package net.minecraft.world.entity.ai.behavior;

import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import java.util.Set;
import java.util.stream.Collectors;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.world.SimpleContainer;
import net.minecraft.world.entity.EntityType;
import net.minecraft.world.entity.LivingEntity;
import net.minecraft.world.entity.ai.memory.MemoryModuleType;
import net.minecraft.world.entity.ai.memory.MemoryStatus;
import net.minecraft.world.entity.npc.Villager;
import net.minecraft.world.entity.npc.VillagerProfession;
import net.minecraft.world.item.Item;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.item.Items;

public class TradeWithVillager extends Behavior<Villager> {
	private Set<Item> trades = ImmutableSet.of();

	public TradeWithVillager() {
		super(
			ImmutableMap.of(
				MemoryModuleType.INTERACTION_TARGET, MemoryStatus.VALUE_PRESENT, MemoryModuleType.NEAREST_VISIBLE_LIVING_ENTITIES, MemoryStatus.VALUE_PRESENT
			)
		);
	}

	protected boolean checkExtraStartConditions(ServerLevel level, Villager owner) {
		return BehaviorUtils.targetIsValid(owner.getBrain(), MemoryModuleType.INTERACTION_TARGET, EntityType.VILLAGER);
	}

	protected boolean canStillUse(ServerLevel level, Villager entity, long gameTime) {
		return this.checkExtraStartConditions(level, entity);
	}

	protected void start(ServerLevel level, Villager entity, long gameTime) {
		Villager villager = (Villager)entity.getBrain().getMemory(MemoryModuleType.INTERACTION_TARGET).get();
		BehaviorUtils.lockGazeAndWalkToEachOther(entity, villager, 0.5F, 2);
		this.trades = figureOutWhatIAmWillingToTrade(entity, villager);
	}

	protected void tick(ServerLevel level, Villager owner, long gameTime) {
		Villager villager = (Villager)owner.getBrain().getMemory(MemoryModuleType.INTERACTION_TARGET).get();
		if (!(owner.distanceToSqr(villager) > 5.0)) {
			BehaviorUtils.lockGazeAndWalkToEachOther(owner, villager, 0.5F, 2);
			owner.gossip(level, villager, gameTime);
			boolean bl = owner.getVillagerData().profession().is(VillagerProfession.FARMER);
			if (owner.hasExcessFood() && (bl || villager.wantsMoreFood())) {
				throwHalfStack(owner, Villager.FOOD_POINTS.keySet(), villager);
			}

			if (bl && owner.getInventory().countItem(Items.WHEAT) > Items.WHEAT.getDefaultMaxStackSize() / 2) {
				throwHalfStack(owner, ImmutableSet.of(Items.WHEAT), villager);
			}

			if (!this.trades.isEmpty() && owner.getInventory().hasAnyOf(this.trades)) {
				throwHalfStack(owner, this.trades, villager);
			}
		}
	}

	protected void stop(ServerLevel level, Villager entity, long gameTime) {
		entity.getBrain().eraseMemory(MemoryModuleType.INTERACTION_TARGET);
	}

	private static Set<Item> figureOutWhatIAmWillingToTrade(Villager villager, Villager other) {
		ImmutableSet<Item> immutableSet = other.getVillagerData().profession().value().requestedItems();
		ImmutableSet<Item> immutableSet2 = villager.getVillagerData().profession().value().requestedItems();
		return (Set<Item>)immutableSet.stream().filter(item -> !immutableSet2.contains(item)).collect(Collectors.toSet());
	}

	private static void throwHalfStack(Villager villager, Set<Item> stack, LivingEntity entity) {
		SimpleContainer simpleContainer = villager.getInventory();
		ItemStack itemStack = ItemStack.EMPTY;
		int i = 0;

		while (i < simpleContainer.getContainerSize()) {
			ItemStack itemStack2;
			Item item;
			int j;
			label28: {
				itemStack2 = simpleContainer.getItem(i);
				if (!itemStack2.isEmpty()) {
					item = itemStack2.getItem();
					if (stack.contains(item)) {
						if (itemStack2.getCount() > itemStack2.getMaxStackSize() / 2) {
							j = itemStack2.getCount() / 2;
							break label28;
						}

						if (itemStack2.getCount() > 24) {
							j = itemStack2.getCount() - 24;
							break label28;
						}
					}
				}

				i++;
				continue;
			}

			itemStack2.shrink(j);
			itemStack = new ItemStack(item, j);
			break;
		}

		if (!itemStack.isEmpty()) {
			BehaviorUtils.throwItem(villager, itemStack, entity.position());
		}
	}
}