package io.gitlab.jfronny.resclone;

import com.google.gson.Gson;
import io.gitlab.jfronny.resclone.api.PackFetcher;
import io.gitlab.jfronny.resclone.api.RescloneApi;
import io.gitlab.jfronny.resclone.api.RescloneEntry;
import io.gitlab.jfronny.resclone.data.PackMetaLoaded;
import io.gitlab.jfronny.resclone.data.PackMetaUnloaded;
import io.gitlab.jfronny.resclone.api.PackProcessor;
import io.gitlab.jfronny.resclone.processors.RemoveEmptyProcessor;
import io.gitlab.jfronny.resclone.processors.RootPathProcessor;
import io.gitlab.jfronny.resclone.util.PackUrlCache;
import io.gitlab.jfronny.resclone.util.Result;
import net.fabricmc.api.ModInitializer;
import net.fabricmc.loader.api.FabricLoader;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import java.io.IOException;
import java.net.URI;
import java.nio.file.FileSystem;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.*;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

public class Resclone implements ModInitializer, RescloneApi {
    public static final Set<PackMetaUnloaded> conf = new LinkedHashSet<>();
    public static final Map<String, PackFetcher> fetcherInstances = new LinkedHashMap<>();
    public static final Set<PackProcessor> processors = new LinkedHashSet<>();
    public static final Set<PackMetaLoaded> downloadedPacks = new LinkedHashSet<>();
    public static final Set<PackMetaLoaded> newPacks = new LinkedHashSet<>();
    public static final Gson gson = new Gson();

    public static final String MOD_ID = "resclone";
    public static final Logger LOGGER = LogManager.getLogger(MOD_ID);

    public static PackUrlCache urlCache;

    public static int COUNT = 0;

    @Override
    public void onInitialize() {
        LOGGER.info("Initialising Resclone.");

        urlCache = new PackUrlCache(getConfigPath().resolve("urlCache.properties"));
        conf.clear();
        fetcherInstances.clear();
        processors.clear();
        downloadedPacks.clear();

        addProcessor(new RootPathProcessor()); //This should be run before any other processor to make sure the path is valid
        for (RescloneEntry entry : FabricLoader.getInstance().getEntrypoints(MOD_ID, RescloneEntry.class)) {
            try {
                entry.init(this);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        addProcessor(new RemoveEmptyProcessor());
        reload();

        LOGGER.info("Installed {} resource pack{}.", COUNT, COUNT == 1 ? "" : "s");
    }

    @Override
    public void addFetcher(PackFetcher fetcher) {
        fetcherInstances.put(fetcher.getSourceTypeName(), fetcher);
    }

    @Override
    public void addProcessor(PackProcessor processor) {
        processors.add(processor);
    }

    @Override
    public void addPack(String fetcher, String pack, String name) {
        addPack(fetcher, pack, name, false);
    }

    @Override
    public void addPack(String fetcher, String pack, String name, boolean forceRedownload) {
        addPack(fetcher, pack, name, forceRedownload, false);
    }

    @Override
    public void addPack(String fetcher, String pack, String name, boolean forceRedownload, boolean forceEnable) {
        conf.add(new PackMetaUnloaded(fetcher, pack, name, forceRedownload, forceEnable));
    }

    @Override
    public void reload() {
        Set<PackMetaLoaded> metas = new LinkedHashSet<>();
        try {
            ExecutorService pool = Executors.newFixedThreadPool(conf.size());
            for (PackMetaUnloaded s : conf) {
                pool.submit(generateTask(s, metas));
            }
            pool.shutdown();
            if (!pool.awaitTermination(Long.MAX_VALUE, TimeUnit.MILLISECONDS)) {
                LOGGER.error("Download timed out. This shouldn't be possible");
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        urlCache.save();
        downloadedPacks.clear();
        downloadedPacks.addAll(metas);
    }

    private Runnable generateTask(PackMetaUnloaded meta, Set<PackMetaLoaded> metas) {
        return () -> {
            try {
                if (!fetcherInstances.containsKey(meta.fetcher))
                    throw new Exception("Invalid fetcher: " + meta.fetcher);
                Path cacheDir = getConfigPath().resolve("cache");
                PackMetaLoaded p;
                try {
                    boolean isNew = !urlCache.containsKey(meta.source);
                    //Download
                    Result fr = fetcherInstances.get(meta.fetcher).get(meta.source, cacheDir, meta.forceDownload);
                    p = new PackMetaLoaded(fr.downloadPath, meta.name, meta.forceEnable);
                    metas.add(p);
                    if (isNew)
                        newPacks.add(p);
                    if (fr.freshDownload) {
                        //Process
                        Map<String, String> props = new HashMap<>();
                        props.put("create", "false");
                        URI zipfile = URI.create("jar:" + p.zipPath.toUri());
                        try (FileSystem zipfs = FileSystems.newFileSystem(zipfile, props)) {
                            for (PackProcessor processor : processors) {
                                processor.process(zipfs);
                            }

                        } catch (Throwable e) {
                            e.printStackTrace();
                        }
                    }
                } catch (Throwable e) {
                    throw new Exception("Failed to download pack", e);
                }
            } catch (Throwable e) {
                LOGGER.error("Encountered issue while preparing " + meta.name, e);
            }
        };
    }

    @Override
    public Path getConfigPath() {
        Path configPath = FabricLoader.getInstance().getConfigDir().resolve("resclone");
        if (!Files.isDirectory(configPath.resolve("cache"))) {
            try {
                Files.createDirectories(configPath.resolve("cache"));
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return configPath;
    }
}