import SwiftUI
import AVFoundation
import Vision

class CameraViewModel: NSObject, ObservableObject {
    @Published var detectedRects: [CGRect] = []
    private let session = AVCaptureSession()
    private var videoOutput = AVCaptureVideoDataOutput()
    private var visionRequest = VNDetectRectanglesRequest()

    override init() {
        super.init()
        setupSession()
        setupVision()
    }

    func setupSession() {
        guard let captureDevice = AVCaptureDevice.default(for: .video) else { return }
        session.beginConfiguration()

        // Set up input
        if let input = try? AVCaptureDeviceInput(device: captureDevice), session.canAddInput(input) {
            session.addInput(input)
        }

        // Set up output
        videoOutput.setSampleBufferDelegate(self, queue: DispatchQueue(label: "camera.frame.processing"))
        if session.canAddOutput(videoOutput) {
            session.addOutput(videoOutput)
        }

        session.commitConfiguration()
    }

    func setupVision() {
        visionRequest.minimumAspectRatio = 1.58 / 1.0
        visionRequest.maximumAspectRatio = 1.6 / 1.0
        visionRequest.minimumSize = 0.2 // Minimum size as a fraction of the image
        visionRequest.maximumObservations = 1
        visionRequest.quadratureTolerance = 45.0
    }

    func startSession() {
        session.startRunning()
    }

    func stopSession() {
        session.stopRunning()
    }
}

extension CameraViewModel: AVCaptureVideoDataOutputSampleBufferDelegate {
    func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) {
        guard let pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer) else { return }
        let requestHandler = VNImageRequestHandler(cvPixelBuffer: pixelBuffer, options: [:])

        do {
            try requestHandler.perform([visionRequest])
            if let results = visionRequest.results as? [VNRectangleObservation] {
                DispatchQueue.main.async {
                    self.detectedRects = results.map { observation in
                        CGRect(
                            x: observation.boundingBox.origin.x,
                            y: 1 - observation.boundingBox.origin.y - observation.boundingBox.size.height,
                            width: observation.boundingBox.size.width,
                            height: observation.boundingBox.size.height
                        )
                    }
                }
            }
        } catch {
            print("Error performing vision request: \(error)")
        }
    }
}