import AVFoundation
import SwiftUI

struct CameraPreviewView: UIViewRepresentable {
    let session: AVCaptureSession

    func makeUIView(context: Context) -> PreviewView {
        let view = PreviewView()
        view.previewLayer.session = session
        view.previewLayer.videoGravity = .resizeAspectFill
        return view
    }

    func updateUIView(_ uiView: PreviewView, context: Context) {
        uiView.previewLayer.session = session
    }
}

final class PreviewView: UIView {
    override class var layerClass: AnyClass { AVCaptureVideoPreviewLayer.self }

    var previewLayer: AVCaptureVideoPreviewLayer {
        guard let layer = layer as? AVCaptureVideoPreviewLayer else {
            fatalError("PreviewView requires AVCaptureVideoPreviewLayer.")
        }
        return layer
    }
}