001/*
002 * Trident - A Multithreaded Server Alternative
003 * Copyright 2014 The TridentSDK Team
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *    http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package net.tridentsdk.inventory.trade;
019
020import net.tridentsdk.inventory.Item;
021
022/**
023 * Represents a Trade offered by an {@link net.tridentsdk.entity.traits.Tradeable}
024 *
025 * @author TridentSDK Team
026 */
027public interface Trade {
028    /**
029     * Whether or not this trade rewards xp
030     *
031     * @return Whether or not this trade should reward xp
032     */
033    boolean rewardExp();
034
035    /**
036     * How many times this trade can be fulfilled
037     *
038     * @return the number of times this trade can be fulfilled
039     */
040    int maxUses();
041
042    /**
043     * How many times this trade has been fulfilled
044     *
045     * @return how many times this trade has been fulfilled
046     */
047    int uses();
048
049    /**
050     * The itemstack given as a result of this trade
051     *
052     * @return the itemstack that is given as a result of fulfilling this trade
053     */
054    Item offer();
055
056    /**
057     * The itemstacks required to be input in order to fulfilled this trade This accepts both implementations of
058     * ItemPair, including a null second offer
059     *
060     * @return the input that will fulfill this trade
061     */
062    ItemPair input();
063}