/*
 * KubaTech - Gregtech Addon Copyright (C) 2022 - 2023 kuba6000 This library is free software; you can redistribute it
 * and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software
 * Foundation; either version 3 of the License, or (at your option) any later version. This library is distributed in
 * the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have
 * received a copy of the GNU Lesser General Public License along with this library. If not, see
 * <https://www.gnu.org/licenses/>.
 */

package kubatech.config;

import java.io.File;
import java.io.Reader;
import java.io.Writer;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import kubatech.Tags;
import kubatech.api.ConstructableItemStack;
import kubatech.api.LoaderReference;
import kubatech.api.helpers.ReflectionHelper;
import kubatech.api.mobhandler.MobDrop;
import kubatech.api.utils.GSONUtils;

import net.minecraft.entity.EntityList;
import net.minecraft.entity.EntityLiving;
import net.minecraft.init.Items;
import net.minecraft.item.ItemStack;
import net.minecraft.nbt.JsonToNBT;
import net.minecraft.nbt.NBTTagCompound;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import com.dreammaster.main.MainRegistry;
import com.dreammaster.modcustomdrops.CustomDrops;
import com.google.common.io.Files;
import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;

import cpw.mods.fml.common.registry.GameRegistry;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;

public class OverridesConfig {

    private static final Logger LOG = LogManager.getLogger(Tags.MODID + "[Config-Overrides]");

    public static class MobDropSimplified {

        @GSONUtils.SkipGSON
        ItemStack stack;

        ConstructableItemStack reconstructableStack;
        MobDrop.DropType type;

        private MobDropSimplified() {}

        public MobDropSimplified(ItemStack stack, MobDrop.DropType type) {
            reconstructableStack = new ConstructableItemStack(stack);
            this.type = type;
        }

        public void reconstructStack() {
            stack = reconstructableStack.construct();
        }

        public boolean isMatching(MobDrop drop) {
            return reconstructableStack.isSame(drop.reconstructableStack, true);
        }

        private static final ByteBuf BufHelper = Unpooled.buffer();

        public void writeToByteBuf(ByteBuf byteBuf) {
            BufHelper.clear();
            reconstructableStack.writeToByteBuf(BufHelper);
            BufHelper.writeInt(type.ordinal());
            byteBuf.writeInt(BufHelper.readableBytes());
            byteBuf.writeBytes(BufHelper);
        }

        public static MobDropSimplified readFromByteBuf(ByteBuf byteBuf) {
            MobDropSimplified mobDropSimplified = new MobDropSimplified();
            int size = byteBuf.readInt();
            mobDropSimplified.reconstructableStack = ConstructableItemStack.readFromByteBuf(byteBuf);
            mobDropSimplified.type = MobDrop.DropType.get(byteBuf.readInt());
            mobDropSimplified.reconstructStack();
            return mobDropSimplified;
        }
    }

    public static class MobOverride {

        public boolean removeAll = false;
        public List<MobDrop> additions = new ArrayList<>();
        public List<MobDropSimplified> removals = new ArrayList<>();

        private static final ByteBuf BufHelper = Unpooled.buffer();

        public void writeToByteBuf(ByteBuf byteBuf) {
            BufHelper.clear();
            BufHelper.writeBoolean(removeAll);
            BufHelper.writeInt(additions.size());
            additions.forEach(drop -> drop.writeToByteBuf(BufHelper));
            BufHelper.writeInt(removals.size());
            removals.forEach(drop -> drop.writeToByteBuf(BufHelper));
            byteBuf.writeInt(BufHelper.readableBytes());
            byteBuf.writeBytes(BufHelper);
        }

        public static MobOverride readFromByteBuf(ByteBuf byteBuf) {
            int size = byteBuf.readInt();
            MobOverride mobOverride = new MobOverride();
            mobOverride.removeAll = byteBuf.readBoolean();
            int additionssize = byteBuf.readInt();
            for (int i = 0; i < additionssize; i++) mobOverride.additions.add(MobDrop.readFromByteBuf(byteBuf));
            int removalssize = byteBuf.readInt();
            for (int i = 0; i < removalssize; i++) mobOverride.removals.add(MobDropSimplified.readFromByteBuf(byteBuf));
            return mobOverride;
        }
    }

    public static Map<String, MobOverride> overrides = new HashMap<>();
    private static File overrideFile = null;

    private static final Gson gson = GSONUtils.GSON_BUILDER_PRETTY.create();

    @SuppressWarnings("UnstableApiUsage")
    public static void LoadConfig() {
        LOG.info("Loading Config");
        if (overrideFile == null) overrideFile = Config.getConfigFile("MobOverrides.cfg");
        if (!overrideFile.exists()) writeExampleFile();
        Reader reader = null;
        try {
            reader = Files.newReader(overrideFile, StandardCharsets.UTF_8);
            overrides = gson.fromJson(reader, new TypeToken<Map<String, MobOverride>>() {}.getType());
            overrides.remove("ExampleMob");
            overrides.values().forEach(o -> o.additions.forEach(MobDrop::reconstructStack));
            if (LoaderReference.GTNHCoreMod) {
                LOG.info("Detected GTNH Core Mod, parsing custom drops from there.");
                CustomDrops coredrops = ReflectionHelper
                        .getField(MainRegistry.Module_CustomDrops, "_mCustomDrops", null);
                if (coredrops != null) {
                    @SuppressWarnings("unchecked")
                    ArrayList<CustomDrops.CustomDrop> customdrops = (ArrayList<CustomDrops.CustomDrop>) ((ArrayList<CustomDrops.CustomDrop>) coredrops
                            .getCustomDrops()).clone();
                    for (CustomDrops.CustomDrop customdrop : customdrops) {
                        try {
                            Class<?> eclass = Class.forName(customdrop.getEntityName());
                            if (!EntityLiving.class.isAssignableFrom(eclass)) continue;
                            String ename = (String) EntityList.classToStringMapping.get(eclass);
                            if (ename == null) continue;
                            MobOverride override = overrides.computeIfAbsent(ename, k -> new MobOverride());
                            for (CustomDrops.CustomDrop.Drop drop : customdrop.getDrops()) {
                                String[] parts = drop.getItemName().split(":");
                                ItemStack stack = GameRegistry.findItemStack(parts[0], parts[1], 1);
                                if (stack == null) continue;
                                if (parts.length > 2) stack.setItemDamage(Integer.parseInt(parts[2]));
                                String pNBT = ReflectionHelper.getField(drop, "mTag", null);
                                if (pNBT != null && !pNBT.isEmpty()) {
                                    try {
                                        stack.stackTagCompound = (NBTTagCompound) JsonToNBT.func_150315_a(pNBT);
                                    } catch (Exception ignored) {}
                                }
                                int chance = drop.getChance() * 100;
                                int amount = drop.getAmount();
                                if (drop.getIsRandomAmount()) {
                                    // average chance formula
                                    // chance *= ((((amount * (amount + 1d)) / 2d)) + 1d) / (amount + 1d);
                                    chance *= (2d + (amount * amount) + amount) / (2d * (amount + 1d));
                                    amount = 1;
                                    if (chance > 10000) {
                                        int div = (int) Math.ceil(chance / 10000d);
                                        amount *= div;
                                        chance /= div;
                                    }
                                }
                                stack.stackSize = amount;
                                // Drops from coremod are player only
                                override.additions.add(
                                        new MobDrop(stack, MobDrop.DropType.Normal, chance, null, null, false, true));
                            }
                        } catch (Exception e) {
                            e.printStackTrace();
                        }
                    }
                }
            }
        } catch (Exception ex) {
            ex.printStackTrace();
        } finally {
            if (reader != null) try {
                reader.close();
            } catch (Exception ignored) {}
        }
    }

    @SuppressWarnings("UnstableApiUsage")
    private static void writeExampleFile() {
        LOG.info("No config has been detected, writing an example one");
        Writer writer = null;
        try {
            writer = Files.newWriter(overrideFile, StandardCharsets.UTF_8);
            Map<String, MobOverride> example = new HashMap<>(1);
            MobOverride ex1 = new MobOverride();
            ex1.removals.add(new MobDropSimplified(new ItemStack(Items.rotten_flesh, 1), MobDrop.DropType.Normal));
            HashMap<Integer, Integer> exdamages = new HashMap<>(3);
            exdamages.put(1, 1);
            exdamages.put(2, 5);
            exdamages.put(3, 10);
            ex1.additions.add(
                    new MobDrop(
                            new ItemStack(Items.diamond_sword),
                            MobDrop.DropType.Rare,
                            500,
                            20,
                            exdamages,
                            true,
                            false));
            example.put("ExampleMob", ex1);
            gson.toJson(example, writer);
            writer.flush();
        } catch (Exception ex) {
            ex.printStackTrace();
        } finally {
            if (writer != null) try {
                writer.close();
            } catch (Exception ignored) {}
        }
    }
}