//
// File: ParameterAliasable.h
// Created by: Julien Dutheil
// Created on: Thu May 14 16:53 2009
//

/*
  Copyright or © or Copr. Bio++ Development Team, (November 17, 2004)

  This software is a computer program whose purpose is to provide classes
  for numerical calculus.

  This software is governed by the CeCILL  license under French law and
  abiding by the rules of distribution of free software.  You can  use, 
  modify and/ or redistribute the software under the terms of the CeCILL
  license as circulated by CEA, CNRS and INRIA at the following URL
  "http://www.cecill.info". 

  As a counterpart to the access to the source code and  rights to copy,
  modify and redistribute granted by the license, users are provided only
  with a limited warranty  and the software's author,  the holder of the
  economic rights,  and the successive licensors  have only  limited
  liability. 

  In this respect, the user's attention is drawn to the risks associated
  with loading,  using,  modifying and/or developing or reproducing the
  software by the user in light of its specific status of free software,
  that may mean  that it is complicated to manipulate,  and  that  also
  therefore means  that it is reserved for developers  and  experienced
  professionals having in-depth computer knowledge. Users are therefore
  encouraged to load and test the software's suitability as regards their
  requirements in conditions enabling the security of their systems and/or 
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  same conditions as regards security. 

  The fact that you are presently reading this means that you have had
  knowledge of the CeCILL license and that you accept its terms.
*/

#ifndef _PARAMETERALIASABLE_H_
#define _PARAMETERALIASABLE_H_

#include "Parametrizable.h"
#include "ParameterExceptions.h"
#include "ParameterList.h"

//From the STL:
#include <string>
#include <map>

namespace bpp
{

/**
 * @brief Extend the Parametrizable interface with support for parameter aliases.
 *
 * Parameter aliases allows several parameter to be constrained together, and 
 * for instance, be jointly estimated.
 * The alias relationship is not symmetric:
 * @code
 * aliasParameters("a","b");
 * @endcode
 * results in the value of "b" being updated when a is modified, but a will not be updated upon modification of "a".
 * "b" will also be removed of the list of "independent" parameters.
 * Furthermore, a parameter can only be aliased with another one:
 * @code
 * aliasParameters("a","b");
 * aliasParameters("c","b"); //ERROR, throws an exception.
 * @endcode
 * However, several parameters can be aliased to the same one:
 * @code
 * aliasParameters("a","b");
 * aliasParameters("a","c");
 * @endcode
 * In this case, modifying "a" will automatically update the values of "b" and "c", and "b" and "c" are removed from the list of indepedent parameters.
 * Finally, parameters can be chained:
 * @code
 * aliasParameters("a","b");
 * aliasParameters("b","c");
 * @endcode
 * is equivallent to the previous example.
 */
  class ParameterAliasable :
    public virtual Parametrizable
  {
  public:
    ParameterAliasable() {}
    virtual ~ParameterAliasable() {}

  public:

    /**
     * @brief Get the number of independent parameters.
     *
     * @return The number of independent parameters.
     * If no parameters are aliased, this is equivalent to the getNumberOfParameters() method.
     */
    virtual size_t getNumberOfIndependentParameters() const = 0;

    /**
     * @brief Set two parameters as 'aliased'.
     *
     * The values of the two parameters will be synchronized, so that setting the value of one parameter will automatically set the value of the other one accordingly.
     * @param p1 Original parameter.
     * @param p2 Aliased parameter.
     * @throw ParameterNotFoundException if p1 or p2 do not correspond to existing parameters.
     * @throw Exception when trying to perform non-valid association.
     */
    virtual void aliasParameters(const std::string & p1, const std::string & p2)
      noexcept(false) = 0;

    /**
     * @brief alias the parameters following the links described in a
     * map, and update the object accordingly. Cycles in aliasing are
     * detected and forbidden.
     *
     * @param unparsedParams the map of the links : <A,B> matches for A->B aliasing.
     * @param verbose verbosity
     *
     **/
    
    virtual void aliasParameters(std::map<std::string, std::string>& unparsedParams, bool verbose) = 0;

    /**
     * @brief Detach two parameters previously set as 'aliased'.
     *
     * The values of the two parameters will now be independent.
     * @param p1 Original parameter.
     * @param p2 Aliased parameter.
     * @throw ParameterNotFoundException if p1 or p2 do not correspond to existing parameters.
     * @throw Exception when trying to perform non-valid dissociation.
     */
    virtual void unaliasParameters(const std::string & p1, const std::string & p2)
      noexcept(false) = 0;

    /**
     * @brief Get the minimal list of parameters to set the model.
     *
     * If no parameters are aliased, this is the same a getParameters().
     *
     * @return A minimal set of parameters.
     */
    virtual const ParameterList & getIndependentParameters() const = 0;

    /**
     * @return The list of names of the parameters that are aliased with a given parameter.
     * Depending on the implementation, the function may be recursive or not...
     * @param name The name of the parameter to look for.
     */
    virtual std::vector<std::string> getAlias(const std::string& name) const = 0;

    /**
     * @return the map of the aliases.
     *
     **/
    
    virtual std::map<std::string, std::string> getAliases() const = 0;

  };




/**
 * @brief A low-level implementation of the ParameterAliasable interface with void functions.
 *
 * @see Parameter, ParameterList, ParameterAliasable
 */
  class ParameterAliasableAdapter:
    public ParametrizableAdapter
  {
  public:
    ParameterAliasableAdapter() {}
    virtual ~ParameterAliasableAdapter() {}

  public:

    /**
     * @name The ParameterAliasable interface.
     *
     * @{
     */
    const ParameterList & getIndependentParameters() const { return getParameters(); }
    void aliasParameters(const std::string &, const std::string &)
      noexcept(false) {}
    void unaliasParameters(const std::string &, const std::string &)
      noexcept(false) {}
    unsigned int getNumberOfIndependentParameters() const{ return 0; }
    std::vector<std::string> getAlias(const std::string&) const { return std::vector<std::string>(); }
    std::map<std::string, std::string> getAliases() const { return std::map<std::string, std::string>(); }
    /** @} */

  };

} // end of namespace bpp.

#endif // _PARAMETERALIASABLE_H_

