#include "main.h"
#include <QCoreApplication>
#include <QAudioFormat>
#if QT_VERSION_MAJOR > 5
#  include <QAudioSink>
#  include <QAudioDevice>
#  include <QMediaDevices>
#else
#  include <QAudioOutput>
#  include <QAudioDeviceInfo>
#endif
#include <QDebug>

Tester::Tester (QByteArray loop, bool underrun, QObject *parent) :
    QIODevice(parent),
    simUnderrun(underrun),
    loop(loop),
    looppos(0),
    bytesRead(0)
{
    open(QIODevice::ReadOnly);
    timer.start();
}

qint64 Tester::bytesAvailable () const {
    if (simUnderrun) {
        simUnderrun = false;
        return 0;
    }
    return loop.size();
}

qint64 Tester::writeData (const char *, qint64) {
    return -1;
}

qint64 Tester::readData (char *data, qint64 maxlen) {
    for (qint64 k = 0; k < maxlen; ++ k) {
        data[k] = loop.at(looppos ++);
        looppos %= loop.size();
    }
    bytesRead += maxlen;
    if (bytesRead >= 256*1024) {
        float Bps = bytesRead / (timer.nsecsElapsed() / 1000000000.0);
        float sps = Bps / sizeof(float);
        qDebug() << "current read rate" << sps << "samples/sec";
        bytesRead = 0;
        timer.restart();
    }
    return maxlen;
}

int main (int argc, char *argv[]) {

#if QT_VERSION_MAJOR > 5
    using DeviceInfo = QAudioDevice;
    using Output = QAudioSink;
    const auto Outputs = [](){return QMediaDevices::audioOutputs();};
    const auto DeviceName = [](auto dev){return dev.description();};
#else
    using DeviceInfo = QAudioDeviceInfo;
    using Output = QAudioOutput;
    const auto Outputs = [](){return QAudioDeviceInfo::availableDevices(QAudio::AudioOutput);};
    const auto DeviceName = [](auto dev){return dev.deviceName();};
#endif

    QCoreApplication a(argc, argv);
    DeviceInfo device;
    bool underrun;

    // usage: audioissue
    //        audioissue <devindex> [<underrun>]
    // no params = list devices
    // <devindex> = device index
    // <underrun> = can be anything; simulate underrun if set.
    if (argc < 2) {
        auto devs = Outputs();
        for (int k = 0; k < devs.size(); ++ k)
            qDebug() << k << DeviceName(devs[k]);
        return 0;
    } else {
        device = Outputs()[atoi(argv[1])];
        underrun = (argc >= 3);
    }

    QAudioFormat format = device.preferredFormat();
    format.setChannelCount(1);
#if QT_VERSION_MAJOR > 5
    format.setSampleFormat(QAudioFormat::Float);
#else
    format.setSampleSize(32);
    format.setSampleType(QAudioFormat::Float);
#endif
    assert(device.isFormatSupported(format));

    Output *output = new Output(device, format);

    // 1 second of a 440hz sine wave
    QByteArray loop;
    for (int k = 0; k < format.sampleRate(); ++ k) {
        float val = sinf(440.0f * 2.0f * 3.141592653f * k / format.sampleRate());
        loop.append((const char *)&val, sizeof(float));
    }

    Tester *tester = new Tester(loop, underrun);
    output->start(tester);
    qDebug() << output->state() << output->error();

    return a.exec();

}