/*
 *  pluginmanager.hpp
 *
 *  Copyright 2009 Max Christian Pohle <coderz@gmx.de>
 *
 *  This program 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.
 *
 *  This program 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 this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 *  MA 02110-1301, USA.
 */

#ifndef pluginmanager
#define pluginmanager
  #define PLUGIN_ENGINE_VERSION 1

  #include <string>
  #include <map>
  #include <sstream>
  #include <dlfcn.h>
  #include <iostream>
  #include <list>

  #include "plugins/plugin.hpp"

  using namespace std;

  template <class T>
  class PluginManager
  {
    private:
      int engine_version;
      typedef T create();
      map<string,create*> plugins;
      typename map<string, create*>::iterator iter;

    public:
      PluginManager<T>() : engine_version(PLUGIN_ENGINE_VERSION) {}

      T get_instance(string t)
      {
        iter = plugins.find(t);
        if (iter != plugins.end())
        { return iter->second(); }
      }

      list<string> list_plugins()
      {
        list<string> retval;
        for(iter=plugins.begin(); iter!=plugins.end(); ++iter)
        { retval.push_front(iter->first); }
        return retval;
      }

      void load_plugin(string filename)
      {
        std::stringstream serr;
        char* dlsym_error;
        std::cerr << "\n> OPENING " << filename << "...";
        void* plugin2open = dlopen(filename.c_str(), RTLD_LAZY);
        if (dlsym_error = dlerror())
        {
          std::stringstream a;
          a <<
            std::string(filename) <<
            std::string(" is not a valid plugin\n\t") <<
            std::string(dlsym_error);
          throw (char*) a.str().c_str();
        }
        else
        {
          std::cerr << "done.\n";
        }

        create* f_creator = (create*) dlsym(plugin2open, "create");
        if (dlsym_error = dlerror())
        {
          throw (char*)"plugin has no creation-interface"
            ", so is obviously no subclass of 'Plugin'";
        }
        else
        {
          std::cout << "> LOADING " << filename << "...";
          plugins.insert(make_pair(filename, f_creator));
          std::cout << "done.\n";
        }
      }
  };

#endif