mars-rover-kata/src/main/java/cat/hack3/codingtests/marsrover/MapIncrementalPositionResolver.java

package cat.hack3.codingtests.marsrover;

public class MapIncrementalPositionResolver {

    private final int firstPositionInMap;
    private final int incrementUnit;

    public MapIncrementalPositionResolver(int firstPositionInMap, int incrementUnit) {
        this.firstPositionInMap = firstPositionInMap;
        this.incrementUnit = incrementUnit;
    }

    int getIncrementedPosition(int currentPosition, int threshold) {
        return currentPosition + incrementUnit > threshold
                ? firstPositionInMap
                : ++currentPosition;
    }

    int getDecrementedPosition(int currentPosition, int threshold) {
        return currentPosition - incrementUnit < firstPositionInMap
                ? threshold
                : --currentPosition;
    }
}