Async / await capture photo

AVCapturePhotoOutput+Utils.swift

import AVKit

extension AVCapturePhotoOutput {
    
    enum Failure: Error {
        case capturePhotoFailed
    }
    
    private final class CaptureDelegate: NSObject, AVCapturePhotoCaptureDelegate {
        
        typealias OnTakePhoto = (CIImage?) -> Void
        
        let isFrontCamera: Bool
        var onTakePhoto: OnTakePhoto?
        
        init(isFrontCamera: Bool, onTakePhoto: OnTakePhoto? = nil) {
            self.isFrontCamera = isFrontCamera
            self.onTakePhoto = onTakePhoto
        }
        
        public func photoOutput(_ output: AVCapturePhotoOutput, willCapturePhotoFor resolvedSettings: AVCaptureResolvedPhotoSettings) {
            // Hack, using for dispose system shutter sound
            AudioServicesDisposeSystemSoundID(1108)
        }
        
        public func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {
            var image: CIImage?
            if let data = photo.fileDataRepresentation() {
                image = CIImage( // best way for convert AVCapturePhoto to CIImage without loose metadata
                    data: data,
                    options: [
                        .properties : photo.metadata,
                        .applyOrientationProperty : true,
                    ]
                )
            }
            if isFrontCamera {
                image = image?.oriented(.upMirrored)
            }
            onTakePhoto?(image)
        }
        
    }
    
    func capturePhoto(with settings: AVCapturePhotoSettings, isFrontCamera: Bool = false) async throws -> CIImage {
        try await withCheckedThrowingContinuation { continuation in
            guard settings as? AVCapturePhotoBracketSettings == nil else {
                continuation.resume(throwing: Failure.capturePhotoFailed)
                return assertionFailure()
            }
            
            let delegate = CaptureDelegate(isFrontCamera: isFrontCamera)
            delegate.onTakePhoto = { [delegate] in // looped delegate reference for avoid auto release
                if let image = $0 {
                    continuation.resume(returning: image)
                } else {
                    continuation.resume(throwing: Failure.capturePhotoFailed)
                }
                delegate.onTakePhoto = nil // release
            }
            self.capturePhoto(with: settings, delegate: delegate)
        }
    }
    
    func capturePhotoBracket(with settings: AVCapturePhotoSettings, isFrontCamera: Bool) -> AsyncStream<CIImage> {
        AsyncStream(bufferingPolicy: .unbounded) { continuation in
            guard let settings = settings as? AVCapturePhotoBracketSettings else {
                continuation.finish()
                return assertionFailure()
            }
            
            var takedPhotos = 0
            let delegate = CaptureDelegate(isFrontCamera: isFrontCamera)
            delegate.onTakePhoto = { [delegate] photo in  // looped delegate reference for avoid auto release
                takedPhotos += 1
                if let photo {
                    continuation.yield(photo)
                }
                if takedPhotos == settings.bracketedSettings.count {
                    continuation.finish()
                    delegate.onTakePhoto = nil  // release
                }
            }
            self.capturePhoto(with: settings, delegate: delegate)
        }
    }
    
}