Java tutorial
/* * Copyright (c) 2015 Shervin Asgari * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package no.asgari.civilization.server.model; import com.fasterxml.jackson.annotation.JsonIgnore; import com.fasterxml.jackson.annotation.JsonRootName; import lombok.Data; import lombok.NoArgsConstructor; import java.util.HashMap; import java.util.Map; import java.util.Optional; /** * When player pushes revert or cancel a specific draw, * the system must find out how many players are in the game. * All those players must agree before a undo can be made */ @Data @NoArgsConstructor @JsonRootName(value = "undo") public class Undo { /** * If undo has been performed * */ private boolean done; /** * Although we can find this number each time, its easier to cache it here * */ private int numberOfVotesRequired; /** * Each player_id gets to vote * The value can be true, false or null. Null means not voted yet * */ private Map<String, Boolean> votes = new HashMap<>(); /** * Will vote yes for the player since they initiated the request for undo * * @param numberOfVotesRequired * @param playerId */ public Undo(int numberOfVotesRequired, String playerId) { this.numberOfVotesRequired = numberOfVotesRequired; done = false; vote(playerId, Boolean.TRUE); } /** * Return the number of votes */ @JsonIgnore public int numberOfVotesPerformed() { return votes.size(); } @JsonIgnore public void vote(String playerId, Boolean vote) { votes.put(playerId, vote); } /** * Get the number of votes remaining */ @JsonIgnore public int votesRemaining() { return Math.abs(votes.size() - numberOfVotesRequired); } /** * All must agree for draw to be performed. * If absent/empty, then all players have not voted */ @JsonIgnore public Optional<Boolean> getResultOfVotes() { if (votesRemaining() != 0) return Optional.empty(); if (getVotes().containsValue(Boolean.FALSE)) return Optional.of(Boolean.FALSE); return Optional.of(Boolean.TRUE); } }