;; For stream programming section 3.5
;; We use the R5RS define force and delay which are slightly
;; different from the force and delay defined in the book:
;; delay (aka make-promise) handles recursive forcing.

(define the-empty-stream '())
(define stream-null? null?)
(define stream-car car)
(define (stream-cdr s)
  (force (cdr s)))

(define-syntax cons-stream
  (syntax-rules ()
    ((_ head tail)
     (cons head (delay tail)))))

(load "plotizing.ss")
(load "heartbeat.ss")

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Problem 1

(define sums 'todo)
;; test

(define (add-streams2 s1 s2) 'todo)
;; test

(define prods 'todo)
;; test


(define (bounded-random-stream L U)
  'todo)
;; test

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Problem 2: Nothing to hand in

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Problem 3

(define (binarize s t) 
  'todo)
; test

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Problem 4


(define (peak-positions s) 
  'todo)

; test 


;; part b explanation


; Optional part b code

(define (peak-positions2 n s) 
  'todo)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Problem 5

(define (peak-spacing s)
  'todo)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Problem 6

(define (check-regularity s tolerance n receiver) 
  'todo)

;;; provided test code

(define heartbeat (get-patient-heart-signal))
(define start-of-monitoring
  (peak-spacing (peak-positions2 1000 
                                 (binarize heartbeat 5))))
; get some visual idea of irregularity
;(plot-stream 
;   (map-stream (lambda (x) (- x (stream-car start-of-monitoring)))
;               start-of-monitoring)
;   2 141)

; get a printout
; (limited-print-stream 141 start-of-monitoring)

; now get the automated report
(define tolerance 2)                 ; durations can be at most 1 off
(define runlength 7)
(define (check-some s n)
  (if (= n 0)
      'done
      (check-regularity 
        s
        tolerance
        runlength
        (lambda (s regular)
          (display (if regular 'regular 'irregular))
	  (display " ")
	  (check-some s (- n 1))))))

;(check-some start-of-monitoring 20)  ; depends on heartbeaet...
;(check-some ones 20)                 ; should be all regular
;(check-some (bounded-random-stream 3 6) 20) ;all regular with high probability
;(set! runlength 2)
;(check-some (bounded-random-stream 3 6) 20) ; mix of regular, irregular


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Problem 7

;; a 
;; I recommend an auxilliary procedure taking a number of patients and
;; having patient-stream call the auxilliary procedure with an arbitrary
;; number of your choosing 

(define patient-stream 'todo)

;; b
(define (stream-nth n s)
  'todo)

;;c
(define (stream-nth-tail n s)
  'todo)

;; d
(define (stream-nth-action f)
  'todo)

(define stream-nth (stream-nth-action 'todo))
(define stream-nth-tail (stream-nth-action 'todo))

;; e
(define (plot-heartbeats s n)
  'todo)

;; f
(define (monitor patient-stream tolerance n)
  'todo)