import java.io.*;
import java.nio.file.Files;
import java.nio.file.StandardCopyOption;
import java.nio.file.attribute.BasicFileAttributes;
import java.time.ZoneId;
import java.util.*;

public class Main {
    private static final Set<String> IMAGE_EXTENSIONS;

    static {
        var exts = new HashSet<String>();
        exts.add("jpg");
        exts.add("jpeg");
        exts.add("png");
        exts.add("svg");
        exts.add("jfif");
        exts.add("jpg_large");
        exts.add("webp");
        exts.add("gif");
        IMAGE_EXTENSIONS = exts;
    }

    public static String getName(File file) {
        var index = file.getName().lastIndexOf('.');
        return file.getName().substring(0, index);
    }

    public static String getExtension(File file) {
        var index = file.getAbsolutePath().lastIndexOf('.');
        return file.getAbsolutePath().substring(index + 1);
    }

    private record FileSortKey(int year, int month) {
    }

    public static FileSortKey getSortKey(File file) throws IOException {
        var attrs = Files.readAttributes(file.toPath(), BasicFileAttributes.class);
        var time = attrs.lastModifiedTime().toInstant().atZone(ZoneId.systemDefault()).toLocalDate();
        return new FileSortKey(time.getYear(), time.getMonthValue());
    }

    public static void main(String[] args) throws Throwable {
        final var srcDir = new File("/home/sci4me/Pictures");
        final var dstDir = new File("/home/sci4me/Pictures2");

        int copied = 0;

        for (var file : srcDir.listFiles()) {
            if (file.isDirectory()) {
                System.out.printf("Skipped directory '%s'\n", file);
                continue;
            }

            var ext = getExtension(file);
            if (!IMAGE_EXTENSIONS.contains(ext)) continue;

            if (Files.isSymbolicLink(file.toPath())) continue;

            var sort = getSortKey(file);
            var fileDstDir = new File(dstDir, String.format("%d/%d", sort.year, sort.month));
            if (!fileDstDir.exists()) fileDstDir.mkdirs();

            var fileNameAndExt = (getName(file) + "." + getExtension(file)).replaceAll(".jpg_large", ".jpg");
            var dstFile = new File(fileDstDir, fileNameAndExt);
            try {
                Files.copy(file.toPath(), dstFile.toPath(), StandardCopyOption.REPLACE_EXISTING, StandardCopyOption.COPY_ATTRIBUTES);
            } catch (Throwable t) {
                System.out.println("Error copying " + file);
                t.printStackTrace();
            } finally {
                file.delete();
            }

            System.out.println("Copied " + file + " to " + dstFile);

            copied++;
        }

        System.out.println("Copied " + copied + " files");
    }
}