import Cocoa

/* NSImage -> jfif utility category. */

extension NSImage { // (JFIFConversionUtils)

    /* returns jpeg file interchange format encoded data for an NSImage regardless of the
     original NSImage encoding format.  compressionValue is between 0 and 1.
     values 0.6 thru 0.7 are fine for most purposes.  */
    func jfifData(compressionValue: CGFloat) -> Data? {

        /* convert the NSImage into a raster representation. */
        guard
            let tiffData = self.tiffRepresentation(using: .jpeg, factor: compressionValue),
            let myBitmapImageRep = NSBitmapImageRep(data: tiffData)
            else {
                assertionFailure("Could not generate TIFF representation")
                return nil
        }


        /* convert the bitmap raster representation into a jfif data stream and return the jfif encoded data */
        return myBitmapImageRep.representation(using: .jpeg, properties: [.compressionFactor : NSNumber(value: compressionValue)])
    }
}