Facebook Account Kit API Wrapper Class

AccountKitBaseViewController.swift

//
//  AccountKitBaseViewController.swift
//
//  Created by Michael Martinez on 29/12/2017.
//  Copyright © 2017 Michael Martinez. All rights reserved.
//

import Foundation
import AccountKit

//MARK: - Protocol
protocol AccountKitBaseViewControllerDelegate: class {
    
    func accountKitOnLoginSuccess(accountID: String, email: String)
    func accountKitOnLoginFailure(error: Error)
}

//MARK: - AccountKitBaseViewController
class AccountKitBaseViewController: UIViewController {
    
    /// AccountKit Connection Handling Events
    public var delegate: AccountKitBaseViewControllerDelegate?
    /// Whether user is connected to AccountKit or not
    public var isUserLoggedIn: Bool = false
    
    private var _accountKit: AKFAccountKit!
    private var _pendingLoginViewController: AKFViewController?
    
    override func viewDidLoad() {
        
        super.viewDidLoad()
        
        if _accountKit == nil {
            _accountKit = AKFAccountKit.init(responseType: .accessToken)
        }
        _pendingLoginViewController = _accountKit?.viewControllerForLoginResume()
        _pendingLoginViewController?.delegate = self
    }
    
    override func viewDidAppear(_ animated: Bool) {
        
        super.viewDidAppear(animated)
        
        if _accountKit.currentAccessToken != nil { // already logged in
            
            requestAccount()
        } else if (_pendingLoginViewController != nil) { // Resume pending login if any
            self.isUserLoggedIn = false
            self.present(_pendingLoginViewController as! UIViewController, animated: animated, completion: nil)
            _pendingLoginViewController = nil
        } else {
            self.isUserLoggedIn = false
        }
    }
    
    public func accountKitLogin(email: String?, completion: (() -> Swift.Void)? = nil) {
        
        guard isUserLoggedIn == false else { return }
        guard let email = email else { return }
        
        let inputState = NSUUID(uuidString: "ARFactory")?.uuidString
        let viewController = _accountKit?.viewControllerForEmailLogin(withEmail: email, state: inputState)
        viewController?.delegate = self
        self.present(viewController!, animated: true, completion: nil)
        completion?()
    }
    
    public func accountKitLogout(completion: (() -> Swift.Void)? = nil) {
        
        guard isUserLoggedIn == true else { return }
        
        isUserLoggedIn = false
        _accountKit?.logOut()
        completion?()
    }
    
    //MARK: - Internal
    private func requestAccount() {
      
        _accountKit?.requestAccount { (account, error) in
            
            guard error == nil, let account = account else {
                self.delegate?.accountKitOnLoginFailure(error: error!)
                return
            }
            
            self.isUserLoggedIn = true
            self.delegate?.accountKitOnLoginSuccess(accountID: account.accountID, email: account.emailAddress ?? "")
        }
    }
}

//MARK: - AKFViewControllerDelegate
extension AccountKitBaseViewController: AKFViewControllerDelegate {
    
    func viewController(_ viewController: (UIViewController & AKFViewController)!, didCompleteLoginWith accessToken: AKFAccessToken!, state: String!) {
        
        _accountKit = AKFAccountKit(responseType: .accessToken)
        requestAccount()
    }
    
    func viewController(_ viewController: (UIViewController & AKFViewController)!, didFailWithError error: Error!) {
        
        self.isUserLoggedIn = false
        self.delegate?.accountKitOnLoginFailure(error: error)
    }
}