Undo.java

/*
 * 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);
    }
}