/*
* Copyright 2011 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.examples.sudoku;
import java.util.Formatter;
import java.util.HashSet;
import java.util.Set;
import org.drools.KnowledgeBase;
import org.drools.event.rule.ObjectInsertedEvent;
import org.drools.event.rule.ObjectRetractedEvent;
import org.drools.event.rule.ObjectUpdatedEvent;
import org.drools.event.rule.WorkingMemoryEventListener;
import org.drools.examples.sudoku.swing.AbstractSudokuGridModel;
import org.drools.examples.sudoku.swing.SudokuGridEvent;
import org.drools.examples.sudoku.swing.SudokuGridModel;
import org.drools.runtime.StatefulKnowledgeSession;
import org.drools.runtime.rule.FactHandle;
/**
* An object of this class solves Sudoku problems.
*/
public class Sudoku extends AbstractSudokuGridModel implements SudokuGridModel {
public static Sudoku sudoku;
public Cell[][] cells;
private CellSqr[][] sqrs = new CellSqr[][]{ new CellSqr[3], new CellSqr[3], new CellSqr[3] };
private CellRow[] rows = new CellRow[9];
private CellCol[] cols = new CellCol[9];
private KnowledgeBase kBase;
private StatefulKnowledgeSession session;
private SudokuWorkingMemoryListener workingMemoryListener = new SudokuWorkingMemoryListener();
private Counter counter;
private Boolean explain = false;
private FactHandle steppingFactHandle;
private Stepping stepping;
private boolean unsolvable = false;
/**
* Constructor.
* @param kBase a Knowledge Base with rules for solving Sudoku problems.
*/
public Sudoku(KnowledgeBase kBase) {
this.kBase = kBase;
sudoku = this;
}
/*
* (non-Javadoc)
* @see org.drools.examples.sudoku.swing.SudokuGridModel#getCellValue(int, int)
*/
public String getCellValue(int iRow, int iCol) {
if (cells == null) return " ";
return cells[iRow][iCol].valueAsString();
}
/**
* Nice printout of the grid.
*/
public void dumpGrid() {
Formatter fmt = new Formatter(System.out);
fmt.format(" ");
for (int iCol = 0; iCol < 9; iCol++) {
fmt.format("Col: %d ", iCol);
}
System.out.println();
for (int iRow = 0; iRow < 9; iRow++) {
System.out.print("Row " + iRow + ": ");
for (int iCol = 0; iCol < 9; iCol++) {
if (cells[iRow][iCol].getValue() != null) {
fmt.format(" --- %d --- ", cells[iRow][iCol].getValue());
} else {
StringBuilder sb = new StringBuilder();
Set<Integer> perms = cells[iRow][iCol].getFree();
for (int i = 1; i <= 9; i++) {
if (perms.contains(i)) {
sb.append(i);
} else {
sb.append(' ');
}
}
fmt.format(" %-10s", sb.toString());
}
}
System.out.println();
}
}
/**
* Checks that everything is still according to the sudoku rules.
*/
public void consistencyCheck() {
for (int iRow = 0; iRow < 9; iRow++) {
for (int iCol = 0; iCol < 9; iCol++) {
Cell cell = cells[iRow][iCol];
Integer value = cell.getValue();
if (value != null) {
if (! cell.getFree().isEmpty()) {
throw new IllegalStateException("free not empty");
}
// any containing group
for (Cell other: cell.getExCells()) {
// must not occur in any of the other cells
if (value.equals(other.getValue())) {
throw new IllegalStateException("duplicate");
}
// must not occur in the permissibles of any of the other cells
if (other.getFree().contains(value)) {
throw new IllegalStateException("not eliminated");
}
}
}
}
}
for (int i = 0; i < rows.length; i++) {
Set<Integer> aSet = new HashSet<Integer>();
for (int j = 0; j < rows[i].getCells().size(); j++) {
Cell cell = rows[i].getCells().get(j);
Integer value = cell.getValue();
if (value != null) {
aSet.add(value);
} else {
aSet.addAll(cell.getFree());
}
}
if (! aSet.equals(CellGroup.allNine)) {
throw new IllegalStateException("deficit in row");
}
}
for (int i = 0; i < cols.length; i++) {
Set<Integer> aSet = new HashSet<Integer>();
for (int j = 0; j < cols[i].getCells().size(); j++) {
Cell cell = cols[i].getCells().get(j);
Integer value = cell.getValue();
if (value != null) {
aSet.add(value);
} else {
aSet.addAll(cell.getFree());
}
}
if (! aSet.equals(CellGroup.allNine)) {
throw new IllegalStateException("deficit in column");
}
}
for (int ir = 0; ir < sqrs.length; ir++) {
for (int ic = 0; ic < sqrs[ir] .length; ic++) {
Set<Integer> aSet = new HashSet<Integer>();
for (int j = 0; j < sqrs[ir][ic].getCells().size(); j++) {
Cell cell = sqrs[ir][ic].getCells().get(j);
Integer value = cell.getValue();
if (value != null) {
aSet.add(value);
} else {
aSet.addAll(cell.getFree());
}
}
if (! aSet.equals(CellGroup.allNine)) {
throw new IllegalStateException("deficit in square");
}
}
}
System.out.println("+++ check OK +++");
}
/*
* (non-Javadoc)
* @see org.drools.examples.sudoku.swing.SudokuGridModel#solve()
*/
public void solve() {
if (this.isSolved()) return;
explain = false;
session.setGlobal("explain", explain);
if( steppingFactHandle != null ){
session.retract( steppingFactHandle );
steppingFactHandle = null;
stepping = null;
}
this.session.fireAllRules();
// dumpGrid();
}
/*
* (non-Javadoc)
* @see org.drools.examples.sudoku.swing.SudokuGridModel#step()
*/
public void step() {
if (this.isSolved()) return;
explain = true;
session.setGlobal("explain", explain);
this.counter.setCount(1);
session.update(session.getFactHandle(this.counter), this.counter);
if( steppingFactHandle == null ){
steppingFactHandle = session.insert( stepping = new Stepping() );
}
this.session.fireUntilHalt();
if( stepping.isEmergency() ){
this.unsolvable = true;
}
// dumpGrid();
}
public boolean isSolved() {
for (int iRow = 0; iRow < 9; iRow++) {
for (int iCol = 0; iCol < 9; iCol++) {
if (cells[iRow][iCol].getValue() == null) return false;
}
}
return true;
}
public boolean isUnsolvable(){
return unsolvable;
}
private void create() {
for (int i = 0; i < 9; i++) {
session.insert(Integer.valueOf(i+1));
rows[i] = new CellRow(i);
cols[i] = new CellCol(i);
}
cells = new Cell[9][];
for (int iRow = 0; iRow < 9; iRow++) {
cells[iRow] = new Cell[9];
for (int iCol = 0; iCol < 9; iCol++) {
Cell cell = cells[iRow][iCol] = new Cell();
rows[iRow].addCell(cell);
cols[iCol].addCell(cell);
}
}
for (int i = 0; i < 3; i++) {
for (int j = 0; j < 3; j++) {
sqrs[i][j] = new CellSqr(rows[i*3], rows[i*3+1], rows[i*3+2],
cols[j*3], cols[j*3+1], cols[j*3+2]);
}
}
for (int iRow = 0; iRow < 9; iRow++) {
for (int iCol = 0; iCol < 9; iCol++) {
cells[iRow][iCol].makeReferences(rows[iRow], cols[iCol], sqrs[iRow/3][iCol/3]);
session.insert(cells[iRow][iCol]);
}
session.insert(rows[iRow]);
session.insert(cols[iRow]);
session.insert(sqrs[iRow/3][iRow%3]);
}
}
/*
* (non-Javadoc)
* @see org.drools.examples.sudoku.swing.SudokuGridModel#setCellValues(java.lang.Integer[][])
*/
public void setCellValues(Integer[][] cellValues) {
if (session != null) {
session.removeEventListener(workingMemoryListener);
session.dispose();
steppingFactHandle = null;
}
this.session = kBase.newStatefulKnowledgeSession();
session.setGlobal("explain", explain);
session.addEventListener(workingMemoryListener);
Setting s000 = new Setting(0, 0, 0);
FactHandle fh000 = this.session.insert(s000);
this.create();
int initial = 0;
for (int iRow = 0; iRow < 9; iRow++) {
for (int iCol = 0; iCol < 9; iCol++) {
Integer value = cellValues[iRow][iCol];
if (value != null) {
session.insert(new Setting(iRow, iCol, value));
initial++;
}
}
}
this.counter = new Counter(initial);
this.session.insert(counter);
this.session.retract(fh000);
this.session.fireUntilHalt();
}
/*
* (non-Javadoc)
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("Sudoku:").append('\n');
for (int iRow = 0; iRow < 9; iRow++) {
sb.append(" ").append(rows[iRow].toString()).append('\n');
}
return sb.toString();
}
class SudokuWorkingMemoryListener implements WorkingMemoryEventListener {
public void objectInserted(ObjectInsertedEvent ev) {
if (ev.getObject() instanceof Counter) {
fireRestartEvent(null);
}
}
public void objectRetracted(ObjectRetractedEvent ev) {
}
public void objectUpdated(ObjectUpdatedEvent ev) {
if (ev.getObject() instanceof Cell) {
Cell cell = (Cell) ev.getObject();
if (cell.getValue() != null) {
fireCellUpdatedEvent(new SudokuGridEvent(this,
cell.getRowNo(),
cell.getColNo(),
cell.getValue()));
}
}
}
}
public void validate(){
session.getAgenda().getAgendaGroup( "validate" ).setFocus();
session.fireUntilHalt();
}
}