/**
 * Copyright (C) 2022 by Martin Robillard. See https://codesample.info/about.html
 */
package e2.chapter2;

import java.util.ArrayList;
import java.util.Collections;
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.
 */
public class Deck {
	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);
	}
}