Camera Session

CameraSessionViewController.swift

import UIKit
import AVFoundation

enum CameraSession: Error {
    case inValidInput
    case inValidOutput
}

final class CameraSessionViewController: UIViewController {
    // Camera Setting
    private let captureSession = AVCaptureSession()
    private var photoOutput: AVCapturePhotoOutput = {
        let output = AVCapturePhotoOutput()
        output.setPreparedPhotoSettingsArray([.init(format: [
            AVVideoCodecKey: AVVideoCodecType.jpeg
        ])])
        return output
    }()
    // Output
    var takenImage: UIImage?
    weak var delegate: AVCapturePhotoCaptureDelegate?

    override func viewDidLoad() {
        super.viewDidLoad()
        prepareCamera()
    }

    private func prepareCamera() {
        checkAuthorization()
    }

    func takeAPicture() {
        guard let delegate = delegate else {
            return
        }
        let photoSettings = AVCapturePhotoSettings()
        photoOutput.capturePhoto(with: photoSettings, delegate: delegate)
    }
}

// MARK: Authorization
extension CameraSessionViewController {
    private func checkAuthorization() {
        let authorizationStatus = AVCaptureDevice.authorizationStatus(for: .video)
        switch authorizationStatus {
        case .authorized:
            setupCaptureSession()
        case .notDetermined, .denied:
            requestAuthorization()
        default:
            dismiss(animated: true)
        }
    }

    private func requestAuthorization() {
        AVCaptureDevice.requestAccess(for: .video) { granted in
            if granted {
                DispatchQueue.main.async {
                    self.setupCaptureSession()
                }
            }
        }
    }
}

// MARK: Setup Camera
extension CameraSessionViewController {
    private func setupCaptureSession() {
        if let device = AVCaptureDevice.default(for: .video) {
            do {
                let input = try AVCaptureDeviceInput(device: device)
                // Add camera as input
                guard captureSession.canAddInput(input) else {
                    throw CameraSession.inValidInput
                }
                captureSession.addInput(input)

                // Add output
                guard captureSession.canAddOutput(photoOutput) else {
                    throw CameraSession.inValidOutput
                }
                captureSession.addOutput(photoOutput)

                // Add camera preview
                addCameraPreview()

                // Start camera session
                captureSession.startRunning()

            } catch let error {
                Logger.log(type: .error, message: error.localizedDescription)
            }
        }
    }

    private func addCameraPreview() {
        let cameraPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
        cameraPreviewLayer.frame = view.frame
        cameraPreviewLayer.videoGravity = .resizeAspectFill
        view.layer.addSublayer(cameraPreviewLayer)
    }
}