#include <stdio.h>
#include <stdlib.h>
#include <alsa/asoundlib.h>

#include <math.h>

#include "main.h"

double fclip(double value, double start, double end) {
  return 0.5 * ( fabs(value-start) + (start+end) - fabs(value-end) );
}

void play(struct user_data_s* data) {

  static char* device = "default";

  /* snd_output_t* output = NULL; */

  int err;
  snd_pcm_t* handle;
  snd_pcm_sframes_t frames;

  short buffer[data->audio_info_save->frames];
  for(unsigned long int i = 0; i < data->audio_info_save->frames; i++ ) {
    buffer[i] = (short)fclip( 32767.0 * data->mono_channel[i], -32767, +32768 );
  }

  if ((err = snd_pcm_open(&handle, device, SND_PCM_STREAM_PLAYBACK, 0)) < 0) {
    printf("Playback open error: %s\n", snd_strerror(err));
    exit(1);
  }

  if ((err = snd_pcm_set_params(handle, SND_PCM_FORMAT_S16,
                SND_PCM_ACCESS_RW_INTERLEAVED, 1,
                data->audio_info_save->samplerate,
                1, 500000)) < 0) {
    printf("Playback open error: %s\n", snd_strerror(err));
    exit(1);
  }

  for (int i = 0; i < 1; i++) {
    frames = snd_pcm_writei(handle, buffer, data->audio_info_save->frames);

    if (frames < 0) {
      frames = snd_pcm_recover(handle, frames, 0);
    }
    if (frames < 0) {
      printf("snd_pcm_writei failed: %s\n", snd_strerror(err));
      break;
    }
    if (frames > 0 && frames < (long)data->audio_info_save->frames) {
      printf("Short write (expected %li, wrote %li)\n",
         (long)data->audio_info_save->frames, frames);
    }
  }

  snd_pcm_close(handle);

}