AppleSignInViewController.swift

//
//  AppleSignInViewController.swift
//
//  Created by Rasmus Styrk on 26/11/2019.
//  Copyright © 2019 House of Code ApS. All rights reserved.
//

import UIKit
import AuthenticationServices

class AppleSignInViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // TODO: Add button to call self.inititateAppleLogin()
    }
    
    func inititateAppleLogin() {
        if #available(iOS 13.0, *) {
            let appleIDProvider = ASAuthorizationAppleIDProvider()
            let request = appleIDProvider.createRequest()
            request.requestedScopes = [.fullName, .email]
            
            let authorizationController = ASAuthorizationController(authorizationRequests: [request])
            authorizationController.delegate = self
            authorizationController.presentationContextProvider = self
            authorizationController.performRequests()
        } else {
            // TODO: Show error?
        }
    }
    
    func validateWithServer(name: String, userIdentity: String, jwt: String) {
        // TODO: Send off userIdeneity, name and jwtToken to server for validation
        print("User: \(userIdentity), with name: \(name) and jwt token: \(jwt)")
    }
}

@available(iOS 13.0, *)
extension AppleSignInViewController: ASAuthorizationControllerDelegate {
    func authorizationController(controller: ASAuthorizationController, didCompleteWithAuthorization authorization: ASAuthorization) {
        if let appleIDCredential = authorization.credential as? ASAuthorizationAppleIDCredential {
            
            let userIdentity = appleIDCredential.user
            var name: String = "No Name"
            
            if let fullName = appleIDCredential.fullName {
                var nameComponents: [String] = []
                if let givenName = fullName.givenName {
                    nameComponents.append(givenName)
                }
                
                if let familyName = fullName.familyName {
                    nameComponents.append(familyName)
                }
                
                if nameComponents.count > 0 {
                    name = nameComponents.joined(separator: " ")
                }
            }
            
            if let jwtData = appleIDCredential.identityToken,
                let jwtToken = String(data: jwtData, encoding: .utf8) {
                self.validateWithServer(name: name, userIdentity: userIdentity, jwt: jwtToken)
            } else {
                // Show error? Missing jwt token
            }
        }
    }
    
    func authorizationController(controller: ASAuthorizationController, didCompleteWithError error: Error) {
        // Show error
    }
}

@available(iOS 13.0, *)
extension AppleSignInViewController: ASAuthorizationControllerPresentationContextProviding {
    func presentationAnchor(for controller: ASAuthorizationController) -> ASPresentationAnchor {
        return self.view.window!
    }
}