001package org.cpsolver.exam.model;
002
003import java.util.HashMap;
004import java.util.HashSet;
005import java.util.Map;
006import java.util.Set;
007
008import org.cpsolver.coursett.IdConvertor;
009import org.cpsolver.ifs.assignment.Assignment;
010import org.cpsolver.ifs.model.Model;
011import org.cpsolver.ifs.util.DataProperties;
012import org.dom4j.Element;
013
014
015/**
016 * Room sharing model based on a pre-defined list of examination pairs. The relation needs to be populated
017 * using {@link PredefinedExamRoomSharing#addPair(Exam, Exam)} and it is persisted with the solution XML (see
018 * {@link ExamModel#save(Assignment)}, canShareRoom element for each exam containing a comma separated list of exam ids).
019 * <br>
020 * 
021 * @version ExamTT 1.3 (Examination Timetabling)<br>
022 *          Copyright (C) 2008 - 2014 Tomáš Müller<br>
023 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
024 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
025 * <br>
026 *          This library is free software; you can redistribute it and/or modify
027 *          it under the terms of the GNU Lesser General Public License as
028 *          published by the Free Software Foundation; either version 3 of the
029 *          License, or (at your option) any later version. <br>
030 * <br>
031 *          This library is distributed in the hope that it will be useful, but
032 *          WITHOUT ANY WARRANTY; without even the implied warranty of
033 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
034 *          Lesser General Public License for more details. <br>
035 * <br>
036 *          You should have received a copy of the GNU Lesser General Public
037 *          License along with this library; if not see
038 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
039 */
040public class PredefinedExamRoomSharing extends ExamRoomSharing {
041    private Map<Long, Set<Long>> iSharingMatrix = new HashMap<Long, Set<Long>>();
042    
043    public PredefinedExamRoomSharing(Model<Exam, ExamPlacement> model, DataProperties config) {
044        super(model, config);
045    }
046
047    @Override
048    public boolean canShareRoom(Exam x1, Exam x2) {
049        if (x1.getId() < x2.getId()) {
050            Set<Long> exams = iSharingMatrix.get(x1.getId());
051            return exams != null && exams.contains(x2.getId());
052        } else {
053            Set<Long> exams = iSharingMatrix.get(x2.getId());
054            return exams != null && exams.contains(x1.getId());
055        }
056    }
057    
058    /** Add a pair of exams that are allowed to share a room 
059     * @param x1 first exam
060     * @param x2 second exam
061     **/
062    public void addPair(Exam x1, Exam x2) {
063        addPair(x1.getId(), x2.getId());
064    }
065    
066    /** Add a pair of exams that are allowed to share a room 
067     * @param examId1 first exam unique id
068     * @param examId2 second exam unique id
069     **/
070    public void addPair(Long examId1, Long examId2) {
071        if (examId1 < examId2) {
072            Set<Long> exams = iSharingMatrix.get(examId1);
073            if (exams == null) { exams = new HashSet<Long>(); iSharingMatrix.put(examId1, exams); }
074            exams.add(examId2);
075        } else {
076            Set<Long> exams = iSharingMatrix.get(examId2);
077            if (exams == null) { exams = new HashSet<Long>(); iSharingMatrix.put(examId2, exams); }
078            exams.add(examId1);
079        }        
080    }
081    
082    /** Clear examination pairs */
083    public void clear() {
084        iSharingMatrix.clear();
085    }
086    
087    @Override
088    public void save(Exam exam, Element element, IdConvertor idConvertor) {
089        Set<Long> exams = iSharingMatrix.get(exam.getId());
090        if (exams != null) {
091            String ids = "";
092            for (Long id: exams) {
093                if (!ids.isEmpty()) ids += ",";
094                ids += (idConvertor == null ? id.toString() : idConvertor.convert("exam", id.toString()));
095            }
096            element.addElement("canShareRoom").setText(ids);
097        }
098    }
099    
100    @Override
101    public void load(Exam exam, Element element) {
102        Element canShareRoom = element.element("canShareRoom");
103        if (canShareRoom == null) return;
104        for (String id: canShareRoom.getTextTrim().split(","))
105            addPair(exam.getId(), Long.valueOf(id.trim()));
106    }
107}