//
//  QRCode.swift
//  OS Vault
//
//  Author: Simon-Pierre Boucher
//  Mail: contact@spboucher.ai
//

import AppKit
import CoreImage

enum QRCode {
    /// Renders a crisp (non-interpolated) QR code for the given string.
    static func image(for string: String, side: CGFloat = 240) -> NSImage? {
        guard let filter = CIFilter(name: "CIQRCodeGenerator") else { return nil }
        filter.setValue(Data(string.utf8), forKey: "inputMessage")
        filter.setValue("M", forKey: "inputCorrectionLevel")
        guard let output = filter.outputImage else { return nil }

        let scale = side / output.extent.width
        let scaled = output.transformed(by: CGAffineTransform(scaleX: scale, y: scale))
        guard let cgImage = CIContext().createCGImage(scaled, from: scaled.extent) else { return nil }
        return NSImage(cgImage: cgImage, size: NSSize(width: side, height: side))
    }
}