COVIDSafe code from version 1.10 (#20)

CovidSafe/OnboardingStep1ViewController.swift

@@ -7,7 +7,44 @@
 
 import UIKit
 import SafariServices
+import KeychainSwift
 
 class OnboardingStep1ViewController: UIViewController {
-
+    
+    let keychain = KeychainSwift()
+    
+    override func viewWillAppear(_ animated: Bool) {
+        super.viewWillAppear(animated)
+        
+        switch UIApplication.shared.isProtectedDataAvailable {
+        case true  :
+            checkToken()
+            break
+        case false:
+            NotificationCenter.default.addObserver(self, selector: #selector(setKeychainAvailable(_:)), name: UIApplication.protectedDataDidBecomeAvailableNotification, object: nil)
+            break
+        }
+    }
+    
+    @objc
+    func setKeychainAvailable(_ notification: Notification) {
+        NotificationCenter.default.removeObserver(self, name: UIApplication.protectedDataDidBecomeAvailableNotification, object: nil)
+        checkToken()
+    }
+    
+    func checkToken() {
+        let isLoggedIn: Bool = (keychain.get("JWT_TOKEN") != nil)
+        
+        if isLoggedIn {
+            DispatchQueue.main.async {
+                guard let homeVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "HomeVC") as? HomeViewController else {
+                    return
+                }
+                homeVC.modalPresentationStyle = .overFullScreen
+                homeVC.modalTransitionStyle = .coverVertical
+                
+                self.present(homeVC, animated: true, completion: nil)
+            }
+        }
+    }
 }