PlantGuide/PlantGuide/Presentation/Scenes/Camera/CameraPreviewView.swift

//
//  CameraPreviewView.swift
//  PlantGuide
//
//  Created by Trey Tartt on 1/21/26.
//

import SwiftUI
import AVFoundation

/// UIViewRepresentable wrapper for AVCaptureVideoPreviewLayer
struct CameraPreviewView: UIViewRepresentable {
    let session: AVCaptureSession

    func makeUIView(context: Context) -> CameraPreviewUIView {
        let view = CameraPreviewUIView()
        view.session = session
        return view
    }

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

/// UIView subclass that hosts the AVCaptureVideoPreviewLayer
final class CameraPreviewUIView: UIView {
    // MARK: - Properties

    var session: AVCaptureSession? {
        didSet {
            previewLayer.session = session
        }
    }

    private var previewLayer: AVCaptureVideoPreviewLayer {
        guard let layer = layer as? AVCaptureVideoPreviewLayer else {
            fatalError("Expected AVCaptureVideoPreviewLayer but got \(type(of: layer))")
        }
        return layer
    }

    // MARK: - Layer Class Override

    override class var layerClass: AnyClass {
        AVCaptureVideoPreviewLayer.self
    }

    // MARK: - Initialization

    override init(frame: CGRect) {
        super.init(frame: frame)
        configurePreviewLayer()
    }

    required init?(coder: NSCoder) {
        super.init(coder: coder)
        configurePreviewLayer()
    }

    // MARK: - Configuration

    private func configurePreviewLayer() {
        previewLayer.videoGravity = .resizeAspectFill
        backgroundColor = .black
    }

    // MARK: - Layout

    override func layoutSubviews() {
        super.layoutSubviews()

        // Update preview layer connection orientation if needed
        updatePreviewLayerOrientation()
    }

    private func updatePreviewLayerOrientation() {
        guard let connection = previewLayer.connection,
              connection.isVideoRotationAngleSupported(0) else {
            return
        }

        // Get the current interface orientation
        let windowScene = window?.windowScene
        let interfaceOrientation = windowScene?.interfaceOrientation ?? .portrait

        // Map interface orientation to video rotation angle
        let rotationAngle: CGFloat
        switch interfaceOrientation {
        case .portrait:
            rotationAngle = 90
        case .portraitUpsideDown:
            rotationAngle = 270
        case .landscapeLeft:
            rotationAngle = 180
        case .landscapeRight:
            rotationAngle = 0
        @unknown default:
            rotationAngle = 90
        }

        if connection.isVideoRotationAngleSupported(rotationAngle) {
            connection.videoRotationAngle = rotationAngle
        }
    }
}

// MARK: - Preview Provider

#Preview {
    CameraPreviewView(session: AVCaptureSession())
        .ignoresSafeArea()
}