InvalidModIdentifier.java

/*
 * Copyright (c) Forge Development LLC and contributors
 * SPDX-License-Identifier: LGPL-2.1-only
 */

package net.minecraftforge.fml.loading.moddiscovery;

import cpw.mods.modlauncher.api.LamdbaExceptionUtils.Supplier_WithExceptions;
import net.minecraftforge.fml.loading.StringUtils;

import java.nio.file.Path;
import java.util.Optional;
import java.util.function.BiPredicate;
import java.util.stream.Stream;
import java.util.zip.ZipFile;

import static cpw.mods.modlauncher.api.LamdbaExceptionUtils.*;

// TODO: [FML][Loader] By the time this is reached, most stuff this checks for is already filtered out - needs fixing.
public enum InvalidModIdentifier {

    OLDFORGE(filePresent("mcmod.info")),
    FABRIC(filePresent("fabric.mod.json")),
    LITELOADER(filePresent("litemod.json")),
    OPTIFINE(filePresent("optifine/Installer.class")),
    BUKKIT(filePresent("plugin.yml")),
    INVALIDZIP((f,zf) -> zf.isEmpty()); // note: only this one INVALIDZIP check is ran until the todo on this class is fixed

    private final BiPredicate<Path, Optional<ZipFile>> ident;

    InvalidModIdentifier(BiPredicate<Path, Optional<ZipFile>> identifier)
    {
        this.ident = identifier;
    }

    private String getReason()
    {
        return "fml.modloading.brokenfile." + StringUtils.toLowerCase(name());
    }

    public static Optional<String> identifyJarProblem(Path path)
    {
        Optional<ZipFile> zfo = optionalFromException(() -> new ZipFile(path.toFile()));
        Optional<String> result = Stream.of(INVALIDZIP).
                                         filter(i -> i.ident.test(path, zfo)).
                                         map(InvalidModIdentifier::getReason).
                                         findAny();
        zfo.ifPresent(rethrowConsumer(ZipFile::close));
        return result;
    }

    private static BiPredicate<Path, Optional<ZipFile>> filePresent(String filename)
    {
        return (f, zfo) -> zfo.map(zf -> zf.getEntry(filename) != null).orElse(false);
    }

    private static <T> Optional<T> optionalFromException(Supplier_WithExceptions<T, ? extends Exception> supp)
    {
        try
        {
            return Optional.of(supp.get());
        }
        catch (Exception e)
        {
            return Optional.empty();
        }
    }

}