package net.minecraft.world.entity;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import net.minecraft.core.component.DataComponents;
import net.minecraft.resources.ResourceKey;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.item.equipment.Equippable;
import net.minecraft.world.level.storage.loot.LootParams;
import net.minecraft.world.level.storage.loot.LootTable;
import org.jspecify.annotations.Nullable;

public interface EquipmentUser {
	void setItemSlot(final EquipmentSlot slot, final ItemStack stack);

	ItemStack getItemBySlot(final EquipmentSlot slot);

	void setDropChance(final EquipmentSlot slot, final float dropChance);

	default void equip(final EquipmentTable equipment, final LootParams lootParams) {
		this.equip(equipment.lootTable(), lootParams, equipment.slotDropChances());
	}

	default void equip(final ResourceKey<LootTable> lootTable, final LootParams lootParams, final Map<EquipmentSlot, Float> dropChances) {
		this.equip(lootTable, lootParams, 0L, dropChances);
	}

	default void equip(
		final ResourceKey<LootTable> lootTable, final LootParams lootParams, final long optionalLootTableSeed, final Map<EquipmentSlot, Float> dropChances
	) {
		LootTable table = lootParams.getLevel().getServer().reloadableRegistries().getLootTable(lootTable);
		if (table != LootTable.EMPTY) {
			List<ItemStack> possibleEquipment = table.getRandomItems(lootParams, optionalLootTableSeed);
			List<EquipmentSlot> insertedIntoSlots = new ArrayList();

			for (ItemStack toEquip : possibleEquipment) {
				EquipmentSlot slot = this.resolveSlot(toEquip, insertedIntoSlots);
				if (slot != null) {
					ItemStack equipped = slot.limit(toEquip);
					this.setItemSlot(slot, equipped);
					Float dropChance = (Float)dropChances.get(slot);
					if (dropChance != null) {
						this.setDropChance(slot, dropChance);
					}

					insertedIntoSlots.add(slot);
				}
			}
		}
	}

	@Nullable
	default EquipmentSlot resolveSlot(final ItemStack toEquip, final List<EquipmentSlot> alreadyInsertedIntoSlots) {
		if (toEquip.isEmpty()) {
			return null;
		} else {
			Equippable equippable = toEquip.get(DataComponents.EQUIPPABLE);
			if (equippable != null) {
				EquipmentSlot slot = equippable.slot();
				if (!alreadyInsertedIntoSlots.contains(slot)) {
					return slot;
				}
			} else if (!alreadyInsertedIntoSlots.contains(EquipmentSlot.MAINHAND)) {
				return EquipmentSlot.MAINHAND;
			}

			return null;
		}
	}
}