    001package net.sf.cpsolver.exam.model;
    002
    003import java.util.HashMap;
    004import java.util.HashSet;
    005import java.util.Map;
    006import java.util.Set;
    007
    008import org.dom4j.Element;
    009
    010import net.sf.cpsolver.coursett.IdConvertor;
    011import net.sf.cpsolver.ifs.model.Model;
    012import net.sf.cpsolver.ifs.util.DataProperties;
    013
    014/**
    015 * Room sharing model based on a pre-defined list of examination pairs. The relation needs to be populated
    016 * using {@link PredefinedExamRoomSharing#addPair(Exam, Exam)} and it is persisted with the solution XML (see
    017 * {@link ExamModel#save()}, canShareRoom element for each exam containing a comma separated list of exam ids).
    018 * <br>
    019 *
    020 * @version ExamTT 1.2 (Examination Timetabling)<br>
    021 *          Copyright (C) 2008 - 2012 Tomáš Müller<br>
    022 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    023 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    024 * <br>
    025 *          This library is free software; you can redistribute it and/or modify
    026 *          it under the terms of the GNU Lesser General Public License as
    027 *          published by the Free Software Foundation; either version 3 of the
    028 *          License, or (at your option) any later version. <br>
    029 * <br>
    030 *          This library is distributed in the hope that it will be useful, but
    031 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    032 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    033 *          Lesser General Public License for more details. <br>
    034 * <br>
    035 *          You should have received a copy of the GNU Lesser General Public
    036 *          License along with this library; if not see
    037 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    038 */
    039public class PredefinedExamRoomSharing extends ExamRoomSharing {
    040    private Map<Long, Set<Long>> iSharingMatrix = new HashMap<Long, Set<Long>>();
    041
    042    public PredefinedExamRoomSharing(Model<Exam, ExamPlacement> model, DataProperties config) {
    043        super(model, config);
    044    }
    045
    046    @Override
    047    public boolean canShareRoom(Exam x1, Exam x2) {
    048        if (x1.getId() < x2.getId()) {
    049            Set<Long> exams = iSharingMatrix.get(x1.getId());
    050            return exams != null && exams.contains(x2.getId());
    051        } else {
    052            Set<Long> exams = iSharingMatrix.get(x2.getId());
    053            return exams != null && exams.contains(x1.getId());
    054        }
    055    }
    056
    057    /** Add a pair of exams that are allowed to share a room */
    058    public void addPair(Exam x1, Exam x2) {
    059        addPair(x1.getId(), x2.getId());
    060    }
    061
    062    /** Add a pair of exams that are allowed to share a room */
    063    public void addPair(Long examId1, Long examId2) {
    064        if (examId1 < examId2) {
    065            Set<Long> exams = iSharingMatrix.get(examId1);
    066            if (exams == null) { exams = new HashSet<Long>(); iSharingMatrix.put(examId1, exams); }
    067            exams.add(examId2);
    068        } else {
    069            Set<Long> exams = iSharingMatrix.get(examId2);
    070            if (exams == null) { exams = new HashSet<Long>(); iSharingMatrix.put(examId2, exams); }
    071            exams.add(examId1);
    072        }
    073    }
    074
    075    /** Clear examination pairs */
    076    public void clear() {
    077        iSharingMatrix.clear();
    078    }
    079
    080    @Override
    081    public void save(Exam exam, Element element, IdConvertor idConvertor) {
    082        Set<Long> exams = iSharingMatrix.get(exam.getId());
    083        if (exams != null) {
    084            String ids = "";
    085            for (Long id: exams) {
    086                if (!ids.isEmpty()) ids += ",";
    087                ids += (idConvertor == null ? id.toString() : idConvertor.convert("exam", id.toString()));
    088            }
    089            element.addElement("canShareRoom").setText(ids);
    090        }
    091    }
    092
    093    @Override
    094    public void load(Exam exam, Element element) {
    095        Element canShareRoom = element.element("canShareRoom");
    096        if (canShareRoom == null) return;
    097        for (String id: canShareRoom.getTextTrim().split(","))
    098            addPair(exam.getId(), Long.valueOf(id.trim()));
    099    }
    100}