/****************************************************************************
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** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
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** This file is part of the QtMultimedia module of the Qt Toolkit.
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** 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
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** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
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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.
//

#ifndef QAUDIOOUTPUT_SYMBIAN_P_H
#define QAUDIOOUTPUT_SYMBIAN_P_H

#include <QtMultimedia/qaudioengine.h>
#include <QTime>
#include <QTimer>
#include <sounddevice.h>
#include "qaudio_symbian_p.h"

QT_BEGIN_NAMESPACE

class QAudioOutputPrivate;

class SymbianAudioOutputPrivate : public QIODevice
{
    friend class QAudioOutputPrivate;
    Q_OBJECT
public:
    SymbianAudioOutputPrivate(QAudioOutputPrivate *audio);
    ~SymbianAudioOutputPrivate();

    qint64 readData(char *data, qint64 len);
    qint64 writeData(const char *data, qint64 len);

private:
    QAudioOutputPrivate *const m_audioDevice;
};

class QAudioOutputPrivate
    :   public QAbstractAudioOutput
{
    friend class SymbianAudioOutputPrivate;
    Q_OBJECT
public:
    QAudioOutputPrivate(const QByteArray &device,
                       const QAudioFormat &audioFormat);
    ~QAudioOutputPrivate();

    // QAbstractAudioOutput
    QIODevice* start(QIODevice *device = 0);
    void stop();
    void reset();
    void suspend();
    void resume();
    int bytesFree() const;
    int periodSize() const;
    void setBufferSize(int value);
    int bufferSize() const;
    void setNotifyInterval(int milliSeconds);
    int notifyInterval() const;
    qint64 processedUSecs() const;
    qint64 elapsedUSecs() const;
    QAudio::Error error() const;
    QAudio::State state() const;
    QAudioFormat format() const;

private slots:
    void dataReady();
    void underflowTimerExpired();
    void devsoundInitializeComplete(int err);
    void devsoundBufferToBeFilled(CMMFBuffer *);
    void devsoundPlayError(int err);

private:
   void open();
   void startPlayback();
   void writePaddingData();
   qint64 pushData(const char *data, qint64 len);
   void pullData();
   void bufferFilled();
   void lastBufferFilled();
   Q_INVOKABLE void close();

   qint64 getSamplesPlayed() const;

   void setError(QAudio::Error error);
   void setState(SymbianAudio::State state);

   bool isDataReady() const;

private:
    const QByteArray m_device;
    const QAudioFormat m_format;

    int m_clientBufferSize;
    int m_notifyInterval;
    QScopedPointer<QTimer> m_notifyTimer;
    QTime m_elapsed;
    QAudio::Error m_error;

    SymbianAudio::State m_internalState;
    QAudio::State m_externalState;

    bool m_pullMode;
    QIODevice *m_source;

    SymbianAudio::DevSoundWrapper* m_devSound;

    // Buffer provided by DevSound, to be filled with data.
    CMMFDataBuffer *m_devSoundBuffer;

    int m_devSoundBufferSize;

    // Number of bytes transferred from QIODevice to QAudioOutput.  It is
    // necessary to count this because data is dropped when suspend() is
    // called.  The difference between the position reported by DevSound and
    // this value allows us to calculate m_bytesPadding;
    quint32 m_bytesWritten;

    // True if client has provided data while the audio subsystem was not
    // ready to consume it.
    bool m_pushDataReady;

    // Number of zero bytes which will be written when client calls resume().
    quint32 m_bytesPadding;

    // True if PlayError(KErrUnderflow) has been called.
    bool m_underflow;

    // True if a buffer marked with the "last buffer" flag has been provided
    // to DevSound.
    bool m_lastBuffer;

    // Some DevSound implementations ignore all underflow errors raised by the
    // audio driver, unless the last buffer flag has been set by the client.
    // In push-mode playback, this flag will never be set, so the underflow
    // error will never be reported.  In order to work around this, a timer
    // is used, which gets reset every time the client provides more data.  If
    // the timer expires, an underflow error is raised by this object.
    QScopedPointer<QTimer> m_underflowTimer;

    // Result of previous call to CMMFDevSound::SamplesPlayed().  This value is
    // used to determine whether, when m_underflowTimer expires, an
    // underflow error has actually occurred.
    quint32 m_samplesPlayed;

    // Samples played up to the last call to suspend().  It is necessary
    // to cache this because suspend() is implemented using
    // CMMFDevSound::Stop(), which resets DevSound's SamplesPlayed() counter.
    quint32 m_totalSamplesPlayed;

};

QT_END_NAMESPACE

#endif
