FirefighterBoard.java

package firefighter.model;

import firefighter.util.Position;

import java.util.*;


public class FirefighterBoard implements Board<List<ModelElement>> {
  private final int columnCount;
  private final int rowCount;
  private final int initialFireCount;
  private final int initialFirefighterCount;
  private List<Position> firefighterPositions;
  private Set<Position> firePositions;
  private int step = 0;
  private final Random randomGenerator = new Random();

  public FirefighterBoard(int columnCount, int rowCount, int initialFireCount, int initialFirefighterCount) {
    this.columnCount = columnCount;
    this.rowCount = rowCount;
    this.initialFireCount = initialFireCount;
    this.initialFirefighterCount = initialFirefighterCount;
    initializeElements();
  }

  public void initializeElements() {
    firefighterPositions = new ArrayList<>();
    firePositions = new HashSet<>();
    for (int index = 0; index < initialFireCount; index++)
      firePositions.add(randomPosition());
    for (int index = 0; index < initialFirefighterCount; index++)
      firefighterPositions.add(randomPosition());
  }

  private Position randomPosition() {
    return new Position(randomGenerator.nextInt(rowCount), randomGenerator.nextInt(columnCount));
  }

  @Override
  public List<ModelElement> getState(Position position) {
    List<ModelElement> result = new ArrayList<>();
    for(Position firefighterPosition : firefighterPositions)
      if (firefighterPosition.equals(position))
        result.add(ModelElement.FIREFIGHTER);
    if(firePositions.contains(position))
      result.add(ModelElement.FIRE);
    return result;
  }

  @Override
  public int rowCount() {
    return rowCount;
  }

  @Override
  public int columnCount() {
    return columnCount;
  }

  public List<Position> updateToNextGeneration() {
    List<Position> result = activateFirefighters();
    result.addAll(activateFires());
    step++;
    return result;
  }

  private List<Position> activateFires() {
    List<Position> result = new ArrayList<>();
    if (step % 2 == 0) {
      List<Position> newFirePositions = new ArrayList<>();