RacingCarGame.java

package racingcar;

import camp.nextstep.edu.missionutils.Console;
import camp.nextstep.edu.missionutils.Randoms;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

public class RacingCarGame {
    Map<String, Integer> carMap = new HashMap<>();

    public Map<String, Integer> getCarMap() {
        return carMap;
    }

    public void play() {
        readCarNames();
        int numOfGames = receiceNumOfGames();
        System.out.println("\n실행결과");
        for (int i = 0; i < numOfGames; i++) {
            playOneRound();
        }
        announceWinners();
    }

    public void playOneRound() {
        for (Map.Entry<String, Integer> entry : carMap.entrySet()) {
            int numOfDice = Randoms.pickNumberInRange(0, 9);
            moveForward(entry.getKey(), numOfDice);
            System.out.println(entry.getKey() + " : " + "-".repeat(carMap.get(entry.getKey())));
        }
        System.out.println("\n");
    }

    private void moveForward(String carName, int numOfDice) {
        if (numOfDice >= 4) {
            carMap.put(carName, carMap.get(carName) + 1);
        }
    }


    public void readCarNames() {
        System.out.println("경주할 자동차 이름을 입력하세요.(이름은 쉼표(,) 기준으로 구분)");
        String input = Console.readLine();
        String[] carNames = input.split(",");
        for (String carName : carNames) {
            validateCarName(carName);
            carMap.put(carName, 0);
        }
    }

    private void validateCarName(String carName) {
        if (carName.length() > 5) {
            throw new IllegalArgumentException("자동차 이름은 5자 이하만 가능합니다.");
        }
    }

    public int receiceNumOfGames() {
        System.out.println("시도할 횟수는 몇 회인가요?");
        String numOfGames = Console.readLine();
        return validateNumOfGames(numOfGames);
    }

    private int validateNumOfGames(String numOfGames) {
        try {
            return Integer.parseInt(numOfGames);
        } catch (NumberFormatException e) {
            throw new IllegalArgumentException("정수가 아닌 값을 입력했습니다.");
        }
    }

    private List<String> calculateWinners() {
        if (carMap.isEmpty()) return Collections.emptyList();
        int max = carMap.values().stream().mapToInt(Integer::intValue).max().orElse(0);
        return carMap.entrySet().stream()
                .filter(e -> e.getValue() == max)
                .map(Map.Entry::getKey)
                .collect(Collectors.toList());
    }

    public String getWinnersLine() {
        List<String> winners = calculateWinners();
        return "최종 우승자 : " + String.join(", ", winners);
    }


    public void announceWinners() {
        System.out.println();
        System.out.println(getWinnersLine());
    }
}