package kata.gameoflife.a20170806;

/**
  * Game of Life Kata.
  * Copyright (c) 2017, Peter Kofler, licensed under BSD License.
  */
public class ClassifyPopulation implements Classify {

    private final int numberOfAliveNeigbours;

    public static ClassifyPopulation havingNeighbours(int count) {
        return new ClassifyPopulation(count);
    }

    private ClassifyPopulation(int numberOfAliveNeigbours) {
        this.numberOfAliveNeigbours = numberOfAliveNeigbours;
    }

    @Override
    public boolean asOptimal() {
        return !asUnderpopulated() && !asOverpopulated();
    }

    private boolean asUnderpopulated() {
        return numberOfAliveNeigbours < 2;
    }

    private boolean asOverpopulated() {
        return numberOfAliveNeigbours >= 4;
    }

    // It is having neighbours, but that is an implementation detail.
    // What it really is doing: checking for under or over population.
}