;;; Leider war das Übungsblatt ein bisschen mit der heissen Nadel
;;; gestrickt. Mittlerweile haben sich einige Fehler
;;; herausgestellt. Ich habe ein neues Übungsblatt erstellt, das Silke
;;; am Montag in die Übung mitbringen wird. 
;;;
;;; Falls Du die neue Version nicht trotzdem nicht bekommen könnt,
;;; hier sind die Änderungen gegenüber dem in der Vorlesung
;;; ausgegebenen Übungsblatt:
;;;
;;; * Die Trumpfkarten heißen natuerlich "herz" und nicht "rot"
;;;
;;; * Die Prozedur lowest-card ist etwas einfacher als auf dem Übungsblatt
;;;
;;; * Der Datentyp Deck sollte zusätzlich noch die Prozedur
;;;   deck-empty?  bereitstellen
;;;
;;; * Der Datentyp Game-Stack sollte zusätzlich noch die Prozedur
;;;   game-state-replace-decks bereitstellen
;;;
;;; * computer-reply und computer-first-move geben einfach die Karte
;;;   zurück, die der Computer spielt
;;;
;;; * Der Konstruktor make-card soll als Argument den Namen der Karte
;;;   akzeptiern. Die Prozedur name->value am Ende dieser Datei kann
;;;   verwendet werden um aus dem Namen den Wert zu bestimmen
;;;
;;; Sorry für das Chaos...



;;; Dieser Code implementiert den Computerspieler. 

(define computer-reply 
  (lambda (deck other-card)
    (let ((my-card (choose-card deck other-card)))
      (display "My move: ")
      (display-card my-card)
      my-card)))
  
(define choose-card 
  (lambda (deck other-card)
    (let ((same-colors (deck-cards-with-color deck (card-color other-card))))
      (if (null? same-colors)
	  (let ((trump-cards (deck-cards-with-color deck 'herz)))
	    (if (null? trump-cards)
		(deck-any-card deck)
		(lowest-card trump-cards)))
	  (higher-or-lowest-card same-colors other-card)))))
	
(define lowest-card 
  (lambda (card-list)
    (lowest-card-helper (cdr card-list) (car card-list))))

(define lowest-card-helper 
  (lambda (card-list maybe-lowest)
    (if (null? card-list)
	maybe-lowest
	(if (card< (car card-list) maybe-lowest)
	    (lowest-card-helper (cdr card-list) (car card-list))
	    (lowest-card-helper (cdr card-list) maybe-lowest)))))

(define computer-first-move 
  (lambda (deck)
    (let ((card (deck-any-card deck)))
      (display "I play ")
      (display-card card)
      card)))

(define higher-or-lowest-card 
  (lambda (card-list the-card)
    (let ((a-higher-card (higher-card card-list the-card)))
      (if a-higher-card
	  a-higher-card
	  (lowest-card card-list)))))

(define higher-card 
  (lambda (card-list other-card)
    (if (null? card-list)
	#f
	(if (card< other-card (car card-list))
	    (car card-list)
	    (higher-card (cdr card-list) other-card)))))

;;;; Hier beginnt der Code fuer das eigentliche Spiel

(define play-herzblatt
  (lambda (game-state player)
    (let ((computer-deck (game-state-computer-deck game-state))
	  (human-deck (game-state-human-deck game-state)))
      (cond ((game-over? game-state)
	     (announce-winner game-state))
	    ((equal? player 'human)
	     (let ((human-card (human-first-move human-deck)))
	       (let ((computer-card 
		      (computer-reply computer-deck human-card)))
		(let ((new-state.winner
		       (rate-move computer-card human-card game-state #t)))
		  (play-herzblatt (car new-state.winner) (cdr new-state.winner))))))
	    ((equal? player 'computer)
	     (let ((computer-card 
		    (computer-first-move computer-deck)))
	       (let ((human-card 
		      (human-reply human-deck)))
		 (let ((new-state.winner
			(rate-move computer-card human-card game-state #f)))
		   (play-herzblatt (car new-state.winner) (cdr new-state.winner))))))))))


(define human-reply 
  (lambda (human-deck)
    (display "Your deck: ")
    (newline)
    (display-deck human-deck)
    (display "Enter the color of the card you want to play: ")
    (let ((color (read)))
	(newline)
	(display "Enter the name of the card you want to play: ")
	(let ((name (read)))
	  (make-card name color)))))

(define human-first-move human-reply)

(define rate-move 
  (lambda (computer-card human-card game-state first-player-is-human)
    (let ((turn-value (+ (card-value human-card)
			  (card-value computer-card)))
	  (game-state-with-new-decks (remove-cards game-state computer-card human-card)))
      (if (if first-player-is-human
	      (not (card< human-card computer-card))
	      (card< computer-card human-card))
	  (begin
	    (display "You get ")
	    (display turn-value)
	    (display " points.")
	    (newline)
	    (cons (game-state-increment-human game-state-with-new-decks turn-value) 
		  'human))
	  (begin
	    (display "I get ")
	    (display turn-value)
	    (display " points.")
	    (newline)
	    (cons (game-state-increment-computer game-state-with-new-decks turn-value)
		  'computer))))))

(define (remove-cards game-state computer-card human-card)
  (let ((old-computer-deck (game-state-computer-deck game-state))
	(old-human-deck (game-state-human-deck game-state)))
    (let ((new-computer-deck (deck-remove-card old-computer-deck computer-card))
	  (new-human-deck (deck-remove-card old-human-deck human-card)))
      (game-state-replace-decks game-state new-computer-deck new-human-deck))))

(define announce-winner 
  (lambda (game-state)
    (if (equal? (winner game-state) 'human)
	(display "You win!")
	(display "You lose!"))))
      

(define (name->value name)
  (if (number? name)
      (if (< name 10)
	  0
	  10)
      (cond ((equal? name 'bube)
	     2)
	    ((equal? name 'dame)
	     3)
	    ((equal? name 'koenig)
	     4)
	    ((equal? name 'ass)
	     11)
	    (else (error "Unknown name of card" name)))))

::; Beispielablauf:
:::
(define deck1 (make-deck (list (make-card 'ass 'herz)
			       (make-card 7 'pik)
			       (make-card 'koenig 'pik)
			       (make-card 10 'karo)
			       (make-card 9 'karo))))

(define deck2 (make-deck (list (make-card 'dame 'herz)
			       (make-card 8 'pik)
			       (make-card 10 'kreuz)
			       (make-card 'bube 'karo)
			       (make-card 'dame 'karo))))

;(play-herzblatt (make-game-state deck1 deck2) 'human)
;Your deck: 
;herz dame
;pik 8
;kreuz 10
;karo bube
;karo dame
;Enter the color of the card you want to play: herz

;Enter the name of the card you want to play: dame
;My move: herz ass
;I get 14 points.
;I play pik 7
;Your deck: 
;pik 8
;kreuz 10
;karo bube
;karo dame
;Enter the color of the card you want to play: pik

;Enter the name of the card you want to play: 8
;You get 0 points.
;Your deck: 
;kreuz 10
;karo bube
;karo dame
;Enter the color of the card you want to play: kreuz

;Enter the name of the card you want to play: 10
;My move: pik koenig
;You get 14 points.
;Your deck: 
;karo bube
;karo dame
;Enter the color of the card you want to play: karo

;Enter the name of the card you want to play: bube
;My move: karo 10
;I get 12 points.
;I play karo 9
;Your deck: 
;karo dame
;Enter the color of the card you want to play: karo

;Enter the name of the card you want to play: dame
;You get 3 points.
;You lose!