FalsePatternLib/src/main/java/com/falsepattern/lib/FalsePatternLib.java

package com.falsepattern.lib;

import com.google.common.eventbus.EventBus;
import com.google.common.eventbus.Subscribe;
import cpw.mods.fml.common.DummyModContainer;
import cpw.mods.fml.common.FMLCommonHandler;
import cpw.mods.fml.common.LoadController;
import cpw.mods.fml.common.ModMetadata;
import cpw.mods.fml.common.event.FMLPreInitializationEvent;
import lombok.val;
import lombok.var;
import net.minecraft.launchwrapper.Launch;
import net.minecraft.launchwrapper.LaunchClassLoader;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import scala.actors.threadpool.Arrays;

import javax.net.ssl.HttpsURLConnection;
import javax.swing.*;
import java.io.*;
import java.net.URL;
import java.util.*;


@SuppressWarnings("UnstableApiUsage")
public class FalsePatternLib extends DummyModContainer {
    public static Logger libLog = LogManager.getLogger(ModInfo.MODNAME);
    public static final boolean developerEnvironment = (boolean) Launch.blackboard.get("fml.deobfuscatedEnvironment");

    private static Map<String, String> loadedLibraries = new HashMap<>();
    private static Set<String> mavenRepositories = new HashSet<>();

    private static boolean modWasDownloaded = false;

    public FalsePatternLib() {
        super(new ModMetadata());
        libLog.info("FalsePatternLib has been awakened!");
        libLog.info("All your libraries are belong to us!");
        val meta = getMetadata();
        meta.modId = ModInfo.MODID;
        meta.name = ModInfo.MODNAME;
        meta.version = ModInfo.VERSION;
        meta.url = ModInfo.URL;
        meta.credits = ModInfo.CREDITS;
        meta.authorList = Arrays.asList(ModInfo.AUTHORS);
        meta.description = ModInfo.DESCRIPTION;
        meta.useDependencyInformation = true;
    }

    @Override
    public boolean registerBus(EventBus bus, LoadController controller) {
        bus.register(this);

        return true;
    }

    @Subscribe
    public void preInit(FMLPreInitializationEvent evt) {
        if (modWasDownloaded) {
            JOptionPane.showMessageDialog(null,
                    "A mod has downloaded another mod as a dependency, and the game requires a restart so that the " +
                    "downloaded mod is initialized properly! After you close this popup, FalsePatternLib will close the game.", "Reload Required", JOptionPane.WARNING_MESSAGE, null);
            FMLCommonHandler.instance().exitJava(0, false);
        }
    }

    public static void addMavenRepo(String url) {
        mavenRepositories.add(url);
    }

    public static void loadLibrary(String groupId, String artifactId, String version, String devSuffix, boolean isMod) {
        libLog.info("Adding library {}:{}:{}", groupId, artifactId, version);
        var artifact = groupId + ":" + artifactId;
        if (loadedLibraries.containsKey(artifact)) {
            val currentVer = loadedLibraries.get(artifact);
            if (!version.equals(currentVer)) {
                libLog.warn("Tried to load library {}:{}:{}, but version {} was already loaded!", groupId, artifactId, version, currentVer);
                return;
            }
        }
        val modsDir = new File(CoreLoadingPlugin.mcDir, "mods");
        val jarName = String.format("%s-%s%s.jar", artifactId, version, (developerEnvironment && devSuffix != null) ? ("-" + devSuffix) : "");
        File file;
        if (isMod) {
            file = new File(modsDir, jarName);
        } else {
            val libDir = new File(modsDir, "falsepattern");
            if (!libDir.exists()) {
                libDir.mkdirs();
            }
            file = new File(libDir, jarName);
        }
        if (file.exists()) {
            try {
                if (!isMod) {
                    addToClasspath(file);
                }
                loadedLibraries.put(artifact, version);
                libLog.info("Library {}:{}:{} successfully loaded from disk!", groupId, artifactId, version);
                return;
            } catch (RuntimeException e) {
                libLog.warn("Failed to load library {}:{}:{} from file! Redownloading...", groupId, artifactId, version);
                file.delete();
            }
        }
        for (var repo: mavenRepositories) {
            try {
                if (!repo.endsWith("/")) repo = repo + "/";
                val url = new URL(String.format("%s%s/%s/%s/%s", repo, groupId.replace('.', '/'), artifactId, version, jarName));

                val connection = (HttpsURLConnection) url.openConnection();
                connection.setConnectTimeout(1500);
                connection.setReadTimeout(1500);
                connection.setRequestProperty("User-Agent", "FalsePatternLib Downloader");
                if (connection.getResponseCode() != 200) {
                    libLog.info("Artifact {}:{}:{} was not found on repo {}", groupId, artifactId, version, repo);
                    connection.disconnect();
                    continue;
                }
                libLog.info("Downloading {}:{}:{} from {}", groupId, artifactId, version, repo);
                download(connection.getInputStream(), file);
                libLog.info("Downloaded {}:{}:{}", groupId, artifactId, version);
                loadedLibraries.put(artifact, version);
                if (isMod) {
                    if (!modWasDownloaded) {
                        modWasDownloaded = true;
                        libLog.warn("A Minecraft mod was downloaded as a library! This will require a game restart! The game restart will trigger on preInit!");
                    }
                    return;
                }
                addToClasspath(file);
                return;
            } catch (IOException ignored) {}
        }
        throw new IllegalStateException("Failed to download library " + groupId + ":" + artifactId + ":" + version + " from any repository!");
    }

    private static void addToClasspath(File file) {
        try {
            val cl = (LaunchClassLoader) FalsePatternLib.class.getClassLoader();
            cl.addURL(file.toURI().toURL());
            libLog.info("Injected file {} into classpath!", file.getPath());
        } catch (Exception e) {
            throw new RuntimeException("Failed to add library to classpath: " + file.getAbsolutePath(), e);
        }
    }

    private static void download(InputStream is, File target) throws IOException {
        if (target.exists()) return;
        val name = target.getName();

        var bytesRead = 0;

        val fileOutput = new BufferedOutputStream(new FileOutputStream(target));
        byte[] smallBuffer = new byte[4096];
        while ((bytesRead = is.read(smallBuffer)) >= 0) {
            fileOutput.write(smallBuffer, 0, bytesRead);
        }
        fileOutput.close();
        is.close();
    }
}