/*
* 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.move.factory;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
import java.util.NoSuchElementException;
import org.drools.planner.core.move.CompositeMove;
import org.drools.planner.core.move.Move;
import org.drools.planner.core.move.factory.AbstractMoveFactory;
import org.drools.planner.core.solution.Solution;
import org.drools.planner.examples.nurserostering.domain.ShiftAssignment;
import org.drools.planner.examples.nurserostering.domain.Employee;
import org.drools.planner.examples.nurserostering.domain.NurseRoster;
import org.drools.planner.examples.nurserostering.domain.solver.EmployeeWorkSequence;
import org.drools.planner.examples.nurserostering.solver.move.EmployeeMultipleChangeMove;
public class ShiftAssignmentPillarPartSwapMoveFactory extends AbstractMoveFactory {
public List<Move> createMoveList(Solution solution) {
NurseRoster nurseRoster = (NurseRoster) solution;
List<Employee> employeeList = nurseRoster.getEmployeeList();
// This code assumes the shiftAssignmentList is sorted
List<ShiftAssignment> shiftAssignmentList = nurseRoster.getShiftAssignmentList();
// Hash the assignments per employee
Map<Employee, List<AssignmentSequence>> employeeToAssignmentSequenceListMap
= new HashMap<Employee, List<AssignmentSequence>>(employeeList.size());
int assignmentSequenceCapacity = nurseRoster.getShiftDateList().size() + 1 / 2;
for (Employee employee : employeeList) {
employeeToAssignmentSequenceListMap.put(employee,
new ArrayList<AssignmentSequence>(assignmentSequenceCapacity));
}
for (ShiftAssignment shiftAssignment : shiftAssignmentList) {
Employee employee = shiftAssignment.getEmployee();
List<AssignmentSequence> assignmentSequenceList = employeeToAssignmentSequenceListMap.get(employee);
if (assignmentSequenceList.isEmpty()) {
AssignmentSequence assignmentSequence = new AssignmentSequence(employee, shiftAssignment);
assignmentSequenceList.add(assignmentSequence);
} else {
AssignmentSequence lastAssignmentSequence = assignmentSequenceList // getLast()
.get(assignmentSequenceList.size() - 1);
if (lastAssignmentSequence.belongsHere(shiftAssignment)) {
lastAssignmentSequence.add(shiftAssignment);
} else {
AssignmentSequence assignmentSequence = new AssignmentSequence(employee, shiftAssignment);
assignmentSequenceList.add(assignmentSequence);
}
}
}
// The create the move list
List<Move> moveList = new ArrayList<Move>();
// For every 2 distinct employees
for (ListIterator<Employee> leftEmployeeIt = employeeList.listIterator(); leftEmployeeIt.hasNext();) {
Employee leftEmployee = leftEmployeeIt.next();
List<AssignmentSequence> leftAssignmentSequenceList
= employeeToAssignmentSequenceListMap.get(leftEmployee);
for (ListIterator<Employee> rightEmployeeIt = employeeList.listIterator(leftEmployeeIt.nextIndex());
rightEmployeeIt.hasNext();) {
Employee rightEmployee = rightEmployeeIt.next();
List<AssignmentSequence> rightAssignmentSequenceList = employeeToAssignmentSequenceListMap.get(
rightEmployee);
LowestDayIndexAssignmentSequenceIterator lowestIt = new LowestDayIndexAssignmentSequenceIterator(
leftAssignmentSequenceList, rightAssignmentSequenceList);
// For every pillar part duo
while (lowestIt.hasNext()) {
AssignmentSequence pillarPartAssignmentSequence = lowestIt.next();
// Note: the initialCapacity is probably to high,
// which is bad for memory, but the opposite is bad for performance (which is worse)
List<Move> moveListByPillarPartDuo = new ArrayList<Move>(
leftAssignmentSequenceList.size() + rightAssignmentSequenceList.size());
int lastDayIndex = pillarPartAssignmentSequence.getLastDayIndex();
Employee otherEmployee;
int leftMinimumFirstDayIndex = Integer.MIN_VALUE;
int rightMinimumFirstDayIndex = Integer.MIN_VALUE;
if (lowestIt.isLastNextWasLeft()) {
otherEmployee = rightEmployee;
leftMinimumFirstDayIndex = lastDayIndex;
} else {
otherEmployee = leftEmployee;
rightMinimumFirstDayIndex = lastDayIndex;
}
moveListByPillarPartDuo.add(new EmployeeMultipleChangeMove(
pillarPartAssignmentSequence.getEmployee(),
pillarPartAssignmentSequence.getShiftAssignmentList(),
otherEmployee));
// For every AssignmentSequence in that pillar part duo
while (lowestIt.hasNextWithMaximumFirstDayIndexes(
leftMinimumFirstDayIndex, rightMinimumFirstDayIndex)) {
pillarPartAssignmentSequence = lowestIt.next();
lastDayIndex = pillarPartAssignmentSequence.getLastDayIndex();
if (lowestIt.isLastNextWasLeft()) {
otherEmployee = rightEmployee;
leftMinimumFirstDayIndex = Math.max(leftMinimumFirstDayIndex, lastDayIndex);
} else {
otherEmployee = leftEmployee;
rightMinimumFirstDayIndex = Math.max(rightMinimumFirstDayIndex, lastDayIndex);
}
moveListByPillarPartDuo.add(new EmployeeMultipleChangeMove(
pillarPartAssignmentSequence.getEmployee(),
pillarPartAssignmentSequence.getShiftAssignmentList(),
otherEmployee));
}
moveList.add(new CompositeMove(moveListByPillarPartDuo));
}
}
}
return moveList;
}
/**
* TODO DRY with {@link EmployeeWorkSequence}
*/
private static class AssignmentSequence {
private Employee employee;
private List<ShiftAssignment> shiftAssignmentList;
private int firstDayIndex;
private int lastDayIndex;
private AssignmentSequence(Employee employee, ShiftAssignment shiftAssignment) {
this.employee = employee;
shiftAssignmentList = new ArrayList<ShiftAssignment>();
shiftAssignmentList.add(shiftAssignment);
firstDayIndex = shiftAssignment.getShiftDateDayIndex();
lastDayIndex = firstDayIndex;
}
public Employee getEmployee() {
return employee;
}
public List<ShiftAssignment> getShiftAssignmentList() {
return shiftAssignmentList;
}
public int getFirstDayIndex() {
return firstDayIndex;
}
public int getLastDayIndex() {
return lastDayIndex;
}
private void add(ShiftAssignment shiftAssignment) {
shiftAssignmentList.add(shiftAssignment);
int dayIndex = shiftAssignment.getShiftDateDayIndex();
if (dayIndex < lastDayIndex) {
throw new IllegalStateException("The shiftAssignmentList is expected to be sorted by shiftDate.");
}
lastDayIndex = dayIndex;
}
private boolean belongsHere(ShiftAssignment shiftAssignment) {
return shiftAssignment.getShiftDateDayIndex() <= (lastDayIndex + 1);
}
}
private static class LowestDayIndexAssignmentSequenceIterator implements Iterator<AssignmentSequence> {
private Iterator<AssignmentSequence> leftIterator;
private Iterator<AssignmentSequence> rightIterator;
private boolean leftHasNext = true;
private boolean rightHasNext = true;
private AssignmentSequence nextLeft;
private AssignmentSequence nextRight;
private boolean lastNextWasLeft;
public LowestDayIndexAssignmentSequenceIterator(
List<AssignmentSequence> leftAssignmentList, List<AssignmentSequence> rightAssignmentList) {
// Buffer the nextLeft and nextRight
leftIterator = leftAssignmentList.iterator();
if (leftIterator.hasNext()) {
nextLeft = leftIterator.next();
} else {
leftHasNext = false;
nextLeft = null;
}
rightIterator = rightAssignmentList.iterator();
if (rightIterator.hasNext()) {
nextRight = rightIterator.next();
} else {
rightHasNext = false;
nextRight = null;
}
}
public boolean hasNext() {
return leftHasNext || rightHasNext;
}
public boolean hasNextWithMaximumFirstDayIndexes(
int leftMinimumFirstDayIndex, int rightMinimumFirstDayIndex) {
if (!hasNext()) {
return false;
}
boolean nextIsLeft = nextIsLeft();
if (nextIsLeft) {
int firstDayIndex = nextLeft.getFirstDayIndex();
// It should not be conflict in the same pillar and it should be in conflict with the other pillar
return firstDayIndex > leftMinimumFirstDayIndex && firstDayIndex <= rightMinimumFirstDayIndex;
} else {
int firstDayIndex = nextRight.getFirstDayIndex();
// It should not be conflict in the same pillar and it should be in conflict with the other pillar
return firstDayIndex > rightMinimumFirstDayIndex && firstDayIndex <= leftMinimumFirstDayIndex;
}
}
public AssignmentSequence next() {
lastNextWasLeft = nextIsLeft();
// Buffer the nextLeft or nextRight
AssignmentSequence lowest;
if (lastNextWasLeft) {
lowest = nextLeft;
if (leftIterator.hasNext()) {
nextLeft = leftIterator.next();
} else {
leftHasNext = false;
nextLeft = null;
}
} else {
lowest = nextRight;
if (rightIterator.hasNext()) {
nextRight = rightIterator.next();
} else {
rightHasNext = false;
nextRight = null;
}
}
return lowest;
}
private boolean nextIsLeft() {
boolean returnLeft;
if (leftHasNext) {
if (rightHasNext) {
int leftFirstDayIndex = nextLeft.getFirstDayIndex();
int rightFirstDayIndex = nextRight.getFirstDayIndex();
returnLeft = leftFirstDayIndex <= rightFirstDayIndex;
} else {
returnLeft = true;
}
} else {
if (rightHasNext) {
returnLeft = false;
} else {
throw new NoSuchElementException();
}
}
return returnLeft;
}
public void remove() {
throw new UnsupportedOperationException("Remove not supported.");
}
public boolean isLastNextWasLeft() {
return lastNextWasLeft;
}
}
}