/* 
 *            Copyright 2009-2018 The VOTCA Development Team
 *                       (http://www.votca.org)
 *
 *      Licensed under the Apache License, Version 2.0 (the "License")
 *
 * You may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *              http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#ifndef VOTCA_XTP_GRID_H
#define	VOTCA_XTP_GRID_H


#include <string>
#include <vector>
#include <votca/xtp/qmatom.h>
#include <votca/xtp/logger.h>
#include <votca/xtp/qmmolecule.h>
/**
* \brief Takes a list of atoms, and creates CHELPG grid.
*
* 
* 
*/


namespace votca { namespace xtp {
   
  class Grid{
    public:
               
        const std::vector< Eigen::Vector3d > &getGridPositions() const {return _gridpoints;}
        
        Eigen::VectorXd &getGridValues(){return _gridvalues;}
        const Eigen::VectorXd &getGridValues() const{return _gridvalues;}
        unsigned size(){return _gridpoints.size();}
        
        void printGridtoxyzfile(std::string filename);
       
        
       
        void setupCHELPGGrid(const QMMolecule& Atomlist){
            _padding=3*tools::conv::ang2bohr; // Additional distance from molecule to set up grid according to CHELPG paper [Journal of Computational Chemistry 11, 361, 1990]
            _gridspacing=0.3*tools::conv::ang2bohr; // Grid spacing according to same paper 
            _cutoff=2.8*tools::conv::ang2bohr;
            setupgrid(Atomlist);
        }
       
      
  private:
     
      
      void setupgrid(const QMMolecule& Atomlist);
      std::vector< Eigen::Vector3d > _gridpoints;
      Eigen::VectorXd _gridvalues;
     
      double _cutoff;
      double _gridspacing;
      double _padding;
 
    };   
    
}}

#endif	// VOTCA_XTP_GRID_H