    001package net.sf.cpsolver.studentsct.constraint;
    002
    003import java.util.Set;
    004
    005import net.sf.cpsolver.ifs.model.GlobalConstraint;
    006import net.sf.cpsolver.studentsct.model.Config;
    007import net.sf.cpsolver.studentsct.model.Enrollment;
    008import net.sf.cpsolver.studentsct.model.Request;
    009import net.sf.cpsolver.studentsct.reservation.Reservation;
    010
    011/**
    012 * Required reservation constraint. This global constraint ensures that reservations
    013 * with {@link Reservation#mustBeUsed()} flags are used. That is, an enrollment
    014 * is conflicting when there is a reservation for the student that must be used,
    015 * but the given enrollment does not use it.
    016 *
    017 * @version StudentSct 1.2 (Student Sectioning)<br>
    018 *          Copyright (C) 2014 Tomáš Müller<br>
    019 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    020 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    021 * <br>
    022 *          This library is free software; you can redistribute it and/or modify
    023 *          it under the terms of the GNU Lesser General Public License as
    024 *          published by the Free Software Foundation; either version 3 of the
    025 *          License, or (at your option) any later version. <br>
    026 * <br>
    027 *          This library is distributed in the hope that it will be useful, but
    028 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    029 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    030 *          Lesser General Public License for more details. <br>
    031 * <br>
    032 *          You should have received a copy of the GNU Lesser General Public
    033 *          License along with this library; if not see
    034 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    035 */
    036public class RequiredReservation extends GlobalConstraint<Request, Enrollment> {
    037
    038    /**
    039     * A given enrollment is conflicting, if there is a reservation that
    040     * the student must use, but the given enrollment does not use it.
    041     *
    042     * @param enrollment {@link Enrollment} that is being considered
    043     * @param conflicts all computed conflicting requests are added into this set
    044     */
    045    @Override
    046    public void computeConflicts(Enrollment enrollment, Set<Enrollment> conflicts) {
    047        if (inConflict(enrollment))
    048            conflicts.add(enrollment);
    049    }
    050
    051    /**
    052     * A given enrollment is conflicting, if there is a reservation that
    053     * the student must use, but the given enrollment does not use it.
    054     *
    055     * @param enrollment {@link Enrollment} that is being considered
    056     * @return true, if the enrollment does not follow a reservation that must be used
    057     */
    058    @Override
    059    public boolean inConflict(Enrollment enrollment) {
    060        // enrollment's config
    061        Config config = enrollment.getConfig();
    062
    063        // exclude free time requests
    064        if (config == null) return false;
    065
    066        // no reservations
    067        if (!config.getOffering().hasReservations())
    068            return false;
    069
    070        // enrollment's reservation
    071        Reservation reservation = enrollment.getReservation();
    072
    073        // already has a reservation that must be used
    074        if (reservation != null && reservation.mustBeUsed()) return false;
    075
    076        // if a reservation is required for the student, fail
    077        for (Reservation r: config.getOffering().getReservations())
    078            if (r.mustBeUsed() && r.isApplicable(enrollment.getStudent()))
    079                return true;
    080
    081        return false;
    082    }
    083
    084    @Override
    085    public String toString() {
    086        return "RequiredReservation";
    087    }
    088}