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General classes for dealing with social choice theory.
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package io.github.oliviercailloux.j_voting.profiles.management;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Objects;

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

import com.google.common.base.Preconditions;

import io.github.oliviercailloux.j_voting.Alternative;
import io.github.oliviercailloux.j_voting.OldCompletePreferenceImpl;
import io.github.oliviercailloux.j_voting.OldLinearPreferenceImpl;
import io.github.oliviercailloux.j_voting.Voter;
import io.github.oliviercailloux.j_voting.profiles.ImmutableStrictProfileI;
import io.github.oliviercailloux.j_voting.profiles.StrictProfileI;

/**
 * 
 * This class builds a strict profile.
 *
 */
public class StrictProfileBuilder extends ProfileBuilder {

	private static final Logger LOGGER = LoggerFactory.getLogger(StrictProfileBuilder.class.getName());

	/**
	 * Factory method for StrictProfileBuilder without parameter
	 * 
	 * @return StrictProfileBuilder
	 */
	public static StrictProfileBuilder createStrictProfileBuilder() {
		LOGGER.debug("StrictProfileBuilder Factory without parameter");
		return new StrictProfileBuilder();
	}

	/**
	 * Factory method for StrictProfileBuilder with parameter
	 * 
	 * @param prof
	 * @return new StrictProfileBuilder
	 */
	public static StrictProfileBuilder createStrictProfileBuilder(StrictProfileI prof) {
		LOGGER.debug("StrictProfileBuilder Factory with parameter");
		if (Objects.equals(prof, null))
			return createStrictProfileBuilder();
		return new StrictProfileBuilder(prof);
	}

	private StrictProfileBuilder() {
		LOGGER.debug("constructor empty:");
		votes = new HashMap<>();
	}

	private StrictProfileBuilder(StrictProfileI prof) {
		LOGGER.debug("parameter prof : {}", prof);
		votes = castMapExtendsToRegularVoterPref(prof.getProfile());
	}

	/**
	 * 
	 * @param v    not  null 
	 * @param pref not  null 
	 * 
	 *             adds the preference pref for the voter v in the map. If the
	 *             preference isn't strict, it throws an IllegalArgumentException.
	 */
	@Override
	public void addVote(Voter v, OldCompletePreferenceImpl pref) {
		LOGGER.debug("addProfile:");
		Preconditions.checkNotNull(v);
		Preconditions.checkNotNull(pref);
		LOGGER.debug("parameters: voter {} pref {}", v, pref);
		if (!pref.isStrict()) {
			throw new IllegalArgumentException("The preference must be strict.");
		}
		votes.put(v, pref);
	}

	/**
	 * From a StrictProfileI, creates an ImmutableStrictProfileI where only the
	 * first alternative of each preference is taken into account.
	 * 
	 * @return
	 */
	public ImmutableStrictProfileI createOneAlternativeProfile() {
		LOGGER.debug("createOneAlternativeProfile");
		for (Voter v : votes.keySet()) {
			List alters = new ArrayList<>();
			alters.add(votes.get(v).getAlternative(0));
			OldLinearPreferenceImpl prefOneAlter = OldLinearPreferenceImpl.createStrictCompletePreferenceImpl(alters);
			addVote(v, prefOneAlter);
		}
		return ImmutableStrictProfileI.createImmutableStrictProfileI(votes);
	}
}