// src/backend/pyloader/python_policy_manager.hh - Copyright 2005, 2006, University
//               of Padova, dept. of Pure and Applied
//               Mathematics
//
// This file is part of SGPEMv2.
//
// This 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.
//
// SGPEMv2 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 SGPEMv2; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

#ifndef PYTHON_POLICY_MANAGER_HH
#define PYTHON_POLICY_MANAGER_HH 1

#include "config.h"

#include <Python.h>

#include "policy_manager.hh"
#include "python_policy.hh"

namespace sgpem
{
  //class PolicyManager;
  class PythonPolicyManager;

  /** \brief Manages Python user-implemented policies
   * 
   * This singleton manages the creation and destruction 
   * of a Python policy.
   */
  class SG_DLLEXPORT PythonPolicyManager : public PolicyManager
  {
  public:
    /** \brief Returns a reference to the active policy.
     *
     * For the moment, it will sufficit to keep and return 
     * just one Policy for PolicyManager. 
     * In the next milestones it will be possible to manage 
     * more than one, and to retrieve the correct Policy by 
     * passing a unique ID.
     */
    Policy& get_policy();

    /** \brief Initialize the Python interpreter.
     *
     * If the interpreter has already been initialized, it terminates it, cleanups old policies,
     * and restarts it.
     */
    void init();

      /** \brief Returns the singleton instance of 
       * PythonPolicyManager.
       * 
       * Please note that the first time you'll request 
       * it, it will be still uninitialized.
       * @see init()
       */
    static PythonPolicyManager* const get_instance();	
		
  protected:
    /** The selected and active PyhonPolicy object. */
    PythonPolicyManager();
    std::auto_ptr<PythonPolicy>	_python_policy;

  private:
    PythonPolicyManager(const PythonPolicyManager&);
    PythonPolicyManager& operator=(const PythonPolicyManager&);

    /** Singleton support. */
    static PythonPolicyManager* _instance;

    bool _initialized;
  };

}

#endif