package net.minecraft.world.level.validation;

import java.io.IOException;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.LinkOption;
import java.nio.file.NoSuchFileException;
import java.nio.file.Path;
import java.nio.file.PathMatcher;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;

public class DirectoryValidator {
	private final PathMatcher symlinkTargetAllowList;

	public DirectoryValidator(final PathMatcher symlinkTargetAllowList) {
		this.symlinkTargetAllowList = symlinkTargetAllowList;
	}

	public void validateSymlink(final Path path, final List<ForbiddenSymlinkInfo> issues) throws IOException {
		Path target = Files.readSymbolicLink(path);
		if (!this.symlinkTargetAllowList.matches(target)) {
			issues.add(new ForbiddenSymlinkInfo(path, target));
		}
	}

	public List<ForbiddenSymlinkInfo> validateSymlink(final Path path) throws IOException {
		List<ForbiddenSymlinkInfo> result = new ArrayList();
		this.validateSymlink(path, result);
		return result;
	}

	public List<ForbiddenSymlinkInfo> validateDirectory(Path directory, final boolean allowTopSymlink) throws IOException {
		List<ForbiddenSymlinkInfo> issues = new ArrayList();

		BasicFileAttributes targetAttributes;
		try {
			targetAttributes = Files.readAttributes(directory, BasicFileAttributes.class, LinkOption.NOFOLLOW_LINKS);
		} catch (NoSuchFileException var6) {
			return issues;
		}

		if (targetAttributes.isRegularFile()) {
			throw new IOException("Path " + directory + " is not a directory");
		} else {
			if (targetAttributes.isSymbolicLink()) {
				if (!allowTopSymlink) {
					this.validateSymlink(directory, issues);
					return issues;
				}

				directory = Files.readSymbolicLink(directory);
			}

			this.validateKnownDirectory(directory, issues);
			return issues;
		}
	}

	public void validateKnownDirectory(final Path directory, final List<ForbiddenSymlinkInfo> issues) throws IOException {
		Files.walkFileTree(directory, new SimpleFileVisitor<Path>() {
			{
				Objects.requireNonNull(DirectoryValidator.this);
			}

			private void validateSymlink(final Path path, final BasicFileAttributes attrs) throws IOException {
				if (attrs.isSymbolicLink()) {
					DirectoryValidator.this.validateSymlink(path, issues);
				}
			}

			public FileVisitResult preVisitDirectory(final Path dir, final BasicFileAttributes attrs) throws IOException {
				this.validateSymlink(dir, attrs);
				return super.preVisitDirectory(dir, attrs);
			}

			public FileVisitResult visitFile(final Path file, final BasicFileAttributes attrs) throws IOException {
				this.validateSymlink(file, attrs);
				return super.visitFile(file, attrs);
			}
		});
	}
}