/*
  Copyright (C) 2004, 2005 Benjamin Meyer <ben at meyerhome dot net>

  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.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*/

#ifndef AUDIOCD_ENCODER_H
#define AUDIOCD_ENCODER_H

#include <sys/types.h>
#include <kio/slavebase.h>
#include <QtCore/QList>

#include <libkcddb/cdinfo.h>

class KConfigSkeleton;
using namespace KCDDB;

class KDE_EXPORT AudioCDEncoder {

public:
  /**
   * Constructor.
   * @param slave parent that this classes can use to call data() with
   * when finished encoding bits.
   */ 
  explicit AudioCDEncoder(KIO::SlaveBase *slave) : ioslave(slave) {}
  
  /**
   * Deconstructor.
   */
  virtual ~AudioCDEncoder(){}
  
  /**
   * Initiallizes the decoder, loading libraries, etc.  Encoders
   * that don't return true will will deleted and not used.
   * @returns false if unable to initialize the encoder.
   */
  virtual bool init() = 0;

  /**
   * The encoder should read in its config data here.
   */ 
  virtual void loadSettings() = 0;

  /**
   * Helper function to determine the end size of a
   * encoded file.
   * @param time_secs the lengh of the audio track in seconds.
   * @returns the size of a file if it is time_secs in length.
   */ 
  virtual unsigned long size(long time_secs) const = 0;

  /**
   * @returns the generic user string type/name of this encoder
   * Examples: "MP3", "Ogg Vorbis", "Wav", "FID Level 2", etc
   */ 
  virtual QString type() const = 0;
  
  /**
   * @returns the mime type for the files this encoder produces.
   * Example: "audio/x-wav"
   */ 
  virtual const char * mimeType() const = 0;

  /**
   * @returns the file type for the files this encoder produces.
   * Used in naming of the file for example foo.mp3
   * Examples: "mp3", "ogg", "wav"
   */ 
  virtual const char * fileType() const = 0;

  /**
   * Before the read functions are called this is 
   * called to allow the encoders to store the cddb
   * information if they want to so it can be inserted 
   * where necessary (start, middle, end, or combos etc).
   */ 
  virtual void fillSongInfo( KCDDB::CDInfo info, int track, const QString &comment ) = 0;
  
  /**
   * Perform any initial file creation necessary for a new song (that
   * has just been sent via fillSongInfo())
   * @param size - the total binary size of the end file (via size()).
   * @return size of the data that was created by this function.
   */ 
  virtual long readInit(long size) = 0;
  
  /**
   * Passes a little bit of cd data to be encoded
   * This function is most likly called many many times.
   * @param buf pointer to the audio that has been read in so far
   * @param frames the number of frames of audio that are in buf
   * @return size of the data that was created by this function, -1 on error.
   */
  virtual long read(int16_t * buf, int frames) = 0;

  /**
   * Perform any final file creation/padding that is necessary
   * @return size of the data that was created by this function.
   */ 
  virtual long readCleanup() = 0;

  /**
   * Returns a configure widget for the encoder
   */ 
  virtual QWidget* getConfigureWidget(KConfigSkeleton** manager) const
                   { Q_UNUSED(manager); return NULL; } 
 
  /**
   * Returns the last error message; called when e.g. read() returns -1.
   */
  virtual QString lastErrorMessage() const { return QString(); }

  /**
   * Helper function to load all of the AudioCD Encoders from libraries.
   * Uses KStandardDirs to find where libraries could be, opens all of the ones
   * that we might own audiocd_encoder_* and then uses the symbol 
   * create_audiocd_encoders to obtain the encoders from that library.
   * @param slave ioslave needed if the plugin is going to be used to encode something.
   * @param encoders container for new encoders.
   */
  static void findAllPlugins(KIO::SlaveBase *slave, QList<AudioCDEncoder*> &encoders);

protected:
  /**
   * Pointer to the ioslave that is running this encoder.
   * Used (only?) for the data() function to pass back encoded data.
   */
  KIO::SlaveBase *ioslave;

};

#endif // AUDIOCD_ENCODER_H