@import MasterpassQRScanSDK;
@import AVFoundation;

- (IBAction)scanAction:(id)sender {
  if (![QRCodeReader isAvailable] || ![QRCodeReader supportsQRCode]) {
      return;
  }
  __weak typeof(self) weakSelf = self;
  [self checkCameraPermission: ^{

      __block __weak QRCodeReader* reader;
      QRCodeReaderViewController* qrVC = [QRCodeReaderViewController readerWithBuilderBlock:^(QRCodeReaderViewControllerBuilder *builder){
          reader = builder.reader;
      }];

      //block to read the result
      [reader setCompletionWithBlock:^(NSString *result) {
          [reader stopScanning];
          [self dismissViewControllerAnimated:YES completion: nil];
          self.scanResult.text = result;
      }];

      //block when cancel is pressed
      [qrVC setCompletionWithBlock:^(NSString *result) {
          [reader stopScanning];
          [self dismissViewControllerAnimated:YES completion: nil];
      }];

      // Retrieve the QRCode content via delegate
      qrVC.delegate = weakSelf;

      [weakSelf presentViewController:qrVC animated:true completion:nil];
  }];
}

// Check camera permissions
- (void)checkCameraPermission:(void (^)(void))completion {
    AVAuthorizationStatus status = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
    if (status == AVAuthorizationStatusDenied) {
        [self showAlertWithTitle:@"Error" message: @"Camera permissions are required for scanning QR. Please turn on Settings -> MasterpassQR Demo -> Camera"];
        return;
    } else if (status == AVAuthorizationStatusRestricted) {
        [self showAlertWithTitle:@"Error" message: @"Camera permissions are restricted for scanning QR"];
        return;
    } else if (status == AVAuthorizationStatusAuthorized) {
        completion();
    } else if (status == AVAuthorizationStatusNotDetermined) {
        __weak __typeof(self) weakSelf = self;
        [AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {
            dispatch_async(dispatch_get_main_queue(), ^{
                if (granted) {
                    completion();
                } else {
                    [weakSelf showAlertWithTitle:@"Error" message: @"Camera permissions are required for scanning QR. Please turn on Settings -> MasterpassQR Demo -> Camera"];
                }
            });
        }];
    }
}

- (void)showAlertWithTitle:(NSString *)title message:(NSString *)message {
    UIAlertController *controller = [UIAlertController alertControllerWithTitle:title message:message preferredStyle:UIAlertControllerStyleAlert];
    [controller addAction:[UIAlertAction actionWithTitle:@"Ok" style:UIAlertActionStyleCancel handler:nil]];
    [self presentViewController:controller animated:true completion:nil];
}

# pragma mark - QRCodeReaderViewControllerDelegate Methods
- (void)reader:(QRCodeReaderViewController *)reader didScanResult:(NSString *)result {
    [reader stopScanning];
    [self dismissViewControllerAnimated:YES completion: nil];
    self.scanResult.text = result;
}

- (void)readerDidCancel:(QRCodeReaderViewController *)reader {
    [reader stopScanning];
    [self dismissViewControllerAnimated:YES completion: nil];
}

@import MasterpassQRScanSDK;

@interface CustomViewController () <QRCodeReaderDelegate>

@property (nonatomic, strong) QRCodeReaderViewController *qrVC;

@end

@implementation CustomViewController

@implementation CustomViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    QRCodeReaderViewControllerBuilder *builder = [[QRCodeReaderViewControllerBuilder alloc] init];
    QRCodeReaderView *readerView = (QRCodeReaderView *) builder.readerView;

    // Setup overlay view
    QRCodeReaderViewOverlay *overlayView = (QRCodeReaderViewOverlay *)[readerView getOverlay];
    overlayView.cornerColor = UIColor.purpleColor;
    overlayView.cornerWidth = 6;
    overlayView.cornerLength = 75;
    overlayView.indicatorSize = CGSizeMake(250, 250);

    // Setup scanning region
    builder.scanRegionSize = CGSizeMake(250, 250);

    // Hide torch button provided by default view
    builder.showTorchButton = false;

    // Hide cancel button provided by default view
    builder.showCancelButton = false;

    // Don't start scanning when this view is loaded i.e initialized
    builder.startScanningAtLoad = false;

    builder.showSwitchCameraButton = false;

    self.qrVC = [[QRCodeReaderViewController alloc] initWithBuilder:builder];
    self.qrVC.delegate = self;

    // Add the reader as child view controller
    [self addChildViewController:self.qrVC];

    // Add reader view to the bottom
    [self.view insertSubview:self.qrVC.view atIndex: 0];

    NSDictionary *dictionary = @{@"qrVC": self.qrVC.view};
    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[qrVC]|" options:0 metrics:nil views:dictionary]];
    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[qrVC]|" options:0 metrics:nil views:dictionary]];

    [self.qrVC didMoveToParentViewController:self];
}

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    [self.qrVC startScanning];
}

- (void)viewWillDisappear:(BOOL)animated {
    [super viewDidDisappear:animated];
    [self.qrVC stopScanning];
}

#pragma mark - Actions
- (IBAction)torchButtonPressed:(id)sender {
    [self.qrVC.codeReader toggleTorch];
}

#pragma mark - QRCodeReaderViewControllerDelegate methods
- (void)reader:(QRCodeReaderViewController *)reader didScanResult:(NSString *)result {
    [reader stopScanning];
}

- (void)readerDidCancel:(QRCodeReaderViewController *)reader {
    [reader stopScanning];
}

#import <MasterpassQRScanSDK/MasterpassQRScanSDK.h>

@interface QRCodeReaderViewControllerSubClass : QRCodeReaderViewController
@end

@implementation QRCodeReaderViewControllerSubClass

#pragma mark - Overriden
- (void)setupUIComponentsWithCancelButtonTitle:(NSString *)cancelButtonTitle cameraView:(nullable QRCodeReaderView*) cameraView
{
    self.cameraView = cameraView;
    if (!self.cameraView) {
        self.cameraView                                       = [[QRCodeReaderView alloc] init];
        self.cameraView.translatesAutoresizingMaskIntoConstraints = NO;
        self.cameraView.clipsToBounds                             = YES;
    }
    [self.view addSubview:self.cameraView];

    //setup other components

}

- (void)setupAutoLayoutConstraints
{
    NSDictionary *views = @{ @"cameraView" : self.cameraView};
    [self.view addConstraints:
     [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-50-[cameraView]-50-|" options:0 metrics:nil views:views]];
    [self.view addConstraints:
     [NSLayoutConstraint constraintsWithVisualFormat:@"H:|-50-[cameraView]-50-|" options:0 metrics:nil views:views]];

     //setup other components
}

@end