import AppKit

// macOS displays the supplied silhouette; unlike iOS it does not mask an opaque master.
// Keep the approved square master intact and derive a padded Mac icon from it.
let sourceURL = URL(fileURLWithPath: CommandLine.arguments[1])
let outputURL = URL(fileURLWithPath: CommandLine.arguments[2])
guard let source = NSImage(contentsOf: sourceURL),
  let bitmap = NSBitmapImageRep(bitmapDataPlanes: nil, pixelsWide: 1024, pixelsHigh: 1024,
    bitsPerSample: 8, samplesPerPixel: 4, hasAlpha: true, isPlanar: false,
    colorSpaceName: .deviceRGB, bytesPerRow: 0, bitsPerPixel: 0),
  let context = NSGraphicsContext(bitmapImageRep: bitmap)
else { fatalError("Cannot load or render the app’s icon") }
NSGraphicsContext.saveGraphicsState()
NSGraphicsContext.current = context
context.imageInterpolation = .high
let tile = NSRect(x: 100, y: 100, width: 824, height: 824)
NSBezierPath(roundedRect: tile, xRadius: 184, yRadius: 184).addClip()
source.draw(in: tile, from: .zero, operation: .copy, fraction: 1)
NSGraphicsContext.restoreGraphicsState()
guard let png = bitmap.representation(using: .png, properties: [:]) else {
  fatalError("Cannot encode the app’s icon")
}
try png.write(to: outputURL)