#lang racket

(provide flot->liste)
(provide gen-signal)
(provide quantification)
(provide passage-par-zero)

; ***************** IFT359 / TP4 Groupe 2
; ***************** Lafreniere, Jonathan 17084316
; ***************** Pelletier, Robin 17056187

(define (car-flot f)
(car f))
(define (cdr-flot f)
(force (cdr f)))
(define flot-null null)
(define (flot-null? f)
(null? f))
(define-syntax consflot
(syntax-rules ()
((consflot a b) (cons a (delay b)))))



(define (gen-signal a b dt c)
  (gen-signal_inter a b dt c 0)
  )

(define (gen-signal_inter a b dt c step)
 (let* (
    [signal (lambda(x) (* a (sin (+ c (* b (* x dt))))))]
    [flot (consflot (signal step) (gen-signal_inter a b dt c (+ step 1)))]
    ) flot))



(define (flot->liste n flot)
  (flot->liste_inter 0 n flot)
  )

(define (flot->liste_inter i n flot)
  (
   if (= i n) '()
       (cons (car-flot flot) (flot->liste_inter (+ i 1) n (cdr-flot flot)))

  ))


(define (quantification flot amplitude nbits)
  (consflot (trouverInterval(car-flot flot) amplitude nbits)
             (quantification (cdr-flot flot) amplitude nbits)
 ))

(define (trouverInterval f amp nbits [debut (* amp -1)])
  (if (= debut amp) (- amp (/ amp (/ (expt 2 nbits) 2)))
      (cond[(= f (* amp -1)) (* amp -1)]
           [(<= f (+ debut (/ amp (/ (expt 2 nbits) 2 )))) debut]
           [else (trouverInterval f amp nbits (+ debut(/ amp (/ (expt 2 nbits) 2))))]))
  )


(define (passage-par-zero flot)
  (passage-par-zero_inter (cdr-flot flot) (car-flot flot))
 )

(define (passage-par-zero_inter flot prev_value)
  (let*(
        [current_value (car-flot flot)]
        [flot_value (if (and ( < prev_value 0) (>= current_value 0)) 1
                        (if(and (>= prev_value 0) (< current_value 0)) -1 0)

                        )

            ]
        [res (consflot flot_value (passage-par-zero_inter (cdr-flot flot) current_value))]

        ) res
    )
  )