/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#define LOG_TAG "bluetooth-a2dp"

#include "a2dp_aac_decoder.h"

#include <aacdecoder_lib.h>
#include <bluetooth/log.h>

#include <cstddef>
#include <cstdint>
#include <cstring>

#include "FDK_audio.h"
#include "a2dp_codec_api.h"
#include "machine_type.h"
#include "osi/include/allocator.h"
#include "stack/include/bt_hdr.h"

#define DECODE_BUF_LEN (8 * 2 * 1024)

using namespace bluetooth;

typedef struct {
  HANDLE_AACDECODER aac_handle;
  bool has_aac_handle;  // True if aac_handle is valid
  INT_PCM* decode_buf = nullptr;
  decoded_data_callback_t decode_callback;
} tA2DP_AAC_DECODER_CB;

static tA2DP_AAC_DECODER_CB a2dp_aac_decoder_cb;

bool A2DP_LoadDecoderAac(void) {
  // Nothing to do - the library is statically linked
  return true;
}

void A2DP_UnloadDecoderAac(void) { a2dp_aac_decoder_cleanup(); }

bool a2dp_aac_decoder_init(decoded_data_callback_t decode_callback) {
  a2dp_aac_decoder_cleanup();

  a2dp_aac_decoder_cb.aac_handle = aacDecoder_Open(TT_MP4_LATM_MCP1, 1 /* nrOfLayers */);
  a2dp_aac_decoder_cb.has_aac_handle = true;
  a2dp_aac_decoder_cb.decode_buf = static_cast<INT_PCM*>(
          osi_malloc(sizeof(a2dp_aac_decoder_cb.decode_buf[0]) * DECODE_BUF_LEN));
  a2dp_aac_decoder_cb.decode_callback = decode_callback;
  return true;
}

void a2dp_aac_decoder_cleanup(void) {
  if (a2dp_aac_decoder_cb.has_aac_handle) {
    aacDecoder_Close(a2dp_aac_decoder_cb.aac_handle);
  }
  osi_free(a2dp_aac_decoder_cb.decode_buf);
  memset(&a2dp_aac_decoder_cb, 0, sizeof(a2dp_aac_decoder_cb));
}

bool a2dp_aac_decoder_decode_packet(BT_HDR* p_buf) {
  auto* pBuffer = reinterpret_cast<UCHAR*>(p_buf->data + p_buf->offset);
  UINT bufferSize = p_buf->len;
  UINT bytesValid = p_buf->len;
  while (bytesValid > 0) {
    AAC_DECODER_ERROR err =
            aacDecoder_Fill(a2dp_aac_decoder_cb.aac_handle, &pBuffer, &bufferSize, &bytesValid);
    if (err != AAC_DEC_OK) {
      log::error("aacDecoder_Fill failed: 0x{:x}", static_cast<unsigned>(err));
      return false;
    }

    while (true) {
      err = aacDecoder_DecodeFrame(a2dp_aac_decoder_cb.aac_handle, a2dp_aac_decoder_cb.decode_buf,
                                   DECODE_BUF_LEN, 0 /* flags */);
      if (err == AAC_DEC_NOT_ENOUGH_BITS) {
        break;
      }
      if (err != AAC_DEC_OK) {
        log::error("aacDecoder_DecodeFrame failed: 0x{:x}", static_cast<int>(err));
        break;
      }

      CStreamInfo* info = aacDecoder_GetStreamInfo(a2dp_aac_decoder_cb.aac_handle);
      if (!info || info->sampleRate <= 0) {
        log::error("Invalid stream info");
        break;
      }

      size_t frame_len =
              info->frameSize * info->numChannels * sizeof(a2dp_aac_decoder_cb.decode_buf[0]);
      a2dp_aac_decoder_cb.decode_callback(
              reinterpret_cast<uint8_t*>(a2dp_aac_decoder_cb.decode_buf), frame_len);
    }
  }

  return true;
}