001package ball.game.sudoku;
002/*-
003 * ##########################################################################
004 * Game Applications and Utilities
005 * %%
006 * Copyright (C) 2010 - 2022 Allen D. Ball
007 * %%
008 * Licensed under the Apache License, Version 2.0 (the "License");
009 * you may not use this file except in compliance with the License.
010 * You may obtain a copy of the License at
011 *
012 *      http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing, software
015 * distributed under the License is distributed on an "AS IS" BASIS,
016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
017 * See the License for the specific language governing permissions and
018 * limitations under the License.
019 * ##########################################################################
020 */
021import java.util.Collection;
022import java.util.Collections;
023import java.util.List;
024import java.util.SortedSet;
025import java.util.TreeSet;
026import java.util.stream.IntStream;
027import lombok.NoArgsConstructor;
028
029import static java.util.stream.Collectors.toCollection;
030
031/**
032 * Sudoku {@link Digits}.
033 *
034 * @author {@link.uri mailto:ball@hcf.dev Allen D. Ball}
035 */
036@NoArgsConstructor
037public class Digits extends TreeSet<Integer> {
038    private static final long serialVersionUID = 3540373718233836695L;
039
040    protected static final SortedSet<Integer> ALL;
041
042    static {
043        var all = IntStream.rangeClosed(1, 9).boxed().collect(toCollection(TreeSet::new));
044
045        ALL = Collections.unmodifiableSortedSet(all);
046    }
047
048    protected static final int SUM = ALL.stream().mapToInt(Integer::intValue).sum();
049
050    /**
051     * See {@link #addAll(Collection)}.
052     *
053     * @param   digits          The digits to add.
054     *
055     * @return  {@code true} if {@link.this} {@link Digits} changes;
056     *          {@code false} otherwise.
057     */
058    public boolean addAll(Integer... digits) {
059        return Collections.addAll(this, digits);
060    }
061
062    /**
063     * See {@link #removeAll(Collection)}.
064     *
065     * @param   digits          The digits to remove.
066     *
067     * @return  {@code true} if {@link.this} {@link Digits} changes;
068     *          {@code false} otherwise.
069     */
070    public boolean removeAll(Integer... digits) {
071        return removeAll(List.of(digits));
072    }
073
074    /**
075     * See {@link #retainAll(Collection)}.
076     *
077     * @param   digits          The digits to retain.
078     *
079     * @return  {@code true} if {@link.this} {@link Digits} changes;
080     *          {@code false} otherwise.
081     */
082    public boolean retainAll(Integer... digits) {
083        return retainAll(List.of(digits));
084    }
085
086    @Override
087    public boolean add(Integer digit) {
088        if (! ALL.contains(digit)) {
089            throw new IllegalArgumentException(String.valueOf(digit));
090        }
091
092        return super.add(digit);
093    }
094
095    @Override
096    public boolean addAll(Collection<? extends Integer> collection) {
097        boolean modified = super.addAll(collection);
098
099        if (retainAll(ALL)) {
100            throw new IllegalArgumentException(String.valueOf(collection));
101        }
102
103        return modified;
104    }
105}