/* 
 *
 * $Id: k3baudiodatasource.cpp 619556 2007-01-03 17:38:12Z trueg $
 * Copyright (C) 2004 Sebastian Trueg <trueg@k3b.org>
 *
 * This file is part of the K3b project.
 * Copyright (C) 1998-2007 Sebastian Trueg <trueg@k3b.org>
 *
 * 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.
 * See the file "COPYING" for the exact licensing terms.
 */

#include "k3baudiodatasource.h"
#include "k3baudiotrack.h"
#include "k3baudiodoc.h"


K3bAudioDataSource::K3bAudioDataSource()
  : m_track(0),
    m_prev(0),
    m_next(0)
{
}


K3bAudioDataSource::K3bAudioDataSource( const K3bAudioDataSource& source )
  : m_track( 0 ),
    m_prev( 0 ),
    m_next( 0 ),
    m_startOffset( source.m_startOffset ),
    m_endOffset( source.m_endOffset )
{
}


K3bAudioDataSource::~K3bAudioDataSource()
{
  take();
}


K3bAudioDoc* K3bAudioDataSource::doc() const
{
  if( m_track )
    return m_track->doc();
  else
    return 0;
}


K3bAudioDataSource* K3bAudioDataSource::take()
{
  // if we do not have a track we are not in any list
  if( m_track ) {
    if( !m_prev )
      m_track->setFirstSource( m_next );
    
    if( m_prev )
      m_prev->m_next = m_next;
    if( m_next )
      m_next->m_prev = m_prev;
    
    m_prev = m_next = 0;
    
    emitChange();
    m_track = 0;
  }

  return this;
}


void K3bAudioDataSource::moveAfter( K3bAudioDataSource* source )
{
  // cannot create a list outside a track!
  if( !source->track() )
    return;

  if( source == this )
    return;

  // remove this from the list
  take();
  
  K3bAudioDataSource* oldNext = source->m_next;
    
  // set track as prev
  source->m_next = this;
  m_prev = source;

  // set oldNext as next
  if( oldNext )
    oldNext->m_prev = this;
  m_next = oldNext;

  m_track = source->track();
  emitChange();
}


void K3bAudioDataSource::moveAhead( K3bAudioDataSource* source )
{
  // cannot create a list outside a track!
  if( !source->track() )
    return;

  if( source == this )
    return;

  // remove this from the list
  take();

  K3bAudioDataSource* oldPrev = source->m_prev;

  // set track as next
  m_next = source;
  source->m_prev = this;

  // set oldPrev as prev
  m_prev = oldPrev;
  if( oldPrev )
    oldPrev->m_next = this;

  m_track = source->track();

  if( !m_prev )
    m_track->setFirstSource( this );

  emitChange();
}


void K3bAudioDataSource::emitChange()
{
  if( m_track )
    m_track->sourceChanged( this );
}


K3bAudioDataSource* K3bAudioDataSource::split( const K3b::Msf& pos )
{
  if( pos < length() ) {
    K3bAudioDataSource* s = copy();
    s->setStartOffset( startOffset() + pos );
    s->setEndOffset( endOffset() );
    setEndOffset( startOffset() + pos );
    s->moveAfter( this );
    emitChange();
    return s;
  }
  else
    return 0;
}


K3b::Msf K3bAudioDataSource::lastSector() const
{
  if( endOffset() > 0 )
    return endOffset()-1;
  else
    return originalLength()-1;
}


K3b::Msf K3bAudioDataSource::length() const
{
  if( originalLength() == 0 )
    return 0;
  else if( lastSector() < m_startOffset )
    return 1;
  else
    return lastSector() - m_startOffset + 1;
}


void K3bAudioDataSource::setStartOffset( const K3b::Msf& msf )
{
  m_startOffset = msf;
  fixupOffsets();
  emitChange();
}


void K3bAudioDataSource::setEndOffset( const K3b::Msf& msf )
{
  m_endOffset = msf;
  fixupOffsets();
  emitChange();
}


void K3bAudioDataSource::fixupOffsets()
{
  // no length available yet
  if( originalLength() == 0 )
    return;

  if( startOffset() >= originalLength() ) {
    setStartOffset( 0 );
  }
  if( endOffset() > originalLength() ) {
    setEndOffset( 0 ); // whole source
  }
  if( endOffset() > 0 && endOffset() <= startOffset() ) {
    setEndOffset( startOffset() );
  }
}