/**
 * @file soundmanagerutil.h
 * @author Bill Good <bkgood at gmail dot com>
 * @date 20100611
 */

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef SOUNDMANAGERUTIL_U
#define SOUNDMANAGERUTIL_U

#include <QString>
#include <QMutex>
#include <QDomElement>
#include <QList>

#include "util/types.h"
#include "util/fifo.h"

/**
 * @class ChannelGroup
 * @brief Describes a group of channels, typically a pair for stereo sound in
 *        Mixxx.
 */
class ChannelGroup {
public:
    ChannelGroup(unsigned char channelBase, unsigned char channels);
    unsigned char getChannelBase() const;
    unsigned char getChannelCount() const;
    bool operator==(const ChannelGroup &other) const;
    bool clashesWith(const ChannelGroup &other) const;
    unsigned int getHash() const;
private:
    unsigned char m_channelBase; // base (first) channel used on device
    unsigned char m_channels; // number of channels used (s/b 2 in most cases)
};

/**
 * @class AudioPath
 * @brief Describes a path for audio to take.
 * @note This needs a new name, the current one sucks. If you find one,
 *       feel free to rename as necessary.
 */
class AudioPath {
public:
    // XXX if you add a new type here, be sure to add it to the various
    // methods including getStringFromType, isIndexed, getTypeFromInt,
    // channelsNeededForType (if necessary), the subclasses' getSupportedTypes
    // (if necessary), etc. -- bkgood
    enum AudioPathType {
        MASTER,
        HEADPHONES,
        BOOTH,
        BUS,
        DECK,
        VINYLCONTROL,
        MICROPHONE,
        AUXILIARY,
        RECORD_BROADCAST,
        INVALID, // if this isn't last bad things will happen -bkgood
    };
    AudioPath(unsigned char channelBase, unsigned char channels);
    virtual ~AudioPath() = default;
    AudioPathType getType() const;
    ChannelGroup getChannelGroup() const;
    unsigned char getIndex() const;
    bool operator==(const AudioPath &other) const;
    unsigned int getHash() const;
    bool channelsClash(const AudioPath &other) const;
    QString getString() const;
    static QString getStringFromType(AudioPathType type);
    static QString getTrStringFromType(AudioPathType type, unsigned char index);
    static AudioPathType getTypeFromString(QString string);
    static bool isIndexed(AudioPathType type);
    static AudioPathType getTypeFromInt(int typeInt);

    // Returns the minimum number of channels needed on a sound device for an
    // AudioPathType.
    static unsigned char minChannelsForType(AudioPathType type);

    // Returns the maximum number of channels needed on a sound device for an
    // AudioPathType.
    static unsigned char maxChannelsForType(AudioPathType type);

protected:
    virtual void setType(AudioPathType type) = 0;
    AudioPathType m_type;
    ChannelGroup m_channelGroup;
    unsigned char m_index;
};

/**
 * @class AudioOutput
 * @extends AudioPath
 * @brief A source of audio in Mixxx that is to be output to a group of
 *        channels on an audio interface.
 */
class AudioOutput : public AudioPath {
  public:
    AudioOutput(AudioPathType type, unsigned char channelBase,
                unsigned char channels,
                unsigned char index = 0);
    ~AudioOutput() override = default;
    QDomElement toXML(QDomElement *element) const;
    static AudioOutput fromXML(const QDomElement &xml);
    static QList<AudioPathType> getSupportedTypes();
    bool isHidden();
  protected:
    void setType(AudioPathType type) override;
};

// This class is required to add the buffer, without changing the hash used as ID
class AudioOutputBuffer : public AudioOutput {
  public:
    AudioOutputBuffer(const AudioOutput& out, const CSAMPLE* pBuffer)
           : AudioOutput(out),
             m_pBuffer(pBuffer) {

    };
    inline const CSAMPLE* getBuffer() const { return m_pBuffer; }
  private:
    const CSAMPLE* m_pBuffer;
};

/**
 * @class AudioInput
 * @extends AudioPath
 * @brief A source of audio at a group of channels on an audio interface
 *        that is be processed in Mixxx.
 */
class AudioInput : public AudioPath {
  public:
    AudioInput(AudioPathType type = INVALID, unsigned char channelBase = 0,
               unsigned char channels = 0, unsigned char index = 0);
    virtual ~AudioInput();
    QDomElement toXML(QDomElement *element) const;
    static AudioInput fromXML(const QDomElement &xml);
    static QList<AudioPathType> getSupportedTypes();
  protected:
    void setType(AudioPathType type) override;
};

// This class is required to add the buffer, without changing the hash used as
// ID
class AudioInputBuffer : public AudioInput {
  public:
    AudioInputBuffer(const AudioInput& id, CSAMPLE* pBuffer)
            : AudioInput(id),
              m_pBuffer(pBuffer) {

    }
    inline CSAMPLE* getBuffer() const { return m_pBuffer; }
  private:
    CSAMPLE* m_pBuffer;
};


class AudioSource {
public:
  virtual const CSAMPLE* buffer(const AudioOutput& output) const = 0;

  // This is called by SoundManager whenever an output is connected for this
  // source. When this is called it is guaranteed that no callback is
  // active.
  virtual void onOutputConnected(const AudioOutput& output) {
      Q_UNUSED(output);
  };

    // This is called by SoundManager whenever an output is disconnected for
    // this source. When this is called it is guaranteed that no callback is
    // active.
  virtual void onOutputDisconnected(const AudioOutput& output) {
      Q_UNUSED(output);
  };
};

class AudioDestination {
public:
    // This is called by SoundManager whenever there are new samples from the
    // configured input to be processed. This is run in the clock reference
    // callback thread
  virtual void receiveBuffer(const AudioInput& input,
          const CSAMPLE* pBuffer,
          unsigned int iNumFrames) = 0;

  // This is called by SoundManager whenever an input is configured for this
  // destination. When this is called it is guaranteed that no callback is
  // active.
  virtual void onInputConfigured(const AudioInput& input) {
      Q_UNUSED(input);
  };

    // This is called by SoundManager whenever an input is unconfigured for this
    // destination. When this is called it is guaranteed that no callback is
    // active.
  virtual void onInputUnconfigured(const AudioInput& input) {
      Q_UNUSED(input);
  };
};

typedef AudioPath::AudioPathType AudioPathType;

class SoundDeviceId {
  public:
    QString name;
    // The "hw:X,Y" device name. Remains an empty string if not using ALSA
    // or using a non-hw ALSA device such as "default" or "pulse".
    QString alsaHwDevice;
    int portAudioIndex;

    QString debugName() const;

    SoundDeviceId()
       : portAudioIndex(-1) {}
};

// This must be registered with QMetaType::registerComparators for
// QVariant::operator== to use it, which is required for QComboBox::findData to
// work in DlgPrefSoundItem.
inline bool operator==(const SoundDeviceId& lhs, const SoundDeviceId& rhs) {
    return lhs.name == rhs.name
            && lhs.alsaHwDevice == rhs.alsaHwDevice
            && lhs.portAudioIndex == rhs.portAudioIndex;
}

// There is not really a use case for this, but it is required for QMetaType::registerComparators.
inline bool operator<(const SoundDeviceId& lhs, const SoundDeviceId& rhs) {
    return lhs.portAudioIndex < rhs.portAudioIndex;
}

Q_DECLARE_METATYPE(SoundDeviceId);

inline unsigned int qHash(const SoundDeviceId& id) {
    return qHash(id.name) + qHash(id.alsaHwDevice) + id.portAudioIndex;
}

inline QDebug operator<<(QDebug dbg, const SoundDeviceId& soundDeviceId) {
    return dbg << QString("SoundDeviceId(" + soundDeviceId.debugName() + ")");
}

// globals for QHash
unsigned int qHash(const ChannelGroup &group);
unsigned int qHash(const AudioOutput &output);
unsigned int qHash(const AudioInput &input);

#endif