Check connectivity with the API before start the transaction to buy a new plan

PIALibrary/Resources/UI/iOS/en.lproj/Welcome.strings

@@ -28,6 +28,9 @@
 "purchase.login.button" = "Sign in";
 "purchase.error.title" = "Purchase";
 "purchase.error.validation" = "You must enter an email address.";
+"purchase.error.connectivity.title" = "Connection Failure";
+"purchase.error.connectivity.description" = "We are unable to reach Private Internet Access. This may due to poor internet or our service is blocked in your country.";
+
 
 "redeem.title" = "Redeem gift card";
 "redeem.subtitle" = "Type in your email address and the %lu digit PIN from your gift card or trial card below.";

PIALibrary/Sources/Core/Account/AccountProvider.swift

@@ -90,6 +90,13 @@ public protocol AccountProvider: class {
      */
     func purchase(plan: Plan, _ callback: LibraryCallback<InAppTransaction>?)
     
+    /**
+     Check if the user has access to our servers from the country where is based.
+     
+     - Parameter callback: Returns a boolean indicating if the operation was successfully or not.
+     */
+    func isAPIEndpointAvailable(_ callback: LibraryCallback<Bool>?)
+
     /**
      Restores the purchase history, possibly recovering from corruption.
      

PIALibrary/Sources/Library/Account/DefaultAccountProvider.swift

@@ -351,4 +351,12 @@ class DefaultAccountProvider: AccountProvider, ConfigurationAccess, DatabaseAcce
     var webServices: WebServices {
         return customWebServices ?? accessedWebServices
     }
+    
+    func isAPIEndpointAvailable(_ callback: LibraryCallback<Bool>?) {
+        let task = webServices.taskForConnectivityCheck { (_, error) in
+            callback?(error == nil, error)
+        }
+        task.resume()
+    }
+    
 }

PIALibrary/Sources/Mock/MockAccountProvider.swift

@@ -220,4 +220,9 @@ public class MockAccountProvider: AccountProvider, WebServicesConsumer {
         delegate.renew(with: request, callback)
     }
     #endif
+    
+    public func isAPIEndpointAvailable(_ callback: LibraryCallback<Bool>?) {
+        callback?(true, nil)
+    }
+    
 }

PIALibrary/Sources/UI/iOS/PIAWelcomeViewController.swift

@@ -413,4 +413,16 @@ class EphemeralAccountProvider: AccountProvider, ProvidersAccess, InAppAccess {
     func renew(with request: RenewRequest, _ callback: ((UserAccount?, Error?) -> Void)?) {
         fatalError("Not implemented")
     }
+    
+    func isAPIEndpointAvailable(_ callback: LibraryCallback<Bool>?) {
+        guard let webServices = webServices else {
+            callback?(false, nil)
+            return
+        }
+        let task = webServices.taskForConnectivityCheck { (_, error) in
+            callback?(error == nil, error)
+        }
+        task.resume()
+    }
+
 }

PIALibrary/Sources/UI/iOS/PurchaseViewController.swift

@@ -169,19 +169,39 @@ class PurchaseViewController: AutolayoutViewController, WelcomeChild {
             present(alert, animated: true, completion: nil)
             return
         }
+
+        preset?.accountProvider.isAPIEndpointAvailable({ [weak self] (isAvailable, error) in
+            guard let isAvailable = isAvailable,
+                isAvailable else {
+                let alert = Macros.alert(
+                    L10n.Welcome.Purchase.Error.Connectivity.title,
+                    L10n.Welcome.Purchase.Error.Connectivity.description
+                )
+                alert.addCancelAction(L10n.Ui.Global.close)
+                self?.present(alert, animated: true, completion: nil)
+                return
+            }
+            self?.startPurchaseProcessWithEmail(email,
+                                                andPlan: plan)
+        })
+        
+    }
+    
+    private func startPurchaseProcessWithEmail(_ email: String,
+                                               andPlan plan: PurchasePlan) {
         
         textEmail.text = email
         log.debug("Will purchase plan: \(plan.product)")
-
+        
         disableInteractions(fully: true)
         
         preset?.accountProvider.purchase(plan: plan.plan) { (transaction, error) in
             self.enableInteractions()
-
+            
             guard let transaction = transaction else {
                 if let error = error {
                     log.error("Purchase failed (error: \(error))")
-
+                    
                     let alert = Macros.alert(
                         L10n.Welcome.Iap.Error.title,
                         error.localizedDescription
@@ -193,13 +213,14 @@ class PurchaseViewController: AutolayoutViewController, WelcomeChild {
                 }
                 return
             }
-
+            
             log.debug("Purchased with transaction: \(transaction)")
-
+            
             self.signupEmail = email
             self.signupTransaction = transaction
             self.perform(segue: StoryboardSegue.Welcome.signupViaPurchaseSegue)
         }
+
     }
     
     @IBAction private func logIn(_ sender: Any?) {

PIALibrary/Sources/UI/iOS/SwiftGen+Strings.swift

@@ -127,6 +127,14 @@ enum L10n {
         static let title = L10n.tr("Welcome", "purchase.error.title")
         /// You must enter an email address.
         static let validation = L10n.tr("Welcome", "purchase.error.validation")
+        
+        enum Connectivity {
+            /// Connection Failure
+            static let title = L10n.tr("Welcome", "purchase.error.connectivity.title")
+            /// We are unable to reach Private Internet Access. This may due to poor internet or our service is blocked in your country.
+            static let description = L10n.tr("Welcome", "purchase.error.connectivity.description")
+        }
+
       }
 
       enum Login {