001package org.cpsolver.coursett.constraint;
002
003import java.util.Set;
004
005import org.cpsolver.coursett.criteria.additional.StudentOnlineConflict;
006import org.cpsolver.coursett.model.Lecture;
007import org.cpsolver.coursett.model.Placement;
008import org.cpsolver.coursett.model.RoomLocation;
009import org.cpsolver.coursett.model.TimetableModel;
010import org.cpsolver.ifs.assignment.Assignment;
011import org.cpsolver.ifs.model.GlobalConstraint;
012import org.cpsolver.ifs.model.Model;
013import org.cpsolver.ifs.util.DataProperties;
014
015/**
016 * An experimental global constraints that prohibits cases where a student has an online and in-person
017 * class on the same day. Online classes are identified by a regular expression matching the room name
018 * and set in the General.OnlineRoom parameter (defaults to (?i)ONLINE|). Classes without a 
019 * room are considered online when the General.OnlineRoom parameter matches a blank string.
020 * If a class has multiple rooms, all rooms must be online for the class to be considered online. 
021 * See {@link StudentOnlineConflict} criterion for a soft variant.
022 * <br>
023 * 
024 * @author  Tomáš Müller
025 * @version CourseTT 1.3 (University Course Timetabling)<br>
026 *          Copyright (C) 2013 - 2023 Tomáš Müller<br>
027 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
028 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
029 * <br>
030 *          This library is free software; you can redistribute it and/or modify
031 *          it under the terms of the GNU Lesser General Public License as
032 *          published by the Free Software Foundation; either version 3 of the
033 *          License, or (at your option) any later version. <br>
034 * <br>
035 *          This library is distributed in the hope that it will be useful, but
036 *          WITHOUT ANY WARRANTY; without even the implied warranty of
037 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
038 *          Lesser General Public License for more details. <br>
039 * <br>
040 *          You should have received a copy of the GNU Lesser General Public
041 *          License along with this library; if not see
042 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
043 */
044public class NoStudentOnlineConflicts extends GlobalConstraint<Lecture, Placement>{
045    private String iOnlineRoom = null;
046    
047    @Override
048    public void setModel(Model<Lecture, Placement> model) {
049        super.setModel(model);
050        if (model != null && model instanceof TimetableModel) {
051            DataProperties config = ((TimetableModel)model).getProperties();
052            iOnlineRoom = config.getProperty("General.OnlineRoom", "(?i)ONLINE|");
053        }
054    }
055
056    @Override
057    public void computeConflicts(Assignment<Lecture, Placement> assignment, Placement placement, Set<Placement> conflicts) {
058        Lecture lecture = placement.variable();
059        for (JenrlConstraint jenrl: lecture.jenrlConstraints()) {
060            if (jenrl.getJenrl() > 0l) {
061                Placement other = assignment.getValue(jenrl.another(lecture));
062                if (isConsistent(placement, other))
063                    conflicts.add(other);
064            }
065        }
066    }
067    
068    @Override
069    public boolean inConflict(Assignment<Lecture, Placement> assignment, Placement placement) {
070        Lecture lecture = placement.variable();
071        for (JenrlConstraint jenrl: lecture.jenrlConstraints()) {
072            if (jenrl.getJenrl() > 0l && isConsistent(placement, assignment.getValue(jenrl.another(lecture))))
073                return true;
074        }
075        return false;
076    }
077
078    @Override
079    public boolean isConsistent(Placement p1, Placement p2) {
080        if (p1 == null || p2 == null) {
081            // at least one class is not assigned > not a problem
082            return false;
083        } else if (p1.getTimeLocation().shareDays(p2.getTimeLocation()) && p1.getTimeLocation().shareWeeks(p2.getTimeLocation())) {
084            return isOnline(p1) != isOnline(p2);
085        } else {
086            // different days > not a problem
087            return false;
088        }
089    }
090    
091    protected boolean isOnline(Placement p) {
092        if (iOnlineRoom == null) return false;
093        // no room -- General.OnlineRoom must allow for a blank string
094        if (p.getNrRooms() == 0)
095            return "".matches(iOnlineRoom);
096        // one room -- room name must match StudentConflict.OnlineRoom
097        if (p.getNrRooms() == 1)
098            return (p.getRoomLocation().getName() != null && p.getRoomLocation().getName().matches(iOnlineRoom));
099        // multiple rooms -- all rooms must match StudentConflict.OnlineRoom
100        for (RoomLocation r: p.getRoomLocations())
101            if (r.getName() == null || !r.getName().matches(iOnlineRoom)) return false;
102        return true;
103    }
104    
105    @Override
106    public String getName() {
107        return "No Student Online Conflicts";
108    }
109    
110    @Override
111    public String toString() {
112        return "No Student Online Conflicts";
113    }
114}