001package org.cpsolver.studentsct.constraint; 002 003import java.util.Set; 004 005import org.cpsolver.ifs.assignment.Assignment; 006import org.cpsolver.ifs.model.GlobalConstraint; 007import org.cpsolver.studentsct.model.Config; 008import org.cpsolver.studentsct.model.Enrollment; 009import org.cpsolver.studentsct.model.Request; 010import org.cpsolver.studentsct.model.Section; 011import org.cpsolver.studentsct.reservation.Reservation; 012 013 014/** 015 * Disabled sections constraint. This global constraint ensures that no enrollment 016 * containing a disabled sections (using {@link Section#isEnabled()}) is used, unless 017 * there is a reservation allowing for the use of disabled sections 018 * (using {@link Reservation#isAllowDisabled()}). 019 * 020 * @version StudentSct 1.3 (Student Sectioning)<br> 021 * Copyright (C) 2014 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 DisabledSections extends GlobalConstraint<Request, Enrollment> { 040 041 /** 042 * A given enrollment is conflicting, if there is a section that 043 * is disabled and there is not a matching reservation that would allow for that. 044 * 045 * @param enrollment {@link Enrollment} that is being considered 046 * @param conflicts all computed conflicting requests are added into this set 047 */ 048 @Override 049 public void computeConflicts(Assignment<Request, Enrollment> assignment, Enrollment enrollment, Set<Enrollment> conflicts) { 050 if (inConflict(assignment, enrollment)) 051 conflicts.add(enrollment); 052 } 053 054 /** 055 * A given enrollment is conflicting, if there is a section that 056 * is disabled and there is not a matching reservation that would allow for that. 057 * 058 * @param enrollment {@link Enrollment} that is being considered 059 * @return true, if the enrollment does not follow a reservation that must be used 060 */ 061 @Override 062 public boolean inConflict(Assignment<Request, Enrollment> assignment, Enrollment enrollment) { 063 // enrollment's config 064 Config config = enrollment.getConfig(); 065 066 // exclude free time requests 067 if (config == null) return false; 068 069 // student allows for disabled sections >> no problem 070 if (enrollment.getStudent().isAllowDisabled()) return false; 071 072 boolean hasDisabledSection = false; 073 // check all sections of the given enrollment 074 for (Section section: enrollment.getSections()) 075 if (!section.isEnabled()) { 076 hasDisabledSection = true; 077 break; 078 } 079 080 // no disabled section >> no conflict 081 if (!hasDisabledSection) return false; 082 083 // no reservations >> conflict not allowed 084 if (!config.getOffering().hasReservations()) 085 return true; 086 087 // enrollment's reservation 088 Reservation reservation = enrollment.getReservation(); 089 090 // already has a reservation that all for disabled sections 091 if (reservation != null && reservation.isAllowDisabled()) return false; 092 093 // if a there is some other reservation that allows for disabled sections >> also fine 094 for (Reservation r: config.getOffering().getReservations()) 095 if (r.isAllowDisabled() && r.isApplicable(enrollment.getStudent()) && r.isIncluded(enrollment)) 096 return false; 097 098 return true; 099 } 100 101 @Override 102 public String toString() { 103 return "DisabledSections"; 104 } 105}