[NTV-1896] Present Payment Sheet With Feature Flag Enabled. (#1731)

* added boilerplate for showing sheet without create_setup_intent

* updates to gql schema that support the create_setup_intent with no project id

* payment sheet presented on payment method settings.

* added tests

* pr corrections

Kickstarter-iOS/Features/PaymentMethods/Controller/PaymentMethodsViewController.swift

@@ -1,11 +1,13 @@
 import KsApi
 import Library
 import Prelude
+import Stripe
 import UIKit
 
 internal final class PaymentMethodsViewController: UIViewController, MessageBannerViewControllerPresenting {
   private let dataSource = PaymentMethodsDataSource()
   private let viewModel: PaymentMethodsViewModelType = PaymentMethodsViewModel()
+  private var paymentSheetFlowController: PaymentSheet.FlowController?
 
   @IBOutlet private var tableView: UITableView!
 
@@ -93,7 +95,15 @@ internal final class PaymentMethodsViewController: UIViewController, MessageBann
         self?.goToAddCardScreen(with: intent)
       }
 
-    self.viewModel.outputs.errorLoadingPaymentMethods
+    self.viewModel.outputs.goToPaymentSheet
+      .observeForUI()
+      .observeValues { [weak self] data in
+        guard let strongSelf = self else { return }
+
+        strongSelf.goToPaymentSheet(data: data)
+      }
+
+    self.viewModel.outputs.errorLoadingPaymentMethodsOrSetupIntent
       .observeForUI()
       .observeValues { [weak self] message in
         self?.messageBannerViewController?.showBanner(with: .error, message: message)
@@ -143,6 +153,69 @@ internal final class PaymentMethodsViewController: UIViewController, MessageBann
 
   // MARK: - Private Helpers
 
+  private func goToPaymentSheet(data: PaymentSheetSetupData) {
+    PaymentSheet.FlowController
+      .create(
+        setupIntentClientSecret: data.clientSecret,
+        configuration: data.configuration
+      ) { [weak self] result in
+        guard let strongSelf = self else { return }
+
+        switch result {
+        case let .failure(error):
+          /** TODO: https://kickstarter.atlassian.net/browse/PAY-1954
+           * strongSelf.viewModel.inputs.shouldCancelPaymentSheetAppearance(state: true)
+           */
+
+          strongSelf.messageBannerViewController?
+            .showBanner(with: .error, message: error.localizedDescription)
+        case let .success(paymentSheetFlowController):
+          strongSelf.paymentSheetFlowController = paymentSheetFlowController
+          strongSelf.paymentSheetFlowController?.presentPaymentOptions(from: strongSelf) { [weak self] in
+            guard let strongSelf = self else { return }
+
+            /** TODO: https://kickstarter.atlassian.net/browse/PAY-1900
+             * strongSelf.confirmPaymentResult(with: data.clientSecret)
+             */
+          }
+        }
+      }
+  }
+
+  private func confirmPaymentResult(with _: String) {
+    guard self.paymentSheetFlowController?.paymentOption != nil else {
+      /** TODO: https://kickstarter.atlassian.net/browse/PAY-1954
+       * strongSelf.viewModel.inputs.shouldCancelPaymentSheetAppearance(state: true)
+       */
+
+      return
+    }
+
+    self.paymentSheetFlowController?.confirm(from: self) { [weak self] paymentResult in
+
+      guard let strongSelf = self else { return }
+
+      /** TODO: https://kickstarter.atlassian.net/browse/PAY-1954
+       * strongSelf.viewModel.inputs.shouldCancelPaymentSheetAppearance(state: true)
+       */
+
+      guard let existingPaymentOption = strongSelf.paymentSheetFlowController?.paymentOption else { return }
+
+      switch paymentResult {
+      case .completed:
+        /** TODO: https://kickstarter.atlassian.net/browse/PAY-1898
+         * strongSelf.viewModel.inputs.paymentSheetDidAdd(newCard: existingPaymentOption, setupIntent: clientSecret)
+         */
+        fatalError()
+      case .canceled:
+        strongSelf.messageBannerViewController?
+          .showBanner(with: .error, message: Strings.general_error_something_wrong())
+      case let .failed(error):
+        strongSelf.messageBannerViewController?.showBanner(with: .error, message: error.localizedDescription)
+      }
+    }
+  }
+
   private func configureHeaderFooterViews() {
     if let header = SettingsTableViewHeader.fromNib(nib: Nib.SettingsTableViewHeader) {
       header.configure(with: Strings.Any_payment_methods_you_saved_to_Kickstarter())

KsApi/GraphAPI.swift

@@ -254,23 +254,24 @@ public enum GraphAPI {
     ///   - stripeToken
     ///   - stripeCardId
     ///   - reusable
+    ///   - intentClientSecret
     ///   - clientMutationId: A unique identifier for the client performing the mutation.
-    public init(paymentType: PaymentTypes, stripeToken: String, stripeCardId: Swift.Optional<String?> = nil, reusable: Swift.Optional<Bool?> = nil, clientMutationId: Swift.Optional<String?> = nil) {
-      graphQLMap = ["paymentType": paymentType, "stripeToken": stripeToken, "stripeCardId": stripeCardId, "reusable": reusable, "clientMutationId": clientMutationId]
+    public init(paymentType: Swift.Optional<PaymentTypes?> = nil, stripeToken: Swift.Optional<String?> = nil, stripeCardId: Swift.Optional<String?> = nil, reusable: Swift.Optional<Bool?> = nil, intentClientSecret: Swift.Optional<String?> = nil, clientMutationId: Swift.Optional<String?> = nil) {
+      graphQLMap = ["paymentType": paymentType, "stripeToken": stripeToken, "stripeCardId": stripeCardId, "reusable": reusable, "intentClientSecret": intentClientSecret, "clientMutationId": clientMutationId]
     }
 
-    public var paymentType: PaymentTypes {
+    public var paymentType: Swift.Optional<PaymentTypes?> {
       get {
-        return graphQLMap["paymentType"] as! PaymentTypes
+        return graphQLMap["paymentType"] as? Swift.Optional<PaymentTypes?> ?? Swift.Optional<PaymentTypes?>.none
       }
       set {
         graphQLMap.updateValue(newValue, forKey: "paymentType")
       }
     }
 
-    public var stripeToken: String {
+    public var stripeToken: Swift.Optional<String?> {
       get {
-        return graphQLMap["stripeToken"] as! String
+        return graphQLMap["stripeToken"] as? Swift.Optional<String?> ?? Swift.Optional<String?>.none
       }
       set {
         graphQLMap.updateValue(newValue, forKey: "stripeToken")
@@ -295,6 +296,15 @@ public enum GraphAPI {
       }
     }
 
+    public var intentClientSecret: Swift.Optional<String?> {
+      get {
+        return graphQLMap["intentClientSecret"] as? Swift.Optional<String?> ?? Swift.Optional<String?>.none
+      }
+      set {
+        graphQLMap.updateValue(newValue, forKey: "intentClientSecret")
+      }
+    }
+
     /// A unique identifier for the client performing the mutation.
     public var clientMutationId: Swift.Optional<String?> {
       get {
@@ -349,13 +359,13 @@ public enum GraphAPI {
     /// - Parameters:
     ///   - projectId
     ///   - clientMutationId: A unique identifier for the client performing the mutation.
-    public init(projectId: GraphQLID, clientMutationId: Swift.Optional<String?> = nil) {
+    public init(projectId: Swift.Optional<GraphQLID?> = nil, clientMutationId: Swift.Optional<String?> = nil) {
       graphQLMap = ["projectId": projectId, "clientMutationId": clientMutationId]
     }
 
-    public var projectId: GraphQLID {
+    public var projectId: Swift.Optional<GraphQLID?> {
       get {
-        return graphQLMap["projectId"] as! GraphQLID
+        return graphQLMap["projectId"] as? Swift.Optional<GraphQLID?> ?? Swift.Optional<GraphQLID?>.none
       }
       set {
         graphQLMap.updateValue(newValue, forKey: "projectId")