package wtf.beatrice;

import java.io.File;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class Renamer
{

    public static String path = "D:\\path\\to\\directory";

    public static void main(String[]args)
    {
        Set<String> listaFoto = listFilesUsingJavaIO(path);
        System.out.println(listaFoto.toString());

        for(String currentFile : listaFoto)
        {
            System.out.println("Orig: " +  currentFile);
            System.out.println("Nums: " + currentFile.replaceAll("[^\\d]", ""));

            String onlyNumbers = currentFile.replaceAll("[^\\d]", "");
            String everythingElse = currentFile.replaceAll("[\\d]", "");
            if(onlyNumbers.length() >= 3 || onlyNumbers.length() == 0) continue;

            String newName = "";

            if(onlyNumbers.length() == 2)
            {
                System.out.println("size 2");
                newName = "0" + onlyNumbers;
            }
            else
            if(onlyNumbers.length() == 1)
            {
                System.out.println("size 1");
                newName = "00" + onlyNumbers;
            }
            else newName = onlyNumbers;

            newName = newName + everythingElse;

            System.out.println("New: " + newName);

            File original = new File(path + "\\" + currentFile);
            File destination = new File(path + "\\" + newName);

            original.renameTo(destination);

        }

    }

    public static Set<String> listFilesUsingJavaIO(String dir) {
        return Stream.of(new File(dir).listFiles())
                .filter(file -> !file.isDirectory())
                .map(File::getName)
                .collect(Collectors.toSet());
    }
}