;; The first three lines of this file were inserted by DrScheme. They record metadata
;; about the language level of this file in a form that our tools can easily process.
#reader(lib "htdp-beginner-reader.ss" "lang")((modname war-player-simple) (read-case-sensitive #t) (teachpacks ((lib "testing.ss" "teachpack" "htdp") (lib "universe.ss" "teachpack" "2htdp"))) (htdp-settings #(#t constructor repeating-decimal #f #t none #f ((lib "testing.ss" "teachpack" "htdp") (lib "universe.ss" "teachpack" "2htdp")))))
;; a World is a list of strings: card value and suit:

;; a sample World -- a deck of cards:
(define deck (list "Kh" "Qd" "3s" "8c"))

;; draw the world as simple text in a 40 x 60 scene
;; show-card: String -> 
(define (show-card alist)
  (cond 
    [(empty? alist) (empty-scene 40 60)]
    [else (place-image (text (first alist) 10 'black)
                       10 10
                       (empty-scene 40 60))]))

(show-card deck)
(show-card empty)

;;-----------------------------------------------------------------------------
;;---
;; receive a message: if 'done - stop the world
;; else append the card you won to the end of your list
;; receive-world: (World [Listof String] -> World
(define (receive-world w msg)
  (cond 
    [(symbol? msg) 'stop-the-world]
    [else (append w msg)]))

;; test receive-world:
(check-expect (receive-world deck 'done) 'stop-the-world)
(check-expect (receive-world deck empty) deck)
(check-expect (receive-world deck (list "4s" "Jc")) 
              (list "Kh" "Qd" "3s" "8c" "4s" "Jc"))

;;---
;; on key event (space bar) 
;; if space bar is pressed
;;   remove the top card from the deck and put it on the bottom
;;   the next card will now be seen by us
;; ignore all other keys, or when our deck is empty
;; on-key-event: World KeyEvent -> World
(define (on-key-event alist ke)
  (cond 
    [(string=? ke " ") 
    (cond 
      [(empty? alist) 'stop-the-world]
      [else (append (rest alist) (list (first alist)))])]
    [else alist]))

;; test on-key-event:
(check-expect (on-key-event deck "right") deck)
(check-expect (on-key-event empty " ") 'stop-the-world)
(check-expect (on-key-event deck " ")  (list "Qd" "3s" "8c" "Kh"))
    
    
;; define the condition for ending the world
;; end-the-world?: World -> Boolean
(define (end-the-world? w)
  (empty? w))

;; test end-the-world
(check-expect (end-the-world? deck) false)
(check-expect (end-the-world? empty) true)


;; run the world
(big-bang deck
          (stop-when end-the-world?)
          (on-receive receive-world)
          (on-key on-key-event)
          (on-draw show-card))