/* Copyright Statement:
 * *
 * * This software/firmware and related documentation ("MediaTek Software") are
 * * protected under relevant copyright laws. The information contained herein
 * * is confidential and proprietary to MediaTek Inc. and/or its licensors.
 * * Without the prior written permission of MediaTek inc. and/or its licensors,
 * * any reproduction, modification, use or disclosure of MediaTek Software,
 * * and information contained herein, in whole or in part, shall be strictly
 * * prohibited.
 * *
 * * MediaTek Inc. (C) 2016. All rights reserved.
 * *
 * * BY OPENING THIS FILE, RECEIVER HEREBY UNEQUIVOCALLY ACKNOWLEDGES AND AGREES
 * * THAT THE SOFTWARE/FIRMWARE AND ITS DOCUMENTATIONS ("MEDIATEK SOFTWARE")
 * * RECEIVED FROM MEDIATEK AND/OR ITS REPRESENTATIVES ARE PROVIDED TO RECEIVER
 * * ON AN "AS-IS" BASIS ONLY. MEDIATEK EXPRESSLY DISCLAIMS ANY AND ALL
 * * WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
 * * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * * NONINFRINGEMENT.
 * * NEITHER DOES MEDIATEK PROVIDE ANY WARRANTY WHATSOEVER WITH RESPECT TO THE
 * * SOFTWARE OF ANY THIRD PARTY WHICH MAY BE USED BY, INCORPORATED IN, OR
 * * SUPPLIED WITH THE MEDIATEK SOFTWARE, AND RECEIVER AGREES TO LOOK ONLY TO
 * * SUCH THIRD PARTY FOR ANY WARRANTY CLAIM RELATING THERETO. RECEIVER
 * * EXPRESSLY ACKNOWLEDGES THAT IT IS RECEIVER'S SOLE RESPONSIBILITY TO OBTAIN
 * * FROM ANY THIRD PARTY ALL PROPER LICENSES CONTAINED IN MEDIATEK SOFTWARE.
 * * MEDIATEK SHALL ALSO NOT BE RESPONSIBLE FOR ANY MEDIATEK SOFTWARE RELEASES
 * * MADE TO RECEIVER'S SPECIFICATION OR TO CONFORM TO A PARTICULAR STANDARD OR
 * * OPEN FORUM. RECEIVER'S SOLE AND EXCLUSIVE REMEDY AND MEDIATEK'S ENTIRE AND
 * * CUMULATIVE LIABILITY WITH RESPECT TO THE MEDIATEK SOFTWARE RELEASED
 * * HEREUNDER WILL BE, AT MEDIATEK'S OPTION, TO REVISE OR REPLACE THE MEDIATEK
 * * SOFTWARE AT ISSUE, OR REFUND ANY SOFTWARE LICENSE FEES OR SERVICE CHARGE
 * * PAID BY RECEIVER TO MEDIATEK FOR SUCH MEDIATEK SOFTWARE AT ISSUE.
 * *
 * * The following software/firmware and/or related documentation ("MediaTek Software")
 * * have been modified by MediaTek Inc. All revisions are subject to any receiver's
 * * applicable license agreements with MediaTek Inc.
 * */


#define LOG_TAG "a2dp_aac_vbr"
#define ATRACE_TAG ATRACE_TAG_AUDIO

#include <stdlib.h>
#ifndef OS_GENERIC
#include <cutils/trace.h>
#endif
#include <dlfcn.h>
#include <inttypes.h>
#include <stdio.h>
#include <string.h>

#include "common/time_util.h"
#include "osi/include/log.h"
#include "osi/include/osi.h"
#include "mtk_btif_av.h"

#include "a2dp_aac_encoder.h"
#include "a2dp_aac_constants.h"
#include "osi/include/properties.h"
#include "mediatek/stack/include/a2dp_aac_vbr.h"

#if defined(MTK_INTEROP_EXTENSION) && (MTK_INTEROP_EXTENSION == TRUE)
#include "interop_mtk.h"
#include "btif_av.h"
#endif

static bool bPropSupportVbr;
static int iPeerSupportVbrVal;
static bool bPropUpdate = false;
static int iMaxVbrMode;

// Here, Set VBR params:
#define DOWN_QUEUE_LENGTH      (2)  /*!< If >= DOWN_QUEUE_LENGTH, It's mean link bad state */
#define UP_QUEUE_LENGTH        (0)  /*!< If = UP_QUEUE_LENGTH, It's mean link good state */
#define DOWN_SAMPLE_COUNT      (10) /*!< Down: Sample 10*20ms=200ms. */
#define UP_SAMPLE_COUNT        (50) /*!< Up: Sample 50*20ms=1s. */
#define DOWN_ADJ_VBR_LEVEL     (2)  /*!< If the current mode >= mode3, adjust to reduce two level */

#define MIN_A2DP_VBR_MODE      (AACENC_BR_MODE_VBR_1)
#define MAX_A2DP_VBR_MODE      (AACENC_BR_MODE_VBR_5)
#define AAC_VBR_DEFAULT_MODE   (AACENC_BR_MODE_VBR_4)

struct vbr_helper_st {
  unsigned int dnBitrateCnt;
  unsigned int dnBitrateSum;
  unsigned int dnthreshold;

  unsigned int upBitrateCnt;
  unsigned int upBitrateSum;
  unsigned int upthreshold;

  int last_mode;
  int cur_mode;
};

static struct vbr_helper_st stVbrHelper = {
  0, 0, DOWN_SAMPLE_COUNT, 0, 0, UP_SAMPLE_COUNT, AACENC_BR_MODE_INVALID, AAC_VBR_DEFAULT_MODE};

static void resetDnBitRateParam() {
  stVbrHelper.dnBitrateCnt = 0;
  stVbrHelper.dnBitrateSum = 0;
}

static void resetUpBitRateParam() {
  stVbrHelper.upBitrateCnt = 0;
  stVbrHelper.upBitrateSum = 0;
}

void mtk_aac_vbr_prop_updated() {
  bPropUpdate = false;
}

void mtk_aac_vbr_set_support(int bitrate_support_val) {
  iPeerSupportVbrVal = bitrate_support_val;
}

void mtk_aac_vbr_set_max_mode(int max_vbr_mode) {
  iMaxVbrMode = max_vbr_mode;
}

int mtk_aac_vbr_get_max_mode() {
  return (int)iMaxVbrMode > MAX_A2DP_VBR_MODE ? AAC_VBR_DEFAULT_MODE : iMaxVbrMode;
}

/*******************************************************************************
**
** Function         mtk_aac_vbr_enabled
**
** Description      Check AAC VBR for enable, Input three Vaule:
**                  1). persist.bluetooth.a2dp_aac_vbr.enable.
**                  2). iPeerSupportVbrVal.
**                  3). bPropUpdate.
**
** Returns          bool
**
*******************************************************************************/
bool mtk_aac_vbr_enabled() {
  if (!bPropUpdate) {
    char value_aacvbr[PROPERTY_VALUE_MAX] = {'\0'};
    osi_property_get("vendor.bluetooth.a2dp_aac_vbr.enable", value_aacvbr, "true");
    bPropSupportVbr = (strcmp(value_aacvbr, "true") == 0);
    bPropUpdate = true;
  }
  return (iPeerSupportVbrVal == A2DP_AAC_VARIABLE_BIT_RATE_ENABLED) &&
          bPropUpdate && bPropSupportVbr;
}

/*******************************************************************************
**
** Function         mtk_aac_vbr_get_mode
**
** Description      Input queueLen to gets the current VBR mode.
**
** Returns          int vbr_mode
**
*******************************************************************************/
int mtk_aac_vbr_get_mode(size_t queueLen) {
  int vbr_mode = AACENC_BR_MODE_INVALID;

  stVbrHelper.upBitrateSum += queueLen;
  stVbrHelper.dnBitrateSum += queueLen;
  stVbrHelper.upBitrateCnt++;
  stVbrHelper.dnBitrateCnt++;

  if (stVbrHelper.dnBitrateCnt >= stVbrHelper.dnthreshold) {
    size_t queueLength = stVbrHelper.dnBitrateSum / stVbrHelper.dnBitrateCnt;
    resetDnBitRateParam();
    if (queueLength >= DOWN_QUEUE_LENGTH && stVbrHelper.cur_mode > MIN_A2DP_VBR_MODE) {
      if (stVbrHelper.cur_mode >= AACENC_BR_MODE_VBR_3) stVbrHelper.cur_mode -= DOWN_ADJ_VBR_LEVEL;
      else stVbrHelper.cur_mode = MIN_A2DP_VBR_MODE;
      LOG_INFO("%s: [Down Bitrate] Adjust to low VBR mode(%d), queue length(%zu)",
                __func__, stVbrHelper.cur_mode, queueLength);
      resetUpBitRateParam();
    }
  }

  if (stVbrHelper.upBitrateCnt >= stVbrHelper.upthreshold) {
    size_t queueLength = stVbrHelper.upBitrateSum / stVbrHelper.upBitrateCnt;
    resetUpBitRateParam();
    int support_max_vbr_mode = mtk_aac_vbr_get_max_mode();
    if (queueLength == UP_QUEUE_LENGTH && stVbrHelper.cur_mode < support_max_vbr_mode) {
      stVbrHelper.cur_mode++;
      if (stVbrHelper.cur_mode > support_max_vbr_mode) stVbrHelper.cur_mode = support_max_vbr_mode;
      LOG_INFO("%s: [Up Bitrate] Adjust to high VBR mode(%d)",
                __func__, stVbrHelper.cur_mode);
      resetDnBitRateParam();
    }
  }

  if (stVbrHelper.last_mode != stVbrHelper.cur_mode) {
    vbr_mode = stVbrHelper.cur_mode;
    stVbrHelper.last_mode = vbr_mode;
  }
  return vbr_mode;
}

#undef ATRACE_TAG