(define-struct card (suit rank))


;; bestsuit: card card - > string
;;Helping function that distinguishes the better suit of two cards

(define (bestsuit a b)
  (if (equal? (card-suit a) 'spades)
      'spades
      (if (or (equal? (card-suit a) 'hearts) (equal? (card-suit b) 'hearts))
          'hearts
          (if (or (equal? (card-suit a) 'diamonds)(equal? (card-suit b) 'diamonds))
              'diamonds
              'clubs))))



;;bestrank nat nat - > nat
;;Helping function that distinguises the highest rank of two cards.

(define (bestrank a b)
  (cond
    [(< (card-rank a) (card-rank b)) (card-rank b)]
    [(> (card-rank a) (card-rank b)) (card-rank a)]
    [(equal? (card-rank a) (card-rank b)) (card-rank a)]))

;;better-card card card - > card
;;This function will intake two cards and then produce
;;the card with the highest suit. If both suits are equal,
;;the function will produce the card with highest rank.

(define (better-card a b)
  (if (equal? (card-suit a)(card-suit b))
      (make-card (card-suit a) (bestrank a b))
      (if (equal? (bestsuit a b) a)
          (make-card (card-suit a)(card-rank a))
          (make-card (card-suit b)(card-rank b)))))


;;straight: card card card - > bool
;;Helping function which will consume three card and, if they are of the same suit,
;;will produce either true if each card has a distance of one from another, or
;;false if this is not the case.

(define (straight a b c)
  (if (equal? (card-suit a)(card-suit b)(card-suit c))
      (if (and (or
                (equal? (- (bestrank (bestrank a b) c) 1)(card-rank a))
                (equal? (- (bestrank (bestrank a b) c) 1)(card-rank b))
                (equal? (- (bestrank (bestrank a b) c) 1)(card-rank c)))
               (equal? (- (bestrank (bestrank a b) c) 2)(card-rank a))
               (equal? (- (bestrank (bestrank a b) c) 2)(card-rank b))
               (equal? (- (bestrank (bestrank a b) c) 2)(card-rank c)))
          true
          false)
      false))

;;hand-value: card card card - > string
;;This function will consume three cards and produce
;;a string corresponding to the rules at the beginning
;;of this assigment.

(define (hand-value a b c)
  (if (equal? (card-suit a)(card-suit b)(card-suit c))
      (if (straight a b c)
          'straightflush
          'flush)
      (if (straight a b c)
          'straight
          (if (and (equal? (card-rank a)(card-rank b))
                   (equal? (card-rank b)(card-rank c)))
              'three-of-a-kind
              (if (or (equal? (card-rank a)(card-rank b))
                      (equal? (card-rank b)(card-rank c))
                      (equal? (card-rank c)(card-rank a)))
                  'pair
                  'high-card)))))