package io.gitlab.jfronny.modsmod;

import net.fabricmc.loader.FabricLoader;
import net.fabricmc.loader.ModContainer;
import net.fabricmc.loader.discovery.ModCandidate;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class FabricLoaderInterface {
    public static final Logger logger = LogManager.getLogger("modsmod");

    private static final Method addModMethod;
    private static final Field modsField;

    //private static final Field abstractListModCount;

    static {
        try {
            addModMethod = FabricLoader.class.getDeclaredMethod("addMod", ModCandidate.class);
            addModMethod.setAccessible(true);

            modsField = FabricLoader.class.getDeclaredField("mods");
            modsField.setAccessible(true);

            //abstractListModCount = AbstractList.class.getDeclaredField("modCount");
            //abstractListModCount.setAccessible(true);
        } catch (NoSuchMethodException | NoSuchFieldException e) {
            logger.error("Failed to get reference to fabric-loader internals. The fabric-loader version may be incompatible with patchwork-runtime.", e);
            throw new IllegalStateException(e);
        }
    }

    public static void synchronize(FabricLoader fabricLoader) {
        try {
            modsField.set(fabricLoader, new IteratorCallbackList((List<ModContainer>)modsField.get(fabricLoader),
                    (s) -> {
                        try {
                            modsField.set(fabricLoader, s);
                        } catch (IllegalAccessException e) {
                            logger.error("Failed to reset mods field", e);
                            e.printStackTrace();
                        }
                    }));
        } catch (IllegalAccessException e) {
            logger.error("Failed to make mods list synchronized.", e);
            throw new IllegalStateException(e);
        }
    }

    public static void addMod(FabricLoader fabricLoader, ModCandidate modCandidate) {
        try {
            addModMethod.invoke(fabricLoader, modCandidate);
        } catch (IllegalAccessException | InvocationTargetException e) {
            logger.error("Failed to inject mod into fabric-loader.", e);
            throw new IllegalStateException(e);
        }
    }

    public static List<ModContainer> getMods(FabricLoader fabricLoader) {
        try {
            return (List<ModContainer>) modsField.get(fabricLoader);
        } catch (IllegalAccessException e) {
            logger.error("Failed to get mods from fabric-loader.", e);
            throw new IllegalStateException(e);
        }
    }
}