package net.radsteve.islanders.mixin;

import com.google.common.collect.Iterators;
import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
import it.unimi.dsi.fastutil.ints.Int2ObjectMaps;
import net.minecraft.item.Item;
import net.minecraft.item.Items;
import net.minecraft.network.packet.c2s.play.ClickSlotC2SPacket;
import net.minecraft.registry.entry.RegistryEntry;
import net.minecraft.registry.tag.ItemTags;
import net.minecraft.screen.ScreenHandler;
import net.minecraft.screen.slot.Slot;
import net.minecraft.screen.sync.ItemStackHash;
import net.minecraft.server.network.ServerPlayNetworkHandler;
import net.minecraft.server.network.ServerPlayerEntity;
import net.radsteve.islanders.Islanders;
import org.spongepowered.asm.mixin.Mixin;
import org.spongepowered.asm.mixin.Shadow;
import org.spongepowered.asm.mixin.Unique;
import org.spongepowered.asm.mixin.injection.At;
import org.spongepowered.asm.mixin.injection.Inject;
import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;

/// Warning: This is a huge mess and you should not touch this with a ten-foot pole
/// This prevents special items from being put into bundles.
/// Time counter: 5h
@Mixin(ServerPlayNetworkHandler.class)
public class BundleHandlerMixin {
  @Shadow
  public ServerPlayerEntity player;

  /// DIRECTION ONE - item clicked first and dragged onto bundle

  @Unique
  private ClickSlotC2SPacket islanders$lastClickPacket = null;

  @Unique
  private Item islanders$lastClickedItem = null;

  @Inject(method = "onClickSlot", at = @At(value = "INVOKE", target = "Lnet/minecraft/screen/ScreenHandler;disableSyncing()V"), cancellable = true)
  private void islanders$onClickSlot(ClickSlotC2SPacket packet, CallbackInfo ci) {
    if (islanders$lastClickPacket == null) {
      islanders$lastClickPacket = packet;
      return;
    }

    final var modifiedStacks = packet.modifiedStacks();
    if (modifiedStacks.size() != 1) {
      islanders$lastClickPacket = packet;
      return;
    }

    final int slotIdx = Iterators.getOnlyElement(modifiedStacks.keySet().iterator());
    final Slot currentSlot = player.currentScreenHandler.slots.get(slotIdx);
    if (!currentSlot.getStack().itemMatches((entry) -> entry.isIn(ItemTags.BUNDLES))) {
      islanders$lastClickPacket = packet;
      islanders$lastClickedItem = currentSlot.getStack().getItem();
      return;
    }

    if (!(modifiedStacks.get(slotIdx) instanceof ItemStackHash.Impl)) {
      islanders$lastClickPacket = packet;
      return;
    }

    final var lastModifiedStacks = islanders$lastClickPacket.modifiedStacks();
    if (lastModifiedStacks.size() != 1) {
      islanders$lastClickPacket = packet;
      return;
    }

    final Item specialItem = islanders$lastClickedItem;

    if (!(specialItem == Items.DRAGON_EGG || specialItem == Items.MACE || specialItem == Items.POPPED_CHORUS_FRUIT /* TODO: extra validation */)) {
      islanders$lastClickPacket = packet;
      return;
    }

    final ScreenHandler screenHandler = player.currentScreenHandler;

    for (Int2ObjectMap.Entry<ItemStackHash> entry : Int2ObjectMaps.fastIterable(packet.modifiedStacks())) {
      screenHandler.setReceivedHash(entry.getIntKey(), entry.getValue());
    }

    screenHandler.setReceivedCursorHash(packet.cursor());
    screenHandler.enableSyncing();
    screenHandler.updateToClient();
    screenHandler.sendContentUpdates();
    ci.cancel();

    islanders$lastClickPacket = packet;

    Islanders.getLogger().info("{} tried moving special item into bundle", player.getNameForScoreboard());
  }

  /// DIRECTION TWO - bundle clicked first and dragged onto item
  /// This is a mess. Do not touch :)

  @Unique
  private ClickSlotC2SPacket islanders$lastClickPacket$0 = null;
  @Unique
  private RegistryEntry<Item> islanders$lastClickedItem$0 = null;

  @Inject(method = "onClickSlot", at = @At(value = "INVOKE", target = "Lnet/minecraft/screen/ScreenHandler;disableSyncing()V"), cancellable = true)
  private void islanders$onClickSlot$0(ClickSlotC2SPacket packet, CallbackInfo ci) {
    if (islanders$lastClickPacket$0 == null) {
      islanders$lastClickPacket$0 = packet;
    }

    final var modifiedStacks = packet.modifiedStacks();

    if (islanders$lastClickedItem$0 == null) {
      islanders$lastClickPacket$0 = packet;
      if (!modifiedStacks.isEmpty()) {
        final int slotIdx = Iterators.get(modifiedStacks.keySet().iterator(), 0);
        final Slot currentSlot = player.currentScreenHandler.slots.get(slotIdx);
        islanders$lastClickedItem$0 = currentSlot.getStack().getRegistryEntry();
      }
      return;
    }

    final boolean lastIsBundle = islanders$lastClickedItem$0.isIn(ItemTags.BUNDLES);

    if (modifiedStacks.isEmpty() && !lastIsBundle) {
      islanders$lastClickPacket$0 = packet;
      return;
    }

    RegistryEntry<Item> currentItem;
    if (modifiedStacks.isEmpty()) {
      currentItem = islanders$lastClickedItem$0;
    } else {
      final int slotIdx = Iterators.get(modifiedStacks.keySet().iterator(), 0);
      final Slot currentSlot = player.currentScreenHandler.slots.get(slotIdx);
      currentItem = currentSlot.getStack().getRegistryEntry();
    }

    if (islanders$lastClickPacket$0 == null) {
      return;
    }

    if (!islanders$lastClickedItem$0.isIn(ItemTags.BUNDLES)) {
      islanders$lastClickPacket$0 = packet;
      islanders$lastClickedItem$0 = currentItem;
      return;
    }

    final Item specialItem = currentItem.value();

    if (!(specialItem == Items.DRAGON_EGG || specialItem == Items.MACE || specialItem == Items.POPPED_CHORUS_FRUIT /* TODO: extra validation */)) {
      islanders$lastClickPacket$0 = packet;
      islanders$lastClickedItem$0 = currentItem;
      return;
    }

    final ScreenHandler screenHandler = player.currentScreenHandler;

    for (Int2ObjectMap.Entry<ItemStackHash> entry : Int2ObjectMaps.fastIterable(packet.modifiedStacks())) {
      screenHandler.setReceivedHash(entry.getIntKey(), entry.getValue());
    }

    screenHandler.setReceivedCursorHash(packet.cursor());
    screenHandler.enableSyncing();
    screenHandler.updateToClient();
    screenHandler.sendContentUpdates();
    ci.cancel();

    islanders$lastClickPacket$0 = packet;
    Islanders.getLogger().info("{} tried moving special item into bundle", player.getNameForScoreboard());
  }
}