(require rsound)
(require 2htdp/universe)

;;; DATA DEFINITIONS ;;;

; a second is a number
; representing a length of time

; a frame is a number
; representing a length of time

; a playerstate is a (make-playerstate boolean boolean number)
(define-struct playerstate (1? 2? songpos))
; where
; 1? represents whether the first track is playing,
; 2? represents whether the second track is playing,
; and
; songpos represents the number of frames that have passed
; ex
(make-playerstate #t
                  #t
                  0)

;;; GLOBAL CONSTANTS ;;;
(define FR 48000)
(define TRACK1 (rs-read "sounds/1a.wav"))
(define TRACK2 (rs-read "sounds/1b.wav"))
(define INIT (make-playerstate #t
                               #t
                               0))
(define STREAM (make-pstream))

;;; HELPER FUNCTIONS ;;;

; second -> frame
; convert seconds to frames
(define (sec s)
  (* s FR))
(check-expect (sec 5) (* 5 FR))
(check-expect (sec 0) 0)

; ps -> boolean
; decide whether the pstream should queue another sound
(define (queue? ps)
  #true)



;;; BIG BANG FUNCTIONS ;;;

; if its time to play then assemble a sound from all of the currently playing sections
; overlay into one sound and play that or queue each sound

; ps -> ps
; process a new playerstate
(define (tock ps)
  (cond [(queue? ps)
         (cond [(playerstate-1? ps) (andqueue STREAM TRACK1 (playerstate-songpos ps)
                                              ps)]
               [(playerstate-2? ps) (andqueue STREAM TRACK2 (playerstate-songpos ps)
                                              ps)]
               [else ...] ; do nothing
               )]
        [else ...] ; do nothing
        ))

; ps -> image
; render an image based on the playerstate
(define (render ps)
  (empty-scene 200 200))

; ps ke -> ps
; handle key input and return a new playerstate
(define (key-handler ps ke)
  (
  )

(define (main x)
  (big-bang INIT
            [on-tick tock (/ 1 48000]
            [to-draw render]
            [on-key key-handler]))