Deck.java

/*******************************************************************************
 * Companion code for the book "Introduction to Software Design with Java",
 * 3rd edition by Martin P. Robillard.
 *
 * Copyright (C) 2025 by Martin P. Robillard
 *
 * This code is licensed under a Creative Commons 
 * Attribution-NonCommercial-NoDerivatives 4.0 International License.
 * 
 * See http://creativecommons.org/licenses/by-nc-nd/4.0/
 * 
 *******************************************************************************/
package e3.chapter3;

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

/**
 * Represents a deck of playing cards. In this version, the cards in the deck
 * are stored in a list and the list of cards in the deck can be obtained by
 * client code using an immutable wrapper object.
 * 
 * This version of the Deck class also implements {@link CardSource} and has a
 * sort() method to demonstrate the use of comparators.
 * 
 * The Deck is also iterable: it fulfills the role of ConcreteIterable in the
 * Iterator design pattern.
 */
public class Deck implements CardSource, Iterable<Card> {

	private List<Card> aCards = new ArrayList<>();

	/**
	 * Creates a new deck of 52 cards, shuffled.
	 */
	public Deck() {
		shuffle();
	}

	/**
	 * Reinitializes the deck with all 52 cards, and shuffles them.
	 */
	public void shuffle() {
		aCards.clear();
		for (Suit suit : Suit.values()) {
			for (Rank rank : Rank.values()) {
				aCards.add(new Card(rank, suit));
			}
		}
		Collections.shuffle(aCards);
	}

	/**
	 * Places pCard on top of the deck.
	 * 
	 * @param pCard The card to place on top of the deck.
	 * @pre pCard !=null
	 */
	public void push(Card pCard) {
		assert pCard != null;
		aCards.add(pCard);
	}

	/**
	 * Draws a card from the deck: removes the card from the top of the deck and
	 * returns it.
	 * 
	 * @return The card drawn.
	 * @pre !isEmpty()
	 */
	public Card draw() {
		assert !isEmpty();
		return aCards.remove(aCards.size() - 1);
	}

	/**
	 * @return True if and only if there are no cards in the deck.
	 */
	public boolean isEmpty() {
		return aCards.isEmpty();
	}

	/**
	 * @return An unmodifiable list of all the cards in the deck.
	 */
	public List<Card> getCards() {
		return Collections.unmodifiableList(aCards);
	}

	/**
	 * Sorts the cards in the deck by ascending rank.
	 */
	public void sort() {
		Collections.sort(aCards, new Comparator<Card>() {

			public int compare(Card pCard1, Card pCard2) {
				return pCard1.rank().compareTo(pCard2.rank());
			}
		});
	}

	@Override
	public Iterator<Card> iterator() {
		return aCards.iterator();
	}
}