minecraft-src/net/minecraft/world/inventory/MerchantMenu.java

package net.minecraft.world.inventory;

import net.minecraft.server.level.ServerPlayer;
import net.minecraft.sounds.SoundSource;
import net.minecraft.world.Container;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.entity.npc.ClientSideMerchant;
import net.minecraft.world.entity.player.Inventory;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.item.trading.ItemCost;
import net.minecraft.world.item.trading.Merchant;
import net.minecraft.world.item.trading.MerchantOffer;
import net.minecraft.world.item.trading.MerchantOffers;

public class MerchantMenu extends AbstractContainerMenu {
	protected static final int PAYMENT1_SLOT = 0;
	protected static final int PAYMENT2_SLOT = 1;
	protected static final int RESULT_SLOT = 2;
	private static final int INV_SLOT_START = 3;
	private static final int INV_SLOT_END = 30;
	private static final int USE_ROW_SLOT_START = 30;
	private static final int USE_ROW_SLOT_END = 39;
	private static final int SELLSLOT1_X = 136;
	private static final int SELLSLOT2_X = 162;
	private static final int BUYSLOT_X = 220;
	private static final int ROW_Y = 37;
	private final Merchant trader;
	private final MerchantContainer tradeContainer;
	private int merchantLevel;
	private boolean showProgressBar;
	private boolean canRestock;

	public MerchantMenu(int containerId, Inventory playerInventory) {
		this(containerId, playerInventory, new ClientSideMerchant(playerInventory.player));
	}

	public MerchantMenu(int containerId, Inventory playerInventory, Merchant trader) {
		super(MenuType.MERCHANT, containerId);
		this.trader = trader;
		this.tradeContainer = new MerchantContainer(trader);
		this.addSlot(new Slot(this.tradeContainer, 0, 136, 37));
		this.addSlot(new Slot(this.tradeContainer, 1, 162, 37));
		this.addSlot(new MerchantResultSlot(playerInventory.player, trader, this.tradeContainer, 2, 220, 37));
		this.addStandardInventorySlots(playerInventory, 108, 84);
	}

	public void setShowProgressBar(boolean showProgressBar) {
		this.showProgressBar = showProgressBar;
	}

	@Override
	public void slotsChanged(Container container) {
		this.tradeContainer.updateSellItem();
		super.slotsChanged(container);
	}

	public void setSelectionHint(int currentRecipeIndex) {
		this.tradeContainer.setSelectionHint(currentRecipeIndex);
	}

	@Override
	public boolean stillValid(Player player) {
		return this.trader.stillValid(player);
	}

	public int getTraderXp() {
		return this.trader.getVillagerXp();
	}

	public int getFutureTraderXp() {
		return this.tradeContainer.getFutureXp();
	}

	public void setXp(int xp) {
		this.trader.overrideXp(xp);
	}

	public int getTraderLevel() {
		return this.merchantLevel;
	}

	public void setMerchantLevel(int level) {
		this.merchantLevel = level;
	}

	public void setCanRestock(boolean canRestock) {
		this.canRestock = canRestock;
	}

	public boolean canRestock() {
		return this.canRestock;
	}

	@Override
	public boolean canTakeItemForPickAll(ItemStack stack, Slot slot) {
		return false;
	}

	@Override
	public ItemStack quickMoveStack(Player player, int index) {
		ItemStack itemStack = ItemStack.EMPTY;
		Slot slot = this.slots.get(index);
		if (slot != null && slot.hasItem()) {
			ItemStack itemStack2 = slot.getItem();
			itemStack = itemStack2.copy();
			if (index == 2) {
				if (!this.moveItemStackTo(itemStack2, 3, 39, true)) {
					return ItemStack.EMPTY;
				}

				slot.onQuickCraft(itemStack2, itemStack);
				this.playTradeSound();
			} else if (index != 0 && index != 1) {
				if (index >= 3 && index < 30) {
					if (!this.moveItemStackTo(itemStack2, 30, 39, false)) {
						return ItemStack.EMPTY;
					}
				} else if (index >= 30 && index < 39 && !this.moveItemStackTo(itemStack2, 3, 30, false)) {
					return ItemStack.EMPTY;
				}
			} else if (!this.moveItemStackTo(itemStack2, 3, 39, false)) {
				return ItemStack.EMPTY;
			}

			if (itemStack2.isEmpty()) {
				slot.setByPlayer(ItemStack.EMPTY);
			} else {
				slot.setChanged();
			}

			if (itemStack2.getCount() == itemStack.getCount()) {
				return ItemStack.EMPTY;
			}

			slot.onTake(player, itemStack2);
		}

		return itemStack;
	}

	private void playTradeSound() {
		if (!this.trader.isClientSide()) {
			Entity entity = (Entity)this.trader;
			entity.level().playLocalSound(entity.getX(), entity.getY(), entity.getZ(), this.trader.getNotifyTradeSound(), SoundSource.NEUTRAL, 1.0F, 1.0F, false);
		}
	}

	@Override
	public void removed(Player player) {
		super.removed(player);
		this.trader.setTradingPlayer(null);
		if (!this.trader.isClientSide()) {
			if (!player.isAlive() || player instanceof ServerPlayer && ((ServerPlayer)player).hasDisconnected()) {
				ItemStack itemStack = this.tradeContainer.removeItemNoUpdate(0);
				if (!itemStack.isEmpty()) {
					player.drop(itemStack, false);
				}

				itemStack = this.tradeContainer.removeItemNoUpdate(1);
				if (!itemStack.isEmpty()) {
					player.drop(itemStack, false);
				}
			} else if (player instanceof ServerPlayer) {
				player.getInventory().placeItemBackInInventory(this.tradeContainer.removeItemNoUpdate(0));
				player.getInventory().placeItemBackInInventory(this.tradeContainer.removeItemNoUpdate(1));
			}
		}
	}

	public void tryMoveItems(int selectedMerchantRecipe) {
		if (selectedMerchantRecipe >= 0 && this.getOffers().size() > selectedMerchantRecipe) {
			ItemStack itemStack = this.tradeContainer.getItem(0);
			if (!itemStack.isEmpty()) {
				if (!this.moveItemStackTo(itemStack, 3, 39, true)) {
					return;
				}

				this.tradeContainer.setItem(0, itemStack);
			}

			ItemStack itemStack2 = this.tradeContainer.getItem(1);
			if (!itemStack2.isEmpty()) {
				if (!this.moveItemStackTo(itemStack2, 3, 39, true)) {
					return;
				}

				this.tradeContainer.setItem(1, itemStack2);
			}

			if (this.tradeContainer.getItem(0).isEmpty() && this.tradeContainer.getItem(1).isEmpty()) {
				MerchantOffer merchantOffer = (MerchantOffer)this.getOffers().get(selectedMerchantRecipe);
				this.moveFromInventoryToPaymentSlot(0, merchantOffer.getItemCostA());
				merchantOffer.getItemCostB().ifPresent(itemCost -> this.moveFromInventoryToPaymentSlot(1, itemCost));
			}
		}
	}

	private void moveFromInventoryToPaymentSlot(int paymentSlotIndex, ItemCost payment) {
		for (int i = 3; i < 39; i++) {
			ItemStack itemStack = this.slots.get(i).getItem();
			if (!itemStack.isEmpty() && payment.test(itemStack)) {
				ItemStack itemStack2 = this.tradeContainer.getItem(paymentSlotIndex);
				if (itemStack2.isEmpty() || ItemStack.isSameItemSameComponents(itemStack, itemStack2)) {
					int j = itemStack.getMaxStackSize();
					int k = Math.min(j - itemStack2.getCount(), itemStack.getCount());
					ItemStack itemStack3 = itemStack.copyWithCount(itemStack2.getCount() + k);
					itemStack.shrink(k);
					this.tradeContainer.setItem(paymentSlotIndex, itemStack3);
					if (itemStack3.getCount() >= j) {
						break;
					}
				}
			}
		}
	}

	/**
	 * {@link net.minecraft.client.multiplayer.ClientPacketListener} uses this to set offers for the client side MerchantContainer.
	 */
	public void setOffers(MerchantOffers offers) {
		this.trader.overrideOffers(offers);
	}

	public MerchantOffers getOffers() {
		return this.trader.getOffers();
	}

	public boolean showProgressBar() {
		return this.showProgressBar;
	}
}