/*
 This file is part of CDO. CDO is a collection of Operators to
 manipulate and analyse Climate model Data.
 
 Copyright (C) 2003-2016 Uwe Schulzweida, <uwe.schulzweida AT mpimet.mpg.de>
 See COPYING file for copying and redistribution conditions.
 
 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; version 2 of the License.
 
 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.
 */

/*
 This module contains the following operators:
 
 Eofcoeff             eofcoeff             process eof coefficients
*/
#define WEIGHTS 1

#include <cdi.h>
#include "cdo.h"
#include "cdo_int.h"
#include "pstream.h"
#include "grid.h"


// NO MISSING VALUE SUPPORT ADDED SO FAR

void *Eofcoeff(void * argument)
{
  char eof_name[8], oname[1024], filesuffix[32];
  const char *refname;
  //double *w;
  double missval1 = -999, missval2;
  double *xvals, *yvals;  
  field_t ***eof;  
  field_t in;  
  field_t out;
  //int operatorID;  
  int gridsize;
  int i, varID, recID, levelID, tsID, eofID;    
  int gridID1, gridID3;
  int nrecs, nvars, nlevs, neof, nchars, nmiss, ngrids; 
  int streamID1, streamID2, *streamIDs;
  int taxisID2, taxisID3;
  int vlistID1, vlistID2, vlistID3;
   
  cdoInitialize(argument);
  cdoOperatorAdd("eofcoeff",  0,       0, NULL);
  //operatorID = cdoOperatorID();
     
  streamID1 = streamOpenRead(cdoStreamName(0));
  streamID2 = streamOpenRead(cdoStreamName(1));
  
  vlistID1 = streamInqVlist(streamID1);
  vlistID2 = streamInqVlist(streamID2);
  vlistID3 = vlistDuplicate(vlistID2);   
  
  //taxisID1 = vlistInqTaxis(vlistID1);  
  taxisID2 = vlistInqTaxis(vlistID2); 
  taxisID3 = taxisDuplicate(taxisID2);
  
  gridID1 = vlistInqVarGrid(vlistID1, 0);
  //gridID2 = vlistInqVarGrid(vlistID2, 0);
  
  if ( vlistGridsizeMax(vlistID1)==vlistGridsizeMax(vlistID2) )
    gridsize = vlistGridsizeMax(vlistID1);  
  else
    {
      gridsize = -1;
      cdoAbort ("Gridsize of input files does not match");
    }
      
  
  if ( vlistNgrids(vlistID2) > 1 || vlistNgrids(vlistID1) > 1 )
    cdoAbort("Too many grids in input");
  
  nvars = vlistNvars(vlistID1)==vlistNvars(vlistID2) ? vlistNvars(vlistID1) : -1;
  nlevs = zaxisInqSize(vlistInqVarZaxis(vlistID1, 0));
  //w = (double*) Malloc(gridsize*sizeof(double));
  //gridWeights(gridID2, w);
  
  
  
  if (vlistGridsizeMax(vlistID2)   != gridsize ||
      vlistInqVarGrid(vlistID2, 0) != gridID1 )
    cdoAbort("EOFs (%s) and data (%s) defined on different grids", cdoStreamName(0)->args, cdoStreamName(1)->args);    
 
  
  strcpy(oname, cdoStreamName(2)->args);
  nchars = strlen(oname);
  
  refname = cdoStreamName(0)->argv[cdoStreamName(0)->argc-1];
  filesuffix[0] = 0;
  cdoGenFileSuffix(filesuffix, sizeof(filesuffix), streamInqFiletype(streamID1), vlistID1, refname);
  
  eof = (field_t***) Malloc(nvars * sizeof(field_t**));
  for ( varID=0; varID<nvars; varID++)
    eof[varID] = (field_t**) Malloc(nlevs*sizeof(field_t*));

  eofID = 0;
  while ( 1 )       
   {     
     nrecs = streamInqTimestep(streamID1, eofID);
     if ( nrecs == 0) break;

     for ( recID = 0; recID < nrecs; recID++ )
       {         
         streamInqRecord(streamID1, &varID, &levelID);
         missval1 = vlistInqVarMissval(vlistID1, varID);
         if ( eofID == 0 )
           eof[varID][levelID] = (field_t*) Malloc(1*sizeof(field_t));
         else
           eof[varID][levelID] = (field_t*) Realloc(eof[varID][levelID], (eofID+1)*sizeof(field_t));
         eof[varID][levelID][eofID].grid   = gridID1;
         eof[varID][levelID][eofID].nmiss  = 0;
         eof[varID][levelID][eofID].missval= missval1;
         eof[varID][levelID][eofID].ptr    = (double*) Malloc(gridsize*sizeof(double));
         memset(&eof[varID][levelID][eofID].ptr[0], missval1, gridsize*sizeof(double));
         if ( varID >= nvars )
           cdoAbort("Internal error - too high varID");
         if ( levelID >= nlevs )
           cdoAbort("Internal error - too high levelID");
         
         streamReadRecord(streamID1, eof[varID][levelID][eofID].ptr, &nmiss);
         eof[varID][levelID][eofID].nmiss = (size_t) nmiss;
       }
     eofID++;
   }
  neof = eofID;  
  
  if ( cdoVerbose ) cdoPrint("%s contains %i eof's", cdoStreamName(0)->args, neof);
  // Create 1x1 Grid for output
  gridID3 = gridCreate(GRID_LONLAT, 1);
  gridDefXsize(gridID3, 1);
  gridDefYsize(gridID3, 1);
  xvals= (double*) Malloc(1*sizeof(double));
  yvals= (double*) Malloc(1*sizeof(double));
  xvals[0]=0;
  yvals[0]=0;
  gridDefXvals(gridID3, xvals);
  gridDefYvals(gridID3, yvals);
  
  // Create var-list and time-axis for output
      
  ngrids = vlistNgrids(vlistID3);
  
  for ( i = 0; i < ngrids; i++ )
    vlistChangeGridIndex(vlistID3, i, gridID3);     
  
  vlistDefTaxis(vlistID3, taxisID3);
  for (varID =0; varID<nvars; varID++)
    vlistDefVarTsteptype(vlistID3, varID, TSTEP_INSTANT);
  
  // open streams for eofcoeff output
  streamIDs = (int*) Malloc(neof*sizeof(int)); 
  for ( eofID = 0; eofID < neof; eofID++)
    {
      oname[nchars] = '\0';                       
      for(varID=0; varID<nvars; varID++) 
      sprintf(eof_name, "%5.5i", eofID);
      strcat(oname, eof_name);
      if ( filesuffix[0] )
        strcat(oname, filesuffix);
      
      argument_t *fileargument = file_argument_new(oname);
      streamIDs[eofID] = streamOpenWrite(fileargument, cdoFiletype());
      file_argument_free(fileargument);

      if (cdoVerbose) 
        cdoPrint("opened %s ('w')  as stream%i for %i. eof", oname, streamIDs[eofID], eofID+1);
      
      streamDefVlist(streamIDs[eofID], vlistID3);
    
    }
  
  // ALLOCATE temporary fields for data read and write
  in.ptr = (double*) Malloc(gridsize*sizeof(double));
  in.grid = gridID1;  
  out.missval = missval1;
  out.nmiss = 0;
  out.ptr = (double*) Malloc(1*sizeof(double));
 
  tsID=0;
  while ( 1 )
    {      
      nrecs = streamInqTimestep(streamID2, tsID);
      if ( nrecs == 0 ) break;
      
      taxisCopyTimestep(taxisID3, taxisID2);
      /*for ( eofID=0; eofID<neof; eofID++)
        {
          fprintf(stderr, "defining ts %i\n", tsID);
          streamDefTimestep(streamIDs[eofID],tsID);
        }
      */
      for ( recID =0; recID< nrecs; recID++ )
        {
          streamInqRecord(streamID2, &varID, &levelID);
          missval2 = vlistInqVarMissval(vlistID2, varID);
          streamReadRecord(streamID2, in.ptr, &nmiss);  
          in.nmiss = (size_t) nmiss;
          
          for (eofID = 0; eofID < neof; eofID++ )
            {
              if ( recID == 0 ) streamDefTimestep(streamIDs[eofID],tsID);
              //if ( recID == 0 ) fprintf(stderr, "ts%i rec%i eof%i\n", tsID, recID, eofID);
              out.ptr[0]  = 0;
              out.grid    = gridID3;
              out.missval = missval2;            
              for(i=0;i<gridsize;i++)
                {                  
                  if (! DBL_IS_EQUAL(in.ptr[i],missval2) && 
                      ! DBL_IS_EQUAL(eof[varID][levelID][eofID].ptr[i],missval1 ))
                    {
		      // double tmp = w[i]*in.ptr[i]*eof[varID][levelID][eofID].ptr[i];
                      double tmp = in.ptr[i]*eof[varID][levelID][eofID].ptr[i];
                      out.ptr[0] += tmp;                   
                    }
                }            
              if ( ! DBL_IS_EQUAL(out.ptr[0],0.) ) nmiss=0;
              else { nmiss=1; out.ptr[0]=missval2; }
                      
              streamDefRecord(streamIDs[eofID], varID, levelID);
              //fprintf(stderr, "%d %d %d %d %d %g\n", streamIDs[eofID],tsID, recID, varID, levelID,*out.ptr);
              streamWriteRecord(streamIDs[eofID],out.ptr,nmiss);
            }
          if ( varID >= nvars )
            cdoAbort("Internal error - too high varID");
          if ( levelID >= nlevs )
            cdoAbort("Internal error - too high levelID");                              
        }
      tsID++;
    }
  
  for ( eofID = 0; eofID < neof; eofID++) streamClose(streamIDs[eofID]);

  streamClose(streamID2);
  streamClose(streamID1);
  
  cdoFinish();

  return 0;
}

