//  This file is part of par2cmdline (a PAR 2.0 compatible file verification and
//  repair tool). See http://parchive.sourceforge.net for details of PAR 2.0.
//
//  Copyright (c) 2003 Peter Brian Clements
//
//  par2cmdline 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.
//
//  par2cmdline 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

#include "libpar2internal.h"

Result par2create(std::ostream &sout,
		  std::ostream &serr,
		  const NoiseLevel noiselevel,
		  const size_t memorylimit,
		  const string &basepath,
#ifdef _OPENMP
		  const u32 nthreads,
		  const u32 filethreads,
#endif
		  const string &parfilename,
		  const vector<string> &extrafiles,
		  const u64 blocksize,
		  const u32 firstblock,
		  const Scheme recoveryfilescheme,
		  const u32 recoveryfilecount,
		  const u32 recoveryblockcount
		  )
{
  Par2Creator creator(sout, serr, noiselevel);
  Result result = creator.Process(
				  memorylimit,
				  basepath,
#ifdef _OPENMP
				  nthreads,
				  filethreads,
#endif
				  parfilename,
				  extrafiles,
				  blocksize,
				  firstblock,
				  recoveryfilescheme,
				  recoveryfilecount,
				  recoveryblockcount
				  );
  return result;
}


Result par2repair(std::ostream &sout,
		  std::ostream &serr,
		  const NoiseLevel noiselevel,
		  const size_t memorylimit,
		  const string &basepath,
#ifdef _OPENMP
		  const u32 nthreads,
		  const u32 filethreads,
#endif
		  const string &parfilename,
		  const vector<string> &extrafiles,
		  const bool dorepair,   // derived from operation
		  const bool purgefiles,
		  const bool skipdata,
		  const u64 skipleaway
		  )
{
  Par2Repairer repairer(sout, serr, noiselevel);
  Result result = repairer.Process(
				   memorylimit,
				   basepath,
#ifdef _OPENMP
				   nthreads,
				   filethreads,
#endif
				   parfilename,
				   extrafiles,
				   dorepair,
				   purgefiles,
				   skipdata,
				   skipleaway);

  return result;
}


Result par1repair(std::ostream &sout,
		  std::ostream &serr,
		  const NoiseLevel noiselevel,
		  const size_t memorylimit,
		  // basepath is not used by Par1
#ifdef _OPENMP
		  const u32 nthreads,
		  // filethreads is not used by Par1
#endif
		  const string &parfilename,
		  const vector<string> &extrafiles,
		  const bool dorepair,   // derived from operation
		  const bool purgefiles
		  // skipdata is not used by Par1
		  // skipleaway is not used by Par1
		  )
{
  Par1Repairer repairer(sout, serr, noiselevel);
  Result result = repairer.Process(memorylimit,
#ifdef _OPENMP
				   nthreads,
#endif
				   parfilename,
				   extrafiles,
				   dorepair,
				   purgefiles);
  return result;
}


// Determine how many recovery files to create.
bool ComputeRecoveryFileCount(std::ostream &sout,
			      std::ostream &serr,
			      u32 *recoveryfilecount,
			      Scheme recoveryfilescheme,
			      u32 recoveryblockcount,
			      u64 largestfilesize,
			      u64 blocksize)
{
  // Are we computing any recovery blocks
  if (recoveryblockcount == 0)
  {
    *recoveryfilecount = 0;
    return true;
  }

  switch (recoveryfilescheme)
  {
  case scUnknown:
    {
      //assert(false);
      serr << "Scheme unspecified (create, verify, or repair)." << endl;
      return false;
    }
    break;
  case scVariable:
  case scUniform:
    {
      if (*recoveryfilecount == 0)
      {
        // If none specified then then filecount is roughly log2(blockcount)
        // This prevents you getting excessively large numbers of files
        // when the block count is high and also allows the files to have
        // sizes which vary exponentially.

        for (u32 blocks=recoveryblockcount; blocks>0; blocks>>=1)
        {
          (*recoveryfilecount)++;
        }
      }

      if (*recoveryfilecount > recoveryblockcount)
      {
        // You cannot have more recovery files than there are recovery blocks
        // to put in them.
        serr << "Too many recovery files specified." << endl;
        return false;
      }
    }
    break;

  case scLimited:
    {
      // No recovery file will contain more recovery blocks than would
      // be required to reconstruct the largest source file if it
      // were missing. Other recovery files will have recovery blocks
      // distributed in an exponential scheme.

      u32 largest = (u32)((largestfilesize + blocksize-1) / blocksize);
      u32 whole = recoveryblockcount / largest;
      whole = (whole >= 1) ? whole-1 : 0;

      u32 extra = recoveryblockcount - whole * largest;
      *recoveryfilecount = whole;
      for (u32 blocks=extra; blocks>0; blocks>>=1)
      {
        (*recoveryfilecount)++;
      }
    }
    break;
  }

  return true;
}
