package net.minecraft.world.inventory;

import net.minecraft.core.NonNullList;
import net.minecraft.world.Container;
import net.minecraft.world.ContainerHelper;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.item.trading.Merchant;
import net.minecraft.world.item.trading.MerchantOffer;
import net.minecraft.world.item.trading.MerchantOffers;
import org.jetbrains.annotations.Nullable;

public class MerchantContainer implements Container {
	private final Merchant merchant;
	private final NonNullList<ItemStack> itemStacks = NonNullList.withSize(3, ItemStack.EMPTY);
	@Nullable
	private MerchantOffer activeOffer;
	private int selectionHint;
	private int futureXp;

	public MerchantContainer(Merchant merchant) {
		this.merchant = merchant;
	}

	@Override
	public int getContainerSize() {
		return this.itemStacks.size();
	}

	@Override
	public boolean isEmpty() {
		for (ItemStack itemStack : this.itemStacks) {
			if (!itemStack.isEmpty()) {
				return false;
			}
		}

		return true;
	}

	@Override
	public ItemStack getItem(int slot) {
		return this.itemStacks.get(slot);
	}

	@Override
	public ItemStack removeItem(int slot, int amount) {
		ItemStack itemStack = this.itemStacks.get(slot);
		if (slot == 2 && !itemStack.isEmpty()) {
			return ContainerHelper.removeItem(this.itemStacks, slot, itemStack.getCount());
		} else {
			ItemStack itemStack2 = ContainerHelper.removeItem(this.itemStacks, slot, amount);
			if (!itemStack2.isEmpty() && this.isPaymentSlot(slot)) {
				this.updateSellItem();
			}

			return itemStack2;
		}
	}

	/**
	 * if par1 slot has changed, does resetRecipeAndSlots need to be called?
	 */
	private boolean isPaymentSlot(int slot) {
		return slot == 0 || slot == 1;
	}

	@Override
	public ItemStack removeItemNoUpdate(int slot) {
		return ContainerHelper.takeItem(this.itemStacks, slot);
	}

	@Override
	public void setItem(int slot, ItemStack stack) {
		this.itemStacks.set(slot, stack);
		stack.limitSize(this.getMaxStackSize(stack));
		if (this.isPaymentSlot(slot)) {
			this.updateSellItem();
		}
	}

	@Override
	public boolean stillValid(Player player) {
		return this.merchant.getTradingPlayer() == player;
	}

	@Override
	public void setChanged() {
		this.updateSellItem();
	}

	public void updateSellItem() {
		this.activeOffer = null;
		ItemStack itemStack;
		ItemStack itemStack2;
		if (this.itemStacks.get(0).isEmpty()) {
			itemStack = this.itemStacks.get(1);
			itemStack2 = ItemStack.EMPTY;
		} else {
			itemStack = this.itemStacks.get(0);
			itemStack2 = this.itemStacks.get(1);
		}

		if (itemStack.isEmpty()) {
			this.setItem(2, ItemStack.EMPTY);
			this.futureXp = 0;
		} else {
			MerchantOffers merchantOffers = this.merchant.getOffers();
			if (!merchantOffers.isEmpty()) {
				MerchantOffer merchantOffer = merchantOffers.getRecipeFor(itemStack, itemStack2, this.selectionHint);
				if (merchantOffer == null || merchantOffer.isOutOfStock()) {
					this.activeOffer = merchantOffer;
					merchantOffer = merchantOffers.getRecipeFor(itemStack2, itemStack, this.selectionHint);
				}

				if (merchantOffer != null && !merchantOffer.isOutOfStock()) {
					this.activeOffer = merchantOffer;
					this.setItem(2, merchantOffer.assemble());
					this.futureXp = merchantOffer.getXp();
				} else {
					this.setItem(2, ItemStack.EMPTY);
					this.futureXp = 0;
				}
			}

			this.merchant.notifyTradeUpdated(this.getItem(2));
		}
	}

	@Nullable
	public MerchantOffer getActiveOffer() {
		return this.activeOffer;
	}

	public void setSelectionHint(int currentRecipeIndex) {
		this.selectionHint = currentRecipeIndex;
		this.updateSellItem();
	}

	@Override
	public void clearContent() {
		this.itemStacks.clear();
	}

	public int getFutureXp() {
		return this.futureXp;
	}
}