/*=========================================================================
                                                                                
  Program:   gdcm
  Module:    $RCSfile: gdcmRLEFramesInfo.cxx,v $
  Language:  C++
  Date:      $Date: 2005/01/31 05:24:21 $
  Version:   $Revision: 1.9 $
                                                                                
  Copyright (c) CREATIS (Centre de Recherche et d'Applications en Traitement de
  l'Image). All rights reserved. See Doc/License.txt or
  http://www.creatis.insa-lyon.fr/Public/Gdcm/License.html for details.
                                                                                
     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notices for more information.
                                                                                
=========================================================================*/

#include "gdcmRLEFramesInfo.h"
#include "gdcmDebug.h"

namespace gdcm 
{

RLEFramesInfo::~RLEFramesInfo()
{
   for(RLEFrameList::iterator it = Frames.begin(); it != Frames.end(); ++it)
   {
      delete (*it);
   }
   Frames.clear();
}

/**
 * \brief        Print self.
 * @param indent Indentation string to be prepended during printing.
 * @param os     Stream to print to.
 */
void RLEFramesInfo::Print( std::ostream &os, std::string indent )
{
   os << std::endl;
   os << indent
      << "----------------- RLE frames --------------------------------"
      << std::endl;
   os << indent
      << "Total number of Frames : " << Frames.size()
      << std::endl;
   int frameNumber = 0;
   for(RLEFrameList::iterator it = Frames.begin(); it != Frames.end(); ++it)
   {
      os << indent
         << "   frame number :" << frameNumber++
         << std::endl;
      (*it)->Print( os, indent + "   " );
   }
}

void RLEFramesInfo::AddFrame(RLEFrame *frame)
{
   Frames.push_back(frame);
}

RLEFrame *RLEFramesInfo::GetFirstFrame()
{
   ItFrames = Frames.begin();
   if (ItFrames != Frames.end())
      return  *ItFrames;
   return NULL;
}

RLEFrame *RLEFramesInfo::GetNextFrame()
{
   gdcmAssertMacro (ItFrames != Frames.end());

   ++ItFrames;
   if (ItFrames != Frames.end())
      return  *ItFrames;
   return NULL;
}

/**
 * \brief     Reads from disk the Pixel Data of 'Run Length Encoded'
 *            Dicom encapsulated file and decompress it.
 * @param     fp already open File Pointer
 *            at which the pixel data should be copied
 * @return    Boolean
 */
bool RLEFramesInfo::ReadAndDecompressRLEFile( std::ifstream *fp , uint8_t *raw, int xSize, int ySize, int zSize, int bitsAllocated )
{
   uint8_t *subRaw = raw;
   long RawSegmentSize = xSize * ySize;

   // Loop on the frame[s]
   for(RLEFrameList::iterator it = Frames.begin(); it != Frames.end(); ++it)
   {
      // Loop on the fragments
      for( unsigned int k = 1; k <= (*it)->GetNumberOfFragments(); k++ )
      {
         fp->seekg((*it)->GetOffset(k),std::ios::beg);
         ReadAndDecompressRLEFragment(subRaw,
                                      (*it)->GetLength(k),
                                      RawSegmentSize, 
                                      fp);
         subRaw += RawSegmentSize;
      }
   }

   if ( bitsAllocated == 16 )
   {
      // Try to deal with RLE 16 Bits
      (void)DecompressRLE16BitsFromRLE8Bits( raw, xSize, ySize, zSize );
   }

   return true;
}

/**
 * \brief Implementation of the RLE decoding algorithm for decompressing
 *        a RLE fragment. [refer to PS 3.5-2003, section G.3.2 p 86]
 * @param subRaw Sub region of \ref Raw where the decoded fragment
 *        should be placed.
 * @param fragmentSize The length of the binary fragment as found on the disk.
 * @param RawSegmentSize The expected length of the fragment ONCE
 *        Raw.
 * @param fp File Pointer: on entry the position should be the one of
 *        the fragment to be decoded.
 */
bool RLEFramesInfo::ReadAndDecompressRLEFragment( uint8_t *subRaw,
                                                 long fragmentSize,
                                                 long RawSegmentSize,
                                                 std::ifstream *fp )
{
   int8_t count;
   long numberOfOutputBytes = 0;
   long numberOfReadBytes = 0;

   while( numberOfOutputBytes < RawSegmentSize )
   {
      fp->read( (char*)&count, 1 );
      numberOfReadBytes += 1;
      if ( count >= 0 )
      // Note: count <= 127 comparison is always true due to limited range
      //       of data type int8_t [since the maximum of an exact width
      //       signed integer of width N is 2^(N-1) - 1, which for int8_t
      //       is 127].
      {
         fp->read( (char*)subRaw, count + 1);
         numberOfReadBytes   += count + 1;
         subRaw     += count + 1;
         numberOfOutputBytes += count + 1;
      }
      else
      {
         if ( count <= -1 && count >= -127 )
         {
            int8_t newByte;
            fp->read( (char*)&newByte, 1);
            numberOfReadBytes += 1;
            for( int i = 0; i < -count + 1; i++ )
            {
               subRaw[i] = newByte;
            }
            subRaw     += -count + 1;
            numberOfOutputBytes += -count + 1;
         }
      }
      // if count = 128 output nothing
                                                                                
      if ( numberOfReadBytes > fragmentSize )
      {
         gdcmVerboseMacro( "Read more bytes than the segment size.");
         return false;
      }
   }
   return true;
}

/**
 * \brief     Try to deal with RLE 16 Bits. 
 *            We assume the RLE has already been parsed and loaded in
 *            Raw (through \ref ReadAndDecompressJPEGFile ).
 *            We here need to make 16 Bits Pixels from Low Byte and
 *            High Byte 'Planes'...(for what it may mean)
 * @return    Boolean
 */
bool RLEFramesInfo::DecompressRLE16BitsFromRLE8Bits( uint8_t* raw, int xSize, int ySize,int numberOfFrames  )
{
   size_t pixelNumber = xSize * ySize;
   size_t rawSize = xSize * ySize * numberOfFrames;

   // We assumed Raw contains the decoded RLE pixels but as
   // 8 bits per pixel. In order to convert those pixels to 16 bits
   // per pixel we cannot work in place within Raw and hence
   // we copy it in a safe place, say copyRaw.

   uint8_t* copyRaw = new uint8_t[rawSize * 2];
   memmove( copyRaw, raw, rawSize * 2 );

   uint8_t* x = raw;
   uint8_t* a = copyRaw;
   uint8_t* b = a + pixelNumber;

   for ( int i = 0; i < numberOfFrames; i++ )
   {
      for ( unsigned int j = 0; j < pixelNumber; j++ )
      {
         *(x++) = *(b++);
         *(x++) = *(a++);
      }
   }

   delete[] copyRaw;
      
   /// \todo check that operator new []didn't fail, and sometimes return false
   return true;
}


} // end namespace gdcm