From b20b956e15184d39925ac415020ea886c7d47e87 Mon Sep 17 00:00:00 2001
From: xiphon <xiphon@protonmail.com>
Date: Thu, 4 Feb 2021 11:32:30 +0000
Subject: [PATCH] Wallet: estimateTransactionFeeAsync - multi dest support

---
 pages/Transfer.qml         |  4 ++--
 src/libwalletqt/Wallet.cpp | 35 +++++++++++++++++++++++++----------
 src/libwalletqt/Wallet.h   |  9 +++++----
 3 files changed, 32 insertions(+), 16 deletions(-)

diff --git a/pages/Transfer.qml b/pages/Transfer.qml
index 828d7b5d..9a4d8b18 100644
--- a/pages/Transfer.qml
+++ b/pages/Transfer.qml
@@ -361,8 +361,8 @@ Rectangle {
                             return;
                         }
                         currentWallet.estimateTransactionFeeAsync(
-                            addressLine.text,
-                            walletManager.amountFromString(amountLine.text),
+                            [addressLine.text],
+                            [walletManager.amountFromString(amountLine.text)],
                             priorityModelV5.get(priorityDropdown.currentIndex).priority,
                             function (amount) {
                                 estimatedFee = Utils.removeTrailingZeros(amount);
diff --git a/src/libwalletqt/Wallet.cpp b/src/libwalletqt/Wallet.cpp
index 010bb487..66df9077 100644
--- a/src/libwalletqt/Wallet.cpp
+++ b/src/libwalletqt/Wallet.cpp
@@ -626,17 +626,32 @@ void Wallet::disposeTransaction(UnsignedTransaction *t)
     delete t;
 }
 
-void Wallet::estimateTransactionFeeAsync(const QString &destination,
-                                         quint64 amount,
-                                         PendingTransaction::Priority priority,
-                                         const QJSValue &callback)
+void Wallet::estimateTransactionFeeAsync(
+    const QVector<QString> &destinationAddresses,
+    const QVector<quint64> &amounts,
+    PendingTransaction::Priority priority,
+    const QJSValue &callback)
 {
-    m_scheduler.run([this, destination, amount, priority] {
-        const uint64_t fee = m_walletImpl->estimateTransactionFee(
-            {std::make_pair(destination.toStdString(), amount)},
-            static_cast<Monero::PendingTransaction::Priority>(priority));
-        return QJSValueList({QString::fromStdString(Monero::Wallet::displayAmount(fee))});
-    }, callback);
+    m_scheduler.run(
+        [this, destinationAddresses, amounts, priority] {
+            if (destinationAddresses.size() != amounts.size())
+            {
+                return QJSValueList({""});
+            }
+
+            std::vector<std::pair<std::string, uint64_t>> destinations;
+            destinations.reserve(destinationAddresses.size());
+            for (size_t index = 0; index < destinationAddresses.size(); ++index)
+            {
+                destinations.emplace_back(std::make_pair(destinationAddresses[index].toStdString(), amounts[index]));
+            }
+
+            const uint64_t fee = m_walletImpl->estimateTransactionFee(
+                destinations,
+                static_cast<Monero::PendingTransaction::Priority>(priority));
+            return QJSValueList({QString::fromStdString(Monero::Wallet::displayAmount(fee))});
+        },
+        callback);
 }
 
 TransactionHistory *Wallet::history() const
diff --git a/src/libwalletqt/Wallet.h b/src/libwalletqt/Wallet.h
index 0f6d1353..03c3fede 100644
--- a/src/libwalletqt/Wallet.h
+++ b/src/libwalletqt/Wallet.h
@@ -255,10 +255,11 @@ public:
     //! deletes unsigned transaction and frees memory
     Q_INVOKABLE void disposeTransaction(UnsignedTransaction * t);
 
-    Q_INVOKABLE void estimateTransactionFeeAsync(const QString &destination,
-                                                 quint64 amount,
-                                                 PendingTransaction::Priority priority,
-                                                 const QJSValue &callback);
+    Q_INVOKABLE void estimateTransactionFeeAsync(
+        const QVector<QString> &destinationAddresses,
+        const QVector<quint64> &amounts,
+        PendingTransaction::Priority priority,
+        const QJSValue &callback);
 
     //! returns transaction history
     TransactionHistory * history() const;