maze-generator/src/main/java/ch/fritteli/maze/generator/model/Tile.java

package ch.fritteli.maze.generator.model;

import io.vavr.collection.Stream;
import io.vavr.control.Option;
import lombok.AccessLevel;
import lombok.EqualsAndHashCode;
import lombok.Getter;
import lombok.NonNull;
import lombok.ToString;
import lombok.experimental.FieldDefaults;

import java.util.EnumSet;
import java.util.Random;

@FieldDefaults(level = AccessLevel.PRIVATE)
@EqualsAndHashCode
@ToString
public class Tile {
    final Walls walls = new Walls();
    boolean visited = false;
    @Getter
    boolean solution = false;

    public Tile() {
        this.walls.setAll();
    }

    /**
     * INTERNAL API.
     * Exists only for deserialization. Not to be called from user code.
     *
     * @param walls
     * @param solution
     */
    private Tile(@NonNull final EnumSet<Direction> walls, final boolean solution) {
        for (final Direction direction : walls) {
            this.walls.set(direction);
            this.walls.harden(direction);
        }
        this.visited = true;
        this.solution = solution;
    }

    public void preventDiggingToOrFrom(@NonNull final Direction direction) {
        this.walls.harden(direction);
    }

    public void enableDiggingToOrFrom(@NonNull final Direction direction) {
        this.walls.unharden(direction);
    }

    public boolean digFrom(@NonNull final Direction direction) {
        if (this.visited) {
            return false;
        }
        this.visited = true;
        return this.walls.clear(direction);
    }

    public boolean digTo(@NonNull final Direction direction) {
        return this.walls.clear(direction);
    }

    public void undigTo(@NonNull final Direction direction) {
        this.walls.set(direction);
    }

    public Option<Direction> getRandomAvailableDirection(@NonNull final Random random) {
        final Stream<Direction> availableDirections = this.walls.getUnhardenedSet();
        if (availableDirections.isEmpty()) {
            return Option.none();
        }
        final int index = random.nextInt(availableDirections.length());
        return Option.of(availableDirections.get(index));
    }

    public boolean hasWallAt(@NonNull final Direction direction) {
        return this.walls.isSet(direction);
    }

    public void setSolution() {
        this.solution = true;
    }
}