/***************************************************************************
                          kfixedsizebuffer.cpp  -  description
                             -------------------
    begin                : Mit Jun 03 2003
    copyright            : (C) 2003 by Friedrich W. H. Kossebau
    email                : Friedrich.W.H@Kossebau.de
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This library is free software; you can redistribute it and/or         *
 *   modify it under the terms of the GNU Library General Public           *
 *   License version 2 as published by the Free Software Foundation.       *
 *                                                                         *
 ***************************************************************************/

//#include <kdebug.h>
// c specific
#include <string.h>
// lib specific
#include "kfixedsizebuffer.h"

using namespace KHE;

KFixedSizeBuffer::KFixedSizeBuffer( char *D, unsigned int S, char FUC )
  : Data( D ),
   Size( S ),
   FillUpChar( FUC ),
   ReadOnly( true ),
   Modified( false ),
   AutoDelete( false )
{
}

KFixedSizeBuffer::KFixedSizeBuffer( unsigned int S, char FUC )
  : Data( new char[S] ),
   Size( S ),
   FillUpChar( FUC ),
   ReadOnly( false ),
   Modified( false ),
   AutoDelete( true )
{
  reset( 0, S );
}

KFixedSizeBuffer::~KFixedSizeBuffer()
{
  if( AutoDelete )
    delete [] Data;
}



int KFixedSizeBuffer::insert( int Pos, const char* D, int InputLength )
{
  // check all parameters
  if( Pos >= (int)Size || InputLength == 0 )
    return 0;
  if( Pos + InputLength > (int)Size )
    InputLength = Size - Pos;

  unsigned int BehindInsertPos = Pos + InputLength;
  // fmove right data behind the input range
  memmove( &Data[BehindInsertPos], &Data[Pos], Size-BehindInsertPos );
  // insert input
  memcpy( &Data[Pos], D, InputLength );

  Modified = true;
  return InputLength;
}


int KFixedSizeBuffer::remove( KSection Remove )
{
  if( Remove.start() >= (int)Size || Remove.width() == 0 )
    return 0;

  Remove.restrictEndTo( Size-1 );

  int RemoveLength = Remove.width();
  int BehindRemovePos = Remove.end()+1;;
  // fmove right data behind the input range
  memmove( &Data[Remove.start()], &Data[BehindRemovePos], Size-BehindRemovePos );
  // clear freed space
  reset( Size-RemoveLength, RemoveLength );

  Modified = true;
  return RemoveLength;
}


unsigned int KFixedSizeBuffer::replace( KSection Remove, const char* D, unsigned int InputLength )
{
  // check all parameters
  if( Remove.startsBehind( Size-1 ) || (Remove.width()==0 && InputLength==0) )
    return 0;

  Remove.restrictEndTo( Size-1 );
  if( Remove.start() + InputLength > Size )
    InputLength = Size - Remove.start();

  int SizeDiff = InputLength - Remove.width();

  // is input longer than removed?
  if( SizeDiff > 0 )
  {
    unsigned int BehindInsertPos = Remove.start() + InputLength;
    // fmove right data behind the input range
    memmove( &Data[BehindInsertPos], &Data[Remove.end()+1], Size-BehindInsertPos );
  }
  // is input smaller than removed?
  else if( SizeDiff < 0 )
  {
    unsigned int BehindRemovePos = Remove.end()+1;
    // fmove right data behind the input range
    memmove( &Data[Remove.start()+InputLength], &Data[BehindRemovePos], Size-BehindRemovePos );
   // clear freed space
    reset( Size+SizeDiff, -SizeDiff );
  }
  // insert input
  memcpy( &Data[Remove.start()], D, InputLength );

  Modified = true;
  return InputLength;
}


int KFixedSizeBuffer::move( int DestPos, KSection SourceSection )
{
  // check all parameters
  if( SourceSection.start() >= (int)Size || SourceSection.width() == 0
      || DestPos > (int)Size || SourceSection.start() == DestPos )
    return SourceSection.start();

  SourceSection.restrictEndTo( Size-1 );
  bool ToRight = DestPos > SourceSection.start();
  int MovedLength = SourceSection.width();
  int DisplacedLength = ToRight ?  DestPos - SourceSection.end()-1 : SourceSection.start() - DestPos;

  // find out section that is smaller
  int SmallPartLength, LargePartLength, SmallPartStart, LargePartStart, SmallPartDest, LargePartDest;
  // moving part is smaller?
  if( MovedLength < DisplacedLength )
  {
    SmallPartStart = SourceSection.start();
    SmallPartLength = MovedLength;
    LargePartLength = DisplacedLength;
    // moving part moves right?
    if( ToRight )
    {
      SmallPartDest = DestPos - MovedLength;
      LargePartStart = SourceSection.end()+1;
      LargePartDest = SourceSection.start();
    }
    else
    {
      SmallPartDest = DestPos;
      LargePartStart = DestPos;
      LargePartDest = DestPos + MovedLength;
    }
  }
  else
  {
    LargePartStart = SourceSection.start();
    LargePartLength = MovedLength;
    SmallPartLength = DisplacedLength;
    // moving part moves right?
    if( ToRight )
    {
      LargePartDest = DestPos - MovedLength;
      SmallPartStart = SourceSection.end()+1;
      SmallPartDest = SourceSection.start();
    }
    else
    {
      LargePartDest = DestPos;
      SmallPartStart = DestPos;
      SmallPartDest = DestPos + MovedLength;
    }
  }

  // copy smaller part to tempbuffer
  char *Temp = new char[SmallPartLength];
  memcpy( Temp, &Data[SmallPartStart], SmallPartLength );

  // move the larger part
  memmove( &Data[LargePartDest], &Data[LargePartStart], LargePartLength );

  // copy smaller part to its new dest
  memcpy( &Data[SmallPartDest], Temp, SmallPartLength );
  delete [] Temp;

  Modified = true;
  return MovedLength < DisplacedLength ? SmallPartDest : LargePartDest;
}


int KFixedSizeBuffer::fill( const char FChar, int FillLength, unsigned int Pos )
{
  // nothing to fill
  if( Pos >= Size )
    return 0;

  unsigned int LengthToEnd = Size - Pos;

  if( FillLength < 0 || FillLength > (int)LengthToEnd )
    FillLength = LengthToEnd;

  memset( &Data[Pos], FChar, FillLength );
  Modified = true;
  return FillLength;
}


int KFixedSizeBuffer::compare( const KDataBuffer &Other, KSection OtherRange, unsigned int Pos )
{
  //kdDebug() << TQString("Pos: %1, OtherRange: (%3/%4)" ).tqarg(Pos).tqarg(OtherRange.start()).tqarg(OtherRange.end())
  //    << endl;
  // test other values
  if( OtherRange.startsBehind(Other.size()-1) )
    return 1;

  // check own values
  if( Pos >= Size )
    return -1;

  int ValueByLength = 0; // default: equal

  KSection Range( Pos, OtherRange.width(), true );
  int Last = Other.size()-1;
  // 
  if( OtherRange.endsBehind(Last) )
  {
    // make shorter
    OtherRange.setEnd( Last );
    if( OtherRange.width() < Range.width() )
      ValueByLength = 1;
  }
  Last = Size-1;
  if( Range.endsBehind(Last) )
  {
    // make shorter
    Range.setEnd( Last );
    if( OtherRange.width() > Range.width() )
      ValueByLength = -1;
  }
  //kdDebug()
  //    << TQString( "Range: (%1/%2), OtherRange: (%3/%4)" ).tqarg(Range.start()).tqarg(Range.end()).tqarg(OtherRange.start()).tqarg(OtherRange.end())
  //    << endl;
  int oi = OtherRange.start();
  for( int i=Range.start(); i<=Range.end(); ++i,++oi )
  {
    char OD = Other.datum(oi);
    char D = Data[i];
    //kdDebug() << TQString("%1==%2").tqarg((int)D).tqarg((int)OD) << endl;
    if( OD == D )
      continue;
    return OD < D ? 1 : -1;
  }

  return ValueByLength;
}


int KFixedSizeBuffer::find(  const char*/*KeyData*/, int /*Length*/, KSection /*Section*/  ) const { return 0; }
int KFixedSizeBuffer::rfind( const char*, int /*Length*/, int /*Pos*/ ) const { return 0; }


void KFixedSizeBuffer::reset( unsigned int Pos, unsigned int Length )
{
  memset( &Data[Pos], FillUpChar, Length );
}