/****************************************************************************
**
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtMultimedia module of the Qt Toolkit.
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** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
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**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
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****************************************************************************/

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists for the convenience
// of other Qt classes.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//

#include <QtCore/qcoreapplication.h>
#include "qaudioinput_alsa_p.h"
#include "qaudiodeviceinfo_alsa_p.h"

QT_BEGIN_NAMESPACE

//#define DEBUG_AUDIO 1

static const int minimumIntervalTime = 50;

QAudioInputPrivate::QAudioInputPrivate(const QByteArray &device, const QAudioFormat& audioFormat):
    settings(audioFormat)
{
    bytesAvailable = 0;
    handle = 0;
    ahandler = 0;
    access = SND_PCM_ACCESS_RW_INTERLEAVED;
    pcmformat = SND_PCM_FORMAT_S16;
    buffer_size = 0;
    period_size = 0;
    buffer_time = 100000;
    period_time = 20000;
    totalTimeValue = 0;
    intervalTime = 1000;
    audioBuffer = 0;
    errorState = QAudio::NoError;
    deviceState = QAudio::StoppedState;
    audioSource = 0;
    pullMode = true;
    resuming = false;

    m_device = device;

    timer = new QTimer(this);
    connect(timer,SIGNAL(timeout()),SLOT(userFeed()));
}

QAudioInputPrivate::~QAudioInputPrivate()
{
    close();
    disconnect(timer, SIGNAL(timeout()));
    QCoreApplication::processEvents();
    delete timer;
}

QAudio::Error QAudioInputPrivate::error() const
{
    return errorState;
}

QAudio::State QAudioInputPrivate::state() const
{
    return deviceState;
}


QAudioFormat QAudioInputPrivate::format() const
{
    return settings;
}

int QAudioInputPrivate::xrun_recovery(int err)
{
    int  count = 0;
    bool reset = false;

    if(err == -EPIPE) {
        errorState = QAudio::UnderrunError;
        err = snd_pcm_prepare(handle);
        if(err < 0)
            reset = true;
        else {
            bytesAvailable = bytesReady();
            if (bytesAvailable <= 0)
                reset = true;
        }

    } else if((err == -ESTRPIPE)||(err == -EIO)) {
        errorState = QAudio::IOError;
        while((err = snd_pcm_resume(handle)) == -EAGAIN){
            usleep(100);
            count++;
            if(count > 5) {
                reset = true;
                break;
            }
        }
        if(err < 0) {
            err = snd_pcm_prepare(handle);
            if(err < 0)
                reset = true;
        }
    }
    if(reset) {
        close();
        open();
        snd_pcm_prepare(handle);
        return 0;
    }
    return err;
}

int QAudioInputPrivate::setFormat()
{
    snd_pcm_format_t format = SND_PCM_FORMAT_S16;

    if(settings.sampleSize() == 8) {
        format = SND_PCM_FORMAT_U8;
    } else if(settings.sampleSize() == 16) {
        if(settings.sampleType() == QAudioFormat::SignedInt) {
            if(settings.byteOrder() == QAudioFormat::LittleEndian)
                format = SND_PCM_FORMAT_S16_LE;
            else
                format = SND_PCM_FORMAT_S16_BE;
        } else if(settings.sampleType() == QAudioFormat::UnSignedInt) {
            if(settings.byteOrder() == QAudioFormat::LittleEndian)
                format = SND_PCM_FORMAT_U16_LE;
            else
                format = SND_PCM_FORMAT_U16_BE;
        }
    } else if(settings.sampleSize() == 24) {
        if(settings.sampleType() == QAudioFormat::SignedInt) {
            if(settings.byteOrder() == QAudioFormat::LittleEndian)
                format = SND_PCM_FORMAT_S24_LE;
            else
                format = SND_PCM_FORMAT_S24_BE;
        } else if(settings.sampleType() == QAudioFormat::UnSignedInt) {
            if(settings.byteOrder() == QAudioFormat::LittleEndian)
                format = SND_PCM_FORMAT_U24_LE;
            else
                format = SND_PCM_FORMAT_U24_BE;
        }
    } else if(settings.sampleSize() == 32) {
        if(settings.sampleType() == QAudioFormat::SignedInt) {
            if(settings.byteOrder() == QAudioFormat::LittleEndian)
                format = SND_PCM_FORMAT_S32_LE;
            else
                format = SND_PCM_FORMAT_S32_BE;
        } else if(settings.sampleType() == QAudioFormat::UnSignedInt) {
            if(settings.byteOrder() == QAudioFormat::LittleEndian)
                format = SND_PCM_FORMAT_U32_LE;
            else
                format = SND_PCM_FORMAT_U32_BE;
        } else if(settings.sampleType() == QAudioFormat::Float) {
            if(settings.byteOrder() == QAudioFormat::LittleEndian)
                format = SND_PCM_FORMAT_FLOAT_LE;
            else
                format = SND_PCM_FORMAT_FLOAT_BE;
        }
    } else if(settings.sampleSize() == 64) {
        if(settings.byteOrder() == QAudioFormat::LittleEndian)
            format = SND_PCM_FORMAT_FLOAT64_LE;
        else
            format = SND_PCM_FORMAT_FLOAT64_BE;
    }

    return snd_pcm_hw_params_set_format( handle, hwparams, format);
}

QIODevice* QAudioInputPrivate::start(QIODevice* device)
{
    if(deviceState != QAudio::StoppedState)
        close();

    if(!pullMode && audioSource) {
        delete audioSource;
    }

    if(device) {
        //set to pull mode
        pullMode = true;
        audioSource = device;
        deviceState = QAudio::ActiveState;
    } else {
        //set to push mode
        pullMode = false;
        deviceState = QAudio::IdleState;
        audioSource = new InputPrivate(this);
        audioSource->open(QIODevice::ReadOnly | QIODevice::Unbuffered);
    }

    if( !open() )
        return 0;

    emit stateChanged(deviceState);

    return audioSource;
}

void QAudioInputPrivate::stop()
{
    if(deviceState == QAudio::StoppedState)
        return;

    deviceState = QAudio::StoppedState;

    close();
    emit stateChanged(deviceState);
}

bool QAudioInputPrivate::open()
{
#ifdef DEBUG_AUDIO
    QTime now(QTime::currentTime());
    qDebug()<<now.second()<<"s "<<now.msec()<<"ms :open()";
#endif
    clockStamp.restart();
    timeStamp.restart();
    elapsedTimeOffset = 0;

    int dir;
    int err=-1;
    int count=0;
    unsigned int freakuency=settings.frequency();

    QString dev = QString(QLatin1String(m_device.constData()));
    QList<QByteArray> devices = QAudioDeviceInfoInternal::availableDevices(QAudio::AudioInput);
    if(dev.compare(QLatin1String("default")) == 0) {
#if(SND_LIB_MAJOR == 1 && SND_LIB_MINOR == 0 && SND_LIB_SUBMINOR >= 14)
        dev = QLatin1String(devices.first());
#else
        dev = QLatin1String("hw:0,0");
#endif
    } else {
#if(SND_LIB_MAJOR == 1 && SND_LIB_MINOR == 0 && SND_LIB_SUBMINOR >= 14)
        dev = QLatin1String(m_device);
#else
        int idx = 0;
        char *name;

        QString shortName = QLatin1String(m_device.mid(m_device.indexOf('=',0)+1).constData());

        while(snd_card_get_name(idx,&name) == 0) {
            if(qstrncmp(shortName.toLocal8Bit().constData(),name,shortName.length()) == 0)
                break;
            idx++;
        }
        dev = QString(QLatin1String("hw:%1,0")).arg(idx);
#endif
    }

    // Step 1: try and open the device
    while((count < 5) && (err < 0)) {
        err=snd_pcm_open(&handle,dev.toLocal8Bit().constData(),SND_PCM_STREAM_CAPTURE,0);
        if(err < 0)
            count++;
    }
    if (( err < 0)||(handle == 0)) {
        errorState = QAudio::OpenError;
        deviceState = QAudio::StoppedState;
        emit stateChanged(deviceState);
        return false;
    }
    snd_pcm_nonblock( handle, 0 );

    // Step 2: Set the desired HW parameters.
    snd_pcm_hw_params_alloca( &hwparams );

    bool fatal = false;
    QString errMessage;
    unsigned int chunks = 8;

    err = snd_pcm_hw_params_any( handle, hwparams );
    if ( err < 0 ) {
        fatal = true;
        errMessage = QString::fromLatin1("QAudioInput: snd_pcm_hw_params_any: err = %1").arg(err);
    }
    if ( !fatal ) {
        err = snd_pcm_hw_params_set_rate_resample( handle, hwparams, 1 );
        if ( err < 0 ) {
            fatal = true;
            errMessage = QString::fromLatin1("QAudioInput: snd_pcm_hw_params_set_rate_resample: err = %1").arg(err);
        }
    }
    if ( !fatal ) {
        err = snd_pcm_hw_params_set_access( handle, hwparams, access );
        if ( err < 0 ) {
            fatal = true;
            errMessage = QString::fromLatin1("QAudioInput: snd_pcm_hw_params_set_access: err = %1").arg(err);
        }
    }
    if ( !fatal ) {
        err = setFormat();
        if ( err < 0 ) {
            fatal = true;
            errMessage = QString::fromLatin1("QAudioInput: snd_pcm_hw_params_set_format: err = %1").arg(err);
        }
    }
    if ( !fatal ) {
        err = snd_pcm_hw_params_set_channels( handle, hwparams, (unsigned int)settings.channels() );
        if ( err < 0 ) {
            fatal = true;
            errMessage = QString::fromLatin1("QAudioInput: snd_pcm_hw_params_set_channels: err = %1").arg(err);
        }
    }
    if ( !fatal ) {
        err = snd_pcm_hw_params_set_rate_near( handle, hwparams, &freakuency, 0 );
        if ( err < 0 ) {
            fatal = true;
            errMessage = QString::fromLatin1("QAudioInput: snd_pcm_hw_params_set_rate_near: err = %1").arg(err);
        }
    }
    if ( !fatal ) {
        err = snd_pcm_hw_params_set_buffer_time_near(handle, hwparams, &buffer_time, &dir);
        if ( err < 0 ) {
            fatal = true;
            errMessage = QString::fromLatin1("QAudioInput: snd_pcm_hw_params_set_buffer_time_near: err = %1").arg(err);
        }
    }
    if ( !fatal ) {
        err = snd_pcm_hw_params_set_period_time_near(handle, hwparams, &period_time, &dir);
        if ( err < 0 ) {
            fatal = true;
            errMessage = QString::fromLatin1("QAudioInput: snd_pcm_hw_params_set_period_time_near: err = %1").arg(err);
        }
    }
    if ( !fatal ) {
        err = snd_pcm_hw_params_set_periods_near(handle, hwparams, &chunks, &dir);
        if ( err < 0 ) {
            fatal = true;
            errMessage = QString::fromLatin1("QAudioInput: snd_pcm_hw_params_set_periods_near: err = %1").arg(err);
        }
    }
    if ( !fatal ) {
        err = snd_pcm_hw_params(handle, hwparams);
        if ( err < 0 ) {
            fatal = true;
            errMessage = QString::fromLatin1("QAudioInput: snd_pcm_hw_params: err = %1").arg(err);
        }
    }
    if( err < 0) {
        qWarning()<<errMessage;
        errorState = QAudio::OpenError;
        deviceState = QAudio::StoppedState;
        emit stateChanged(deviceState);
        return false;
    }
    snd_pcm_hw_params_get_buffer_size(hwparams,&buffer_frames);
    buffer_size = snd_pcm_frames_to_bytes(handle,buffer_frames);
    snd_pcm_hw_params_get_period_size(hwparams,&period_frames, &dir);
    period_size = snd_pcm_frames_to_bytes(handle,period_frames);
    snd_pcm_hw_params_get_buffer_time(hwparams,&buffer_time, &dir);
    snd_pcm_hw_params_get_period_time(hwparams,&period_time, &dir);

    // Step 3: Set the desired SW parameters.
    snd_pcm_sw_params_t *swparams;
    snd_pcm_sw_params_alloca(&swparams);
    snd_pcm_sw_params_current(handle, swparams);
    snd_pcm_sw_params_set_start_threshold(handle,swparams,period_frames);
    snd_pcm_sw_params_set_stop_threshold(handle,swparams,buffer_frames);
    snd_pcm_sw_params_set_avail_min(handle, swparams,period_frames);
    snd_pcm_sw_params(handle, swparams);

    // Step 4: Prepare audio
    if(audioBuffer == 0)
        audioBuffer = new char[buffer_size];
    snd_pcm_prepare( handle );
    snd_pcm_start(handle);

    // Step 5: Setup timer
    bytesAvailable = bytesReady();

    if(pullMode)
        connect(audioSource,SIGNAL(readyRead()),this,SLOT(userFeed()));

    // Step 6: Start audio processing
    chunks = buffer_size/period_size;
    timer->start(period_time*chunks/2000);

    errorState  = QAudio::NoError;

    totalTimeValue = 0;

    return true;
}

void QAudioInputPrivate::close()
{
    timer->stop();

    if ( handle ) {
        snd_pcm_drop( handle );
        snd_pcm_close( handle );
        handle = 0;
        delete [] audioBuffer;
        audioBuffer=0;
    }
}

int QAudioInputPrivate::bytesReady() const
{
    if(resuming)
        return period_size;

    if(deviceState != QAudio::ActiveState && deviceState != QAudio::IdleState)
        return 0;
    int frames = snd_pcm_avail_update(handle);
    if (frames < 0) return frames;
    if((int)frames > (int)buffer_frames)
        frames = buffer_frames;

    return snd_pcm_frames_to_bytes(handle, frames);
}

qint64 QAudioInputPrivate::read(char* data, qint64 len)
{
    Q_UNUSED(len)

    // Read in some audio data and write it to QIODevice, pull mode
    if ( !handle )
        return 0;

    bytesAvailable = bytesReady();

    if (bytesAvailable < 0) {
        // bytesAvailable as negative is error code, try to recover from it.
        xrun_recovery(bytesAvailable);
        bytesAvailable = bytesReady();
        if (bytesAvailable < 0) {
            // recovery failed must stop and set error.
            close();
            errorState = QAudio::IOError;
            deviceState = QAudio::StoppedState;
            emit stateChanged(deviceState);
            return 0;
        }
    }

    int count=0, err = 0;
    while(count < 5) {
        int chunks = bytesAvailable/period_size;
        int frames = chunks*period_frames;
        if(frames > (int)buffer_frames)
            frames = buffer_frames;
        int readFrames = snd_pcm_readi(handle, audioBuffer, frames);
        if (readFrames >= 0) {
            err = snd_pcm_frames_to_bytes(handle, readFrames);
#ifdef DEBUG_AUDIO
            qDebug()<<QString::fromLatin1("read in bytes = %1 (frames=%2)").arg(err).arg(readFrames).toLatin1().constData();
#endif
            break;
        } else if((readFrames == -EAGAIN) || (readFrames == -EINTR)) {
            errorState = QAudio::IOError;
            err = 0;
            break;
        } else {
            if(readFrames == -EPIPE) {
                errorState = QAudio::UnderrunError;
                err = snd_pcm_prepare(handle);
            } else if(readFrames == -ESTRPIPE) {
                err = snd_pcm_prepare(handle);
            }
            if(err != 0) break;
        }
        count++;
    }
    if(err > 0) {
        // got some send it onward
#ifdef DEBUG_AUDIO
        qDebug()<<"frames to write to QIODevice = "<<
            snd_pcm_bytes_to_frames( handle, (int)err )<<" ("<<err<<") bytes";
#endif
        if(deviceState != QAudio::ActiveState && deviceState != QAudio::IdleState)
            return 0;
        if (pullMode) {
            qint64 l = audioSource->write(audioBuffer,err);
            if(l < 0) {
                close();
                errorState = QAudio::IOError;
                deviceState = QAudio::StoppedState;
                emit stateChanged(deviceState);
            } else if(l == 0) {
                if (deviceState != QAudio::IdleState) {
                    errorState = QAudio::NoError;
                    deviceState = QAudio::IdleState;
                    emit stateChanged(deviceState);
                }
            } else {
                totalTimeValue += err;
                resuming = false;
                if (deviceState != QAudio::ActiveState) {
                    errorState = QAudio::NoError;
                    deviceState = QAudio::ActiveState;
                    emit stateChanged(deviceState);
                }
            }
            return l;

        } else {
            memcpy(data,audioBuffer,err);
            totalTimeValue += err;
            resuming = false;
            if (deviceState != QAudio::ActiveState) {
                errorState = QAudio::NoError;
                deviceState = QAudio::ActiveState;
                emit stateChanged(deviceState);
            }
            return err;
        }
    }
    return 0;
}

void QAudioInputPrivate::resume()
{
    if(deviceState == QAudio::SuspendedState) {
        int err = 0;

        if(handle) {
            err = snd_pcm_prepare( handle );
            if(err < 0)
                xrun_recovery(err);

            err = snd_pcm_start(handle);
            if(err < 0)
                xrun_recovery(err);

            bytesAvailable = buffer_size;
        }
        resuming = true;
        deviceState = QAudio::ActiveState;
        int chunks = buffer_size/period_size;
        timer->start(period_time*chunks/2000);
        emit stateChanged(deviceState);
    }
}

void QAudioInputPrivate::setBufferSize(int value)
{
    buffer_size = value;
}

int QAudioInputPrivate::bufferSize() const
{
    return buffer_size;
}

int QAudioInputPrivate::periodSize() const
{
    return period_size;
}

void QAudioInputPrivate::setNotifyInterval(int ms)
{
    if(ms >= minimumIntervalTime)
        intervalTime = ms;
    else
        intervalTime = minimumIntervalTime;
}

int QAudioInputPrivate::notifyInterval() const
{
    return intervalTime;
}

qint64 QAudioInputPrivate::processedUSecs() const
{
    qint64 result = qint64(1000000) * totalTimeValue /
        (settings.channels()*(settings.sampleSize()/8)) /
        settings.frequency();

    return result;
}

void QAudioInputPrivate::suspend()
{
    if(deviceState == QAudio::ActiveState||resuming) {
        timer->stop();
        deviceState = QAudio::SuspendedState;
        emit stateChanged(deviceState);
    }
}

void QAudioInputPrivate::userFeed()
{
    if(deviceState == QAudio::StoppedState || deviceState == QAudio::SuspendedState)
        return;
#ifdef DEBUG_AUDIO
    QTime now(QTime::currentTime());
    qDebug()<<now.second()<<"s "<<now.msec()<<"ms :userFeed() IN";
#endif
    deviceReady();
}

bool QAudioInputPrivate::deviceReady()
{
    if(pullMode) {
        // reads some audio data and writes it to QIODevice
        read(0,0);
    } else {
        // emits readyRead() so user will call read() on QIODevice to get some audio data
        InputPrivate* a = qobject_cast<InputPrivate*>(audioSource);
        a->trigger();
    }
    bytesAvailable = bytesReady();

    if(deviceState != QAudio::ActiveState)
        return true;

    if((timeStamp.elapsed() + elapsedTimeOffset) > intervalTime) {
        emit notify();
        elapsedTimeOffset = timeStamp.elapsed() + elapsedTimeOffset - intervalTime;
        timeStamp.restart();
    }
    return true;
}

qint64 QAudioInputPrivate::elapsedUSecs() const
{
    if (deviceState == QAudio::StoppedState)
        return 0;

    return clockStamp.elapsed()*1000;
}

void QAudioInputPrivate::reset()
{
    if(handle)
        snd_pcm_reset(handle);
}

void QAudioInputPrivate::drain()
{
    if(handle)
        snd_pcm_drain(handle);
}

InputPrivate::InputPrivate(QAudioInputPrivate* audio)
{
    audioDevice = qobject_cast<QAudioInputPrivate*>(audio);
}

InputPrivate::~InputPrivate()
{
}

qint64 InputPrivate::readData( char* data, qint64 len)
{
    return audioDevice->read(data,len);
}

qint64 InputPrivate::writeData(const char* data, qint64 len)
{
    Q_UNUSED(data)
    Q_UNUSED(len)
    return 0;
}

void InputPrivate::trigger()
{
    emit readyRead();
}

QT_END_NAMESPACE