import Stripe

class MyViewController: UIViewController {
  // ...
  func beginPushProvisioning() {
    let config = STPPushProvisioningContext.requestConfiguration(
      withName: "Jenny Rosen", // the cardholder's name
      description: "RocketRides Card", // optional; a description of your card
      last4: "4242", // optional; the last 4 digits of the card
      brand: .visa // optional; the brand of the card
    )
    let controller = PKAddPaymentPassViewController(requestConfiguration: config, delegate: self)
    self.present(controller!, animated: true, completion: nil)
  }
}

#import <Stripe/Stripe.h>
// Inside a ViewController

- (void)beginPushProvisioning {
  PKAddPaymentPassRequestConfiguration *config = [STPPushProvisioningContext requestConfigurationWithName:@"Jenny Rosen" description:@"RocketRides Card" last4:@"4242" brand:STPCardBrandVisa];
  PKAddPaymentPassViewController *controller = [[PKAddPaymentPassViewController alloc] initWithRequestConfiguration:config delegate:self];
  [self presentViewController:controller animated:YES completion:nil];
}

class MyViewController: UIViewController {
  var pushProvisioningContext: STPPushProvisioningContext? = nil
  // ...
}

extension MyViewController: PKAddPaymentPassViewControllerDelegate {
  func addPaymentPassViewController(_ controller: PKAddPaymentPassViewController, generateRequestWithCertificateChain certificates: [Data], nonce: Data, nonceSignature: Data, completionHandler handler: @escaping (PKAddPaymentPassRequest) -> Void) {
    self.pushProvisioningContext = STPPushProvisioningContext(keyProvider: self)
    // STPPushProvisioningContext implements this delegate method for you, by retrieving encrypted card details from the Stripe API.
    self.pushProvisioningContext?.addPaymentPassViewController(controller, generateRequestWithCertificateChain: certificates, nonce: nonce, nonceSignature: nonceSignature, completionHandler: handler);
  }

  func addPaymentPassViewController(_ controller: PKAddPaymentPassViewController, didFinishAdding pass: PKPaymentPass?, error: Error?) {
    // Depending on if `error` is present, show a success or failure screen.
    self.dismiss(animated: true, completion: nil)
  }
}

@interface ViewController () <PKAddPaymentPassViewControllerDelegate>
@property STPPushProvisioningContext *pushProvisioningContext;
@end

@implementation ViewController

- (void)addPaymentPassViewController:(PKAddPaymentPassViewController *)controller generateRequestWithCertificateChain:(NSArray<NSData *> *)certificates nonce:(NSData *)nonce nonceSignature:(NSData *)nonceSignature completionHandler:(void (^)(PKAddPaymentPassRequest * _Nonnull))handler {
  self.pushProvisioningContext = [[STPPushProvisioningContext alloc] initWithKeyProvider:self];
  // STPPushProvisioningContext implements this delegate method for you, by retrieving encrypted card details from the Stripe API.
  [self.pushProvisioningContext addPaymentPassViewController:controller generateRequestWithCertificateChain:certificates nonce:nonce nonceSignature:nonceSignature completionHandler:handler];
}

- (void)addPaymentPassViewController:(PKAddPaymentPassViewController *)controller didFinishAddingPaymentPass:(PKPaymentPass *)pass error:(NSError *)error {
  // Depending on if `error` is present, show a success or failure screen.
  [self dismissViewControllerAnimated:YES completion:nil];
}

@end

extension MyViewController: STPIssuingCardEphemeralKeyProvider {
  func createIssuingCardKey(withAPIVersion apiVersion: String, completion: @escaping STPJSONResponseCompletionBlock) {
    // This example uses Alamofire for brevity, but you can make the request however you want
    Alamofire.request("https://myapi.com/ephemeral_keys",
      method: .post,
      parameters: ["api_version": apiVersion])
    .responseJSON { response in
      completion(response.result.value, response.result.error)
    }
  }
}

@interface ViewController () <STPIssuingCardEphemeralKeyProvider>
@end

@implementation ViewController
  - (void)createIssuingCardKeyWithAPIVersion:(NSString *)apiVersion completion:(STPJSONResponseCompletionBlock)completion {
    NSURLSession *session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration]];
    NSURL *url = [NSURL URLWithString:@"https://myapi.com/ephemeral_keys"];
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    request.HTTPMethod = @"POST";
    NSString *postBody = [@"api_version=" stringByAppendingString:apiVersion];
    request.HTTPBody = [postBody dataUsingEncoding:NSUTF8StringEncoding];
    [[session dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
      NSDictionary *parsed = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
      completion(parsed, error);
    }] resume];
}
@end