonly_action);
         file->addSeparator();
         file->addAction(openAction);
         file->addAction(signMessageAction);
@@ -832,6 +849,7 @@ void BitcoinGUI::setCurrentWallet(WalletModel* wallet_model)
             break;
         }
     }
+    m_export_watchonly_action->setEnabled(!wallet_model->wallet().privateKeysDisabled());
     updateWindowTitle();
 }
 
@@ -866,6 +884,7 @@ void BitcoinGUI::setWalletActionsEnabled(bool enabled)
     openAction->setEnabled(enabled);
     m_close_wallet_action->setEnabled(enabled);
     m_close_all_wallets_action->setEnabled(enabled);
+    m_export_watchonly_action->setEnabled(enabled);
 }
 
 void BitcoinGUI::createTrayIcon()
diff --git a/src/qt/bitcoingui.h b/src/qt/bitcoingui.h
index babb8961..538e1d19 100644
--- a/src/qt/bitcoingui.h
+++ b/src/qt/bitcoingui.h
@@ -167,6 +167,7 @@ private:
     QAction* m_mask_values_action{nullptr};
     QAction* m_migrate_wallet_action{nullptr};
     QMenu* m_migrate_wallet_menu{nullptr};
+    QAction* m_export_watchonly_action{nullptr};
 #ifdef ENABLE_WALLET
     QLabel *m_wallet_selector_label = nullptr;
     QComboBox* m_wallet_selector = nullptr;
diff --git a/src/wallet/interfaces.cpp b/src/wallet/interfaces.cpp
index 9f9876da..1c5f689e 100644
--- a/src/wallet/interfaces.cpp
+++ b/src/wallet/interfaces.cpp
@@ -21,6 +21,7 @@
 #include <util/ui_change_type.h>
 #include <wallet/coincontrol.h>
 #include <wallet/context.h>
+#include <wallet/export.h>
 #include <wallet/feebumper.h>
 #include <wallet/fees.h>
 #include <wallet/load.h>
@@ -522,6 +523,12 @@ public:
     }
     CWallet* wallet() override { return m_wallet.get(); }
 
+    util::Result<std::string> exportWatchOnlyWallet(const fs::path& destination) override {
+        LOCK(m_wallet->cs_wallet);
+        m_wallet->TopUpKeyPool();
+        return ExportWatchOnlyWallet(*m_wallet, destination, m_context);
+    }
+
     WalletContext& m_context;
     std::shared_ptr<CWallet> m_wallet;
 };