    001package org.cpsolver.studentsct.model;
    002
    003import java.text.DecimalFormat;
    004import java.util.ArrayList;
    005import java.util.Collection;
    006import java.util.Collections;
    007import java.util.HashMap;
    008import java.util.HashSet;
    009import java.util.List;
    010import java.util.Map;
    011import java.util.Set;
    012import java.util.TreeSet;
    013
    014import org.cpsolver.coursett.model.TimeLocation;
    015import org.cpsolver.ifs.assignment.Assignment;
    016import org.cpsolver.ifs.assignment.AssignmentComparator;
    017import org.cpsolver.ifs.util.ToolBox;
    018import org.cpsolver.studentsct.StudentSectioningModel;
    019import org.cpsolver.studentsct.constraint.ConfigLimit;
    020import org.cpsolver.studentsct.constraint.CourseLimit;
    021import org.cpsolver.studentsct.constraint.LinkedSections;
    022import org.cpsolver.studentsct.constraint.SectionLimit;
    023import org.cpsolver.studentsct.reservation.Reservation;
    024import org.cpsolver.studentsct.reservation.Restriction;
    025
    026
    027/**
    028 * Representation of a request of a student for one or more course. A student
    029 * requests one of the given courses, preferably the first one. <br>
    030 * <br>
    031 *
    032 * @author  Tomáš Müller
    033 * @version StudentSct 1.3 (Student Sectioning)<br>
    034 *          Copyright (C) 2007 - 2014 Tomáš Müller<br>
    035 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    036 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    037 * <br>
    038 *          This library is free software; you can redistribute it and/or modify
    039 *          it under the terms of the GNU Lesser General Public License as
    040 *          published by the Free Software Foundation; either version 3 of the
    041 *          License, or (at your option) any later version. <br>
    042 * <br>
    043 *          This library is distributed in the hope that it will be useful, but
    044 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    045 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    046 *          Lesser General Public License for more details. <br>
    047 * <br>
    048 *          You should have received a copy of the GNU Lesser General Public
    049 *          License along with this library; if not see
    050 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    051 */
    052public class CourseRequest extends Request {
    053    private static DecimalFormat sDF = new DecimalFormat("0.000");
    054    private List<Course> iCourses = null;
    055    private Set<Choice> iWaitlistedChoices = new HashSet<Choice>();
    056    private Set<Choice> iSelectedChoices = new HashSet<Choice>();
    057    private Set<Choice> iRequiredChoices = new HashSet<Choice>();
    058    private boolean iWaitlist = false;
    059    private Long iTimeStamp = null;
    060    private Double iCachedMinPenalty = null, iCachedMaxPenalty = null;
    061    public static boolean sSameTimePrecise = false;
    062    private Set<RequestGroup> iRequestGroups = new HashSet<RequestGroup>();
    063    private RequestPriority iPriority = RequestPriority.Normal;
    064    private Enrollment iFixed = null;
    065
    066    /**
    067     * Constructor
    068     *
    069     * @param id
    070     *            request unique id
    071     * @param priority
    072     *            request priority
    073     * @param alternative
    074     *            true if the request is alternative (alternative request can be
    075     *            assigned instead of a non-alternative course requests, if it
    076     *            is left unassigned)
    077     * @param student
    078     *            appropriate student
    079     * @param courses
    080     *            list of requested courses (in the correct order -- first is
    081     *            the requested course, second is the first alternative, etc.)
    082     * @param waitlist
    083     *            time stamp of the request if the student can be put on a wait-list (no alternative
    084     *            course request will be given instead)
    085     * @param critical
    086     *            is the course request is critical for the student in order to move forward in their degree
    087     * @param timeStamp request time stamp
    088     */
    089    public CourseRequest(long id, int priority, boolean alternative, Student student, java.util.List<Course> courses, boolean waitlist, boolean critical, Long timeStamp) {
    090        super(id, priority, alternative, student);
    091        iCourses = new ArrayList<Course>(courses);
    092        for (Course course: iCourses)
    093            course.getRequests().add(this);
    094        iWaitlist = waitlist;
    095        iPriority = (critical ? RequestPriority.Critical : RequestPriority.Normal);
    096        iTimeStamp = timeStamp;
    097    }
    098
    099    /**
    100     * Constructor
    101     *
    102     * @param id
    103     *            request unique id
    104     * @param priority
    105     *            request priority
    106     * @param alternative
    107     *            true if the request is alternative (alternative request can be
    108     *            assigned instead of a non-alternative course requests, if it
    109     *            is left unassigned)
    110     * @param student
    111     *            appropriate student
    112     * @param courses
    113     *            list of requested courses (in the correct order -- first is
    114     *            the requested course, second is the first alternative, etc.)
    115     * @param waitlist
    116     *            time stamp of the request if the student can be put on a wait-list (no alternative
    117     *            course request will be given instead)
    118     * @param importance
    119     *            request priority
    120     * @param timeStamp request time stamp
    121     */
    122    public CourseRequest(long id, int priority, boolean alternative, Student student, java.util.List<Course> courses, boolean waitlist, RequestPriority importance, Long timeStamp) {
    123        super(id, priority, alternative, student);
    124        iCourses = new ArrayList<Course>(courses);
    125        for (Course course: iCourses)
    126            course.getRequests().add(this);
    127        iWaitlist = waitlist;
    128        iPriority = importance;
    129        iTimeStamp = timeStamp;
    130    }
    131
    132    /**
    133     * Constructor
    134     *
    135     * @param id
    136     *            request unique id
    137     * @param priority
    138     *            request priority
    139     * @param alternative
    140     *            true if the request is alternative (alternative request can be
    141     *            assigned instead of a non-alternative course requests, if it
    142     *            is left unassigned)
    143     * @param student
    144     *            appropriate student
    145     * @param courses
    146     *            list of requested courses (in the correct order -- first is
    147     *            the requested course, second is the first alternative, etc.)
    148     * @param waitlist
    149     *            time stamp of the request if the student can be put on a wait-list (no alternative
    150     *            course request will be given instead)
    151     * @param timeStamp request time stamp
    152     */
    153    public CourseRequest(long id, int priority, boolean alternative, Student student, java.util.List<Course> courses, boolean waitlist, Long timeStamp) {
    154        this(id, priority, alternative, student, courses, waitlist, false, timeStamp);
    155    }
    156
    157    /**
    158     * List of requested courses (in the correct order -- first is the requested
    159     * course, second is the first alternative, etc.)
    160     * @return requested course offerings
    161     */
    162    public List<Course> getCourses() {
    163        return iCourses;
    164    }
    165
    166    /**
    167     * Create enrollment for the given list of sections. The list of sections
    168     * needs to be correct, i.e., a section for each subpart of a configuration
    169     * of one of the requested courses.
    170     * @param sections selected sections
    171     * @param reservation selected reservation
    172     * @return enrollment
    173     */
    174    public Enrollment createEnrollment(Set<? extends SctAssignment> sections, Reservation reservation) {
    175        if (sections == null || sections.isEmpty())
    176            return null;
    177        Config config = ((Section) sections.iterator().next()).getSubpart().getConfig();
    178        Course course = null;
    179        for (Course c: iCourses) {
    180            if (c.getOffering().getConfigs().contains(config)) {
    181                course = c;
    182                break;
    183            }
    184        }
    185        return new Enrollment(this, iCourses.indexOf(course), course, config, sections, reservation);
    186    }
    187
    188    /**
    189     * Create enrollment for the given list of sections. The list of sections
    190     * needs to be correct, i.e., a section for each subpart of a configuration
    191     * of one of the requested courses.
    192     * @param course selected course
    193     * @param sections selected sections
    194     * @param reservation selected reservation
    195     * @return enrollment
    196     */
    197    public Enrollment createEnrollment(Course course, Set<? extends SctAssignment> sections, Reservation reservation) {
    198        if (sections == null || sections.isEmpty())
    199            return null;
    200        Config config = ((Section) sections.iterator().next()).getSubpart().getConfig();
    201        return new Enrollment(this, iCourses.indexOf(course), course, config, sections, reservation);
    202    }
    203
    204    /**
    205     * Create enrollment for the given list of sections. The list of sections
    206     * needs to be correct, i.e., a section for each subpart of a configuration
    207     * of one of the requested courses.
    208     * @param assignment current assignment (to guess the reservation)
    209     * @param sections selected sections
    210     * @return enrollment
    211     */
    212    public Enrollment createEnrollment(Assignment<Request, Enrollment> assignment, Set<? extends SctAssignment> sections) {
    213        Enrollment ret = createEnrollment(sections, null);
    214        ret.guessReservation(assignment, true);
    215        return ret;
    216
    217    }
    218
    219    /**
    220     * Maximal domain size (i.e., number of enrollments of a course request), -1 if there is no limit.
    221     * @return maximal domain size, -1 if unlimited
    222     */
    223    protected int getMaxDomainSize() {
    224        StudentSectioningModel model = (StudentSectioningModel) getModel();
    225        return model == null ? -1 : model.getMaxDomainSize();
    226    }
    227
    228    /**
    229     * Return all possible enrollments.
    230     */
    231    @Override
    232    public List<Enrollment> computeEnrollments(Assignment<Request, Enrollment> assignment) {
    233        List<Enrollment> ret = new ArrayList<Enrollment>();
    234        if (isFixed()) {
    235            ret.add(getFixedValue());
    236            return ret;
    237        }
    238        if (getInitialAssignment() != null && getModel() != null && ((StudentSectioningModel)getModel()).isMPP() && ((StudentSectioningModel)getModel()).getKeepInitialAssignments()) {
    239            ret.add(getInitialAssignment());
    240            return ret;
    241        }
    242        int idx = 0;
    243        for (Course course : iCourses) {
    244            for (Config config : course.getOffering().getConfigs()) {
    245                computeEnrollments(assignment, ret, idx, 0, course, config, new HashSet<Section>(), 0, false, false,
    246                        false, false, getMaxDomainSize() <= 0 ? -1 : ret.size() + getMaxDomainSize());
    247            }
    248            idx++;
    249        }
    250        return ret;
    251    }
    252
    253    /**
    254     * Return a subset of all enrollments -- randomly select only up to
    255     * limitEachConfig enrollments of each config.
    256     * @param assignment current assignment
    257     * @param limitEachConfig maximal number of enrollments in each configuration
    258     * @return computed enrollments
    259     */
    260    public List<Enrollment> computeRandomEnrollments(Assignment<Request, Enrollment> assignment, int limitEachConfig) {
    261        List<Enrollment> ret = new ArrayList<Enrollment>();
    262        if (isFixed()) {
    263            ret.add(getFixedValue());
    264            return ret;
    265        }
    266        if (getInitialAssignment() != null && getModel() != null && ((StudentSectioningModel)getModel()).isMPP() && ((StudentSectioningModel)getModel()).getKeepInitialAssignments()) {
    267            ret.add(getInitialAssignment());
    268            return ret;
    269        }
    270        int idx = 0;
    271        for (Course course : iCourses) {
    272            for (Config config : course.getOffering().getConfigs()) {
    273                computeEnrollments(assignment, ret, idx, 0, course, config, new HashSet<Section>(), 0, false, false,
    274                        false, true, (limitEachConfig <= 0 ? limitEachConfig : ret.size() + limitEachConfig));
    275            }
    276            idx++;
    277        }
    278        return ret;
    279    }
    280
    281    /**
    282     * Return true if the both sets of sections contain sections of the same
    283     * subparts, and each pair of sections of the same subpart is offered at the
    284     * same time.
    285     */
    286    private boolean sameTimes(Set<Section> sections1, Set<Section> sections2) {
    287        for (Section s1 : sections1) {
    288            Section s2 = null;
    289            for (Section s : sections2) {
    290                if (s.getSubpart().equals(s1.getSubpart())) {
    291                    s2 = s;
    292                    break;
    293                }
    294            }
    295            if (s2 == null)
    296                return false;
    297            if (!ToolBox.equals(s1.getTime(), s2.getTime()))
    298                return false;
    299        }
    300        return true;
    301    }
    302
    303    /**
    304     * Recursive computation of enrollments
    305     *
    306     * @param enrollments
    307     *            list of enrollments to be returned
    308     * @param priority
    309     *            zero for the course, one for the first alternative, two for the second alternative
    310     * @param penalty
    311     *            penalty of the selected sections
    312     * @param course
    313     *            selected course
    314     * @param config
    315     *            selected configuration
    316     * @param sections
    317     *            sections selected so far
    318     * @param idx
    319     *            index of the subparts (a section of 0..idx-1 subparts has been
    320     *            already selected)
    321     * @param availableOnly
    322     *            only use available sections
    323     * @param skipSameTime
    324     *            for each possible times, pick only one section
    325     * @param selectedOnly
    326     *            select only sections that are selected (
    327     *            {@link CourseRequest#isSelected(Section)} is true)
    328     * @param random
    329     *            pick sections in a random order (useful when limit is used)
    330     * @param limit
    331     *            when above zero, limit the number of selected enrollments to
    332     *            this limit
    333     * @param ignoreDisabled
    334     *            are sections that are disabled for student scheduling allowed to be used
    335     * @param reservations
    336     *            list of applicable reservations
    337     */
    338    private void computeEnrollments(Assignment<Request, Enrollment> assignment, Collection<Enrollment> enrollments, int priority, double penalty, Course course, Config config,
    339            HashSet<Section> sections, int idx, boolean availableOnly, boolean skipSameTime, boolean selectedOnly,
    340            boolean random, int limit) {
    341        if (limit > 0 && enrollments.size() >= limit)
    342            return;
    343        if (availableOnly && course.hasParent()) {
    344            Course parent = course.getParent();
    345            for (Request r: getStudent().getRequests()) {
    346                if (r.hasCourse(parent)) {
    347                    Enrollment e = assignment.getValue(r);
    348                    if (e == null || !parent.equals(e.getCourse())) return;
    349                }
    350            }
    351        }
    352        if (idx == 0) { // run only once for each configuration
    353            if (isNotAllowed(course, config)) return;
    354            boolean canOverLimit = false;
    355            if (availableOnly) {
    356                for (Reservation r: getReservations(course)) {
    357                    if (!r.canBatchAssignOverLimit()) continue;
    358                    if (r.neverIncluded()) continue;
    359                    if (!r.getConfigs().isEmpty() && !r.getConfigs().contains(config)) continue;
    360                    if (r.getReservedAvailableSpace(assignment, this) < getWeight()) continue;
    361                    if (r.getReservedAvailableSpace(assignment, config, this) < getWeight()) continue;
    362                    canOverLimit = true; break;
    363                }
    364            }
    365            if (!canOverLimit) {
    366                if (availableOnly && config.getLimit() >= 0 && ConfigLimit.getEnrollmentWeight(assignment, config, this) > config.getLimit())
    367                    return;
    368                if (availableOnly && course.getLimit() >= 0 && CourseLimit.getEnrollmentWeight(assignment, course, this) > course.getLimit())
    369                    return;
    370                if (config.getOffering().hasReservations()) {
    371                    boolean hasReservation = false, hasConfigReservation = false, reservationMustBeUsed = false;
    372                    for (Reservation r: getReservations(course)) {
    373                        if (r.mustBeUsed()) reservationMustBeUsed = true;
    374                        if (availableOnly && r.getReservedAvailableSpace(assignment, this) < getWeight()) continue;
    375                        if (availableOnly && r.getReservedAvailableSpace(assignment, config, this) < getWeight()) continue;
    376                        if (r.neverIncluded()) {
    377                        } else if (r.getConfigs().isEmpty()) {
    378                            hasReservation = true;
    379                        } else if (r.getConfigs().contains(config)) {
    380                            hasReservation = true;
    381                            hasConfigReservation = true;
    382                        } else if (!r.areRestrictionsInclusive()) {
    383                            hasReservation = true;
    384                        }
    385                    }
    386                    if (!hasConfigReservation && config.getTotalUnreservedSpace() < getWeight())
    387                        return;
    388                    if (!hasReservation && config.getOffering().getTotalUnreservedSpace() < getWeight())
    389                        return;
    390                    if (availableOnly && !hasReservation && config.getOffering().getUnreservedSpace(assignment, this) < getWeight())
    391                        return;
    392                    if (availableOnly && !hasConfigReservation && config.getUnreservedSpace(assignment, this) < getWeight())
    393                        return;
    394                    if (!hasReservation && reservationMustBeUsed)
    395                        return;
    396                }
    397            }
    398        }
    399        if (config.getSubparts().size() == idx) {
    400            if (skipSameTime && sSameTimePrecise) {
    401                boolean waitListedOrSelected = false;
    402                if (!getSelectedChoices().isEmpty() || !getWaitlistedChoices().isEmpty()) {
    403                    for (Section section : sections) {
    404                        if (isWaitlisted(section) || isSelected(section)) {
    405                            waitListedOrSelected = true;
    406                            break;
    407                        }
    408                    }
    409                }
    410                if (!waitListedOrSelected) {
    411                    for (Enrollment enrollment : enrollments) {
    412                        if (sameTimes(enrollment.getSections(), sections))
    413                            return;
    414                    }
    415                }
    416            }
    417            Enrollment e = new Enrollment(this, priority, course, config, new HashSet<SctAssignment>(sections), null);
    418            if (isNotAllowed(e)) {
    419            } else if (!config.getOffering().hasReservations()) {
    420                enrollments.add(e);
    421            } else {
    422                boolean mustHaveReservation = config.getOffering().getTotalUnreservedSpace() < getWeight();
    423                boolean mustHaveConfigReservation = config.getTotalUnreservedSpace() < getWeight();
    424                boolean mustHaveSectionReservation = false;
    425                boolean containDisabledSection = false;
    426                for (Section s: sections) {
    427                    if (s.getTotalUnreservedSpace() < getWeight()) {
    428                        mustHaveSectionReservation = true;
    429                    }
    430                    if (!getStudent().isAllowDisabled() && !s.isEnabled(getStudent())) {
    431                        containDisabledSection = true;
    432                    }
    433                }
    434                boolean canOverLimit = false;
    435                if (availableOnly) {
    436                    for (Reservation r: getReservations(course)) {
    437                        if (!r.canBatchAssignOverLimit() || !r.isIncluded(e)) continue;
    438                        if (r.getReservedAvailableSpace(assignment, config, this) < getWeight()) continue;
    439                        if (containDisabledSection && !r.isAllowDisabled()) continue;
    440                        enrollments.add(new Enrollment(this, priority, null, config, new HashSet<SctAssignment>(sections), r));
    441                        canOverLimit = true;
    442                    }
    443                }
    444                if (!canOverLimit) {
    445                    boolean reservationMustBeUsed = false;
    446                    reservations: for (Reservation r: (availableOnly ? getSortedReservations(assignment, course) : getReservations(course))) {
    447                        if (r.mustBeUsed()) reservationMustBeUsed = true;
    448                        if (!r.isIncluded(e)) continue;
    449                        if (availableOnly && r.getReservedAvailableSpace(assignment, config, this) < getWeight()) continue;
    450                        if (mustHaveConfigReservation && r.getConfigs().isEmpty()) continue;
    451                        if (mustHaveSectionReservation)
    452                            for (Section s: sections)
    453                                if (r.getSections(s.getSubpart()) == null && s.getTotalUnreservedSpace() < getWeight()) continue reservations;
    454                        if (containDisabledSection && !r.isAllowDisabled()) continue;
    455                        enrollments.add(new Enrollment(this, priority, null, config, new HashSet<SctAssignment>(sections), r));
    456                        if (availableOnly) return; // only one available reservation suffice (the best matching one)
    457                    }
    458                    // a case w/o reservation
    459                    if (!(mustHaveReservation || mustHaveConfigReservation || mustHaveSectionReservation) &&
    460                        !(availableOnly && config.getOffering().getUnreservedSpace(assignment, this) < getWeight()) &&
    461                        !reservationMustBeUsed && !containDisabledSection) {
    462                        enrollments.add(new Enrollment(this, priority, !getReservations(course).isEmpty(), null, config, new HashSet<SctAssignment>(sections), null));
    463                    }
    464                }
    465            }
    466        } else {
    467            Subpart subpart = config.getSubparts().get(idx);
    468            HashSet<TimeLocation> times = (skipSameTime ? new HashSet<TimeLocation>() : null);
    469            List<Section> sectionsThisSubpart = subpart.getSections();
    470            if (skipSameTime) {
    471                sectionsThisSubpart = new ArrayList<Section>(subpart.getSections());
    472                Collections.sort(sectionsThisSubpart, new AssignmentComparator<Section, Request, Enrollment>(assignment));
    473            }
    474            List<Section> matchingSectionsThisSubpart = new ArrayList<Section>(subpart.getSections().size());
    475            boolean hasChildren = !subpart.getChildren().isEmpty();
    476            for (Section section : sectionsThisSubpart) {
    477                if (section.isCancelled())
    478                    continue;
    479                if (!isRequired(section))
    480                    continue;
    481                if (getInitialAssignment() != null && (getModel() != null && ((StudentSectioningModel)getModel()).getKeepInitialAssignments()) &&
    482                        !getInitialAssignment().getAssignments().contains(section))
    483                    continue;
    484                if (isFixed() && !getFixedValue().getAssignments().contains(section))
    485                    continue;
    486                if (section.getParent() != null && !sections.contains(section.getParent()))
    487                    continue;
    488                if (section.isOverlapping(sections))
    489                    continue;
    490                if (selectedOnly && hasSelection(section) && !isSelected(section))
    491                    continue;
    492                if (isNotAllowed(course, section))
    493                    continue;
    494                if (!getStudent().isAvailable(section)) {
    495                    boolean canOverlap = false;
    496                    for (Reservation r: getReservations(course)) {
    497                        if (!r.isAllowOverlap()) continue;
    498                        if (r.getSections(subpart) != null && !r.getSections(subpart).contains(section)) continue;
    499                        if (r.getReservedAvailableSpace(assignment, config, this) < getWeight()) continue;
    500                        canOverlap = true; break;
    501                    }
    502                    if (!canOverlap) continue;
    503                }
    504                boolean canOverLimit = false;
    505                if (availableOnly) {
    506                    for (Reservation r: getReservations(course)) {
    507                        if (!r.canBatchAssignOverLimit()) continue;
    508                        if (r.getSections(subpart) != null && !r.getSections(subpart).contains(section)) continue;
    509                        if (r.getReservedAvailableSpace(assignment, config, this) < getWeight()) continue;
    510                        canOverLimit = true; break;
    511                    }
    512                }
    513                if (!canOverLimit) {
    514                    if (availableOnly && section.getLimit() >= 0
    515                            && SectionLimit.getEnrollmentWeight(assignment, section, this) > section.getLimit())
    516                        continue;
    517                    if (config.getOffering().hasReservations()) {
    518                        boolean hasReservation = false, hasSectionReservation = false, reservationMustBeUsed = false;
    519                        for (Reservation r: getReservations(course)) {
    520                            if (r.mustBeUsed()) reservationMustBeUsed = true;
    521                            if (availableOnly && r.getReservedAvailableSpace(assignment, config, this) < getWeight()) continue;
    522                            if (r.getSections(subpart) == null) {
    523                                hasReservation = true;
    524                            } else if (r.getSections(subpart).contains(section)) {
    525                                hasReservation = true;
    526                                hasSectionReservation = true;
    527                            }
    528                        }
    529                        if (!hasSectionReservation && section.getTotalUnreservedSpace() < getWeight())
    530                            continue;
    531                        if (availableOnly && !hasSectionReservation && section.getUnreservedSpace(assignment, this) < getWeight())
    532                            continue;
    533                        if (!hasReservation && reservationMustBeUsed)
    534                            continue;
    535                    }
    536                }
    537                if (!getStudent().isAllowDisabled() && !section.isEnabled(getStudent())) {
    538                    boolean allowDisabled = false;
    539                    for (Reservation r: getReservations(course)) {
    540                        if (!r.isAllowDisabled()) continue;
    541                        if (r.getSections(subpart) != null && !r.getSections(subpart).contains(section)) continue;
    542                        if (!r.getConfigs().isEmpty() && !r.getConfigs().contains(config)) continue;
    543                        allowDisabled = true; break;
    544                    }
    545                    if (!allowDisabled) continue;
    546                }
    547                if (skipSameTime && section.getTime() != null && !hasChildren && !times.add(section.getTime()) && !isSelected(section) && !isWaitlisted(section) &&
    548                        (section.getIgnoreConflictWithSectionIds() == null || section.getIgnoreConflictWithSectionIds().isEmpty()))
    549                    continue;
    550                matchingSectionsThisSubpart.add(section);
    551            }
    552            if (random || limit > 0) {
    553                sectionsThisSubpart = new ArrayList<Section>(sectionsThisSubpart);
    554                Collections.shuffle(sectionsThisSubpart);
    555            }
    556            int i = 0;
    557            for (Section section: matchingSectionsThisSubpart) {
    558                sections.add(section);
    559                computeEnrollments(assignment, enrollments, priority, penalty + section.getPenalty(), course, config, sections, idx + 1,
    560                        availableOnly, skipSameTime, selectedOnly, random,
    561                        limit < 0 ? limit : Math.max(1, limit * (1 + i) / matchingSectionsThisSubpart.size()));
    562                sections.remove(section);
    563                i++;
    564            }
    565        }
    566    }
    567
    568    /** Return all enrollments that are available
    569     * @param assignment current assignment
    570     * @return all available enrollments
    571     **/
    572    public List<Enrollment> getAvaiableEnrollments(Assignment<Request, Enrollment> assignment) {
    573        List<Enrollment> ret = new ArrayList<Enrollment>();
    574        if (isFixed()) {
    575            ret.add(getFixedValue());
    576            return ret;
    577        }
    578        if (getInitialAssignment() != null && getModel() != null && ((StudentSectioningModel)getModel()).isMPP() && ((StudentSectioningModel)getModel()).getKeepInitialAssignments()) {
    579            ret.add(getInitialAssignment());
    580            return ret;
    581        }
    582        int idx = 0;
    583        for (Course course : iCourses) {
    584            for (Config config : course.getOffering().getConfigs()) {
    585                computeEnrollments(assignment, ret, idx, 0, course, config, new HashSet<Section>(), 0, true, false, false, false,
    586                        getMaxDomainSize() <= 0 ? -1 : ret.size() + getMaxDomainSize());
    587            }
    588            idx++;
    589        }
    590        return ret;
    591    }
    592
    593    /**
    594     * Return all enrollments of the first course that are selected (
    595     * {@link CourseRequest#isSelected(Section)} is true)
    596     *
    597     * @param assignment current assignment
    598     * @param availableOnly
    599     *            pick only available sections
    600     * @return selected enrollments
    601     */
    602    public List<Enrollment> getSelectedEnrollments(Assignment<Request, Enrollment> assignment, boolean availableOnly) {
    603        if (getSelectedChoices().isEmpty())
    604            return null;
    605        List<Enrollment> enrollments = new ArrayList<Enrollment>();
    606        if (isFixed()) return enrollments;
    607        if (getInitialAssignment() != null && getModel() != null && ((StudentSectioningModel)getModel()).isMPP() && ((StudentSectioningModel)getModel()).getKeepInitialAssignments())
    608            return enrollments;
    609        for (Course course : iCourses) {
    610            boolean hasChoice = false;
    611            for (Choice choice: getSelectedChoices())
    612                if (course.getOffering().equals(choice.getOffering())) { hasChoice = true; break; }
    613            if (hasChoice)
    614                for (Config config : course.getOffering().getConfigs()) {
    615                    computeEnrollments(assignment, enrollments, 0, 0, course, config, new HashSet<Section>(), 0, availableOnly, false, true, false, -1);
    616                }
    617            break;
    618        }
    619        return enrollments;
    620    }
    621
    622    /**
    623     * Return all enrollments that are available, pick only the first section of
    624     * the sections with the same time (of each subpart, {@link Section}
    625     * comparator is used)
    626     * @param assignment current assignment
    627     * @return available enrollments
    628     */
    629    public List<Enrollment> getAvaiableEnrollmentsSkipSameTime(Assignment<Request, Enrollment> assignment) {
    630        List<Enrollment> ret = new ArrayList<Enrollment>();
    631        if (isFixed()) {
    632            ret.add(getFixedValue());
    633            return ret;
    634        }
    635        if (getInitialAssignment() != null) {
    636            ret.add(getInitialAssignment());
    637            if (getModel() != null && ((StudentSectioningModel)getModel()).isMPP() && ((StudentSectioningModel)getModel()).getKeepInitialAssignments())
    638                return ret;
    639        }
    640        int idx = 0;
    641        for (Course course : iCourses) {
    642            boolean skipSameTime = true;
    643            for (LinkedSections link: getStudent().getLinkedSections())
    644                if (link.getOfferings().contains(course.getOffering())) { skipSameTime = false; break; }
    645            for (Config config : course.getOffering().getConfigs()) {
    646                computeEnrollments(assignment, ret, idx, 0, course, config, new HashSet<Section>(), 0, true, skipSameTime, false, false,
    647                        getMaxDomainSize() <= 0 ? -1 : ret.size() + getMaxDomainSize());
    648            }
    649            idx++;
    650        }
    651        return ret;
    652    }
    653
    654    /**
    655     * Return all possible enrollments, but pick only the first section of
    656     * the sections with the same time (of each subpart, {@link Section}
    657     * comparator is used).
    658     * @param assignment current assignment
    659     * @return computed enrollments
    660     */
    661    public List<Enrollment> getEnrollmentsSkipSameTime(Assignment<Request, Enrollment> assignment) {
    662        List<Enrollment> ret = new ArrayList<Enrollment>();
    663        if (isFixed()) {
    664            ret.add(getFixedValue());
    665            return ret;
    666        }
    667        if (getInitialAssignment() != null) {
    668            ret.add(getInitialAssignment());
    669            if (getModel() != null && ((StudentSectioningModel)getModel()).isMPP() && ((StudentSectioningModel)getModel()).getKeepInitialAssignments())
    670                return ret;
    671        }
    672        int idx = 0;
    673        for (Course course : iCourses) {
    674            for (Config config : course.getOffering().getConfigs()) {
    675                boolean skipSameTime = true;
    676                for (LinkedSections link: getStudent().getLinkedSections())
    677                    if (link.getOfferings().contains(course.getOffering())) { skipSameTime = false; break; }
    678                computeEnrollments(assignment, ret, idx, 0, course, config, new HashSet<Section>(), 0, false, skipSameTime, false, false,
    679                        getMaxDomainSize() <= 0 ? -1 : ret.size() + getMaxDomainSize());
    680            }
    681            idx++;
    682        }
    683        return ret;
    684    }
    685
    686    /** Wait-listed choices
    687     * @return wait-listed choices
    688     **/
    689    public Set<Choice> getWaitlistedChoices() {
    690        return iWaitlistedChoices;
    691    }
    692
    693    /**
    694     * Return true when the given section is wait-listed (i.e., its choice is
    695     * among wait-listed choices)
    696     * @param section given section
    697     * @return true if the given section matches the wait-listed choices
    698     */
    699    public boolean isWaitlisted(Section section) {
    700        for (Choice choice: iWaitlistedChoices)
    701            if (choice.sameChoice(section)) return true;
    702        return false;
    703    }
    704
    705    /** Selected choices
    706     * @return selected choices
    707     **/
    708    public Set<Choice> getSelectedChoices() {
    709        return iSelectedChoices;
    710    }
    711
    712    /**
    713     * Return true when the given section is selected (i.e., its choice is among
    714     * selected choices)
    715     * @param section given section
    716     * @return true if the given section matches the selected choices
    717     */
    718    public boolean isSelected(Section section) {
    719        for (Choice choice: iSelectedChoices)
    720            if (choice.sameSection(section) || choice.sameConfiguration(section)) return true;
    721        return false;
    722    }
    723
    724    /**
    725     * Return true when the given section has a preference (i.e., there is a matching selection),
    726     * or when there is a section preference for a different configuration
    727     * @param section given section
    728     * @return true if the there is a matching choice for the given section that is of the same offering
    729     */
    730    public boolean hasSelection(Section section) {
    731        boolean hasSectionChoices = false, hasSectionChoicesThisConfig = false;
    732        for (Choice choice: iSelectedChoices) {
    733            if (choice.sameOffering(section)) {
    734                if (choice.isMatching(section)) return true;
    735                if (choice.getSubpartId() != null) {
    736                    hasSectionChoices = true;
    737                    for (Subpart subpart: section.getSubpart().getConfig().getSubparts()) {
    738                        if (choice.getSubpartId().equals(subpart.getId())) { hasSectionChoicesThisConfig = true; }
    739                    }
    740                }
    741            }
    742        }
    743        return (hasSectionChoices && !hasSectionChoicesThisConfig);
    744    }
    745
    746    /**
    747     * Required choices
    748     * @return required choices
    749     */
    750    public Set<Choice> getRequiredChoices() {
    751        return iRequiredChoices;
    752    }
    753
    754    /**
    755     * Return true when the given section is required (i.e., its choice is among required choices, or there are no requirements)
    756     * @param section given section
    757     * @return true if the given section matches the required choices
    758     */
    759    public boolean isRequired(Section section) {
    760        if (iRequiredChoices.isEmpty()) return true;
    761        boolean hasConfig = false, hasMatchingConfig = false;
    762        boolean hasSubpart = false, hasMatchingSection = false;
    763        boolean hasSectionReq = false;
    764        for (Choice choice: iRequiredChoices) {
    765            // different offering -> skip
    766            if (!choice.getOffering().equals(section.getSubpart().getConfig().getOffering())) continue;
    767            // has config -> check config
    768            if (choice.getConfigId() != null) {
    769                hasConfig = true;
    770                if (choice.sameConfiguration(section)) hasMatchingConfig = true;
    771            }
    772            // has section of the matching subpart -> check section
    773            if (choice.getSubpartId() != null) {
    774                hasSectionReq = true;
    775                if (choice.getSubpartId().equals(section.getSubpart().getId())) {
    776                    hasSubpart = true;
    777                    if (choice.sameSection(section)) hasMatchingSection = true;
    778                } else if (!hasMatchingConfig) {
    779                    for (Subpart subpart: section.getSubpart().getConfig().getSubparts()) {
    780                        if (choice.getSubpartId().equals(subpart.getId())) {
    781                            hasMatchingConfig = true;
    782                            break;
    783                        }
    784                    }
    785                }
    786            }
    787        }
    788        if (hasConfig && !hasMatchingConfig) return false;
    789        if (hasSubpart && !hasMatchingSection) return false;
    790        // no match, but there are section requirements for a different config -> not satisfied
    791        if (!hasMatchingConfig && !hasMatchingSection && hasSectionReq) return false;
    792        return true;
    793    }
    794
    795    /**
    796     * Request name: A for alternative, 1 + priority, (w) when wait-list, list of
    797     * course names
    798     */
    799    @Override
    800    public String getName() {
    801        String ret = (isAlternative() ? "A" : "")
    802                + (1 + getPriority() + (isAlternative() ? -getStudent().nrRequests() : 0)) + ". "
    803                + (getRequestPriority() != RequestPriority.Normal ?
    804                  (isWaitlist() ? "(" + getRequestPriority().getAbbreviation() + "w) " : "(" + getRequestPriority().getAbbreviation() + ") ")
    805                  : isWaitlist() ? "(w) " : "");
    806        int idx = 0;
    807        for (Course course : iCourses) {
    808            if (idx == 0)
    809                ret += course.getName();
    810            else
    811                ret += ", " + idx + ". alt " + course.getName();
    812            idx++;
    813        }
    814        if (getStudent().getExternalId() != null)
    815            ret = "[" + getStudent().getExternalId() + "] " + ret;
    816        return ret;
    817    }
    818
    819    /**
    820     * True if the student can be put on a wait-list (no alternative course
    821     * request will be given instead)
    822     * @return true if the request can be wait-listed
    823     */
    824    public boolean isWaitlist() {
    825        return iWaitlist;
    826    }
    827
    828    /**
    829     * True if the student can be put on a wait-list (no alternative course
    830     * request will be given instead)
    831     * @param waitlist true if the request can be wait-listed
    832     */
    833    public void setWaitlist(boolean waitlist) {
    834        iWaitlist = waitlist;
    835    }
    836
    837    /**
    838     * True if the course request is critical for the student in order to move forward in their degree
    839     * @param critical true if the request is critical
    840     */
    841    @Deprecated
    842    public void setCritical(boolean critical) {
    843        iPriority = (critical ? RequestPriority.Critical : RequestPriority.Normal);
    844    }
    845
    846    /**
    847     * Time stamp of the request
    848     * @return request time stamp
    849     */
    850    public Long getTimeStamp() {
    851        return iTimeStamp;
    852    }
    853
    854    @Override
    855    public String toString() {
    856        return getName() + (getWeight() != 1.0 ? " (W:" + sDF.format(getWeight()) + ")" : "");
    857    }
    858
    859    /** Return course of the requested courses with the given id
    860     * @param courseId course offering id
    861     * @return course of the given id
    862     **/
    863    public Course getCourse(long courseId) {
    864        for (Course course : iCourses) {
    865            if (course.getId() == courseId)
    866                return course;
    867        }
    868        return null;
    869    }
    870
    871    /** Return configuration of the requested courses with the given id
    872     * @param configId instructional offering configuration unique id
    873     * @return config of the given id
    874     **/
    875    public Config getConfig(long configId) {
    876        for (Course course : iCourses) {
    877            for (Config config : course.getOffering().getConfigs()) {
    878                if (config.getId() == configId)
    879                    return config;
    880            }
    881        }
    882        return null;
    883    }
    884
    885    /** Return subpart of the requested courses with the given id
    886     * @param subpartId scheduling subpart unique id
    887     * @return subpart of the given id
    888     **/
    889    public Subpart getSubpart(long subpartId) {
    890        for (Course course : iCourses) {
    891            for (Config config : course.getOffering().getConfigs()) {
    892                for (Subpart subpart : config.getSubparts()) {
    893                    if (subpart.getId() == subpartId)
    894                        return subpart;
    895                }
    896            }
    897        }
    898        return null;
    899    }
    900
    901    /** Return section of the requested courses with the given id
    902     * @param sectionId class unique id
    903     * @return section of the given id
    904     **/
    905    public Section getSection(long sectionId) {
    906        for (Course course : iCourses) {
    907            for (Config config : course.getOffering().getConfigs()) {
    908                for (Subpart subpart : config.getSubparts()) {
    909                    for (Section section : subpart.getSections()) {
    910                        if (section.getId() == sectionId)
    911                            return section;
    912                    }
    913                }
    914            }
    915        }
    916        return null;
    917    }
    918
    919    /**
    920     * Minimal penalty (minimum of {@link Offering#getMinPenalty()} among
    921     * requested courses)
    922     * @return minimal penalty
    923     */
    924    public double getMinPenalty() {
    925        if (iCachedMinPenalty == null) {
    926            double min = Double.MAX_VALUE;
    927            for (Course course : iCourses) {
    928                min = Math.min(min, course.getOffering().getMinPenalty());
    929            }
    930            iCachedMinPenalty = Double.valueOf(min);
    931        }
    932        return iCachedMinPenalty.doubleValue();
    933    }
    934
    935    /**
    936     * Maximal penalty (maximum of {@link Offering#getMaxPenalty()} among
    937     * requested courses)
    938     * @return maximal penalty
    939     */
    940    public double getMaxPenalty() {
    941        if (iCachedMaxPenalty == null) {
    942            double max = Double.MIN_VALUE;
    943            for (Course course : iCourses) {
    944                max = Math.max(max, course.getOffering().getMaxPenalty());
    945            }
    946            iCachedMaxPenalty = Double.valueOf(max);
    947        }
    948        return iCachedMaxPenalty.doubleValue();
    949    }
    950
    951    /** Clear cached min/max penalties and cached bound */
    952    public void clearCache() {
    953        iCachedMaxPenalty = null;
    954        iCachedMinPenalty = null;
    955    }
    956
    957    /**
    958     * Estimated bound for this request -- it estimates the smallest value among
    959     * all possible enrollments
    960     */
    961    @Override
    962    public double getBound() {
    963        return - getWeight() * ((StudentSectioningModel)getModel()).getStudentWeights().getBound(this);
    964        /*
    965        if (iCachedBound == null) {
    966            iCachedBound = Double.valueOf(-Math.pow(Enrollment.sPriorityWeight, getPriority())
    967                    * (isAlternative() ? Enrollment.sAlterativeWeight : 1.0)
    968                    * Math.pow(Enrollment.sInitialWeight, (getInitialAssignment() == null ? 0 : 1))
    969                    * Math.pow(Enrollment.sSelectedWeight, (iSelectedChoices.isEmpty() ? 0 : 1))
    970                    * Math.pow(Enrollment.sWaitlistedWeight, (iWaitlistedChoices.isEmpty() ? 0 : 1))
    971                    *
    972                    // Math.max(Enrollment.sMinWeight,getWeight()) *
    973                    (getStudent().isDummy() ? Student.sDummyStudentWeight : 1.0)
    974                    * Enrollment.normalizePenalty(getMinPenalty()));
    975        }
    976        return iCachedBound.doubleValue();
    977        */
    978    }
    979
    980    /** Return true if request is assigned. */
    981    @Override
    982    public boolean isAssigned(Assignment<Request, Enrollment> assignment) {
    983        Enrollment e = assignment.getValue(this);
    984        return e != null && !e.getAssignments().isEmpty();
    985    }
    986
    987    @Override
    988    public boolean equals(Object o) {
    989        return super.equals(o) && (o instanceof CourseRequest);
    990    }
    991
    992    /**
    993     * Get reservations for this course requests
    994     * @param course given course
    995     * @return reservations for this course requests and the given course
    996     */
    997    public synchronized List<Reservation> getReservations(Course course) {
    998        if (iReservations == null)
    999            iReservations = new HashMap<Course, List<Reservation>>();
    1000        List<Reservation> reservations = iReservations.get(course);
    1001        if (reservations == null) {
    1002            reservations = new ArrayList<Reservation>();
    1003            boolean mustBeUsed = false;
    1004            for (Reservation r: course.getOffering().getReservations()) {
    1005                if (!r.isApplicable(getStudent())) continue;
    1006                if (!mustBeUsed && r.mustBeUsed()) { reservations.clear(); mustBeUsed = true; }
    1007                if (mustBeUsed && !r.mustBeUsed()) continue;
    1008                reservations.add(r);
    1009            }
    1010            iReservations.put(course, reservations);
    1011        }
    1012        return reservations;
    1013    }
    1014    private Map<Course, List<Reservation>> iReservations = null;
    1015
    1016    /**
    1017     * Get reservations for this course requests ordered using {@link Reservation#compareTo(Assignment, Reservation)}
    1018     * @param course given course
    1019     * @return reservations for this course requests and the given course
    1020     */
    1021    public TreeSet<Reservation> getSortedReservations(Assignment<Request, Enrollment> assignment, Course course) {
    1022        TreeSet<Reservation> reservations = new TreeSet<Reservation>(new AssignmentComparator<Reservation, Request, Enrollment>(assignment));
    1023        reservations.addAll(getReservations(course));
    1024        return reservations;
    1025    }
    1026
    1027    /**
    1028     * Return true if there is a reservation for a course of this request
    1029     * @return true if there is a reservation for a course of this request
    1030     */
    1031    public boolean hasReservations() {
    1032        for (Course course: getCourses())
    1033            if (!getReservations(course).isEmpty())
    1034                return true;
    1035        return false;
    1036    }
    1037
    1038    /**
    1039     * Clear reservation information that was cached on this section
    1040     */
    1041    public synchronized void clearReservationCache() {
    1042        if (iReservations != null) iReservations.clear();
    1043    }
    1044
    1045    /**
    1046     * Get restrictions for this course requests
    1047     * @param course given course
    1048     * @return restrictions for this course requests and the given course
    1049     */
    1050    public synchronized List<Restriction> getRestrictions(Course course) {
    1051        if (iRestrictions == null)
    1052            iRestrictions = new HashMap<Course, List<Restriction>>();
    1053        List<Restriction> restrictions = iRestrictions.get(course);
    1054        if (restrictions == null) {
    1055            restrictions = new ArrayList<Restriction>();
    1056            for (Restriction r: course.getOffering().getRestrictions()) {
    1057                if (r.isApplicable(getStudent()))
    1058                    restrictions.add(r);
    1059            }
    1060            iRestrictions.put(course, restrictions);
    1061        }
    1062        return restrictions;
    1063    }
    1064    private Map<Course, List<Restriction>> iRestrictions = null;
    1065
    1066    /**
    1067     * Return true if there is a restriction for a course of this request
    1068     * @return true if there is a restriction for a course of this request
    1069     */
    1070    public boolean hasRestrictions(Course course) {
    1071        return !getRestrictions(course).isEmpty();
    1072    }
    1073
    1074    /**
    1075     * Return true when there are restrictions for a course of this course request and the given config does not meet any of them
    1076     */
    1077    public boolean isNotAllowed(Course course, Config config) {
    1078        List<Restriction> restrictions = getRestrictions(course);
    1079        if (restrictions.isEmpty()) return false;
    1080        for (Restriction r: restrictions)
    1081            if (r.isIncluded(config)) return false;
    1082        return true;
    1083    }
    1084
    1085    /**
    1086     * Return true when there are restrictions for a course of this course request and the given section does not meet any of them
    1087     */
    1088    public boolean isNotAllowed(Course course, Section section) {
    1089        List<Restriction> restrictions = getRestrictions(course);
    1090        if (restrictions.isEmpty()) return false;
    1091        for (Restriction r: restrictions)
    1092            if (r.isIncluded(section)) return false;
    1093        return true;
    1094    }
    1095
    1096    /**
    1097     * Return true when there are restrictions for a course of this course request and the given enrollment does not meet any of them
    1098     */
    1099    public boolean isNotAllowed(Enrollment e) {
    1100        List<Restriction> restrictions = getRestrictions(e.getCourse());
    1101        if (restrictions.isEmpty()) return false;
    1102        for (Restriction r: restrictions)
    1103            if (r.isIncluded(e)) return false;
    1104        return true;
    1105    }
    1106
    1107    /**
    1108     * Clear restriction information that was cached on this request
    1109     */
    1110    public synchronized void clearRestrictionCache() {
    1111        if (iRestrictions != null) iRestrictions.clear();
    1112    }
    1113
    1114    /**
    1115     * Return true if this request can track MPP
    1116     * @return true if the request is course request and it either has an initial enrollment
    1117     */
    1118    @Override
    1119    public boolean isMPP() {
    1120        StudentSectioningModel model = (StudentSectioningModel) getModel();
    1121        if (model == null || !model.isMPP()) return false;
    1122        return !getStudent().isDummy() && getInitialAssignment() != null;
    1123    }
    1124
    1125    /**
    1126     * Return true if this request has any selection
    1127     * @return true if the request is course request and has some selected choices.
    1128     */
    1129    @Override
    1130    public boolean hasSelection() {
    1131        if (getStudent().isDummy() || getSelectedChoices().isEmpty()) return false;
    1132        for (Choice choice: getSelectedChoices())
    1133            if (choice.getSectionId() != null || choice.getConfigId() != null) return true;
    1134        return false;
    1135    }
    1136
    1137    /**
    1138     * Add request group to this request.
    1139     * @param group request group to be added
    1140     */
    1141    public void addRequestGroup(RequestGroup group) {
    1142        iRequestGroups.add(group);
    1143        group.addRequest(this);
    1144    }
    1145
    1146    /**
    1147     * Removed request group from this request.
    1148     * @param group request group to be removed
    1149     */
    1150    public void removeRequestGroup(RequestGroup group) {
    1151        iRequestGroups.remove(group);
    1152        group.removeRequest(this);
    1153    }
    1154
    1155    /**
    1156     * Lists request groups of this request
    1157     * @return request groups of this course requests
    1158     */
    1159    public Set<RequestGroup> getRequestGroups() {
    1160        return iRequestGroups;
    1161    }
    1162
    1163    @Override
    1164    public void variableAssigned(Assignment<Request, Enrollment> assignment, long iteration, Enrollment enrollment) {
    1165        super.variableAssigned(assignment, iteration, enrollment);
    1166        for (RequestGroup g: getRequestGroups())
    1167            if (g.getCourse().equals(enrollment.getCourse()))
    1168                g.assigned(assignment, enrollment);
    1169    }
    1170
    1171    @Override
    1172    public void variableUnassigned(Assignment<Request, Enrollment> assignment, long iteration, Enrollment enrollment) {
    1173        super.variableUnassigned(assignment, iteration, enrollment);
    1174        for (RequestGroup g: getRequestGroups())
    1175            if (g.getCourse().equals(enrollment.getCourse()))
    1176                g.unassigned(assignment, enrollment);
    1177        if (enrollment != null && enrollment.getCourse() != null && enrollment.getCourse().hasChildren()) {
    1178            for (Request r: enrollment.getStudent().getRequests()) {
    1179                if (r.equals(enrollment.getRequest())) continue;
    1180                Enrollment e = assignment.getValue(r);
    1181                if (e != null && e.getCourse() != null && enrollment.getCourse().equals(e.getCourse().getParent())) {
    1182                    assignment.unassign(iteration, r);
    1183                }
    1184            }
    1185        }
    1186    }
    1187
    1188    @Override
    1189    public float getMinCredit() {
    1190        Float credit = null;
    1191        for (Course course: getCourses()) {
    1192            if (course.hasCreditValue() && (credit == null || credit > course.getCreditValue()))
    1193                    credit = course.getCreditValue();
    1194            for (Config config: course.getOffering().getConfigs()) {
    1195                Float configCredit = config.getCreditValue();
    1196                if (configCredit != null && (credit == null || credit > configCredit))
    1197                        credit = configCredit;
    1198            }
    1199        }
    1200        return (credit == null ? 0 : credit.floatValue());
    1201    }
    1202
    1203    @Override
    1204    public RequestPriority getRequestPriority() {
    1205        return iPriority;
    1206    }
    1207
    1208    public void setRequestPriority(RequestPriority priority) {
    1209        iPriority = priority;
    1210    }
    1211
    1212    public boolean isFixed() { return iFixed != null; }
    1213    public Enrollment getFixedValue() { return iFixed; }
    1214    public void setFixedValue(Enrollment constant) { iFixed = constant; }
    1215
    1216    @Override
    1217    public boolean hasCourse(Course course) {
    1218        return iCourses.contains(course);
    1219    }
    1220
    1221    @Override
    1222    public boolean hasChildren() {
    1223        for (Course course: iCourses)
    1224            if (course.hasChildren()) return true;
    1225        return false;
    1226    }
    1227}