/*
    Bluetooth A2DP audio stream consumer - PWMAudio

    Copyright (c) 2024 Earle F. Philhower, III <earlephilhower@yahoo.com>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

#include "BluetoothAudioConsumerPWM.h"
#include "A2DPSink.h"
#include <functional>

#define CCALLBACKNAME _BTA2DPPWM
#include <ctocppcallback.h>
#define NOPARAMCB(class, cbFcn) \
  (CCALLBACKNAME<void(void), __COUNTER__>::func = std::bind(&class::cbFcn, this), \
   static_cast<void (*)(void)>(CCALLBACKNAME<void(void), __COUNTER__ - 1>::callback))

bool BluetoothAudioConsumerPWM::init(uint8_t channels, uint32_t samplerate, A2DPSink *a2dpSink) {
    _channels = channels;
    _samplerate = samplerate;
    _a2dpSink = a2dpSink;
    _pwm->setStereo(channels == 2);
    _pwm->setBuffers(16, 64);
    _pwm->onTransmit(NOPARAMCB(BluetoothAudioConsumerPWM, fill));
    if (_pwm->begin(samplerate)) {
        _state = STATE_INITIALIZED;
        _gain = 64;
        return true;
    }
    return false;
}

void BluetoothAudioConsumerPWM::setVolume(uint8_t gain) {
    _gain = gain;
}

void BluetoothAudioConsumerPWM::startStream() {
    if (_state != STATE_INITIALIZED) {
        return;
    }
    _state = STATE_STREAMING;
}

void BluetoothAudioConsumerPWM::stopStream() {
    if (_state != STATE_STREAMING) {
        return;
    }
    _state = STATE_INITIALIZED;
}

void BluetoothAudioConsumerPWM::close() {
    if (_state == STATE_STREAMING) {
        stopStream();
    }
    _state = STATE_OFF;
    _pwm->end();
}

void BluetoothAudioConsumerPWM::fill() {
    int num_samples = _pwm->availableForWrite() / 2;
    int16_t buff[32 * 2];
    while (num_samples > 63) {
        _a2dpSink->playback_handler((int16_t *) buff, 32);
        num_samples -= 64;
        for (int i = 0; i < 64; i++) {
            int32_t tmp = buff[i];
            tmp *= _gain;
            tmp >>= 8;
            _pwm->write((int16_t)tmp);
        }
    }
}