// $Id: Extract.cpp,v 1.9 2004-05-13 15:09:45 geuzaine Exp $
//
// Copyright (C) 1997-2004 C. Geuzaine, J.-F. Remacle
//
// 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
// USA.
// 
// Please report all bugs and problems to <gmsh@geuz.org>.

#include "Plugin.h"
#include "Extract.h"
#include "List.h"
#include "Views.h"
#include "Context.h"
#include "Malloc.h"

#if defined(HAVE_MATH_EVAL)
#include "matheval.h"
#endif

extern Context_T CTX;

StringXNumber ExtractOptions_Number[] = {
  {GMSH_FULLRC, "iView", NULL, -1.}
};

StringXString ExtractOptions_String[] = {
  {GMSH_FULLRC, "Expression", NULL, "v0"}
};

extern "C"
{
  GMSH_Plugin *GMSH_RegisterExtractPlugin()
  {
    return new GMSH_ExtractPlugin();
  }
}

GMSH_ExtractPlugin::GMSH_ExtractPlugin()
{
  ;
}

void GMSH_ExtractPlugin::getName(char *name) const
{
  strcpy(name, "Extract");
}

void GMSH_ExtractPlugin::getInfos(char *author, char *copyright, char *help_text) const
{
  strcpy(author, "C. Geuzaine (geuz@geuz.org)");
  strcpy(copyright, "DGR (www.multiphysics.com)");
  strcpy(help_text,
         "Plugin(Extract) extracts a combination of\n"
	 "components from the view `iView', as specified\n"
	 "by `Expression'. In addition to the usual\n"
	 "mathematical functions (Exp, Log, Sqrt, Sin,\n"
	 "Cos, Fabs, etc.) and operators (+, -, *, /, ^),\n"
	 "`Expression' can contain the symbols v0, v1,\n"
	 "v2, ..., vn, which represent the n components\n"
	 "of the field. If `iView' < 0, the plugin is\n"
	 "run on the current view.\n"
	 "\n"
	 "Plugin(Extract) creates one new view.\n");
}

int GMSH_ExtractPlugin::getNbOptions() const
{
  return sizeof(ExtractOptions_Number) / sizeof(StringXNumber);
}

StringXNumber *GMSH_ExtractPlugin::getOption(int iopt)
{
  return &ExtractOptions_Number[iopt];
}

int GMSH_ExtractPlugin::getNbOptionsStr() const
{
  return sizeof(ExtractOptions_String) / sizeof(StringXString);
}

StringXString *GMSH_ExtractPlugin::getOptionStr(int iopt)
{
  return &ExtractOptions_String[iopt];
}

void GMSH_ExtractPlugin::catchErrorMessage(char *errorMessage) const
{
  strcpy(errorMessage, "Extract failed...");
}

static void extract(char *expr, List_T *inList, int inNb, 
		    List_T *outList, int *outNb, 
		    int nbTime, int nbNod, int nbComp)
{
  if(!inNb)
    return;

  // if we have MathEval, we can evaluate arbitrary expressions;
  // otherwise, we only allow to extract single components

#if defined(HAVE_MATH_EVAL)
  void *f = evaluator_create(expr);
  if(!f){
    Msg(GERROR, "Invalid expression '%s'", expr);
    return;
  }
#else
  int comp;
  if     (!strcmp(expr, "v0")) comp = 0;
  else if(!strcmp(expr, "v1")) comp = 1;
  else if(!strcmp(expr, "v2")) comp = 2;
  else if(!strcmp(expr, "v3")) comp = 3;
  else if(!strcmp(expr, "v4")) comp = 4;
  else if(!strcmp(expr, "v5")) comp = 5;
  else if(!strcmp(expr, "v6")) comp = 6;
  else if(!strcmp(expr, "v7")) comp = 7;
  else if(!strcmp(expr, "v8")) comp = 8;
  else{
    Msg(GERROR, "Invalid expression '%s'", expr);
    return;
  }
#endif

  int nb = List_Nbr(inList) / inNb;
  for(int i = 0; i < List_Nbr(inList); i += nb) {
    for(int j = 0; j < 3 * nbNod; j++)
      List_Add(outList, List_Pointer_Fast(inList, i + j));
    for(int j = 0; j < nbTime; j++){
      for(int k = 0; k < nbNod; k++){
	double res, d[9];
	for(int l = 0; l < nbComp; l++)
	  List_Read(inList, i + 3 * nbNod + nbNod * nbComp * j + nbComp * k + l, &d[l]);
	for(int l = nbComp; l < 9; l++)
	  d[l] = 0.;
#if defined(HAVE_MATH_EVAL)
	char *names[] = { "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v8" };
	double values[] = { d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7], d[8] };
	res = evaluator_evaluate(f, sizeof(names)/sizeof(names[0]), names, values);
#else
	res = d[comp];
#endif
	List_Add(outList, &res);
      }
    }
    (*outNb)++;
  }

#if defined(HAVE_MATH_EVAL)
  evaluator_destroy(f);
#endif
}

Post_View *GMSH_ExtractPlugin::execute(Post_View * v)
{
  int iView = (int)ExtractOptions_Number[0].def;
  char *expr = ExtractOptions_String[0].def;
  Post_View *vv;

  if(v && iView < 0)
    vv = v;
  else {
    if(!v && iView < 0)
      iView = 0;
    if(!(vv = (Post_View *) List_Pointer_Test(CTX.post.list, iView))) {
      Msg(WARNING, "View[%d] does not exist", iView);
      return 0;
    }
  }

  // FIXME: this is not secure: if BeginView forces a post.list
  // reallocation, vv is wrong
  Post_View *view = BeginView(1);

  // points
  extract(expr, vv->SP, vv->NbSP, view->SP, &view->NbSP, vv->NbTimeStep, 1, 1);
  extract(expr, vv->VP, vv->NbVP, view->SP, &view->NbSP, vv->NbTimeStep, 1, 3);
  extract(expr, vv->TP, vv->NbTP, view->SP, &view->NbSP, vv->NbTimeStep, 1, 9);
  // lines
  extract(expr, vv->SL, vv->NbSL, view->SL, &view->NbSL, vv->NbTimeStep, 2, 1);
  extract(expr, vv->VL, vv->NbVL, view->SL, &view->NbSL, vv->NbTimeStep, 2, 3);
  extract(expr, vv->TL, vv->NbTL, view->SL, &view->NbSL, vv->NbTimeStep, 2, 9);
  // triangles
  extract(expr, vv->ST, vv->NbST, view->ST, &view->NbST, vv->NbTimeStep, 3, 1);
  extract(expr, vv->VT, vv->NbVT, view->ST, &view->NbST, vv->NbTimeStep, 3, 3);
  extract(expr, vv->TT, vv->NbTT, view->ST, &view->NbST, vv->NbTimeStep, 3, 9);
  // quadrangles
  extract(expr, vv->SQ, vv->NbSQ, view->SQ, &view->NbSQ, vv->NbTimeStep, 4, 1);
  extract(expr, vv->VQ, vv->NbVQ, view->SQ, &view->NbSQ, vv->NbTimeStep, 4, 3);
  extract(expr, vv->TQ, vv->NbTQ, view->SQ, &view->NbSQ, vv->NbTimeStep, 4, 9);
  // tets
  extract(expr, vv->SS, vv->NbSS, view->SS, &view->NbSS, vv->NbTimeStep, 4, 1);
  extract(expr, vv->VS, vv->NbVS, view->SS, &view->NbSS, vv->NbTimeStep, 4, 3);
  extract(expr, vv->TS, vv->NbTS, view->SS, &view->NbSS, vv->NbTimeStep, 4, 9);
  // hexas
  extract(expr, vv->SH, vv->NbSH, view->SH, &view->NbSH, vv->NbTimeStep, 8, 1);
  extract(expr, vv->VH, vv->NbVH, view->SH, &view->NbSH, vv->NbTimeStep, 8, 3);
  extract(expr, vv->TH, vv->NbTH, view->SH, &view->NbSH, vv->NbTimeStep, 8, 9);
  // prisms
  extract(expr, vv->SI, vv->NbSI, view->SI, &view->NbSI, vv->NbTimeStep, 6, 1);
  extract(expr, vv->VI, vv->NbVI, view->SI, &view->NbSI, vv->NbTimeStep, 6, 3);
  extract(expr, vv->TI, vv->NbTI, view->SI, &view->NbSI, vv->NbTimeStep, 6, 9);
  // pyramids
  extract(expr, vv->SY, vv->NbSY, view->SY, &view->NbSY, vv->NbTimeStep, 5, 1);
  extract(expr, vv->VY, vv->NbVY, view->SY, &view->NbSY, vv->NbTimeStep, 5, 3);
  extract(expr, vv->TY, vv->NbTY, view->SY, &view->NbSY, vv->NbTimeStep, 5, 9);

  if(view->empty()) {
    RemoveViewByNumber(view->Num);
  }
  else{
    // copy time data
    for(int i = 0; i < List_Nbr(vv->Time); i++)
      List_Add(view->Time, List_Pointer(vv->Time, i));
    // finalize
    char name[1024], filename[1024];
    sprintf(name, "%s_Extract", vv->Name);
    sprintf(filename, "%s_Extract.pos", vv->Name);
    EndView(view, 1, filename, name);
  }

  return 0;
}