#include "cell.h"

#include <stdlib.h>

#define DR_MP3_IMPLEMENTATION
#include "dr_mp3.h"

static JSValue mp3_make_info(JSContext *js, drmp3_uint32 channels, drmp3_uint32 sample_rate, drmp3_uint64 frames)
{
  JSValue obj = JS_NewObject(js);
  JS_SetPropertyStr(js, obj, "channels", JS_NewInt32(js, channels));
  JS_SetPropertyStr(js, obj, "sample_rate", JS_NewInt32(js, sample_rate));
  JS_SetPropertyStr(js, obj, "bits_per_sample", JS_NewInt32(js, 16));

  double total_frames = frames == DRMP3_UINT64_MAX ? -1.0 : (double)frames;
  JS_SetPropertyStr(js, obj, "total_pcm_frames", JS_NewFloat64(js, total_frames));
  JS_SetPropertyStr(js, obj, "decoded_bytes_per_frame",
    JS_NewInt32(js, (int)((size_t)channels * sizeof(drmp3_int16))));
  JS_SetPropertyStr(js, obj, "format", JS_NewString(js, "s16"));
  return obj;
}

JSC_CCALL(mp3_info,
  size_t len;
  void *data = js_get_blob_data(js, &len, argv[0]);
  if (data == -1)
    return JS_EXCEPTION;

  if (!data)
    return JS_ThrowReferenceError(js, "invalid MP3 data");

  drmp3 mp3;
  if (!drmp3_init_memory(&mp3, data, len, NULL))
    return JS_ThrowReferenceError(js, "invalid MP3 data");

  drmp3_uint32 channels = mp3.channels;
  drmp3_uint32 sample_rate = mp3.sampleRate;
  drmp3_uint64 frames = mp3.totalPCMFrameCount;
  if (frames == DRMP3_UINT64_MAX)
    frames = drmp3_get_pcm_frame_count(&mp3);

  JSValue info = mp3_make_info(js, channels, sample_rate, frames);
  drmp3_uninit(&mp3);
  return info;
)

static int mp3_calc_bytes(drmp3_uint32 channels, drmp3_uint64 frames, size_t *out_bytes)
{
  if (!out_bytes || channels == 0)
    return -1;

  size_t bytes_per_frame = (size_t)channels * sizeof(drmp3_int16);
  if (frames > SIZE_MAX / bytes_per_frame)
    return -1;

  *out_bytes = (size_t)(frames * bytes_per_frame);
  return 0;
}

JSC_CCALL(mp3_decode,
  size_t len;
  void *data = js_get_blob_data(js, &len, argv[0]);
  if (data == -1)
    return JS_EXCEPTION;

  if (!data)
    return JS_ThrowReferenceError(js, "invalid MP3 data");

  drmp3_config config;
  drmp3_uint64 frames = 0;
  float *pcm = drmp3_open_memory_and_read_pcm_frames_f32(data, len, &config, &frames, NULL);
  if (!pcm)
    return JS_ThrowReferenceError(js, "failed to decode MP3 data");

  size_t bytes_per_frame = (size_t)config.channels * sizeof(float);
  size_t total_bytes;
  
  if (frames > SIZE_MAX / bytes_per_frame) {
      drmp3_free(pcm, NULL);
      return JS_ThrowRangeError(js, "MP3 output too large");
  }
  total_bytes = (size_t)(frames * bytes_per_frame);

  JSValue result = mp3_make_info(js, config.channels, config.sampleRate, frames);
  
  // Update format info
  JS_SetPropertyStr(js, result, "format", JS_NewString(js, "f32"));
  JS_SetPropertyStr(js, result, "decoded_bytes_per_frame", JS_NewInt32(js, (int)bytes_per_frame));

  JSValue blob = js_new_blob_stoned_copy(js, pcm, total_bytes);
  JS_SetPropertyStr(js, result, "pcm", blob);
  drmp3_free(pcm, NULL);
  return result;
)

static const JSCFunctionListEntry js_mp3_funcs[] = {
  MIST_FUNC_DEF(mp3, info, 1),
  MIST_FUNC_DEF(mp3, decode, 1)
};

CELL_USE_FUNCS(js_mp3_funcs)