package io.gitlab.jfronny.modsmod;

import me.sargunvohra.mcmods.autoconfig1u.AutoConfig;
import me.sargunvohra.mcmods.autoconfig1u.serializer.JanksonConfigSerializer;
import net.fabricmc.loader.FabricLoader;
import net.fabricmc.loader.discovery.ModCandidate;
import net.fabricmc.loader.discovery.ModResolver;
import net.fabricmc.loader.discovery.RuntimeModRemapper;
import net.fabricmc.loader.launch.common.FabricLauncherBase;
import net.fabricmc.loader.metadata.LoaderModMetadata;
import net.fabricmc.loader.metadata.ModMetadataParser;
import net.fabricmc.loader.metadata.ParseMetadataException;
import net.fabricmc.loader.util.FileSystemUtil;
import org.apache.commons.io.FileUtils;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardCopyOption;
import java.util.Collections;
import java.util.HashSet;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

public class PreLaunch {
    static HashSet<File> m;
    static FabricLoader loader;
    public static void prepare() {
        loader = FabricLoader.INSTANCE;
        //Load config
        AutoConfig.register(Cfg.class, JanksonConfigSerializer::new);
        Cfg cfg = AutoConfig.getConfigHolder(Cfg.class).getConfig();
        Path configDir = loader.getConfigDir();
        String modsmodCfgFileName = "ModsMod.json5";
        //make sure the modsmodcache dir is ok
        File path = new File(configDir.toFile(), "modsmodcache");
        if (!path.isDirectory()) {
            if (path.exists())
                path.delete();
            path.mkdir();
        }
        //remove modsmodcache if the cache is outdated
        try {
            File cfgCache = new File(path, "_basecfg");
            if (cfgCache.exists()) {
                if (cfgCache.isFile()) {
                    if (!FileUtils.contentEquals(new File(configDir.toFile(), modsmodCfgFileName), cfgCache)) {
                        FileUtils.deleteDirectory(path);
                        path.mkdir();
                    }
                }
                else {
                    FileUtils.deleteDirectory(path);
                    path.mkdir();
                }
            }
            Files.copy(Paths.get(configDir.toString(), modsmodCfgFileName), cfgCache.toPath(), StandardCopyOption.REPLACE_EXISTING);
        } catch (IOException e) {
            System.err.println("Failed to validate modsmod config cache, caching will not be available");
            e.printStackTrace();
        }
        m = new HashSet<>();
        //Generate mods
        for (int i = 0; i < cfg.modsCount; i++) {
            File f = new File(path, "f" + (i + 1) + ".jar");
            m.add(f);
            //Do not load if cached
            if (f.exists()) {
                if (cfg.cache) continue;
                else f.delete();
            }
            //Generate jar
            ZipOutputStream out;
            try {
                out = new ZipOutputStream(new FileOutputStream(f));
                //META-INF/MANIFEST.MF (java jar file spec)
                ZipEntry e = new ZipEntry("META-INF/MANIFEST.MF");
                out.putNextEntry(e);
                StringBuilder sb = new StringBuilder();
                sb.append("Manifest-Version: 1.0\n");
                out.write(sb.toString().getBytes());
                out.closeEntry();
                //fabric.mod.json (fabric mod metadata)
                e = new ZipEntry("fabric.mod.json");
                out.putNextEntry(e);
                sb = new StringBuilder();
                sb.append("{");
                sb.append("\"schemaVersion\": 1,");
                sb.append("\"id\": \"modmod_").append(i + 1).append("\",");
                sb.append("\"version\": \"1.0\",");
                sb.append("\"name\": \"ModsMod ").append(i + 1).append("\",");
                //sb.append("\"icon\": \"assets/modsmod/icon_1.png\",");
                sb.append("\"entrypoints\": {},");
                sb.append("\"custom\": {");
                if (cfg.parent) {
                    sb.append("\"modmenu:parent\": \"modsmod\"");
                }
                sb.append("}");
                sb.append("}");
                out.write(sb.toString().getBytes());
                out.closeEntry();
                //Make file available
                out.close();
            } catch (IOException e) {
                System.err.println("Failed to generate mod!");
                e.printStackTrace();
            }
            System.gc();
        }
        FabricLoaderInterface.synchronize(loader);
    }

    public static void init() {
        for (File f : m) {
            loadMod(loader, f.toPath());
        }
    }

    private static void loadMod(FabricLoader loader, Path modPath) {
        ModCandidate candidate = parseMod(modPath);

        if (loader.isDevelopmentEnvironment()) {
            candidate = RuntimeModRemapper.remap(Collections.singletonList(candidate), ModResolver.getInMemoryFs()).stream().findFirst().get();
        }

        FabricLoaderInterface.addMod(loader, candidate);
        FabricLauncherBase.getLauncher().propose(candidate.getOriginUrl());
    }

    private static ModCandidate parseMod(Path modPath) {
        try {
            FileSystemUtil.FileSystemDelegate jarFs = FileSystemUtil.getJarFileSystem(modPath, false);

            Path modJson = jarFs.get().getPath("fabric.mod.json");

            LoaderModMetadata info = ModMetadataParser.parseMetadata(FabricLoaderInterface.logger, modJson);

            return new ModCandidate(info, modPath.toUri().toURL(), 0, true);
        } catch (IOException | ParseMetadataException e) {
            throw new IllegalStateException(e);
        }
    }
}