    001package org.cpsolver.studentsct;
    002
    003import java.util.ArrayList;
    004import java.util.Collection;
    005import java.util.Iterator;
    006import java.util.List;
    007import java.util.Set;
    008
    009import org.cpsolver.ifs.assignment.Assignment;
    010import org.cpsolver.ifs.assignment.DefaultSingleAssignment;
    011import org.cpsolver.ifs.model.Model;
    012import org.cpsolver.ifs.model.Neighbour;
    013import org.cpsolver.ifs.solution.Solution;
    014import org.cpsolver.ifs.util.DataProperties;
    015import org.cpsolver.studentsct.constraint.SectionLimit;
    016import org.cpsolver.studentsct.constraint.StudentConflict;
    017import org.cpsolver.studentsct.heuristics.selection.BranchBoundSelection;
    018import org.cpsolver.studentsct.model.Course;
    019import org.cpsolver.studentsct.model.CourseRequest;
    020import org.cpsolver.studentsct.model.Enrollment;
    021import org.cpsolver.studentsct.model.Request;
    022import org.cpsolver.studentsct.model.Student;
    023
    024
    025/**
    026 * Online student sectioning test (using {@link BranchBoundSelection}
    027 * selection). This class is used by the online student sectioning mock-up page. <br>
    028 * <br>
    029 * Usage:
    030 * <pre><code>
    031 * StudentSctBBTest test = new StudentSctBBTest(student); //student already has all his/her requests defined<br>
    032 * Solution sectioningSolution = test.getSolution(); //solution contains only one student (the given one) with his/her schedule<br>
    033 * Vector sectioningMessages = test.getMessages(); //sectioning messages (to be printed in the GUI).
    034 * </code></pre>
    035 *
    036 * @version StudentSct 1.3 (Student Sectioning)<br>
    037 *          Copyright (C) 2007 - 2014 Tomáš Müller<br>
    038 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    039 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    040 * <br>
    041 *          This library is free software; you can redistribute it and/or modify
    042 *          it under the terms of the GNU Lesser General Public License as
    043 *          published by the Free Software Foundation; either version 3 of the
    044 *          License, or (at your option) any later version. <br>
    045 * <br>
    046 *          This library is distributed in the hope that it will be useful, but
    047 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    048 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    049 *          Lesser General Public License for more details. <br>
    050 * <br>
    051 *          You should have received a copy of the GNU Lesser General Public
    052 *          License along with this library; if not see
    053 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    054 */
    055public class StudentSctBBTest extends Model<Request, Enrollment> {
    056    private Student iStudent = null;
    057    private Solution<Request, Enrollment> iSolution = null;
    058    private long iTime;
    059    private boolean iTimeoutReached = false;
    060
    061    /**
    062     * Constructor
    063     *
    064     * @param student
    065     *            a student to be sectioned
    066     */
    067    public StudentSctBBTest(Student student) {
    068        iStudent = student;
    069        for (Request request : iStudent.getRequests())
    070            addVariable(request);
    071        addGlobalConstraint(new SectionLimit(new DataProperties()));
    072        addConstraint(new StudentConflict(student));
    073    }
    074
    075    /** Return the given student
    076     * @return selected student
    077     **/
    078    public Student getStudent() {
    079        return iStudent;
    080    }
    081
    082    /**
    083     * Compute and return the sectioning solution. It contains only the given
    084     * student with his/her schedule
    085     * @return current solution
    086     */
    087    public Solution<Request, Enrollment> getSolution() {
    088        if (iSolution == null) {
    089            iSolution = new Solution<Request, Enrollment>(this, new DefaultSingleAssignment<Request, Enrollment>());
    090            BranchBoundSelection.Selection selection = new BranchBoundSelection(new DataProperties()).getSelection(iSolution.getAssignment(), getStudent());
    091            Neighbour<Request, Enrollment> neighbour = selection.select();
    092            if (neighbour != null)
    093                neighbour.assign(iSolution.getAssignment(), 0);
    094            iTime = selection.getTime();
    095            iTimeoutReached = selection.isTimeoutReached();
    096        }
    097        return iSolution;
    098    }
    099
    100    /**
    101     * Return a list of messages ({@link Message} objects) from the sectioning
    102     * of the given student
    103     * @return enrollment messages
    104     */
    105    public List<Message> getMessages() {
    106        Assignment<Request, Enrollment> assignment = getSolution().getAssignment();
    107        List<Message> ret = new ArrayList<Message>();
    108        ret.add(new Message(Message.sMsgLevelInfo, null, "<li>Solution found in " + iTime + " ms."));
    109        if (iTimeoutReached)
    110            ret.add(new Message(Message.sMsgLevelInfo, null,
    111                    "<li>Time out reached, solution optimality can not be guaranteed."));
    112        for (Request request : getStudent().getRequests()) {
    113            if (!request.isAlternative() && assignment.getValue(request) == null) {
    114                ret.add(new Message(Message.sMsgLevelWarn, request,
    115                        "<li>Unable to enroll to " + request + ", " + (request instanceof CourseRequest ? ((CourseRequest) request).getCourses().size() == 1 ? "course is" : "courses are" : "time is") + " not available."));
    116                Collection<Enrollment> values = (request instanceof CourseRequest ? (Collection<Enrollment>) ((CourseRequest) request).getAvaiableEnrollmentsSkipSameTime(assignment) : request.computeEnrollments(assignment));
    117                for (Iterator<Enrollment> f = values.iterator(); f.hasNext();) {
    118                    Enrollment enrollment = f.next();
    119                    Set<Enrollment> conf = conflictValues(assignment, enrollment);
    120                    if (conf != null && !conf.isEmpty()) {
    121                        Enrollment conflict = conf.iterator().next();
    122                        if (conflict.equals(enrollment))
    123                            ret.add(new Message(Message.sMsgLevelInfo, request, "<ul>Assignment of " + enrollment.getName().replaceAll("\n", "<br>&nbsp;&nbsp;&nbsp;&nbsp;") + "<br> is not available."));
    124                        else
    125                            ret.add(new Message(Message.sMsgLevelInfo, request, "<ul>Assignment of " + enrollment.getName().replaceAll("\n", "<br>&nbsp;&nbsp;&nbsp;&nbsp;") +
    126                                    "<br> conflicts with " + conflict.getName().replaceAll("\n", "<br>&nbsp;&nbsp;&nbsp;&nbsp;") + "</ul>"));
    127                    }
    128                }
    129            }
    130            if (request instanceof CourseRequest && assignment.getValue(request) != null) {
    131                CourseRequest courseRequest = (CourseRequest) request;
    132                Enrollment enrollment = assignment.getValue(request);
    133                List<Enrollment> selectedEnrollments = courseRequest.getSelectedEnrollments(assignment, false);
    134                if (selectedEnrollments != null && !selectedEnrollments.isEmpty()
    135                        && !selectedEnrollments.contains(enrollment)) {
    136                    Course course = (courseRequest.getSelectedChoices().iterator().next()).getOffering().getCourse(
    137                            getStudent());
    138                    Enrollment selected = selectedEnrollments.get(0);
    139                    Set<Enrollment> conf = conflictValues(assignment, selected);
    140                    if (conf != null && !conf.isEmpty()) {
    141                        ret.add(new Message(Message.sMsgLevelWarn, request,
    142                                "<li>Unable to enroll selected enrollment for " + course.getName() + ", seleted " + (courseRequest.getSelectedChoices().size() == 1 ? "class is" : "classes are") +
    143                                " conflicting with other choices."));
    144                        Enrollment conflict = conf.iterator().next();
    145                        if (conflict.equals(selected))
    146                            ret.add(new Message(Message.sMsgLevelInfo, request, "<ul>Assignment of " + selected.getName().replaceAll("\n", "<br>&nbsp;&nbsp;&nbsp;&nbsp;") + "<br> is not available."));
    147                        else
    148                            ret.add(new Message(Message.sMsgLevelInfo, request, "<ul>Assignment of " + selected.getName().replaceAll("\n", "<br>&nbsp;&nbsp;&nbsp;&nbsp;") +
    149                                    "<br> conflicts with " + conflict.getName().replaceAll("\n", "<br>&nbsp;&nbsp;&nbsp;&nbsp;") + "</ul>"));
    150                    } else {
    151                        ret.add(new Message(Message.sMsgLevelWarn, request, "<li>Unable to enroll selected enrollment for " + course.getName() + "."));
    152                    }
    153                }
    154            }
    155        }
    156        return ret;
    157    }
    158
    159    /** Sectioning message */
    160    public static class Message {
    161        /** Message levels */
    162        public static String[] sMsgLevels = { "INFO", "WARN", "ERROR" };
    163        /** Info message level */
    164        public static int sMsgLevelInfo = 0;
    165        /** Warning message level */
    166        public static int sMsgLevelWarn = 1;
    167        /** Error message level */
    168        public static int sMsgLevelError = 2;
    169
    170        private int iLevel;
    171        private Request iRequest;
    172        private String iMessage;
    173
    174        /**
    175         * Constructor
    176         *
    177         * @param level
    178         *            message level (one of
    179         *            {@link StudentSctBBTest.Message#sMsgLevelInfo},
    180         *            {@link StudentSctBBTest.Message#sMsgLevelWarn}, and
    181         *            {@link StudentSctBBTest.Message#sMsgLevelError})
    182         * @param request
    183         *            related course / free time request
    184         * @param message
    185         *            a message
    186         */
    187        public Message(int level, Request request, String message) {
    188            iLevel = level;
    189            iRequest = request;
    190            iMessage = message;
    191        }
    192
    193        /**
    194         * Message level (one of {@link StudentSctBBTest.Message#sMsgLevelInfo},
    195         * {@link StudentSctBBTest.Message#sMsgLevelWarn}, and
    196         * {@link StudentSctBBTest.Message#sMsgLevelError})
    197         * @return message level
    198         */
    199        public int getLevel() {
    200            return iLevel;
    201        }
    202
    203        /** Message level as string
    204         * @return message level
    205         **/
    206        public String getLevelString() {
    207            return sMsgLevels[iLevel];
    208        }
    209
    210        /** Related course / free time request
    211         * @return associated student request
    212         **/
    213        public Request getRequest() {
    214            return iRequest;
    215        }
    216
    217        /** Message
    218         * @return message text
    219         **/
    220        public String getMessage() {
    221            return iMessage;
    222        }
    223
    224        /** String representation (message level: message) */
    225        @Override
    226        public String toString() {
    227            return getLevelString() + ":" + getMessage();
    228        }
    229    }
    230}