AllRacingCars.java

package racingcar.model.domain;

import static racingcar.common.ErrorMessage.ERROR_SINGLE_RACING_CAR_NAME;

import java.util.List;
import java.util.Map;
import java.util.function.Function;
import java.util.stream.Collectors;


public final class AllRacingCars {

    public static final int MIN_CAR_COUNT = 2;

    private final List<RacingCar> cars;

    private AllRacingCars(List<RacingCar> cars) {
        validate(cars);
        this.cars = cars;
    }

    public static AllRacingCars from(List<String> carNames) {
        return new AllRacingCars(convertToRacingCar(carNames));
    }

    public Round playOneRound() {
        return Round.from(moveAllRacingCars());
    }

    public FinalWinners getFinalWinners() {
        return FinalWinners.of(cars, calculateMaxPosition());
    }

    private void validate(List<RacingCar> cars) {
        if (cars.size() < MIN_CAR_COUNT) {
            throw new IllegalArgumentException(ERROR_SINGLE_RACING_CAR_NAME);
        }
    }

    private static List<RacingCar> convertToRacingCar(List<String> carNames) {
        return carNames.stream().map(RacingCar::from).toList();
    }

    private int calculateMaxPosition() {
        return cars.stream()
                .mapToInt(RacingCar::getPosition)
                .max()
                .orElse(0);
    }

    private Map<RacingCar, Integer> moveAllRacingCars() {
        return cars.stream()
                .map(car -> {
                    car.move();
                    return car;
                })
                .collect(Collectors.toMap(
                        Function.identity(),
                        RacingCar::getPosition
                ));
    }
}