;; This is the main script for the pcm-dispatch tool
;; last main-arg nominates the configuration file

(signal 1 (fn (x) (exit 0)))
(signal 2 (fn (x) (exit 0)))
(signal 15 (fn (x) (exit 0)))

(load "misc.lsp")

; load contexts libasound and ALSA
(load "libasound.lsp")

(unless (> (length (main-args)) 1)
  (die 1 "Usage: <config>"))

(context libc)
(import LIB "dup2" "int"
        "int" ; int oldfd
        "int" ; int newfd
        )
(context MAIN)

(setf
 CONFIGFILE (main-args -1)
 CONFIGTEXT (read-file CONFIGFILE)
 CONFIG (read-expr CONFIGTEXT)
 PCM-LIST (rest (assoc "PCM-LIST" CONFIG))
 )

(define (open-pcm PCM)
  (ALSA:snd_pcm_open PCM libasound:SND_PCM_STREAM_PLAYBACK 0 ))

(define (setup-pcm PCM)
  (libasound:snd_pcm_set_params
   PCM
   libasound:SND_PCM_FORMAT_S16_LE
   libasound:SND_PCM_ACCESS_RW_INTERLEAVED
   2     ; channels
   48000 ; rate
   1     ; soft resample (0/1)
   10000 ; latency (microseconds)
   ))

;(! (format "ls -l /proc/%d/fd" (sys-info 7)))
(let ((REDIR (open "/dev/null" "append"))) ; "/tmp/test1"
  (when (< REDIR) (exit 1))
  (when (< (libc:dup2 REDIR 2)) (exit 1))
  (when (< (libc:dup2 REDIR 1)) (exit 1))
  (close REDIR)
)
;; Change ALSA configuration for this process
(setf KEY "pcm.out1.device" VALUE "20:74:CF:C0:22:81")
(when (!= (setf E (ALSA:set_config_string KEY VALUE)))
  (die 1 "set_config_string " E))

;; Find first usable PCM
(setf PCM (unless (dolist (PCM PCM-LIST (open-pcm PCM)))
            (die 1 "No PCM available")))

(define (ready PCM)
  (dotimes (x 1000 (!= -32 (libasound:snd_pcm_wait PCM -1)))
    (sleep 10)))

(when (!= (setf E (setup-pcm PCM)))
  (libasound:snd_pcm_close PCM)
  (die 1 "set params" E))

;;(die nil "status" (libasound:snd_pcm_start PCM))

(setf N 0 x 0 E 0 i 0)

;(define BUFFER:BUFFER (dup "\000" 1000008))

(setf CACHE nil)
(while (> (or (setf N (read 0 BUFFER 20000000)) 0))
  ;(println "reading " N)
  (setf CACHE BUFFER)
  (while (> N) 
    (ready PCM)
    (when (< (setf E (libasound:snd_pcm_writei PCM CACHE (/ N 4))))
      (libasound:snd_pcm_close PCM)
      (die 1 "writing" E N))
    (setf E (* E 4))
    (setf CACHE (E CACHE))
    ;(println "wrote " E)
    (dec N E)
    )
  )

(libasound:snd_pcm_wait PCM -1)

(libasound:snd_pcm_drain PCM)
(libasound:snd_pcm_close PCM)