Nextflow: Organizando fotos por geoposicion

static def extractCoord( path ){
    def metadata = Imaging.getMetadata(path.toFile())
    if( !metadata || !metadata.metaClass.getMetaMethod("getExif") )
        return null

    def latitude = metadata.exif?.GPS?.latitudeAsDegreesNorth
    def longitude = metadata.exif?.GPS?.longitudeAsDegreesEast

    [latitude, longitude]
}

static double metersTo( a,  b) {
    double lat1 = a[0] as double
    double lng1 = a[1] as double
    double lat2 = b[0] as double
    double lng2 = b[1] as double
    double radioTierra = 6371;
    double dLat = Math.toRadians(lat2 - lat1);
    double dLng = Math.toRadians(lng2 - lng1);
    double sindLat = Math.sin(dLat / 2);
    double sindLng = Math.sin(dLng / 2);
    double va1 = Math.pow(sindLat, 2) + Math.pow(sindLng, 2) * Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2));
    double va2 = 2 * Math.atan2(Math.sqrt(va1), Math.sqrt(1 - va1));
    double meters = radioTierra * va2;
    meters;
}

class Image{
    def file
    def coord
    def order
}

process EXIF_GPS{
    input:
        path fImage
    output:
        val image
    exec:
        coord = Images.extractCoord( file("$params.directory/$fImage") )
        image = new Image(file:fImage, coord: coord)
}

process PROCESS_IMAGE{
    input:
        each img
    output:
        val target
    exec:
        target = file("$params.directory/$img.file").copyTo(file("$params.outputDir/$img.order-$img.file"))
}

workflow{
    def images = Channel.fromPath("$params.directory/*.jpg")

    images //read all images
        | EXIF_GPS // extract gpf information
        | branch { // diferenciate if exif information or not
            no_info: !it.coord?[0]
            with_info: it.coord
        }
        | set{ gps_images } // send to new channel

    gps_images.with_info // only images with gps info
        | toSortedList{ a, b-> // sort respect how far are from origin
            Images.metersTo(origin,a.coord) <=> Images.metersTo(origin, b.coord)
        }
        | map { // assign the index
            it.eachWithIndex{ img, idx-> img.order = idx}
        }
        | set{ images_sorted } //send to new channel

    images_sorted
        | PROCESS_IMAGE
        | view

}