/*
 * SerializablePotential.hpp
 *
 *  Created on: 23.11.2012
 *      Author: heber
 */

#ifndef SERIALIZABLEPOTENTIAL_HPP_
#define SERIALIZABLEPOTENTIAL_HPP_

// include config.h
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <iosfwd>
#include <vector>

/** SerializablePotential is a potential that can be parsed from and stored to
 * a .potentials file.
 *
 * All required functionality for printing and parsing the set of parameters
 * is set as virtual functions and have to be implemented specifically, e.g.
 * -# ParameterNames: Should be static instance as are the same over each
 *    potential type despite although there may be more than one instance.
 *    \note If the parameter name is left empty, the value is neither printed
 *    nor parsed. This may be issued to skip internal parameters (e.g. offset).
 * -# ParticleTypes: has been implemented here, as is different per instance.
 *
 * Specifically, what you need to do when inheriting is:
 * -# implement getParameters() and setParameters()
 * -# have some static const ParameterNames_t in your class and implement
 *    getParameterNames() as a getter for it (or any other way you prefer).
 *    The static instance can be easily initialized via boost::assign::list_of.
 *
 */
class SerializablePotential
{
public:
  //!> typedef for particle designation
  typedef int ParticleType_t;
  //!> typedef for a vector of particle designations
  typedef std::vector<ParticleType_t> ParticleTypes_t;
  //!> typedef for a vector of parameter names
  typedef std::vector<std::string> ParameterNames_t;
  //!> typedef for a single parameter degree of freedom of the function
  typedef double parameter_t;
  //!> typedef for the whole set of parameters of the function
  typedef std::vector<parameter_t> parameters_t;

public:
  SerializablePotential(const ParticleTypes_t &_ParticleTypes) :
    ParticleTypes(_ParticleTypes)
  {}
  virtual ~SerializablePotential() {}

  /** Return the token name of this specific potential.
   *
   * \return token name of the potential
   */
  virtual const std::string& getToken() const=0;

  /** Return the name of this specific potential.
   *
   * This is required for storage in a Registry. The name is the token name
   * followed by "_" and the particle types to make it unique.
   *
   * \return name of the potential
   */
  const std::string getName() const;


  /** Getter for the parameters of this model function.
   *
   * \return current set of parameters of the model function
   */
  virtual parameters_t getParameters() const=0;

  /** Getter for the number of parameters of this model function.
   *
   * \return number of parameters
   */
  virtual size_t getParameterDimension() const=0;

  /** Returns a vector of particle designations.
   *
   * These designations denote the particle types for which this potential
   * has been parametrized.
   *
   * \return vector of particle type
   */
  const ParticleTypes_t& getParticleTypes() const
  { return ParticleTypes; }

  /** Returns a vector of parameter names.
   *
   * This is required from the specific implementation
   *
   * \return vector of strings containing parameter names
   */
  virtual const ParameterNames_t& getParameterNames() const=0;

  /** Returns the index associated to a specific parameter \a _name.
   *
   * \param _name parameter name to look up index for
   * \return index to the given \a _name or (size_t)-1 if none found
   */
  const size_t getParameterIndex(const std::string &_name) const;

  /** Print parameters to given stream \a ost.
   *
   * These are virtual functions to allow for overriding and hence
   * changing the default behavior.
   *
   * @param ost stream to print to
   */
  virtual void stream_to(std::ostream &ost) const;

  /** Parse parameters from given stream \a ist.
   *
   * These are virtual functions to allow for overriding and hence
   * changing the default behavior.
   *
   * @param ist stream to parse from
   */
  virtual void stream_from(std::istream &ist);

protected:

  /** Setter for the parameters of the model function.
   *
   * \param params set of parameters to set
   */
  virtual void setParameters(const parameters_t &params)=0;

  /** Setter for a given particle type.
   *
   * \param index index of type to set
   * \param _designation type to set to
   */
  void setParticleType(const size_t index, const ParticleType_t& _designation)
  {
    if (ParticleTypes.size() <= index)
      const_cast<ParticleTypes_t &>(ParticleTypes).resize(index+1);
    const_cast<ParticleTypes_t &>(ParticleTypes)[index] = _designation;
  }

protected:
  /** Default constructor for class EmpiricalPotential.
   *
   * Callable only by derived functions.
   *
   */
  SerializablePotential();

private:

  //!> static definition of the particle types for this potential
  const ParticleTypes_t ParticleTypes;
};

/** Output operations stores .potentials line containing these parameters
 * coefficients and designations.
 *
 * \param ost output stream to print to
 * \param potential potential whose coefficients to print
 * \return output stream for concatenation
 */
std::ostream& operator<<(std::ostream &ost, const SerializablePotential &potential);

/** Input operation parses coefficients from a given line of a .potentials
 * file.
 *
 * \param ist input stream to parse from
 * \param potential potential to set
 * \return input stream for concatenation
 */
std::istream& operator>>(std::istream &ist, SerializablePotential &potential);


#endif /* SERIALIZABLEPOTENTIAL_HPP_ */