/**
* Copyright 2010 JBoss Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.drools.planner.examples.curriculumcourse.solver.solution.initializer;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.apache.commons.lang.builder.CompareToBuilder;
import org.drools.WorkingMemory;
import org.drools.runtime.rule.FactHandle;
import org.drools.planner.core.localsearch.LocalSearchSolverScope;
import org.drools.planner.core.solution.initializer.AbstractStartingSolutionInitializer;
import org.drools.planner.core.score.Score;
import org.drools.planner.core.score.DefaultHardAndSoftScore;
import org.drools.planner.examples.common.domain.PersistableIdComparator;
import org.drools.planner.examples.curriculumcourse.domain.Course;
import org.drools.planner.examples.curriculumcourse.domain.CurriculumCourseSchedule;
import org.drools.planner.examples.curriculumcourse.domain.Lecture;
import org.drools.planner.examples.curriculumcourse.domain.Period;
import org.drools.planner.examples.curriculumcourse.domain.Room;
import org.drools.planner.examples.curriculumcourse.domain.UnavailablePeriodConstraint;
/**
* @author Geoffrey De Smet
*/
public class CurriculumCourseStartingSolutionInitializer extends AbstractStartingSolutionInitializer {
@Override
public boolean isSolutionInitialized(LocalSearchSolverScope localSearchSolverScope) {
CurriculumCourseSchedule schedule = (CurriculumCourseSchedule) localSearchSolverScope.getWorkingSolution();
return schedule.isInitialized();
}
public void initializeSolution(LocalSearchSolverScope localSearchSolverScope) {
CurriculumCourseSchedule schedule = (CurriculumCourseSchedule) localSearchSolverScope.getWorkingSolution();
initializeLectureList(localSearchSolverScope, schedule);
}
private void initializeLectureList(LocalSearchSolverScope localSearchSolverScope,
CurriculumCourseSchedule schedule) {
List<Period> periodList = schedule.getPeriodList();
List<Room> roomList = schedule.getRoomList();
WorkingMemory workingMemory = localSearchSolverScope.getWorkingMemory();
List<Lecture> lectureList = createLectureList(schedule);
for (Lecture lecture : lectureList) {
Score unscheduledScore = localSearchSolverScope.calculateScoreFromWorkingMemory();
FactHandle lectureHandle = null;
List<PeriodScoring> periodScoringList = new ArrayList<PeriodScoring>(periodList.size());
for (Period period : periodList) {
if (lectureHandle == null) {
lecture.setPeriod(period);
lectureHandle = workingMemory.insert(lecture);
} else {
lecture.setPeriod(period);
workingMemory.update(lectureHandle, lecture);
}
Score score = localSearchSolverScope.calculateScoreFromWorkingMemory();
periodScoringList.add(new PeriodScoring(period, score));
}
Collections.sort(periodScoringList);
boolean almostPerfectMatch = false;
Score bestScore = DefaultHardAndSoftScore.valueOf(Integer.MIN_VALUE, Integer.MIN_VALUE);
Period bestPeriod = null;
Room bestRoom = null;
for (PeriodScoring periodScoring : periodScoringList) {
if (bestScore.compareTo(periodScoring.getScore()) >= 0) {
// No need to check the rest
break;
}
lecture.setPeriod(periodScoring.getPeriod());
workingMemory.update(lectureHandle, lecture);
for (Room room : roomList) {
lecture.setRoom(room);
workingMemory.update(lectureHandle, lecture);
Score score = localSearchSolverScope.calculateScoreFromWorkingMemory();
if (score.compareTo(unscheduledScore) < 0) {
if (score.compareTo(bestScore) > 0) {
bestScore = score;
bestPeriod = periodScoring.getPeriod();
bestRoom = room;
}
} else if (score.compareTo(unscheduledScore) >= 0) {
// TODO due to the score rules, the score can unscheduledScore can be higher than the score
// In theory every possibility should be looked into
almostPerfectMatch = true;
break;
}
}
if (almostPerfectMatch) {
break;
}
}
if (!almostPerfectMatch) {
if (bestPeriod == null || bestRoom == null) {
throw new IllegalStateException("The bestPeriod (" + bestPeriod + ") or the bestRoom ("
+ bestRoom + ") cannot be null.");
}
lecture.setPeriod(bestPeriod);
lecture.setRoom(bestRoom);
workingMemory.update(lectureHandle, lecture);
}
logger.debug(" Lecture ({}) initialized for starting solution.", lecture);
}
Collections.sort(lectureList, new PersistableIdComparator());
schedule.setLectureList(lectureList);
}
public List<Lecture> createLectureList(CurriculumCourseSchedule schedule) {
List<Course> courseList = schedule.getCourseList();
List<CourseInitializationWeight> courseInitializationWeightList
= new ArrayList<CourseInitializationWeight>(courseList.size());
for (Course course : courseList) {
courseInitializationWeightList.add(new CourseInitializationWeight(schedule, course));
}
Collections.sort(courseInitializationWeightList);
List<Lecture> lectureList = new ArrayList<Lecture>(courseList.size() * 5);
int lectureId = 0;
for (CourseInitializationWeight courseInitializationWeight : courseInitializationWeightList) {
Course course = courseInitializationWeight.getCourse();
for (int i = 0; i < course.getLectureSize(); i++) {
Lecture lecture = new Lecture();
lecture.setId((long) lectureId);
lectureId++;
lecture.setCourse(course);
lecture.setLectureIndexInCourse(i);
lectureList.add(lecture);
}
}
return lectureList;
}
private class CourseInitializationWeight implements Comparable<CourseInitializationWeight> {
private Course course;
private int unavailablePeriodConstraintCount;
private CourseInitializationWeight(CurriculumCourseSchedule schedule, Course course) {
this.course = course;
unavailablePeriodConstraintCount = 0;
// TODO this could be improved by iteration the unavailablePeriodConstraintList and using a hashmap
for (UnavailablePeriodConstraint constraint : schedule.getUnavailablePeriodConstraintList()) {
if (constraint.getCourse().equals(course)) {
unavailablePeriodConstraintCount++;
}
}
}
public Course getCourse() {
return course;
}
public int compareTo(CourseInitializationWeight other) {
return new CompareToBuilder()
.append(other.course.getCurriculumList().size(), course.getCurriculumList().size()) // Descending
.append(other.unavailablePeriodConstraintCount, unavailablePeriodConstraintCount) // Descending
.append(other.course.getLectureSize(), course.getLectureSize()) // Descending
.append(other.course.getStudentSize(), course.getStudentSize()) // Descending
.append(other.course.getMinWorkingDaySize(), course.getMinWorkingDaySize()) // Descending
.append(course.getId(), other.course.getId()) // Ascending
.toComparison();
}
}
private class PeriodScoring implements Comparable<PeriodScoring> {
private Period period;
private Score score;
private PeriodScoring(Period period, Score score) {
this.period = period;
this.score = score;
}
public Period getPeriod() {
return period;
}
public Score getScore() {
return score;
}
public int compareTo(PeriodScoring other) {
return -new CompareToBuilder().append(score, other.score).toComparison();
}
}
}