From 5b450a5ccbe66f160b263f006f06b374802e73df Mon Sep 17 00:00:00 2001
From: Matthew Chen <matthew@signal.org>
Date: Fri, 19 Mar 2021 10:30:43 -0300
Subject: [PATCH] Show available balance, not actual balance.

---
 .../SendPaymentCompletionActionSheet.swift    |  6 ++++-
 .../Payments/SendPaymentHelper.swift          | 25 ++++++++++++++++---
 .../Payments/SendPaymentViewController.swift  |  6 ++++-
 .../translations/en.lproj/Localizable.strings |  2 +-
 4 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/Signal/src/ViewControllers/Payments/SendPaymentCompletionActionSheet.swift b/Signal/src/ViewControllers/Payments/SendPaymentCompletionActionSheet.swift
index c37dfe03c1..bd44908ae6 100644
--- a/Signal/src/ViewControllers/Payments/SendPaymentCompletionActionSheet.swift
+++ b/Signal/src/ViewControllers/Payments/SendPaymentCompletionActionSheet.swift
@@ -514,7 +514,11 @@ public class SendPaymentCompletionActionSheet: ActionSheetController {
 
     @objc
     public func updateBalanceLabel() {
-        SendPaymentHelper.updateBalanceLabel(balanceLabel)
+        guard let helper = helper else {
+            Logger.verbose("Missing helper.")
+            return
+        }
+        helper.updateBalanceLabel(balanceLabel)
     }
 
     private func tryToSendPayment(paymentInfo: PaymentInfo) {
diff --git a/Signal/src/ViewControllers/Payments/SendPaymentHelper.swift b/Signal/src/ViewControllers/Payments/SendPaymentHelper.swift
index d1e99d6b15..1ffe491337 100644
--- a/Signal/src/ViewControllers/Payments/SendPaymentHelper.swift
+++ b/Signal/src/ViewControllers/Payments/SendPaymentHelper.swift
@@ -65,12 +65,15 @@ class SendPaymentHelper {
         }
     }
 
+    private var maximumPaymentAmount: TSPaymentAmount?
+
     required init(delegate: SendPaymentHelperDelegate) {
         self.delegate = delegate
 
         addObservers()
 
         updateCurrentCurrencyConversion()
+        updateMaximumPaymentAmount()
     }
 
     private func addObservers() {
@@ -144,9 +147,9 @@ class SendPaymentHelper {
         return label
     }
 
-    public static func updateBalanceLabel(_ balanceLabel: UILabel) {
+    public func updateBalanceLabel(_ balanceLabel: UILabel) {
 
-        guard let paymentBalance = Self.paymentsSwift.currentPaymentBalance else {
+        guard let maximumPaymentAmount = self.maximumPaymentAmount else {
             // Use whitespace to ensure that the height of the label
             // is constant, avoiding layout jitter.
             balanceLabel.text = " "
@@ -156,12 +159,28 @@ class SendPaymentHelper {
         let format = NSLocalizedString("PAYMENTS_NEW_PAYMENT_BALANCE_FORMAT",
                                        comment: "Format for the 'balance' indicator. Embeds {{ the current payments balance }}.")
         balanceLabel.text = String(format: format,
-                                   Self.formatMobileCoinAmount(paymentBalance.amount))
+                                   Self.formatMobileCoinAmount(maximumPaymentAmount))
+    }
+
+    private func updateMaximumPaymentAmount() {
+        firstly {
+            Self.paymentsSwift.maximumPaymentAmount()
+        }.done(on: .main) { [weak self] maximumPaymentAmount in
+            guard let self = self else { return }
+            self.maximumPaymentAmount = maximumPaymentAmount
+            self.delegate?.balanceDidChange()
+        }.catch(on: .global()) { error in
+            owsFailDebugUnlessNetworkFailure(error)
+        }
+
+        delegate?.balanceDidChange()
     }
 
     @objc
     private func currentPaymentBalanceDidChange() {
         delegate?.balanceDidChange()
+
+        updateMaximumPaymentAmount()
     }
 
     @objc
diff --git a/Signal/src/ViewControllers/Payments/SendPaymentViewController.swift b/Signal/src/ViewControllers/Payments/SendPaymentViewController.swift
index e47092db5f..13bc2c6a5a 100644
--- a/Signal/src/ViewControllers/Payments/SendPaymentViewController.swift
+++ b/Signal/src/ViewControllers/Payments/SendPaymentViewController.swift
@@ -673,7 +673,11 @@ public class SendPaymentViewController: OWSViewController {
     }
 
     private func updateBalanceLabel() {
-        SendPaymentHelper.updateBalanceLabel(balanceLabel)
+        guard let helper = helper else {
+            Logger.verbose("Missing helper.")
+            return
+        }
+        helper.updateBalanceLabel(balanceLabel)
     }
 
     private func showInvalidAmountAlert() {
diff --git a/Signal/translations/en.lproj/Localizable.strings b/Signal/translations/en.lproj/Localizable.strings
index 9f6d205abd..3962b7a674 100644
--- a/Signal/translations/en.lproj/Localizable.strings
+++ b/Signal/translations/en.lproj/Localizable.strings
@@ -3392,7 +3392,7 @@
 "PAYMENTS_NEW_PAYMENT_ADD_MEMO" = "Add Note";
 
 /* Format for the 'balance' indicator. Embeds {{ the current payments balance }}. */
-"PAYMENTS_NEW_PAYMENT_BALANCE_FORMAT" = "Balance: %@";
+"PAYMENTS_NEW_PAYMENT_BALANCE_FORMAT" = "Available Balance: %@";
 
 /* Label for the 'confirm payment' button. */
 "PAYMENTS_NEW_PAYMENT_CONFIRM_PAYMENT_BUTTON" = "Confirm Payment";