;; 5
;; A room is:
;; (make-room number string number)
(define-struct room (numbed bed-size base-price))

;; Constructor
;; make-room: number string number -> room

;; Selectors
;; room-numbed: room -> number
;; room-bed-size: room -> string
;; room-base-price: room -> number

;; Predicate
;; room?: any -> boolean

; ;; Template
; ;; room-fun: room -> ?
; ;; given... produces..
; (define (room-fun a-room)
;   (room-numbed a-room)
;   (room-bed-size a-room)
;   (room-base-price a-room))
;
; (check-expect (room-fun ...) ...)
; (check-expect (room-fun ...) ...)
; (check-expect (room-fun ...) ...)


(define RM-119 (make-room 2 "queen" 80))
(define RM-223 (make-room 1 "king" 100))
(define RM-334 (make-room 3 "queen" 120))
(define RM-411 (make-room 2 "queen" 80))

;; compute-room-price: room number -> number
;; given a room and number of occupants, produces a room price per night
(define (compute-room-price a-room num-of-occupants)
  (cond
    [(<= num-of-occupants 2) (room-base-price a-room)]
    [else  (+ (* 10 (- num-of-occupants 2))
              (room-base-price a-room))]))

(check-expect (compute-room-price RM-119 2) 80)
(check-expect (compute-room-price RM-223 3) 110)
(check-expect (compute-room-price RM-334 4) 140)