// A playing card
// Implementation (c) 1997 William Lenhart

// Annotated with discussion of Java syntax
public class Card implements CardInterface {
	
	// "protected" means other classes can't access them (data hiding)

	// instance variables
	protected int suit;		// The suit of the card: CLUBS..SPADES
	protected int rank;		// The rank of the card: TWO..ACE
	
	// Constructors
	
	// Always have a no-operand constructor
	// This one merely invokes the two-argument constructor, using "this" syntax
	// post:  Constructs a card with default value "Ace of Spades"
	public Card() {
		this(ACE,SPADES);
	}
	
	// This version of the constructor does all of the work
	// post:  Constructs a card of the given type
	public Card(int theRank, int theSuit) {
		suit = theSuit;
		rank = theRank;
	}
	
	// This allows different cards to be checked for equality
	// For technical reasons, parameter must be of type "Object"
	// Note: We must "coerce" the type of other to be "Card"
	// "this" refers to the object invoking the method.
	// It is not actually necessary here, but emphasizes the fact that we have
	// two Cards whose instance variables are changing
	// Note:  == is equality test BUT = is assignment
	// Note:  && is logical "and"; || is logical "or"
	// pre:  other is a non-null Card
	// post:  returns true iff this equals other
	public boolean equals(Object other) {
		if (other instanceof Card) {
			Card otherCard = (Card) other;
			return (this.suit == otherCard.suit) && (this.rank == otherCard.rank);
		} else {
			return false;
		}
	}
	
	// Having this method allows Cards to be used in certain data structures
	// For now, just try to return different values for different cards
	// This returns a number in the range 0..51;  different cards yield different values
	// post:  returns hash code for this card
	public int hashCode() {
		return 13*suit + rank - 2;
	}
	
	// post:  returns suit of card
	public int getSuit() {
		return suit;
	}
	
	// post:  returns rank of card
	public int getRank() {
		return rank;
	}
	
	// Java provides a String class with many useful methods
	// "switch" is Java's "case" statement
	// It must end each block with "break", or else next block is also executed
	// It must have "default" block, even if unused
	// post:  returns a string representation of the suit
	protected String getSuitString() {
		String suitStr = null;
		switch (suit) {
			case CLUBS:
				suitStr = "Clubs";
				break;
			case DIAMONDS:
				suitStr = "Diamonds";
				break;
			case HEARTS:
				suitStr = "Hearts";
				break;
			case SPADES:
				suitStr = "Spades";
				break;
			default:
		}			
		return suitStr;	
	}
	
	// post:  returns a string representation of the rank
	protected String getRankString() {
		String rankStr = null;
		switch (rank) {
			case TWO:
				rankStr = "Two";
				break;
			case THREE:
				rankStr = "Three";
				break;
			case FOUR:
				rankStr = "Four";
				break;
			case FIVE:
				rankStr = "Five";
				break;
			case SIX:
				rankStr = "Six";
				break;
			case SEVEN:
				rankStr = "Seven";
				break;
			case EIGHT:
				rankStr = "Eight";
				break;
			case NINE:
				rankStr = "Nine";
				break;
			case TEN:
				rankStr = "Ten";
				break;
			case JACK:
				rankStr = "Jack";
				break;
			case QUEEN:
				rankStr = "Queen";
				break;
			case KING:
				rankStr = "King";
				break;
			case ACE:
				rankStr = "Ace";
				break;
			default:
		}			
		return rankStr;	
	}
	
	// The toString method is special.  It allows for automatic printing of Objects
	// Note:  + for String concatenation
	// post:  returns a string representation of this card
	public String toString() {
		return getRankString() + " of " + getSuitString();
	}

	// If a class contains a main method, that method can be run when the class is compiled
	// I always have one, which I use for testing the class
	// Test Card class
	public static void main(String args[]) {
		// Create some cards
		CardInterface first = new Card(THREE,DIAMONDS);
		CardInterface second = new Card();
		
		System.out.println();
		System.out.println(first);
		System.out.println(second);
		System.out.println();
		
		// Note:  ! is the negation operator
		System.out.print("These cards are ");
		if(!first.equals(second))
			System.out.print("not ");
		System.out.println("equal");
		System.out.println();
		
		// Create an array of cards
		// Note syntax for array declaration
		CardInterface[] hand = new CardInterface[5];
		hand[0] = new Card(ACE,HEARTS);
		hand[1] = new Card(KING,HEARTS);
		hand[2] = new Card(QUEEN,HEARTS);
		hand[3] = new Card(JACK,HEARTS);
		hand[4] = new Card(TEN,HEARTS);
		
		// for loop
		// Note: declaration in for loop; ++ is the "add 1" operator
		for(int i=0;i<4;i++) {
			System.out.print(hand[i] + ", ");
		}
		
		System.out.println(hand[4]);
	}

}