#import "ViewController.h"
#import <CoreImage/CoreImage.h>
#import <AVFoundation/AVFoundation.h>

@interface ViewController () {

}

@property (strong, nonatomic) CIContext *coreImageContext;
@property (strong, nonatomic) AVCaptureSession *cameraSession;
@property (strong, nonatomic) AVCaptureVideoDataOutput *videoOutput;
@property (strong, nonatomic) UIView *blurCameraView;
@property (strong, nonatomic) CIFilter *filter;
@property BOOL cameraOpen;

@end

@implementation ViewController

- (void)viewDidLoad {
       [super viewDidLoad];
       self.blurCameraView = [[UIView alloc]initWithFrame:[[UIScreen mainScreen] bounds]];
       [self.view addSubview:self.blurCameraView];

       //setup filter
       self.filter = [CIFilter filterWithName:@"CIGaussianBlur"];
       [self.filter setDefaults];
       [self.filter setValue:@(3.0f) forKey:@"inputRadius"];

       [self setupCamera];
       [self openCamera];
       // Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning {
       [super didReceiveMemoryWarning];
       // Dispose of any resources that can be recreated.
}

- (void)setupCamera
{
       self.coreImageContext = [CIContext contextWithOptions:@{kCIContextUseSoftwareRenderer : @(YES)}];

       // session
       self.cameraSession = [[AVCaptureSession alloc] init];
       [self.cameraSession setSessionPreset:AVCaptureSessionPresetLow];
       [self.cameraSession commitConfiguration];

       // input
       AVCaptureDevice *shootingCamera = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
       AVCaptureDeviceInput *shootingDevice = [AVCaptureDeviceInput deviceInputWithDevice:shootingCamera error:NULL];
       if ([self.cameraSession canAddInput:shootingDevice]) {
           [self.cameraSession addInput:shootingDevice];
       }

       // video output
       self.videoOutput = [[AVCaptureVideoDataOutput alloc] init];
       self.videoOutput.alwaysDiscardsLateVideoFrames = YES;
       [self.videoOutput setSampleBufferDelegate:self queue:dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0)];
       if ([self.cameraSession canAddOutput:self.videoOutput]) {
           [self.cameraSession addOutput:self.videoOutput];
       }

       if (self.videoOutput.connections.count > 0) {
           AVCaptureConnection *connection = self.videoOutput.connections[0];
           connection.videoOrientation = AVCaptureVideoOrientationPortrait;
       }

       self.cameraOpen = NO;
}

- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection {
       // Get a CMSampleBuffer's Core Video image buffer for the media data
       CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);

       // turn buffer into an image we can manipulate
       CIImage *result = [CIImage imageWithCVPixelBuffer:imageBuffer];

       // filter
       [self.filter setValue:result forKey:@"inputImage"];

       // render image
       CGImageRef blurredImage = [self.coreImageContext createCGImage:self.filter.outputImage fromRect:result.extent];
       dispatch_async(dispatch_get_main_queue(), ^{
           self.blurCameraView.layer.contents = (__bridge id)blurredImage;
           CGImageRelease(blurredImage);
       });
}

- (void)openCamera {
       if (self.cameraOpen) {
           return;
       }

       self.blurCameraView.alpha = 0.0f;
       [self.cameraSession startRunning];
       [self.view layoutIfNeeded];

       [UIView animateWithDuration:3.0f animations:^{

           self.blurCameraView.alpha = 1.0f;

       }];

       self.cameraOpen = YES;
}