//
//  Sound.cpp
//  libraries/audio/src
//
//  Created by Stephen Birarda on 1/2/2014.
//  Copyright 2014 High Fidelity, Inc.
//  Copyright 2023 Overte e.V.
//
//  Distributed under the Apache License, Version 2.0.
//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//  SPDX-License-Identifier: Apache-2.0
//

#include "Sound.h"

#include <stdint.h>

#include <glm/glm.hpp>

#include <QRunnable>
#include <QThreadPool>
#include <QDataStream>
#include <QtCore/QDebug>
#include <QtNetwork/QNetworkRequest>
#include <QtNetwork/QNetworkReply>
#include <qendian.h>

#include <LimitedNodeList.h>
#include <NetworkAccessManager.h>
#include <SharedUtil.h>
#include <ScriptEngine.h>
#include <ScriptValue.h>

#include "AudioRingBuffer.h"
#include "AudioLogging.h"
#include "AudioSRC.h"

#include "flump3dec.h"

int audioDataPointerMetaTypeID = qRegisterMetaType<AudioDataPointer>("AudioDataPointer");

using AudioConstants::AudioSample;

AudioDataPointer AudioData::make(uint32_t numSamples, uint32_t numChannels,
                                 const AudioSample* samples) {
    // Compute the amount of memory required for the audio data object
    const size_t bufferSize = numSamples * sizeof(AudioSample);
    const size_t memorySize = sizeof(AudioData) + bufferSize;

    // Allocate the memory for the audio data object and the buffer
    void* memory = ::calloc(1, memorySize);
    auto audioData = reinterpret_cast<AudioData*>(memory);
    auto buffer = reinterpret_cast<AudioSample*>(audioData + 1);
    assert(((char*)buffer - (char*)audioData) == sizeof(AudioData));

    // Use placement new to construct the audio data object at the memory allocated
    ::new(audioData) AudioData(numSamples, numChannels, buffer);

    // Copy the samples to the buffer
    memcpy(buffer, samples, bufferSize);

    // Return shared_ptr that properly destruct the object and release the memory
    return AudioDataPointer(audioData, [](AudioData* ptr) {
        ptr->~AudioData();
        ::free(ptr);
    });
}


AudioData::AudioData(uint32_t numSamples, uint32_t numChannels, const AudioSample* samples)
    : _numSamples(numSamples),
      _numChannels(numChannels),
      _data(samples)
{}

void Sound::downloadFinished(const QByteArray& data) {
    if (!_self) {
        soundProcessError(301, "Sound object has gone out of scope");
        return;
    }

    // this is a QRunnable, will delete itself after it has finished running
    auto soundProcessor = new SoundProcessor(_self, data);
    connect(soundProcessor, &SoundProcessor::onSuccess, this, &Sound::soundProcessSuccess);
    connect(soundProcessor, &SoundProcessor::onError, this, &Sound::soundProcessError);
    QThreadPool::globalInstance()->start(soundProcessor);
}

void Sound::soundProcessSuccess(AudioDataPointer audioData) {
    qCDebug(audio) << "Setting ready state for sound file" << _url.fileName();

    _audioData = std::move(audioData);
    finishedLoading(true);

    emit ready();
}

void Sound::soundProcessError(int error, QString str) {
    qCCritical(audio) << "Failed to process sound file: code =" << error << str;
    emit failed(QNetworkReply::UnknownContentError);
    finishedLoading(false);
}


SoundProcessor::SoundProcessor(QWeakPointer<Resource> sound, QByteArray data) :
    _sound(sound),
    _data(data)
{
}

void SoundProcessor::run() {
    auto sound = qSharedPointerCast<Sound>(_sound.lock());
    if (!sound) {
        emit onError(301, "Sound object has gone out of scope");
        return;
    }

    auto url = sound->getURL();
    QString fileName = url.fileName().toLower();
    qCDebug(audio) << "Processing sound file" << fileName;

    static const QString WAV_EXTENSION = ".wav";
    static const QString MP3_EXTENSION = ".mp3";
    static const QString RAW_EXTENSION = ".raw";
    static const QString STEREO_RAW_EXTENSION = ".stereo.raw";
    QString fileType;

    QByteArray outputAudioByteArray;
    AudioProperties properties;

    if (fileName.endsWith(WAV_EXTENSION)) {
        fileType = "WAV";
        properties = interpretAsWav(_data, outputAudioByteArray);
    } else if (fileName.endsWith(MP3_EXTENSION)) {
        fileType = "MP3";
        properties = interpretAsMP3(_data, outputAudioByteArray);
    } else if (fileName.endsWith(STEREO_RAW_EXTENSION)) {
        // check if this was a stereo raw file
        // since it's raw the only way for us to know that is if the file was called .stereo.raw
        qCDebug(audio) << "Processing sound of" << _data.size() << "bytes from" << fileName << "as stereo audio file.";
        // Process as 48khz RAW file
        properties.numChannels = 2;
        properties.sampleRate = 48000;
        outputAudioByteArray = _data;
    } else if (fileName.endsWith(RAW_EXTENSION)) {
        // Process as 48khz RAW file
        properties.numChannels = 1;
        properties.sampleRate = 48000;
        outputAudioByteArray = _data;
    } else {
        qCWarning(audio) << "Unknown sound file type";
        emit onError(300, "Failed to load sound file, reason: unknown sound file type");
        return;
    }

    if (properties.sampleRate == 0) {
        qCWarning(audio) << "Unsupported" << fileType << "file type";
        emit onError(300, "Failed to load sound file, reason: unsupported " + fileType + " file type");
        return;
    }

    auto data = downSample(outputAudioByteArray, properties);

    int numSamples = data.size() / AudioConstants::SAMPLE_SIZE;
    auto audioData = AudioData::make(numSamples, properties.numChannels,
                                     (const AudioSample*)data.constData());
    emit onSuccess(audioData);
}

QByteArray SoundProcessor::downSample(const QByteArray& rawAudioByteArray,
                                      AudioProperties properties) {

    // we want to convert it to the format that the audio-mixer wants
    // which is signed, 16-bit, 24Khz

    if (properties.sampleRate == AudioConstants::SAMPLE_RATE) {
        // no resampling needed
        return rawAudioByteArray;
    }

    AudioSRC resampler(properties.sampleRate, AudioConstants::SAMPLE_RATE,
                       properties.numChannels);

    // resize to max possible output
    int numSourceFrames = rawAudioByteArray.size() / (properties.numChannels * AudioConstants::SAMPLE_SIZE);
    int maxDestinationFrames = resampler.getMaxOutput(numSourceFrames);
    int maxDestinationBytes = maxDestinationFrames * properties.numChannels * AudioConstants::SAMPLE_SIZE;
    QByteArray data(maxDestinationBytes, Qt::Uninitialized);

    int numDestinationFrames = resampler.render((int16_t*)rawAudioByteArray.data(),
                                                (int16_t*)data.data(),
                                                numSourceFrames);

    // truncate to actual output
    int numDestinationBytes = numDestinationFrames * properties.numChannels * sizeof(AudioSample);
    data.resize(numDestinationBytes);

    return data;
}

//
// Format description from https://ccrma.stanford.edu/courses/422/projects/WaveFormat/
//
// The header for a WAV file looks like this:
// Positions     Sample Value     Description
//   00-03         "RIFF"       Marks the file as a riff file. Characters are each 1 byte long.
//   04-07         File size (int) Size of the overall file - 8 bytes, in bytes (32-bit integer).
//   08-11         "WAVE"       File Type Header. For our purposes, it always equals "WAVE".
//   12-15         "fmt "       Format chunk marker.
//   16-19         16           Length of format data as listed above
//   20-21         1            Type of format: (1=PCM, 257=Mu-Law, 258=A-Law, 259=ADPCM) - 2 byte integer
//   22-23         2            Number of Channels - 2 byte integer
//   24-27         44100        Sample Rate - 32 byte integer. Sample Rate = Number of Samples per second, or Hertz.
//   28-31         176400       (Sample Rate * BitsPerSample * Channels) / 8.
//   32-33         4            (BitsPerSample * Channels) / 8 - 8 bit mono2 - 8 bit stereo/16 bit mono4 - 16 bit stereo
//   34-35         16           Bits per sample
//   36-39         "data"       Chunk header. Marks the beginning of the data section.
//   40-43         File size (int) Size of the data section.
//   44-??                      Actual sound data
// Sample values are given above for a 16-bit stereo source.
//

struct chunk {
    char        id[4];
    quint32     size;
};

struct RIFFHeader {
    chunk       descriptor;     // "RIFF"
    char        type[4];        // "WAVE"
};

static const int WAVEFORMAT_PCM = 1;
static const int WAVEFORMAT_EXTENSIBLE = 0xfffe;

struct WAVEFormat {
    quint16     audioFormat;    // Format type: 1=PCM, 257=Mu-Law, 258=A-Law, 259=ADPCM
    quint16     numChannels;    // Number of channels: 1=mono, 2=stereo
    quint32     sampleRate;
    quint32     byteRate;       // Sample rate * Number of Channels * Bits per sample / 8
    quint16     blockAlign;     // (Number of Channels * Bits per sample) / 8.1
    quint16     bitsPerSample;
};

// returns wavfile sample rate, used for resampling
SoundProcessor::AudioProperties SoundProcessor::interpretAsWav(const QByteArray& inputAudioByteArray,
                                                               QByteArray& outputAudioByteArray) {
    AudioProperties properties;

    // Create a data stream to analyze the data
    QDataStream waveStream(const_cast<QByteArray *>(&inputAudioByteArray), QIODevice::ReadOnly);

    // Read the "RIFF" chunk
    RIFFHeader riff;
    if (waveStream.readRawData((char*)&riff, sizeof(RIFFHeader)) != sizeof(RIFFHeader)) {
        qCWarning(audio) << "Not a valid WAVE file.";
        return AudioProperties();
    }

    // Parse the "RIFF" chunk
    if (strncmp(riff.descriptor.id, "RIFF", 4) == 0) {
        waveStream.setByteOrder(QDataStream::LittleEndian);
    } else {
        qCWarning(audio) << "Currently not supporting big-endian audio files.";
        return AudioProperties();
    }
    if (strncmp(riff.type, "WAVE", 4) != 0) {
        qCWarning(audio) << "Not a valid WAVE file.";
        return AudioProperties();
    }

    // Read chunks until the "fmt " chunk is found
    chunk fmt;
    while (true) {
        if (waveStream.readRawData((char*)&fmt, sizeof(chunk)) != sizeof(chunk)) {
            qCWarning(audio) << "Not a valid WAVE file.";
            return AudioProperties();
        }
        if (strncmp(fmt.id, "fmt ", 4) == 0) {
            break;
        }
        waveStream.skipRawData(qFromLittleEndian<quint32>(fmt.size));   // next chunk
    }

    // Read the "fmt " chunk
    WAVEFormat wave;
    if (waveStream.readRawData((char*)&wave, sizeof(WAVEFormat)) != sizeof(WAVEFormat)) {
        qCWarning(audio) << "Not a valid WAVE file.";
        return AudioProperties();
    }

    // Parse the "fmt " chunk
    if (qFromLittleEndian<quint16>(wave.audioFormat) != WAVEFORMAT_PCM &&
        qFromLittleEndian<quint16>(wave.audioFormat) != WAVEFORMAT_EXTENSIBLE) {
        qCWarning(audio) << "Currently not supporting non PCM audio files.";
        return AudioProperties();
    }

    properties.numChannels = qFromLittleEndian<quint16>(wave.numChannels);
    if (properties.numChannels != 1 &&
        properties.numChannels != 2 &&
        properties.numChannels != 4) {
        qCWarning(audio) << "Currently not supporting audio files with other than 1/2/4 channels.";
        return AudioProperties();
    }
    if (qFromLittleEndian<quint16>(wave.bitsPerSample) != 16) {
        qCWarning(audio) << "Currently not supporting non 16bit audio files.";
        return AudioProperties();
    }

    // Skip any extra data in the "fmt " chunk
    waveStream.skipRawData(qFromLittleEndian<quint32>(fmt.size) - sizeof(WAVEFormat));

    // Read chunks until the "data" chunk is found
    chunk data;
    while (true) {
        if (waveStream.readRawData((char*)&data, sizeof(chunk)) != sizeof(chunk)) {
            qCWarning(audio) << "Not a valid WAVE file.";
            return AudioProperties();
        }
        if (strncmp(data.id, "data", 4) == 0) {
            break;
        }
        waveStream.skipRawData(qFromLittleEndian<quint32>(data.size));  // next chunk
    }

    // Read the "data" chunk
    quint32 outputAudioByteArraySize = qFromLittleEndian<quint32>(data.size);
    outputAudioByteArray.resize(outputAudioByteArraySize);
    auto bytesRead = waveStream.readRawData(outputAudioByteArray.data(), outputAudioByteArraySize);
    if (bytesRead != (int)outputAudioByteArraySize) {
        qCWarning(audio) << "Error reading WAV file";
        return AudioProperties();
    }

    properties.sampleRate = wave.sampleRate;
    return properties;
}

// returns MP3 sample rate, used for resampling
SoundProcessor::AudioProperties SoundProcessor::interpretAsMP3(const QByteArray& inputAudioByteArray,
                                                               QByteArray& outputAudioByteArray) {
    AudioProperties properties;

    using namespace flump3dec;

    static const int MP3_SAMPLES_MAX = 1152;
    static const int MP3_CHANNELS_MAX = 2;
    static const int MP3_BUFFER_SIZE = MP3_SAMPLES_MAX * MP3_CHANNELS_MAX * sizeof(int16_t);
    uint8_t mp3Buffer[MP3_BUFFER_SIZE];

    // create bitstream
    Bit_stream_struc *bitstream = bs_new();
    if (bitstream == nullptr) {
        return AudioProperties();
    }

    // create decoder
    mp3tl *decoder = mp3tl_new(bitstream, MP3TL_MODE_16BIT);
    if (decoder == nullptr) {
        bs_free(bitstream);
        return AudioProperties();
    }

    // initialize
    bs_set_data(bitstream, (uint8_t*)inputAudioByteArray.data(), inputAudioByteArray.size());
    int frameCount = 0;

    // skip ID3 tag, if present
    Mp3TlRetcode result = mp3tl_skip_id3(decoder);

    while (!(result == MP3TL_ERR_NO_SYNC || result == MP3TL_ERR_NEED_DATA)) {

        mp3tl_sync(decoder);

        // find MP3 header
        const fr_header *header = nullptr;
        result = mp3tl_decode_header(decoder, &header);

        if (result == MP3TL_ERR_OK) {

            if (frameCount++ == 0) {

                qCDebug(audio) << "Decoding MP3 with bitrate =" << header->bitrate
                               << "sample rate =" << header->sample_rate
                               << "channels =" << header->channels;

                // save header info
                properties.sampleRate = header->sample_rate;
                properties.numChannels = header->channels;

                // skip Xing header, if present
                result = mp3tl_skip_xing(decoder, header);
            }

            // decode MP3 frame
            if (result == MP3TL_ERR_OK) {

                result = mp3tl_decode_frame(decoder, mp3Buffer, MP3_BUFFER_SIZE);

                // fill bad frames with silence
                int len = header->frame_samples * header->channels * sizeof(int16_t);
                if (result == MP3TL_ERR_BAD_FRAME) {
                    memset(mp3Buffer, 0, len);
                }

                if (result == MP3TL_ERR_OK || result == MP3TL_ERR_BAD_FRAME) {
                    outputAudioByteArray.append((char*)mp3Buffer, len);
                }
            }
        }
    }

    // free decoder
    mp3tl_free(decoder);

    // free bitstream
    bs_free(bitstream);

    if (outputAudioByteArray.isEmpty()) {
        qCWarning(audio) << "Error decoding MP3 file";
        return AudioProperties();
    }

    return properties;
}


ScriptValue soundSharedPointerToScriptValue(ScriptEngine* engine, const SharedSoundPointer& in) {
    return engine->newQObject(new SoundScriptingInterface(in), ScriptEngine::ScriptOwnership);
}

bool soundSharedPointerFromScriptValue(const ScriptValue& object, SharedSoundPointer& out) {
    if (auto soundInterface = qobject_cast<SoundScriptingInterface*>(object.toQObject())) {
        out = soundInterface->getSound();
    }
    return true;
}

SoundScriptingInterface::SoundScriptingInterface(const SharedSoundPointer& sound) : _sound(sound) {
    // During shutdown we can sometimes get an empty sound pointer back
    if (_sound) {
        QObject::connect(_sound.data(), &Sound::ready, this, &SoundScriptingInterface::ready);
    }
}

Sound::Sound(const QUrl& url, bool isStereo, bool isAmbisonic) : Resource(url) {
    _numChannels = isAmbisonic ? 4 : (isStereo ? 2 : 1);
}