ParticipantCards.java

package blackjack.domain;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class ParticipantCards {

    private static final String COMMA = ", ";

    private final List<Card> cards;

    public ParticipantCards(List<Card> cards) {
        this.cards = new ArrayList<>(cards);
    }

    public void addCards(List<Card> drawCards) {
        cards.addAll(drawCards);
    }

    public int sumCardScore() {
        return cards.stream()
            .reduce(0, (x, y) -> x + y.getScore(x), Integer::sum);
    }

    public List<Card> getCards() {
        return Collections.unmodifiableList(cards);
    }

    public String toString() {
        StringBuilder sb = new StringBuilder();

        for (int i = 0; i < cards.size(); i++) {
            sb.append(cards.get(i).toString());
            if (i != cards.size() - 1) {
                sb.append(COMMA);
            }
        }

        return sb.toString();
    }
}