;; Sid Stamm
;; C211 lab number 2: Lambda & If
;; 9-12-2003
;; ACME Sports Drinks

;; GLOBAL DEFINITION OF PI
(define PI 3.1415926)

;; calculates the volume of a cylinder
;; given a radius and height.
;; the variable PI must be previously defined.
(define cyl-vol
  (lambda (rad ht)
    (* PI rad rad ht)))


;; determines how many cans are needed to can
;; a given volume of drink given a radius and
;; height of a can.
(define vol->cans
  (lambda (vol can-rad can-ht)
    (ceiling (/ vol (cyl-vol can-rad can-ht)))))


;; Determines how many boxes are needed to pack
;; a given number of cans.
(define cans->boxes
  (lambda (cans box-capacity)
    (ceiling (/ cans box-capacity))))


;; Determines how many trucks are needed to ship
;; a given number of boxes.
(define boxes->trucks
  (lambda (boxes truck-capacity)
    (ceiling (/ boxes truck-capacity))))


;; Determines how many trucks are needed to ship
;; a volume of sports drink given conversion procedures.
(define volume->trucks
  (lambda (volume v->c c->b b->t)
    (b->t (c->b (v->c volume 2 6) 24) 1000)))


;; Determines how many trucks are needed to ship
;; a volume of sports drink using previously defined
;; global procedures
(define volume->trucks-noprocs
  (lambda (volume)
    (ceiling
     (boxes->trucks 
      (cans->boxes 
       (vol->cans volume 2 6)
       24)
      1000))))

;; A predicate to determine if there are enough 
;; drivers to ship the entire volume of sports drink.
(define enough-drivers?
  (lambda (num-drivers vol)
    (>= num-drivers
	(volume->trucks-noprocs vol))))

;; prints out whether or not there are
;; enough drivers
;; along with some other information.
(define print-enough-drivers
  (lambda (num-drivers vol)
    (if (enough-drivers? num-drivers vol)
        (begin
          (display "Today we have enough trucks to ship ")
          (display vol)
          (display " units of Sports Drink!")
          (newline))
        (begin
          (display "We need ")
          (display (- (volume->trucks-noprocs vol) num-drivers))
          (display " more drivers to ship today's volume of Sports Drink.")
          (newline)))))