#include "function.h"
#include "SPoint3.h"
#include "MElement.h"
#include <sstream>

// dataCache members
dataCache::dataCache(dataCacheMap *cacheMap) : _valid(false) {
  cacheMap->addDataCache(this); //this dataCache can be deleted when the dataCacheMap is deleted
}

void dataCache::addMeAsDependencyOf (dataCache *newDep)
{
  _dependOnMe.insert(newDep);
  newDep->_iDependOn.insert(this);
  for(std::set<dataCache*>::iterator it = _iDependOn.begin();
      it != _iDependOn.end(); it++) {
    (*it)->_dependOnMe.insert(newDep);
    newDep->_iDependOn.insert(*it);
  }
}

// function static members

std::map<std::string,function*> function::_allFunctions;

bool function::add(const std::string functionName, function *f)
{
  if(_allFunctions.find(functionName)!=_allFunctions.end())
    return false;
  _allFunctions[functionName]=f;
  return true;
}

function *function::get(std::string functionName, bool acceptNull)
{
  std::map<std::string, function*>::iterator it=_allFunctions.find(functionName);
  if (it==_allFunctions.end()) {
    if (acceptNull)
      return NULL;
    else
      throw;
  }
  return it->second;
}

//dataCacheMap members

dataCacheElement &dataCacheMap::getElement(dataCache *caller) 
{
  if(caller)
    _cacheElement->addMeAsDependencyOf(caller);
  return *_cacheElement;
}

dataCacheDouble &dataCacheMap::get(const std::string &functionName, dataCache *caller) 
{
  dataCacheDouble *&r= _cacheDoubleMap[functionName];
  if(r==NULL)
    r = function::get(functionName)->newDataCache(this);
  if(caller)
    r->addMeAsDependencyOf(caller);
  return *r;
}

dataCacheDouble &dataCacheMap::provideData(std::string name)
{
  dataCacheDouble *&r= _cacheDoubleMap[name];
  if(r!=NULL)
    throw;
  r = new providedDataDouble(*this);
  return *r;
}

dataCacheMap::~dataCacheMap()
{
  for (std::set<dataCache*>::iterator it = _toDelete.begin();
      it!=_toDelete.end(); it++) {
    delete *it;
  }
}

// now some example of functions

// get XYZ coordinates
class functionXYZ : public function {
 private:
  class data : public dataCacheDouble{
   private:
    dataCacheElement &_element;
    dataCacheDouble &_uvw;
  int count;
   public:
    data(dataCacheMap *m) : 
      dataCacheDouble(*m, m->getNbEvaluationPoints(),3),
      _element(m->getElement(this)), _uvw(m->get("UVW", this))
    {
    }
    void _eval()
    {
      for(int i = 0; i < _uvw().size1(); i++){
        SPoint3 p;
        _element()->pnt(_uvw(i, 0), _uvw(i, 1), _uvw(i, 2), p);
        _value(i, 0) = p.x();
        _value(i, 1) = p.y();
        _value(i, 2) = p.z();
      }
    }
    ~data(){
    }
  };
 public:
  dataCacheDouble *newDataCache(dataCacheMap *m)
  {
    return new data(m);
  }
};


// constant values copied over each line
class functionConstant::data : public dataCacheDouble {
 const functionConstant *_function;
 public:
 data(const functionConstant * function,dataCacheMap *m):
   dataCacheDouble(*m,m->getNbEvaluationPoints(),function->_source.size1()){
     _function = function;
   }
 void _eval() {
   for(int i=0;i<_value.size1();i++)
     for(int j=0;j<_function->_source.size1();j++)
       _value(i,j)=_function->_source(j,0);
 }
};
dataCacheDouble *functionConstant::newDataCache(dataCacheMap *m)
{
 return new data(this,m);
}
functionConstant::functionConstant(const fullMatrix<double> *source){
 _source = *source;
  static int c=0;
  std::ostringstream oss;
  oss<<"FunctionConstant_"<<c++;
  _name = oss.str();
  function::add(_name,this);
}

// function that enables to interpolate a DG solution using
// geometrical search in a mesh 
/*
class functionSystemOfEquations::data : public dataCacheDouble {
  dgSystemOfEquations *_sys;
  dataCacheDouble &xyz;
public:
  data(dataCacheMap &m, dgSystemOfEquations *sys) :
    _sys(sys), 
    xyz(cacheMap.get("Solution",this)),
    dataCacheDouble(m.getNbEvaluationPoints(), sys->getLaw()->getNbFields())
  {
  }
  void _eval() {
    int nP =xyz().size1();
    if(_value.size1() != nP)
      _value = fullMatrix<double>(nP,sys->getLaw()->getNbFields());
    _value.setAll(0.0);
    double fs[256];
    for (int i=0;i<_value.size1();i++){
      const double x = xyz(i,0);
      const double y = xyz(i,1);
      const double z = xyz(i,2);
      MElement *e = _sys->getModel()->getMeshElementByCoord(SPoint3(x,y,z));
      std::pair<dgGroupOfElements*,int> location = _sys->getElementPosition(e);
      double U[3],X[3]={xyz(i,0),xyz(i,1),xyz(i,2)};
      e->xyz2uvw (X,U);
      location.first->getFunctionSpace().f(U[0],U[1],U[2],fs);      
    }
  }
  dataCacheDouble *newDataCache(dataCacheMap *m)
  {
    return new data(this,_sys);
  }
};
*/


#include "Bindings.h"

void function::registerDefaultFunctions()
{
  function::add("XYZ", new functionXYZ);
}
void function::registerBindings(binding *b){
  classBinding *cb = b->addClass<function>("function");
  cb->setDescription("A generic function that can be evaluated on a set of points. Functions can call other functions and their values are cached so that if two different functions call the same function f, f is only evaluated once.");
  methodBinding *mb;
  mb = cb->addMethod("getName",&function::getName);
  mb->setDescription("Return the string which identifies this function.");
  cb = b->addClass<functionConstant>("functionConstant");
  cb->setDescription("A constant (scalar or vector) function");
  mb = cb->setConstructor<functionConstant,fullMatrix<double>*>();
  mb->setArgNames("v",NULL);
  mb->setDescription("A new constant function wich values 'v' everywhere. v can be a row-vector.");
  cb->setParentClass<function>();
}