Coordinator.swift

final class SignInWithAppleCoordinator: NSObject {

    func getApppleRequest() {
        let appleIdProvider = ASAuthorizationAppleIDProvider()
        let request = appleIdProvider.createRequest()
        request.requestedScopes = [.fullName, .email]
        let authController = ASAuthorizationController(authorizationRequests: [request])
        authController.delegate = self
        authController.performRequests()
    }
    
    private func setUserInfo(for userId: String, fullName: String?, email: String?) {
        ASAuthorizationAppleIDProvider().getCredentialState(forUserID: userId) { credentialState, error in
            var authState: String?
            
            switch credentialState {
                case .authorized: authState = "authorized"
                case .revoked: authState = "revoked"
                case .notFound: authState = "notFound"
                case .transferred: authState = "transferred"
                @unknown default:
                        fatalError()
                }
            
            let user = User(fullName: fullName ?? "not provided", email: email ?? "email", authState: authState ?? "unknown")
            if let userEncoded = try? JSONEncoder().encode(user) {
                UserDefaults.standard.set(userEncoded, forKey: "user")
            }
        }
    }
}

extension SignInWithAppleCoordinator: ASAuthorizationControllerDelegate {
    func authorizationController(controller: ASAuthorizationController, didCompleteWithAuthorization authorization: ASAuthorization) {
        if let credential = authorization.credential as? ASAuthorizationAppleIDCredential {
            let fullName = (credential.fullName?.givenName ?? "")
            setUserInfo(for: credential.user, fullName: fullName, email: credential.email)
        }
    }
    
    func authorizationController(controller: ASAuthorizationController, didCompleteWithError error: Error) {
        print("Sign In with Apple ID Error: \(error.localizedDescription)")
    }
}