Resclone/src/main/java/io/gitlab/jfronny/resclone/processors/PruneVanillaProcessor.java

package io.gitlab.jfronny.resclone.processors;

import io.gitlab.jfronny.resclone.Resclone;
import io.gitlab.jfronny.resclone.util.io.PathPruneVisitor;
import net.minecraft.server.MinecraftServer;
import org.apache.commons.io.IOUtils;

import java.io.IOException;
import java.io.InputStream;
import java.nio.file.*;

public class PruneVanillaProcessor implements PackProcessor {
    @Override
    public void process(FileSystem p) throws Exception {
        ClassLoader cl = MinecraftServer.class.getClassLoader();
        try {
            if (Files.isDirectory(p.getPath("/assets/minecraft"))) {
                Files.walkFileTree(p.getPath("/assets/minecraft"), new PathPruneVisitor((s) -> {
                    if (Files.isDirectory(s))
                        return false;
                    try {
                        InputStream vn = cl.getResourceAsStream(p.getPath("/").relativize(s).toString());
                        if (vn != null) {
                            try (InputStream pk = Files.newInputStream(s, StandardOpenOption.READ)) {
                                return IOUtils.contentEquals(vn, pk);
                            }
                        }
                    } catch (Throwable e) {
                        Resclone.LOGGER.error("Could not prune unchanged assets", e);
                    }
                    return false;
                }));
            }
        } catch (IOException e) {
            throw new Exception("Could not prune vanilla files", e);
        }
    }
}