/*************************************************************************************

    Grid physics library, www.github.com/paboyle/Grid 

    Source file: ./lib/parallelIO/NerscIO.h

    Copyright (C) 2015

    Author: Peter Boyle <paboyle@ph.ed.ac.uk>
    Author: Jamie Hudspith <renwick.james.hudspth@gmail.com>

    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.

    See the full license in the file "LICENSE" in the top level distribution directory
*************************************************************************************/
/*  END LEGAL */

#include <algorithm>
#include <iostream>
#include <iomanip>
#include <fstream>
#include <map>
#include <unistd.h>
#include <sys/utsname.h>
#include <pwd.h>

NAMESPACE_BEGIN(Grid);

///////////////////////////////////////////////////////
// Precision mapping
///////////////////////////////////////////////////////
template<class vobj> static std::string getFormatString (void)
{
  std::string format;
  typedef typename getPrecision<vobj>::real_scalar_type stype;
  if ( sizeof(stype) == sizeof(float) ) {
    format = std::string("IEEE32BIG");
  }
  if ( sizeof(stype) == sizeof(double) ) {
    format = std::string("IEEE64BIG");
  }
  return format;
};

  ////////////////////////////////////////////////////////////////////////////////
  // header specification/interpretation
  ////////////////////////////////////////////////////////////////////////////////
    class FieldNormMetaData : Serializable {
    public:
      GRID_SERIALIZABLE_CLASS_MEMBERS(FieldNormMetaData, double, norm2);
    };
    class FieldMetaData : Serializable {
    public:

      GRID_SERIALIZABLE_CLASS_MEMBERS(FieldMetaData,
				      int, nd,
				      std::vector<int>, dimension,
				      std::vector<std::string>, boundary,
				      int, data_start,
				      std::string, hdr_version,
				      std::string, storage_format,
				      double, link_trace,
				      double, plaquette,
				      uint32_t, checksum,
				      uint32_t, scidac_checksuma,
				      uint32_t, scidac_checksumb,
				      unsigned int, sequence_number,
				      std::string, data_type,
				      std::string, ensemble_id,
				      std::string, ensemble_label,
				      std::string, ildg_lfn,
				      std::string, creator,
				      std::string, creator_hardware,
				      std::string, creation_date,
				      std::string, archive_date,
				      std::string, floating_point);
      // WARNING: non-initialised values might lead to twisted parallel IO
      // issues, std::string are fine because they initliase to size 0
      // as per C++ standard.
      FieldMetaData(void) 
      : nd(4), dimension(4,0), boundary(4, ""), data_start(0),
      link_trace(0.), plaquette(0.), checksum(0),
      scidac_checksuma(0), scidac_checksumb(0), sequence_number(0)
      {}
  };

// PB disable using namespace - this is a header and forces namesapce visibility for all 
// including files
//using namespace Grid;

//////////////////////////////////////////////////////////////////////
// Bit and Physical Checksumming and QA of data
//////////////////////////////////////////////////////////////////////
inline void GridMetaData(GridBase *grid,FieldMetaData &header)
{
  int nd = grid->_ndimension;
  header.nd = nd;
  header.dimension.resize(nd);
  header.boundary.resize(nd);
  header.data_start = 0;
  for(int d=0;d<nd;d++) {
    header.dimension[d] = grid->_fdimensions[d];
  }
  for(int d=0;d<nd;d++) {
    header.boundary[d] = std::string("PERIODIC");
  }
}

inline void MachineCharacteristics(FieldMetaData &header)
{
  // Who
  struct passwd *pw = getpwuid (getuid());
  if (pw) header.creator = std::string(pw->pw_name); 

  // When
  std::time_t t = std::time(nullptr);
  std::tm tm_ = *std::localtime(&t);
  std::ostringstream oss; 
  oss << std::put_time(&tm_, "%c %Z");
  header.creation_date = oss.str();
  header.archive_date  = header.creation_date;

  // What
  struct utsname name;  uname(&name);
  header.creator_hardware = std::string(name.nodename)+"-";
  header.creator_hardware+= std::string(name.machine)+"-";
  header.creator_hardware+= std::string(name.sysname)+"-";
  header.creator_hardware+= std::string(name.release);
}

#define dump_meta_data(field, s)					\
  s << "BEGIN_HEADER"      << std::endl;				\
  s << "HDR_VERSION = "    << field.hdr_version    << std::endl;	\
  s << "DATATYPE = "       << field.data_type      << std::endl;	\
  s << "STORAGE_FORMAT = " << field.storage_format << std::endl;	\
  for(int i=0;i<4;i++){							\
    s << "DIMENSION_" << i+1 << " = " << field.dimension[i] << std::endl ; \
  }									\
  s << "LINK_TRACE = " << std::setprecision(10) << field.link_trace << std::endl; \
  s << "PLAQUETTE  = " << std::setprecision(10) << field.plaquette  << std::endl; \
  for(int i=0;i<4;i++){							\
    s << "BOUNDARY_"<<i+1<<" = " << field.boundary[i] << std::endl;	\
  }									\
									\
  s << "CHECKSUM = "<< std::hex << std::setw(10) << field.checksum << std::dec<<std::endl; \
  s << "SCIDAC_CHECKSUMA = "<< std::hex << std::setw(10) << field.scidac_checksuma << std::dec<<std::endl; \
  s << "SCIDAC_CHECKSUMB = "<< std::hex << std::setw(10) << field.scidac_checksumb << std::dec<<std::endl; \
  s << "ENSEMBLE_ID = "     << field.ensemble_id      << std::endl;	\
  s << "ENSEMBLE_LABEL = "  << field.ensemble_label   << std::endl;	\
  s << "SEQUENCE_NUMBER = " << field.sequence_number  << std::endl;	\
  s << "CREATOR = "         << field.creator          << std::endl;	\
  s << "CREATOR_HARDWARE = "<< field.creator_hardware << std::endl;	\
  s << "CREATION_DATE = "   << field.creation_date    << std::endl;	\
  s << "ARCHIVE_DATE = "    << field.archive_date     << std::endl;	\
  s << "FLOATING_POINT = "  << field.floating_point   << std::endl;	\
  s << "END_HEADER"         << std::endl;

template<class vobj> inline void PrepareMetaData(Lattice<vobj> & field, FieldMetaData &header)
{
  GridBase *grid = field.Grid();
  std::string format = getFormatString<vobj>();
  header.floating_point = format;
  header.checksum = 0x0; // Nersc checksum unused in ILDG, Scidac
  GridMetaData(grid,header); 
  MachineCharacteristics(header);
}
template<class Impl>
class GaugeStatistics
{
public:
  void operator()(Lattice<vLorentzColourMatrixD> & data,FieldMetaData &header)
  {
    header.link_trace = WilsonLoops<Impl>::linkTrace(data);
    header.plaquette  = WilsonLoops<Impl>::avgPlaquette(data);
  }
};
typedef GaugeStatistics<PeriodicGimplD> PeriodicGaugeStatistics;
typedef GaugeStatistics<ConjugateGimplD> ConjugateGaugeStatistics;
template<> inline void PrepareMetaData<vLorentzColourMatrixD>(Lattice<vLorentzColourMatrixD> & field, FieldMetaData &header)
{
  GridBase *grid = field.Grid();
  std::string format = getFormatString<vLorentzColourMatrixD>();
  header.floating_point = format;
  header.checksum = 0x0; // Nersc checksum unused in ILDG, Scidac
  GridMetaData(grid,header); 
  MachineCharacteristics(header);
}

//////////////////////////////////////////////////////////////////////
// Utilities ; these are QCD aware
//////////////////////////////////////////////////////////////////////
inline void reconstruct3(LorentzColourMatrix & cm)
{
  assert( Nc < 4 && Nc > 1 ) ;
  for(int mu=0;mu<Nd;mu++){
    #if Nc == 2
      cm(mu)()(1,0) = -adj(cm(mu)()(0,y)) ;
      cm(mu)()(1,1) =  adj(cm(mu)()(0,x)) ;
    #else
      const int x=0 , y=1 , z=2 ; // a little disinenuous labelling
      cm(mu)()(2,x) = adj(cm(mu)()(0,y)*cm(mu)()(1,z)-cm(mu)()(0,z)*cm(mu)()(1,y)); //x= yz-zy
      cm(mu)()(2,y) = adj(cm(mu)()(0,z)*cm(mu)()(1,x)-cm(mu)()(0,x)*cm(mu)()(1,z)); //y= zx-xz
      cm(mu)()(2,z) = adj(cm(mu)()(0,x)*cm(mu)()(1,y)-cm(mu)()(0,y)*cm(mu)()(1,x)); //z= xy-yx
    #endif
  }
}

////////////////////////////////////////////////////////////////////////////////
// Some data types for intermediate storage
////////////////////////////////////////////////////////////////////////////////
template<typename vtype> using iLorentzColour2x3 = iVector<iVector<iVector<vtype, Nc>, Nc-1>, Nd >;

typedef iLorentzColour2x3<Complex>  LorentzColour2x3;
typedef iLorentzColour2x3<ComplexF> LorentzColour2x3F;
typedef iLorentzColour2x3<ComplexD> LorentzColour2x3D;

/////////////////////////////////////////////////////////////////////////////////
// Simple classes for precision conversion
/////////////////////////////////////////////////////////////////////////////////
template <class fobj, class sobj>
struct BinarySimpleUnmunger {
  typedef typename getPrecision<fobj>::real_scalar_type fobj_stype;
  typedef typename getPrecision<sobj>::real_scalar_type sobj_stype;
  
  void operator()(sobj &in, fobj &out) {
    // take word by word and transform accoding to the status
    fobj_stype *out_buffer = (fobj_stype *)&out;
    sobj_stype *in_buffer = (sobj_stype *)&in;
    size_t fobj_words = sizeof(out) / sizeof(fobj_stype);
    size_t sobj_words = sizeof(in) / sizeof(sobj_stype);
    assert(fobj_words == sobj_words);
    
    for (unsigned int word = 0; word < sobj_words; word++)
      out_buffer[word] = in_buffer[word];  // type conversion on the fly
    
  }
};

template <class fobj, class sobj>
struct BinarySimpleMunger {
  typedef typename getPrecision<fobj>::real_scalar_type fobj_stype;
  typedef typename getPrecision<sobj>::real_scalar_type sobj_stype;

  void operator()(fobj &in, sobj &out) {
    // take word by word and transform accoding to the status
    fobj_stype *in_buffer = (fobj_stype *)&in;
    sobj_stype *out_buffer = (sobj_stype *)&out;
    size_t fobj_words = sizeof(in) / sizeof(fobj_stype);
    size_t sobj_words = sizeof(out) / sizeof(sobj_stype);
    assert(fobj_words == sobj_words);
    
    for (unsigned int word = 0; word < sobj_words; word++)
      out_buffer[word] = in_buffer[word];  // type conversion on the fly
    
  }
};


template<class fobj,class sobj>
struct GaugeSimpleMunger{
  void operator()(fobj &in, sobj &out) {
    for (int mu = 0; mu < Nd; mu++) {
      for (int i = 0; i < Nc; i++) {
	for (int j = 0; j < Nc; j++) {
	  out(mu)()(i, j) = in(mu)()(i, j);
	}}
    }
  };
};

template <class fobj, class sobj>
struct GaugeSimpleUnmunger {
  void operator()(sobj &in, fobj &out) {
    for (int mu = 0; mu < Nd; mu++) {
      for (int i = 0; i < Nc; i++) {
	for (int j = 0; j < Nc; j++) {
	  out(mu)()(i, j) = in(mu)()(i, j);
	}}
    }
  };
};

template<class fobj,class sobj>
struct GaugeDoubleStoredMunger{
  void operator()(fobj &in, sobj &out) {
    for (int mu = 0; mu < Nds; mu++) {
      for (int i = 0; i < Nc; i++) {
        for (int j = 0; j < Nc; j++) {
          out(mu)()(i, j) = in(mu)()(i, j);
        }}
    }
  };
};

template <class fobj, class sobj>
struct GaugeDoubleStoredUnmunger {
  void operator()(sobj &in, fobj &out) {
    for (int mu = 0; mu < Nds; mu++) {
      for (int i = 0; i < Nc; i++) {
        for (int j = 0; j < Nc; j++) {
          out(mu)()(i, j) = in(mu)()(i, j);
        }}
    }
  };
};

template<class fobj,class sobj>
struct Gauge3x2munger{
  void operator() (fobj &in,sobj &out){
    for(int mu=0;mu<Nd;mu++){
      for(int i=0;i<Nc-1;i++){
	for(int j=0;j<Nc;j++){
	  out(mu)()(i,j) = in(mu)(i)(j);
	}}
    }
    reconstruct3(out);
  }
};

template<class fobj,class sobj>
struct Gauge3x2unmunger{
  void operator() (sobj &in,fobj &out){
    for(int mu=0;mu<Nd;mu++){
      for(int i=0;i<Nc-1;i++){
	for(int j=0;j<Nc;j++){
	  out(mu)(i)(j) = in(mu)()(i,j);
	}}
    }
  }
};

NAMESPACE_END(Grid);