feature: displaying a warning before opening a block explorer link

Library/Coordinators/WalletCoordinator.swift

@@ -225,7 +225,7 @@ final class WalletCoordinator: NSObject, Coordinator {
         guard let network = lightningService.infoService.network.value else { return }
         do {
             guard let url = try Settings.shared.blockExplorer.value.url(network: network, code: code, type: type) else { return }
-            presentSafariViewController(for: url)
+            UserDefaults.Keys.didSelectContinueToBlockExplorer.get(defaultValue: false) ? presentSafariViewController(for: url) : presentBlockExplorerWarning(for: url)
         } catch BlockExplorerError.unsupportedNetwork {
             Toast.presentError(L10n.Error.BlockExplorer.unsupportedNetwork(Settings.shared.blockExplorer.value.localized, network.localized))
         } catch {
@@ -302,6 +302,14 @@ final class WalletCoordinator: NSObject, Coordinator {
         safariViewController.preferredControlTintColor = UIColor.Zap.lightningOrange
         (detailViewController ?? rootViewController).present(safariViewController, animated: true)
     }
+
+    private func presentBlockExplorerWarning(for url: URL) {
+        let alertController = UIAlertController.blockExplorerWarningAlertController { [weak self] in
+            guard let self = self else { return }
+            self.presentSafariViewController(for: url)
+        }
+        (detailViewController ?? rootViewController).present(alertController, animated: true)
+    }
 
     private func dismissDetailViewController() {
         detailViewController?.dismiss(animated: true)

Library/Extensions/UIAlertController.swift

@@ -45,4 +45,24 @@ extension UIAlertController {
 
         return alertController
     }
+
+    static func blockExplorerWarningAlertController(continueAction: @escaping () -> Void) -> UIAlertController {
+        let title = L10n.Scene.BlockExplorer.title
+        let message = L10n.Scene.BlockExplorer.message
+        let alertController = UIAlertController(title: title, message: message, preferredStyle: .alert)
+        let cancelAlertAction = UIAlertAction(title: L10n.Generic.cancel, style: .cancel, handler: nil)
+
+        let continueAlertAction = UIAlertAction(title: L10n.Generic.continueString, style: .default) { _ in
+            continueAction()
+        }
+        let alwaysContinueAlertAction = UIAlertAction(title: L10n.Scene.BlockExplorer.alwaysContinue, style: .default) { _ in
+            UserDefaults.Keys.didSelectContinueToBlockExplorer.set(true)
+            continueAction()
+        }
+        alertController.addAction(cancelAlertAction)
+        alertController.addAction(continueAlertAction)
+        alertController.addAction(alwaysContinueAlertAction)
+
+        return alertController
+    }
 }

Library/Extensions/UserDefaults.swift

@@ -10,6 +10,7 @@ import Foundation
 extension UserDefaults {
     enum Keys {
         static let didCreateWallet = DefaultKey<Bool>("didCreateWallet")
+        static let didSelectContinueToBlockExplorer = DefaultKey<Bool>("didSelectContinueToBlockExplorer")
         static let lastSeenHistoryDate = DefaultKey<Date>("lastSeenHistoryDate")
         static let walletDetailExpanded = DefaultKey<Bool>("homeScreenTileExpanded")
         static let migrations = DefaultKey<[String]>("migrations")

Library/Generated/strings.swift

@@ -68,6 +68,8 @@ internal enum L10n {
   internal enum Generic {
     /// Cancel
     internal static let cancel = L10n.tr("Localizable", "generic.cancel")
+    /// Continue
+    internal static let continueString = L10n.tr("Localizable", "generic.continue")
     internal enum Memo {
       /// What is this for?
       internal static let placeholder = L10n.tr("Localizable", "generic.memo.placeholder")
@@ -168,6 +170,14 @@ internal enum L10n {
   }
 
   internal enum Scene {
+    internal enum BlockExplorer {
+      /// Always Continue
+      internal static let alwaysContinue = L10n.tr("Localizable", "scene.block_explorer.always_continue")
+      /// Warning: Privacy Leak
+      internal static let title = L10n.tr("Localizable", "scene.block_explorer.title")
+      /// Looking up your own addresses on a block explorer leaks your privacy to the site operator.
+      internal static let message = L10n.tr("Localizable", "scene.block_explorer.message")
+    }
     internal enum ChannelBackup {
       /// %@ channel.backup
       internal static func cellTitle(_ p1: String) -> String {

Library/Scenes/History/Detail/EventDetailViewController.swift

@@ -15,9 +15,16 @@ final class EventDetailViewController: ModalDetailViewController {
 
     init(event: HistoryEventType, presentBlockExplorer: @escaping (String, BlockExplorer.CodeType) -> Void) {
         viewModel = EventDetailViewModel(event: event)
-
         self.presentBlockExplorer = presentBlockExplorer
+
         super.init(nibName: nil, bundle: nil)
+
+        viewModel.blockExplorerButtonTapped.observeNext { [weak self] blockExplorerItem in
+            guard let self = self else { return }
+            self.dismiss(animated: true) {
+                self.presentBlockExplorer(blockExplorerItem.code, blockExplorerItem.type)
+            }
+        }.dispose(in: reactive.bag)
     }
 
     required init?(coder aDecoder: NSCoder) {
@@ -31,15 +38,7 @@ final class EventDetailViewController: ModalDetailViewController {
     }
 
     private func setupEvent() {
-        let configuration = viewModel.detailConfiguration(delegate: self)
+        let configuration = viewModel.detailConfiguration()
         contentStackView.set(elements: configuration)
     }
 }
-
-extension EventDetailViewController: EventDetailViewModelDelegate {
-    func openBlockExplorer(code: String, type: BlockExplorer.CodeType) {
-        dismiss(animated: true) {
-            self.presentBlockExplorer(code, type)
-        }
-    }
-}

Library/Scenes/History/Detail/EventDetailViewModel.swift

@@ -7,20 +7,24 @@
 
 import Foundation
 import Lightning
+import ReactiveKit
 import SwiftBTC
 
-protocol EventDetailViewModelDelegate: class {
-    func openBlockExplorer(code: String, type: BlockExplorer.CodeType)
+struct BlockExplorerItem {
+    let code: String
+    let type: BlockExplorer.CodeType
 }
 
 final class EventDetailViewModel {
     private let event: HistoryEventType
+
+    let blockExplorerButtonTapped = Subject<BlockExplorerItem, NoError>()
 
     init(event: HistoryEventType) {
         self.event = event
     }
 
-    func detailConfiguration(delegate: EventDetailViewModelDelegate) -> [StackViewElement] {
+    func detailConfiguration() -> [StackViewElement] {
         var result = [StackViewElement]()
 
         switch event {
@@ -29,13 +33,13 @@ final class EventDetailViewModel {
             result.append(contentsOf: amountLabel(title: L10n.Scene.TransactionDetail.amountLabel, amount: event.amount))
             result.append(contentsOf: amountLabel(title: L10n.Scene.TransactionDetail.feeLabel, amount: event.fee, skipZero: true))
             result.append(contentsOf: dateLabel(title: L10n.Scene.TransactionDetail.dateLabel, date: event.date))
-            result.append(contentsOf: blockExplorerButton(title: L10n.Scene.TransactionDetail.transactionIdLabel, code: event.txHash, type: .transactionId, delegate: delegate))
-            result.append(contentsOf: blockExplorerButton(title: L10n.Scene.TransactionDetail.addressLabel, code: event.destinationAddresses.first?.string, type: .address, delegate: delegate))
+            result.append(contentsOf: blockExplorerButton(title: L10n.Scene.TransactionDetail.transactionIdLabel, code: event.txHash, type: .transactionId))
+            result.append(contentsOf: blockExplorerButton(title: L10n.Scene.TransactionDetail.addressLabel, code: event.destinationAddresses.first?.string, type: .address))
         case .channelEvent(let event):
             result.append(contentsOf: headline(L10n.Scene.TransactionDetail.Title.channelEventDetail))
             result.append(contentsOf: amountLabel(title: L10n.Scene.TransactionDetail.feeLabel, amount: event.fee, skipZero: true))
             result.append(contentsOf: dateLabel(title: L10n.Scene.TransactionDetail.dateLabel, date: event.date))
-            result.append(contentsOf: blockExplorerButton(title: L10n.Scene.TransactionDetail.transactionIdLabel, code: event.txHash, type: .transactionId, delegate: delegate))
+            result.append(contentsOf: blockExplorerButton(title: L10n.Scene.TransactionDetail.transactionIdLabel, code: event.txHash, type: .transactionId))
         case .createInvoiceEvent(let event):
             return createInvoiceEvent(event: event)
         case .lightningPaymentEvent(let event):
@@ -155,10 +159,11 @@ final class EventDetailViewModel {
         return label(title: title, content: dateString)
     }
 
-    private func blockExplorerButton(title: String, code: String?, type: BlockExplorer.CodeType, delegate: EventDetailViewModelDelegate?) -> [StackViewElement] {
+    private func blockExplorerButton(title: String, code: String?, type: BlockExplorer.CodeType) -> [StackViewElement] {
         guard let code = code else { return [] }
-        return label(title: title, element: .button(title: code, style: Style.Button.custom(), completion: { _ in
-            delegate?.openBlockExplorer(code: code, type: type)
+        return label(title: title, element: .button(title: code, style: Style.Button.custom(), completion: { [weak self] _ in
+            guard let self = self else { return }
+            self.blockExplorerButtonTapped.send(BlockExplorerItem(code: code, type: type))
         }))
     }
 

Library/Tests/EventDetailViewModelTests.swift

@@ -13,10 +13,6 @@ import XCTest
 // swiftlint:disable force_unwrapping
 final class EventDetailViewModelTests: XCTestCase {
 
-    private final class MockDelegate: EventDetailViewModelDelegate {
-        func openBlockExplorer(code: String, type: BlockExplorer.CodeType) {}
-    }
-
     func testTransactionEventZeroFees() {
         let transaction = Transaction(
             id: "100",
@@ -30,7 +26,7 @@ final class EventDetailViewModelTests: XCTestCase {
         let event = TransactionEvent(transaction: transaction)!
         let eventType = HistoryEventType.transactionEvent(event)
         let viewModel = EventDetailViewModel(event: eventType)
-        let configuration = viewModel.detailConfiguration(delegate: MockDelegate())
+        let configuration = viewModel.detailConfiguration()
 
         XCTAssertEqual(configuration.count, 5)
     }
@@ -48,7 +44,7 @@ final class EventDetailViewModelTests: XCTestCase {
         let event = TransactionEvent(transaction: transaction)!
         let eventType = HistoryEventType.transactionEvent(event)
         let viewModel = EventDetailViewModel(event: eventType)
-        let configuration = viewModel.detailConfiguration(delegate: MockDelegate())
+        let configuration = viewModel.detailConfiguration()
 
         XCTAssertEqual(configuration.count, 6)
         if

Library/en.lproj/Localizable.strings

@@ -4,6 +4,7 @@
 "generic.pasteboard.invalid_address" = "Invalid Address";
 "generic.qr_code.share_button" = "Share";
 "generic.cancel" = "Cancel";
+"generic.continue" = "Continue";
 
 "link.help" = "https://docs.zaphq.io/";
 "link.help.zapconnect" = "https://docs.zaphq.io/docs-ios-remote-node-setup";
@@ -309,6 +310,10 @@
 "scene.manage_wallets.section_title.local" = "Local Wallet";
 "scene.manage_wallets.section_title.remote" = "Remote Wallets";
 
+"scene.block_explorer.always_continue" = "Always Continue";
+"scene.block_explorer.title" = "Warning: Privacy Leak";
+"scene.block_explorer.message" = "Looking up your own addresses on a block explorer leaks your privacy to the site operator.\n\nWould you like to view the block explorer?";
+
 "scene.channel_backup.title" = "Channel Backup";
 "scene.channel_backup.cell_title" = "%@ channel.backup";
 "scene.channel_backup.not_found" = "file not found";