ViewController.swift

//
//  ViewController.swift
//  PaypalDemo
//
//  Created by Hongli Yu on 09/02/2017.
//  Copyright © 2017 Hongli Yu. All rights reserved.
//

import UIKit

class ViewController: UIViewController {
    
    var braintreeClient: BTAPIClient!
    
    override func viewDidLoad() {
        super.viewDidLoad()
//        self.setupPayPalUI()
        self.fetchClientToken()
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    func fetchClientToken() {
        // TODO: Switch this URL to your own authenticated API
        let clientTokenURL = NSURL(string: "https://cryptic-citadel-99786.herokuapp.com/client_token")!
        let clientTokenRequest = NSMutableURLRequest(url: clientTokenURL as URL)
        clientTokenRequest.setValue("text/plain", forHTTPHeaderField: "Accept")
        
        URLSession.shared.dataTask(with: clientTokenRequest as URLRequest) { (data, response, error) -> Void in
            // TODO: Handle errors
            let clientToken = String(data: data!, encoding: String.Encoding.utf8)
            print(clientToken ?? "no token")
            self.showDropIn(clientTokenOrTokenizationKey: clientToken!)
            // As an example, you may wish to present Drop-in at this point.
            // Continue to the next section to learn more...
            }.resume()
    }

    func showDropIn(clientTokenOrTokenizationKey: String) {
        let request =  BTDropInRequest()
        let dropIn = BTDropInController(authorization: clientTokenOrTokenizationKey, request: request)
        { (controller, result, error) in
            if (error != nil) {
                print("ERROR")
            } else if (result?.isCancelled == true) {
                print("CANCELLED")
            } else if let result = result {
                // Use the BTDropInResult properties to update your UI
                print("\(result.paymentOptionType) + \(result.paymentMethod) + \(result.paymentIcon) + \(result.paymentDescription)")
                self.postNonceToServer(paymentMethodNonce: "fake-valid-nonce") // result.paymentMethod
            }
            controller.dismiss(animated: true, completion: nil)
        }
        self.present(dropIn!, animated: true, completion: nil)
    }
    
    func postNonceToServer(paymentMethodNonce: String) {
        // Update URL with your server
        let paymentURL = URL(string: "https://cryptic-citadel-99786.herokuapp.com/checkout")!
//        let paymentURL = URL(string: "https://cryptic-citadel-99786.herokuapp.com/paypal_checkout")!
        
        var request = URLRequest(url: paymentURL)
        request.httpBody = "payment_method_nonce=\(paymentMethodNonce)".data(using: String.Encoding.utf8)
        request.httpMethod = "POST"
        
        URLSession.shared.dataTask(with: request) { (data, response, error) -> Void in
            if data != nil {
                let tempstr = String(data: data!, encoding: String.Encoding.utf8)
                print(tempstr ?? "nothing returned")
            }

            if let response = response {
                print(response)
            }
            
            if let error = error {
                print(error)
            }
            
            }.resume()
    }
    
}

extension ViewController: BTViewControllerPresentingDelegate, BTAppSwitchDelegate {
    
    func setupPayPalUI() {
        self.braintreeClient = BTAPIClient(authorization: "sandbox_pqtk9jxg_2h94hr4c75p4r2cc")
        let customPayPalButton = UIButton(frame: CGRect(x: 0, y: 0, width: 60, height: 120))
        customPayPalButton.addTarget(self, action: #selector(customPayPalButtonTapped(button:)), for: UIControlEvents.touchUpInside)
        customPayPalButton.backgroundColor = UIColor.green
        self.view.addSubview(customPayPalButton)
    }
    
    func customPayPalButtonTapped(button: UIButton) {
        let payPalDriver = BTPayPalDriver(apiClient: self.braintreeClient)
        payPalDriver.viewControllerPresentingDelegate = self
        payPalDriver.appSwitchDelegate = self
        
        // Start the Vault flow, or...
        payPalDriver.authorizeAccount() { (tokenizedPayPalAccount, error) -> Void in
            print(tokenizedPayPalAccount?.nonce ?? "nothing")
            //
        }
    }

    // MARK: - BTViewControllerPresentingDelegate
    func paymentDriver(_ driver: Any, requestsPresentationOf viewController: UIViewController) {
        present(viewController, animated: true, completion: nil)
    }
    
    func paymentDriver(_ driver: Any, requestsDismissalOf viewController: UIViewController) {
        viewController.dismiss(animated: true, completion: nil)
    }
    
    // MARK: - BTAppSwitchDelegate
    // Optional - display and hide loading indicator UI
    func appSwitcherWillPerformAppSwitch(_ appSwitcher: Any) {
        showLoadingUI()
        
        NotificationCenter.default.addObserver(self, selector: #selector(hideLoadingUI),
                                               name: NSNotification.Name.UIApplicationDidBecomeActive, object: nil)
    }
    
    func appSwitcherWillProcessPaymentInfo(_ appSwitcher: Any) {
        hideLoadingUI()
    }
    
    func appSwitcher(_ appSwitcher: Any, didPerformSwitchTo target: BTAppSwitchTarget) {
        
    }
    
    // MARK: - Private methods
    func showLoadingUI() {
        // ...
    }
    
    func hideLoadingUI() {
        NotificationCenter
            .default
            .removeObserver(self, name: NSNotification.Name.UIApplicationDidBecomeActive, object: nil)
        // ...
    }

}