io.github.oliviercailloux.j_voting.profiles.analysis.Dictator Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of j-voting Show documentation

General classes for dealing with social choice theory.

The newest version!

package io.github.oliviercailloux.j_voting.profiles.analysis;

import java.util.Objects;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Preconditions;

import io.github.oliviercailloux.j_voting.OldCompletePreferenceImpl;
import io.github.oliviercailloux.j_voting.Voter;
import io.github.oliviercailloux.j_voting.profiles.ImmutableProfileI;

/**
 * This class is immutable. This class provides a result for an election that is
 * necessarily the preference of the dictator (a Voter).
 */
public class Dictator implements SocialWelfareFunction {

	private Voter dictator;
	private static final Logger LOGGER = LoggerFactory.getLogger(Borda.class.getName());

	/**
	 * Factory method for Dictator
	 * 
	 * @param v not null
	 * @return new Dictator
	 */
	public static Dictator about(Voter v) {
		LOGGER.debug("Dictator Factory");
		Preconditions.checkNotNull(v);
		return new Dictator(v);
	}

	private Dictator(Voter v) {
		LOGGER.debug("Dictator constructor");
		this.dictator = v;
	}

	/**
	 * 
	 * @param profile
	 * @return the dictator's preference
	 */
	@Override
	public OldCompletePreferenceImpl getSocietyPreference(ImmutableProfileI profile) {
		LOGGER.debug("getSocietyStrictPreference");
		Preconditions.checkNotNull(profile);
		Preconditions.checkArgument(profile.getProfile().containsKey(dictator));
		LOGGER.debug("parameter profile : {}", profile);
		LOGGER.debug("Dictator : {}", dictator);
		LOGGER.debug("return preference : {}", profile.getPreference(dictator));
		return profile.getPreference(dictator);
	}

	public Voter getDictator() {
		LOGGER.debug("getDictator");
		return dictator;
	}

	@Override
	public int hashCode() {
		return Objects.hash(dictator);
	}

	/**
	 * @param o1 not null
	 * @return true if both Dictators have the same voter as dictator.
	 */
	@Override
	public boolean equals(Object o) {
		if (this == o)
			return true;
		if (o == null)
			return false;
		if (this.getClass() != o.getClass())
			return false;
		Dictator dict = (Dictator) o;
		return this.getDictator() == dict.getDictator();
	}
}