/*
* 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.nurserostering.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.FactHandle;
import org.drools.WorkingMemory;
import org.drools.planner.core.score.DefaultHardAndSoftScore;
import org.drools.planner.core.score.Score;
import org.drools.planner.core.solution.initializer.AbstractStartingSolutionInitializer;
import org.drools.planner.core.solver.AbstractSolverScope;
import org.drools.planner.examples.common.domain.PersistableIdComparator;
import org.drools.planner.examples.nurserostering.domain.Assignment;
import org.drools.planner.examples.nurserostering.domain.Employee;
import org.drools.planner.examples.nurserostering.domain.NurseRoster;
import org.drools.planner.examples.nurserostering.domain.Shift;
import org.drools.planner.examples.nurserostering.domain.ShiftDate;
public class NurseRosteringStartingSolutionInitializer extends AbstractStartingSolutionInitializer {
@Override
public boolean isSolutionInitialized(AbstractSolverScope abstractSolverScope) {
NurseRoster nurseRoster = (NurseRoster) abstractSolverScope.getWorkingSolution();
return nurseRoster.isInitialized();
}
public void initializeSolution(AbstractSolverScope abstractSolverScope) {
NurseRoster nurseRoster = (NurseRoster) abstractSolverScope.getWorkingSolution();
initializeAssignmentList(abstractSolverScope, nurseRoster);
}
private void initializeAssignmentList(AbstractSolverScope abstractSolverScope,
NurseRoster nurseRoster) {
List<Employee> employeeList = nurseRoster.getEmployeeList();
WorkingMemory workingMemory = abstractSolverScope.getWorkingMemory();
List<Assignment> assignmentList = createAssignmentList(nurseRoster);
for (Assignment assignment : assignmentList) {
FactHandle assignmentHandle = null;
Score bestScore = DefaultHardAndSoftScore.valueOf(Integer.MIN_VALUE, Integer.MIN_VALUE);
Employee bestEmployee = null;
for (Employee employee : employeeList) {
assignment.setEmployee(employee);
if (assignmentHandle == null) {
assignmentHandle = workingMemory.insert(assignment);
} else {
workingMemory.update(assignmentHandle, assignment);
}
Score score = abstractSolverScope.calculateScoreFromWorkingMemory();
if (score.compareTo(bestScore) > 0) {
bestScore = score;
bestEmployee = employee;
}
}
if (bestEmployee == null) {
throw new IllegalStateException("The bestEmployee (" + bestEmployee + ") cannot be null.");
}
assignment.setEmployee(bestEmployee);
workingMemory.update(assignmentHandle, assignment);
logger.debug(" Assignment ({}) initialized for starting solution.", assignment);
}
Collections.sort(assignmentList, new PersistableIdComparator());
nurseRoster.setAssignmentList(assignmentList);
}
public List<Assignment> createAssignmentList(NurseRoster nurseRoster) {
List<Shift> shiftList = nurseRoster.getShiftList();
List<ShiftDate> shiftDateList = nurseRoster.getShiftDateList();
List<ShiftInitializationWeight> shiftInitializationWeightList
= new ArrayList<ShiftInitializationWeight>(shiftList.size());
for (Shift shift : shiftList) {
shiftInitializationWeightList.add(new ShiftInitializationWeight(nurseRoster, shift));
}
Collections.sort(shiftInitializationWeightList);
List<Assignment> assignmentList = new ArrayList<Assignment>(
shiftDateList.size() * nurseRoster.getEmployeeList().size());
int assignmentId = 0;
for (ShiftInitializationWeight shiftInitializationWeight : shiftInitializationWeightList) {
Shift shift = shiftInitializationWeight.getShift();
for (int i = 0; i < shift.getRequiredEmployeeSize(); i++) {
Assignment assignment = new Assignment();
assignment.setId((long) assignmentId);
assignment.setShift(shift);
assignmentList.add(assignment);
assignmentId++;
}
}
return assignmentList;
}
private class ShiftInitializationWeight implements Comparable<ShiftInitializationWeight> {
private Shift shift;
private ShiftInitializationWeight(NurseRoster nurseRoster, Shift shift) {
this.shift = shift;
}
public Shift getShift() {
return shift;
}
public int compareTo(ShiftInitializationWeight other) {
return new CompareToBuilder()
.append(shift.getShiftDate(), other.shift.getShiftDate()) // Ascending
.append(other.shift.getRequiredEmployeeSize(), shift.getRequiredEmployeeSize()) // Descending
.append(shift.getShiftType(), other.shift.getShiftType()) // Ascending
.toComparison();
}
}
}