/* 
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 *
 * 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; version 2 of the
 * License.
 * 
 * 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 St, Fifth Floor, Boston, MA
 * 02110-1301  USA
 */

#include "stdafx.h"

#include "plugin_manager.h"
#include "editor_base.h"
#include "grt_manager.h"
#include "base/string_utilities.h"

#include "interfaces/plugin.h"

using namespace bec;
using namespace grt;



static std::string get_args_hash(const grt::BaseListRef &list)
{
  std::string hash;

  for (size_t c= list.count(), i= 0; i < c; i++)
  {
    switch (list.get(i).type())
    {
    case ObjectType:
      hash+= grt::ObjectRef::cast_from(list.get(i)).id();
      break;
    case ListType:
      hash+= get_args_hash(grt::BaseListRef::cast_from(list.get(i)));
      break;
    default:
      hash+= list.get(i).repr();
      break;
    }
  }

  return hash;
}


PluginManagerImpl::PluginManagerImpl(grt::CPPModuleLoader *loader)
  : superclass(loader)
{
  _grtm= GRTManager::get_instance_for(loader->get_grt());
  
  InterfaceImplBase::Register<PluginInterfaceImpl>(loader->get_grt());
}


/** 
 ****************************************************************************
 * @brief Sets the GRT tree path where the plugin registry is located
 *
 * @param plugins_path
 * @param groups_path
 ****************************************************************************
 */
void PluginManagerImpl::set_registry_paths(const std::string &plugins_path,
                                           const std::string &groups_path)
{
  _registry_path= plugins_path;
  _group_registry_path= groups_path;
}


bool PluginManagerImpl::check_plugin_validity(const app_PluginRef &plugin, grt::Module *module)
{
  if (plugin->pluginType() == GUI_PLUGIN_TYPE)
  {
    // not much that can be tested here, maybe check if the dll actually exists
    return true;
  }
  else if (plugin->pluginType() == STANDALONE_GUI_PLUGIN_TYPE
           || plugin->pluginType() == NORMAL_PLUGIN_TYPE)
  {
    // check if the module matches and the function exists
    if (plugin->moduleName() != module->name())
    {
      g_warning("Plugin '%s' from module %s declares moduleName() as '%s', which doesn't match the module it belongs to",
                plugin->name().c_str(), module->name().c_str(), plugin->moduleName().c_str());
      return false;
    }
    
    {
      std::string f= plugin->moduleFunctionName();
      if (!module->has_function(f))
      {
         g_warning("Plugin '%s' from module %s has invalid moduleFunctionName '%s'",
                  plugin->name().c_str(), module->name().c_str(), f.c_str());
        return false;
      }
    } 
    return true;
  }
  else if (plugin->pluginType() == INTERNAL_PLUGIN_TYPE)
  {
    return true;
  }
  else if (0 == (*plugin->pluginType()).find(CUSTOM_PLUGIN_TYPE))
  {
    return true;
  }
  else
  {    
    g_warning("Plugin '%s' from module %s has invalid type '%s'", plugin->name().c_str(), 
              module->name().c_str(), plugin->pluginType().c_str());
  }
  return false;
}


void PluginManagerImpl::set_plugin_enabled(const app_PluginRef &plugin, bool flag)
{
  grt::StringListRef disabled_list(get_disabled_plugin_names());  
  size_t idx= disabled_list.get_index(plugin->name());
  
  if (flag && idx != grt::BaseListRef::npos)
  {
    disabled_list.remove(idx);
    if (plugin->groups().count() == 0)
      add_plugin_to_group(plugin, "Others/Menu/Ungrouped");
    else
    {
      for (size_t d= plugin->groups().count(), j= 0; j < d; j++)
        add_plugin_to_group(plugin, plugin->groups()[j]);
    }
  }
  else if (!flag && idx == grt::BaseListRef::npos)
  {
    disabled_list.insert(plugin->name());
    // remove the plugin from all groups
    grt::ListRef<app_PluginGroup> groups(get_plugin_groups());
    for (unsigned int c= groups.count(), i= 0; i < c; i++)
      groups[i]->plugins().remove_value(plugin);
  }
}


bool PluginManagerImpl::plugin_enabled(const std::string &plugin_name)
{
  grt::StringListRef names(get_disabled_plugin_names());
  if (names.get_index(plugin_name) == grt::BaseListRef::npos)
    return true;
  return false;
}


grt::StringListRef PluginManagerImpl::get_disabled_plugin_names()
{
  std::string disabled_path(_registry_path);
  base::pop_path_back(disabled_path);
  base::pop_path_back(disabled_path);
  disabled_path.append("/options/disabledPlugins");
  return grt::StringListRef::cast_from(_grtm->get_grt()->get(disabled_path));
}

/** 
 ****************************************************************************
 * @brief Refreshes the list of plugins from the list of modules and DLLs
 *
 * Scans the list of registered modules for plugins.
 * Modules exporting plugins must implement PluginInterface.
 * The list of scanned plugins is stored in the GRT tree.
 *
 ****************************************************************************
 */
void PluginManagerImpl::rescan_plugins()
{
  grt::ListRef<app_Plugin> plugin_list= get_plugin_list();
  grt::GRT *grt= _grtm->get_grt();
  std::set<std::string> disabled_plugins;

  // make a set of disabled plugin names
  {
    grt::StringListRef list= get_disabled_plugin_names();
    if (list.is_valid())
      for (grt::StringListRef::const_iterator i= list.begin(); i != list.end(); ++i)
      {
        disabled_plugins.insert(*i);
      }
  }

  // clear plugin list
  while (plugin_list.count() > 0)
    plugin_list.remove(0);
  
  // clear group contents
  {
    grt::ListRef<app_PluginGroup> groups;
    app_PluginGroupRef group;
  
    groups= get_plugin_groups();
    for (unsigned int c= groups.count(), i= 0; i < c; i++)
    {
      group= groups[i];
      while (group->plugins().count() > 0)
        group->plugins().remove(0);
    }
  }
    
  // get list of modules that implement the plugin interface
  std::vector<Module*> plugin_modules= grt->find_modules_matching("PluginInterface", "");

  _plugin_source_module.clear();
  
  // add all modules to the plugins list
  for (std::vector<Module*>::const_iterator pm= plugin_modules.begin(); pm != plugin_modules.end(); ++pm)
  {
    grt::ListRef<app_Plugin> plist;
    try
    {
      grt::ValueRef result= (*pm)->call_function("getPluginInfo", grt::BaseListRef());
      
      plist= grt::ListRef<app_Plugin>::cast_from(result);
      if (!plist.is_valid() || plist.count() == 0)
      {
        grt->send_warning("Module "+(*pm)->name()+" implements PluginInterface but does not export any plugins", "");
        continue;
      }
    }
    catch (std::exception &exc)
    {
      grt->send_error("Module "+(*pm)->name()+" had an error while executing getPluginInfo: "+exc.what(), 
        "Location: "+(*pm)->path());
      continue;
    }
    
    size_t i, c= plist.count();
    for (i= 0; i < c; i++)
    {
      app_PluginRef plugin= plist[i];
      
      if (_plugin_source_module.find(plugin->name()) != _plugin_source_module.end())
      {
        grt->send_warning("Duplicate plugin name "+*plugin->name(),
                          base::strfmt("There is more than one plugin with the name %s (in %s and %s).",
                          plugin->name().c_str(), (*pm)->name().c_str(), _plugin_source_module[plugin->name()].c_str()));
        // must reset internal references in the object or we get a leak because of the cycles
        plugin->reset_references();
        continue;
      }
      
      if (!check_plugin_validity(plugin, *pm))
      {
        continue;
      }
      _plugin_source_module[plugin->name()]= (*pm)->name();

      // add to the plugin list
      if (plugin_list.is_valid())
        plugin_list.insert(plugin);

      if (disabled_plugins.find(*plugin->name()) != disabled_plugins.end())
      {
        if (grt->verbose())
          grt->send_info("Plugin "+*plugin->name()+" is disabled, skipping...", "");
        continue;
      }

      if (plugin->groups().count() == 0)
        add_plugin_to_group(plugin, "Others/Menu/Ungrouped");
      else
      {
        for (size_t d= plugin->groups().count(), j= 0; j < d; j++)
          add_plugin_to_group(plugin, plugin->groups()[j]);
      }
    }
  }
}




app_PluginGroupRef PluginManagerImpl::get_group(const std::string &group_name)
{
  grt::ListRef<app_PluginGroup> groups;
  app_PluginGroupRef group;

  groups= get_plugin_groups();

  for (unsigned int c= groups.count(), i= 0; i < c; i++)
  {
    if (groups[i]->name() == group_name)
    {
      group= groups[i];
      break;
    }
  }

  return group;
}


void PluginManagerImpl::add_plugin_to_group(const app_PluginRef &plugin, const std::string &group_name)
{
  app_PluginGroupRef group= get_group(group_name);

  if (group.is_valid())
    group->plugins().insert(plugin);
  // TODO: warning for now disabled, fix group loading
  //else 
  //  g_warning("Plugin %s could not be added to unknown group %s", plugin->name().c_str(), group_name.c_str());
}



/** 
 ****************************************************************************
 * @brief Sets callbacks for handling of GUI plugins
 *
 * @param open callback for opening a plugin
 * @param show callback for showing a plugin
 * @param close callback for closing a plugin
 * 
 ****************************************************************************
 */
void PluginManagerImpl::set_gui_plugin_callbacks(const OpenGUIPluginSlot &open,
                                                 const ShowGUIPluginSlot &show,
                                                 const CloseGUIPluginSlot &close)
{
  _open_gui_plugin_slot= open;
  _show_gui_plugin_slot= show;
  _close_gui_plugin_slot= close;
}




/** 
 ****************************************************************************
 * @brief Adds a list of plugins to the plugin registry
 *
 * @param list of plugins
 * 
 ****************************************************************************
 */
void PluginManagerImpl::register_plugins(grt::ListRef<app_Plugin> plugins)
{
  grt::ListRef<app_Plugin> list= get_plugin_list();
  
  for (unsigned int c= plugins.count(), i= 0; i < c; i++)
    list.insert(plugins[i]);
}




/** 
 ****************************************************************************
 * @brief Return list of registered plugin groups 
 *
 * @return List of plugin groups
 ****************************************************************************
 */
grt::ListRef<app_PluginGroup> PluginManagerImpl::get_plugin_groups()
{
  return grt::ListRef<app_PluginGroup>::cast_from(_grtm->get_grt()->get(_group_registry_path));
}



/** 
 ****************************************************************************
 * @brief Returns list of all registered plugins.
 * 
 * The list of plugins is looked up at the GRT tree path set with
 * set_registry_path()
 *
 * @param group optional name of plugin group (allows * wildcards)
 * 
 * @return List of plugins.
 ****************************************************************************
 */
grt::ListRef<app_Plugin> PluginManagerImpl::get_plugin_list(const std::string &group)
{
  if (group.empty())
    return grt::ListRef<app_Plugin>::cast_from(_grtm->get_grt()->get(_registry_path));
  else
  {
    grt::ListRef<app_Plugin> rlist(_grtm->get_grt()), list;
    std::string left, right;

    // groups are expected to be either in group/subgroup format or group (which will be interpreted as group/*)
    
    if (group.find('/') != std::string::npos)
    {
      left= group.substr(0, group.find('/'));
      right= group.substr(group.find('/')+1);
    }
    else
    {
      left= group;
      right= "*";
    }
    
    list= grt::ListRef<app_Plugin>::cast_from(_grtm->get_grt()->get(_registry_path));

    for (size_t c= list.count(), i= 0; i < c; i++)
    {
      app_PluginRef plugin(list[i]);
      grt::StringListRef groups(plugin->groups());
      bool found= false;

      if (!plugin_enabled(plugin->name()))
        continue;
      
      for (size_t gc= groups.count(), g= 0; g < gc; g++)
      {
        std::string gstr(groups[g]);
        std::string gleft, gright;
        std::string::size_type pos;

        if ((pos= gstr.find('/')))
        {
          gleft= gstr.substr(0, pos);
          gright= gstr.substr(pos+1);
        }
        else
        {
          gleft= gstr;
          gright= "";
        }

        if ((left=="*" || left == gleft) && (right=="*" || right == gright))
        {
          found= true;
          break;
        }
      }
      if (found)
        rlist.insert(plugin);
    }
    
    return rlist;
  }
}


bool PluginManagerImpl::check_plugin_input(const app_PluginInputDefinitionRef &def,
                                           const grt::ValueRef &value)
{
  if (def.is_instance(app_PluginFileInput::static_class_name()))
  {
    if (value.is_valid() && value.type() != StringType)
      return false;
  }
  else if (def.is_instance(app_PluginSelectionInput::static_class_name()))
  {
    if (!value.is_valid() || value.type() != ListType)
      return false;

    app_PluginSelectionInputRef sdef(app_PluginSelectionInputRef::cast_from(def));
    grt::ObjectListRef olist(grt::ObjectListRef::cast_from(value));

    for (size_t d= olist.count(), j= 0; j < d; j++)
    {
      grt::ObjectRef value(olist.get(j));
      bool ok= false;

      for (size_t c= sdef->objectStructNames().count(), i= 0; i < c; i++)
      {
        if (value.is_instance(sdef->objectStructNames()[i]))
        {
          ok= true;
          break;
        }
      }
      if (!ok)
        return false;
    }

    std::string card= *sdef->argumentCardinality();
    if (card == "1")
    {
      if (olist.count() != 1)
        return false;
    }
    else if (card == "?")
    {
      if (olist.count() > 1)
        return false;
    }
    else if (card == "+")
    {
      if (olist.count() == 0)
        return false;
    }
    else if (card == "*")
      ;
    else
    {
      if (olist.count() != 1)
        return false;
    }
  }
  else if (def.is_instance(app_PluginObjectInput::static_class_name()))
  {
    if (!value.is_valid() || value.type() != ObjectType)
      return false;

    app_PluginObjectInputRef odef(app_PluginObjectInputRef::cast_from(def));

    if (!grt::ObjectRef::cast_from(value).is_instance(odef->objectStructName()))
      return false;
  }
  else
    return false;

  return true;
}


bool PluginManagerImpl::check_input_for_plugin(const app_PluginRef &plugin, const grt::BaseListRef &args)
{
  if (args.count() != plugin->inputValues().count())
    return false;

  for (size_t c= plugin->inputValues().count(), i= 0; i < c; i++)
  {
    if (!check_plugin_input(plugin->inputValues()[i], args[i]))
      return false;
  }
  return true;
}


app_PluginRef PluginManagerImpl::select_plugin_for_input(const std::string &group, const grt::BaseListRef &args)
{
  ListRef<app_Plugin> plugins= get_plugin_list(group);
  app_PluginRef best_match;
  int rating= -1;

  for (size_t c= plugins.count(), i= 0; i < c; i++)
  {
    app_PluginRef plugin= plugins[i];

    if (check_input_for_plugin(plugin, args) && *plugin->rating() > rating)
    {
      best_match= plugin;
      rating= *plugin->rating();
    }
  }

  return best_match;
}



/** 
 ****************************************************************************
 * @brief Returns list of plugins that can be called on the objects
 *
 *
 * @param objects list of objects
 * @param group optional name of group for filtering (eg: catalog/Editors)
 *
 * @return list of plugins
 ****************************************************************************
 */
//TODO: delete?
std::vector<app_PluginRef> PluginManagerImpl::get_plugins_for_objects(const grt::ObjectListRef &objects,
                                                                   const std::string &group)
{
  std::vector<app_PluginRef> plist;
  grt::ListRef<app_Plugin> plugins;

  plugins= get_plugin_list(group);
  size_t i, c= plugins.count();

  // look for plugins that take 1 ObjectInput arg that is compatible with the obj list
  if (objects.count() == 1)
    for (i= 0; i < c; i++)
    {
      app_PluginRef plugin(plugins[i]);

      if (plugin->inputValues().count() == 1 && 
        plugin->inputValues()[0]->is_instance(app_PluginObjectInput::static_class_name()))
      {
        app_PluginObjectInputRef oinput(app_PluginObjectInputRef::cast_from(plugin->inputValues()[0]));
        std::string struct_name= oinput->objectStructName();
        bool ok= true;

        for (size_t oc= objects.count(), oi= 0; oi < oc; oi++)
        {
          if (!objects[oi].is_instance(struct_name))
          {
            ok= false;
            break;
          }
        }
      
        if (ok)
          plist.push_back(plugin);
      }
    }

  // look for plugins that take selection as input and are compatible with the obj list
  for (i= 0; i < c; i++)
  {
    app_PluginRef plugin(plugins[i]);

    if (plugin->inputValues().count() == 1 && 
      plugin->inputValues()[0]->is_instance(app_PluginSelectionInput::static_class_name()))
    {
      app_PluginSelectionInputRef oinput(app_PluginSelectionInputRef::cast_from(plugin->inputValues()[0]));
      std::string card= *oinput->argumentCardinality();
      grt::StringListRef struct_names(oinput->objectStructNames());
      bool ok= true;

      if (card == "1")
      {
        if (objects.count() != 1)
          continue;
      }
      else if (card == "?")
      {
        if (objects.count() > 1)
          continue;
      }
      else if (card == "+")
      {
        if (objects.count() == 0)
          continue;
      }
      else if (card == "*")
        ;
      else
      {
        if (objects.count() != 1)
          continue;
      }

      for (size_t oc= objects.count(), oi= 0; oi < oc && ok; oi++)
      {
        for (size_t sc= struct_names.count(), si= 0; si < sc && ok; si++)
        {
          if (!objects[oi].is_instance(struct_names[si]))
          {
            ok= false;
            break;
          }
        }
      }

      if (ok)
        plist.push_back(plugin);
    }
  }

  return plist;
}


/** 
 ****************************************************************************
 * @brief Returns list of plugins in the named group.
 *
 * @param group
 *
 * @return List of plugins
 *
 ****************************************************************************
 */
std::vector<app_PluginRef> PluginManagerImpl::get_plugins_for_group(const std::string &group)
{
  std::vector<app_PluginRef> rlist;
  grt::ListRef<app_Plugin> list= get_plugin_list(group);
  
  for (size_t c= list.count(), i= 0; i < c; i++)
    rlist.push_back(list[i]);
  
  return rlist;
}


/** 
 ****************************************************************************
 * @brief Return named plugin 
 *
 * @param name
 *
 * @return plugin
 ****************************************************************************
 */
app_PluginRef PluginManagerImpl::get_plugin(const std::string &name)
{
  grt::ListRef<app_Plugin> plugins= get_plugin_list();
  
  for (size_t c= plugins.count(), i= 0; i < c; i++)
  {
    if (*plugins[i]->name() == name)
      return plugins[i];
  }
  return app_PluginRef();
}


static std::string make_open_plugin_id(const grt::Module *module,
                                       const std::string &class_name,
                                       const grt::BaseListRef &args)
{
  std::string argshash= get_args_hash(args);
  
  return module->name()+"/"+class_name+"//"+argshash;
}




std::vector<NativeHandle> PluginManagerImpl::get_similar_open_plugins(grt::Module *module, const std::string &class_name, grt::BaseListRef)
{
  std::vector<NativeHandle> handles;

  std::string prefix= module->name()+"/"+class_name+"//";

  for (std::map<std::string, NativeHandle>::const_iterator iter= _open_gui_plugins.begin();
       iter != _open_gui_plugins.end(); ++iter)
  {
    if (iter->first.substr(0, prefix.size()) == prefix)
      handles.push_back(iter->second);
  }

  return handles;
}



std::string PluginManagerImpl::open_gui_plugin(const app_PluginRef &plugin, const grt::BaseListRef &args, GUIPluginFlags flags)
{
  if (!plugin.is_valid())
    throw std::invalid_argument("Attempt to open an invalid plugin");
  
  if (*plugin->pluginType() == GUI_PLUGIN_TYPE)
  {
    if (_grtm->in_main_thread())
      return open_gui_plugin_main(plugin, args, flags);
    else
    {
      GRTDispatcher *disp= _grtm->get_dispatcher();

      // request the plugin to be executed and opened by the frontend in the main thread
      DispatcherCallback<std::string> *cb= new DispatcherCallback<std::string>(boost::bind(&PluginManagerImpl::open_gui_plugin_main,this,
                                                                plugin, args, flags));

      disp->call_from_main_thread(cb, false, false);
      
      cb->release();

      grt::Module *module= _grtm->get_grt()->get_module(_plugin_source_module[plugin->name()]);
      // build the handle name ourselves
      return make_open_plugin_id(module, plugin->moduleFunctionName(), args);
    }
  }
  else if (*plugin->pluginType() == STANDALONE_GUI_PLUGIN_TYPE)
  {
    if (_grtm->in_main_thread())
      open_standalone_plugin_main(plugin, args);
    else
    {
      GRTDispatcher *disp= _grtm->get_dispatcher();
      
      // request the plugin to be executed and opened by the frontend in the main thread
      DispatcherCallback<void> *cb= new DispatcherCallback<void>(boost::bind(&PluginManagerImpl::open_standalone_plugin_main, this, 
                                                                  plugin, args));
      
      disp->call_from_main_thread(cb, false, false);
      
      cb->release();
    }
  }
  else if (*plugin->pluginType() == INTERNAL_PLUGIN_TYPE)
  {
    if (_grtm->in_main_thread())
      open_normal_plugin_grt(_grtm->get_grt(), plugin, args);
    else
    {
      GRTDispatcher *disp= _grtm->get_dispatcher();
      
      // request the plugin to be executed and opened by the frontend in the main thread
      DispatcherCallback<grt::ValueRef> *cb= new DispatcherCallback<grt::ValueRef>(boost::bind(&PluginManagerImpl::open_normal_plugin_grt, this, 
                                                                  _grtm->get_grt(), plugin, args));
      
      disp->call_from_main_thread(cb, false, false);
      
      cb->release();
    }
  }
  else // a normal plugin implemented by a GRT module
  {
    if (_grtm->in_main_thread())
    {
      _grtm->get_dispatcher()->execute_simple_function("Open normal plugin",
        boost::bind(&PluginManagerImpl::open_normal_plugin_grt, this, _1, plugin, args));
    }
    else
      open_normal_plugin_grt(_grtm->get_grt(), plugin, args);
  }
  return "";
}


/** 
 ****************************************************************************
 * @brief Executes the plugin with the given list of arguments
 *
 * If the plugin is a GUI type plugin, the GUI plugin callbacks are executed
 * in the main thread and may return a handle to pass back to the frontend
 * and be processed.
 * 
 * If the plugin is a normal type plugin, it will be just executed in the 
 * GRT thread, as usual.
 *
 * @param plugin object
 * @param args list of 
 *
 * @return An identifier/handle for the opened plugin, if it's a GUI plugin
 * or "" for other types of plugins.
 ****************************************************************************
 */
std::string PluginManagerImpl::open_plugin(const app_PluginRef &plugin, const grt::BaseListRef &args)
{
  return open_gui_plugin(plugin, args, NoFlags);
}


grt::ValueRef PluginManagerImpl::execute_plugin_function(const app_PluginRef &plugin, const grt::BaseListRef &args)
{
  grt::Module *module= _grtm->get_grt()->get_module(plugin->moduleName());
  
  if (!module)
    throw grt::grt_runtime_error("Cannot execute plugin "+*plugin->name(), "Called module "+*plugin->moduleName()+" not found");
  
  return module->call_function(*plugin->moduleFunctionName(), args);
}

grt::ValueRef PluginManagerImpl::open_normal_plugin_grt(grt::GRT *grt, const app_PluginRef &plugin,
                                                            const grt::BaseListRef &args)
{
  grt::Module *module= _grtm->get_grt()->get_module(plugin->moduleName());

  if (!module)
    throw grt::grt_runtime_error("Cannot execute plugin "+*plugin->name(), "Called module "+*plugin->moduleName()+" not found");

  return module->call_function(*plugin->moduleFunctionName(), args);
}


void PluginManagerImpl::open_standalone_plugin_main(const app_PluginRef &plugin, const grt::BaseListRef &args)
{
  grt::Module *module= _grtm->get_grt()->get_module(plugin->moduleName());
  
  if (!module)
    throw grt::grt_runtime_error("Cannot execute plugin "+*plugin->name(), "Called module "+*plugin->moduleName()+" not found");
  
  module->call_function(*plugin->moduleFunctionName(), args);
}



std::string PluginManagerImpl::open_gui_plugin_main(const app_PluginRef &plugin,
                                                    const grt::BaseListRef &args,
                                                    GUIPluginFlags flags)
{
  NativeHandle handle;
  grt::Module *module= _grtm->get_grt()->get_module(_plugin_source_module[plugin->name()]);
  std::string open_plugin_id= make_open_plugin_id(module, plugin->moduleFunctionName(), args);

  if (_open_gui_plugins.find(open_plugin_id) != _open_gui_plugins.end())
  {
    handle= _open_gui_plugins[open_plugin_id];
    _show_gui_plugin_slot(handle);
  }
  else
  {
    grt::Module *module= _grtm->get_grt()->get_module(_plugin_source_module[plugin->name()]);

    // open the editor and get a handle for the GUI object to pass to the frontend
    NativeHandle handle= _open_gui_plugin_slot(_grtm,
                                               module,
                                               *plugin->moduleName(),
                                               *plugin->moduleFunctionName(),
                                               args,
                                               flags);
    if (handle)
    {
      _open_gui_plugins[open_plugin_id]= handle;
      _show_gui_plugin_slot(handle);
    }
  }

  return open_plugin_id;
}



/** 
 ****************************************************************************
 * @brief Shows a previously opened (GUI) plugin.
 *
 * @param handle returned by open_plugin
 * 
 * @return always 0 at the moment
 ****************************************************************************
 */
int PluginManagerImpl::show_plugin(const std::string &handle)
{
  if (_grtm->in_main_thread())
    return show_gui_plugin_main(handle);
  else
  {
    GRTDispatcher *disp= _grtm->get_dispatcher();
    // request the plugin to be executed and opened by the frontend in the main thread

    DispatcherCallback<int> *cb= new DispatcherCallback<int>(boost::bind(&PluginManagerImpl::show_gui_plugin_main, this, handle));
    
    disp->call_from_main_thread(cb, false, false);

    cb->release();

    // return value is ignored atm.

    return 0;
  }
}


int PluginManagerImpl::show_gui_plugin_main(const std::string &handle)
{
  if (_open_gui_plugins.find(handle) != _open_gui_plugins.end())
  {
    NativeHandle hdl= _open_gui_plugins[handle];
    _show_gui_plugin_slot(hdl);
  }

  return 1;
}




/** 
 ****************************************************************************
 * @brief Closes a previously opened (GUI) plugin.
 *
 * @param handle return by open_plugin
 * 
 * @return always 0 at the moment
 ****************************************************************************
 */
int PluginManagerImpl::close_plugin(const std::string &handle)
{
  if (_grtm->in_main_thread())
    return close_gui_plugin_main(handle);
  else
  {
    GRTDispatcher *disp= _grtm->get_dispatcher();
    // request the plugin to be executed and opened by the frontend in the main thread

    DispatcherCallback<int> *cb= new DispatcherCallback<int>(boost::bind(&PluginManagerImpl::close_gui_plugin_main, this, handle));
    
    disp->call_from_main_thread(cb, false, false);

    cb->release();

    // return value is ignored atm.

    return 0;
  }
}

//--------------------------------------------------------------------------------------------------

int PluginManagerImpl::close_gui_plugin_main(const std::string &handle)
{
  if (_open_gui_plugins.find(handle) != _open_gui_plugins.end())
  {
    NativeHandle hdl= _open_gui_plugins[handle];
    _close_gui_plugin_slot(hdl);
  }

  return 1;
}

//--------------------------------------------------------------------------------------------------

void PluginManagerImpl::forget_gui_plugin_handle(NativeHandle handle)
{
  for (std::map<std::string,NativeHandle>::iterator iter= _open_gui_plugins.begin();
       iter != _open_gui_plugins.end(); ++iter)
  {
    if (iter->second == handle)
    {
      _open_gui_plugins.erase(iter);
      break;
    }
  }
}

//--------------------------------------------------------------------------------------------------

void PluginManagerImpl::close_and_forget_gui_plugin(NativeHandle handle)
{
  for (std::map<std::string,NativeHandle>::iterator iter= _open_gui_plugins.begin();
    iter != _open_gui_plugins.end(); ++iter)
  {
    if (iter->second == handle)
    {
       _close_gui_plugin_slot(handle);
      _open_gui_plugins.erase(iter);
      break;
    }
  }
}


//--------------------------------------------------------------------------------------------------

grt::ValueRef ArgumentPool::find_match(const app_PluginInputDefinitionRef &pdef, std::string &searched_key_name_ret, bool strict) const
{
  std::string key = pdef.class_name();
  
  if (pdef.class_name() == app_PluginSelectionInput::static_class_name())
  {
    app_PluginSelectionInputRef sdef(app_PluginSelectionInputRef::cast_from(pdef));

    // add source
    key.append(":").append(*pdef->name()).append(":");
    searched_key_name_ret= key;
    
    // find entry
    const_iterator iter;
    if ((iter= find(key)) == end())
      return grt::ValueRef();
    
    if (!iter->second.is_valid() || !grt::ObjectListRef::can_wrap(iter->second))
      return grt::ValueRef();

    grt::ObjectListRef olist(grt::ObjectListRef::cast_from(iter->second));
    
    bool matches= true;
    
    // check if value matches the requirements
    for (size_t d= olist.count(), j= 0; j < d; j++)
    {
      grt::ObjectRef value(olist.get(j));
      bool ok= false;

      for (size_t c= sdef->objectStructNames().count(), i= 0; i < c; i++)
      {
        if (value.is_instance(sdef->objectStructNames()[i]))
        {
          ok= true;
          break;
        }
      }
      if (!ok)
      {
        matches= false;
        break;
      }
    }
    
    std::string card= *sdef->argumentCardinality();
    if (card == "1")
    {
      if (olist.count() != 1)
        matches= false;
    }
    else if (card == "?")
    {
      if (olist.count() > 1)
        matches= false;
    }
    else if (card == "+")
    {
      if (olist.count() == 0)
        matches= false;
    }
    else if (card == "*")
      ;
    else
    {
      if (olist.count() != 1)
        matches= false;
    }
    
    if (matches)
      return olist;
  }
  else
  {
    if (pdef.class_name() == app_PluginObjectInput::static_class_name())
      key.append(":").append(*pdef->name()).append(":").append(*app_PluginObjectInputRef::cast_from(pdef)->objectStructName());
    else if (pdef.class_name() == app_PluginFileInput::static_class_name())
    {
      if (strict)
        key.append(":").append(*pdef->name()).append(":").append(app_PluginFileInputRef::cast_from(pdef)->dialogType());
      else
        key.append(":").append(":").append(app_PluginFileInputRef::cast_from(pdef)->dialogType());
    }
    else if (pdef.class_name() == app_PluginInputDefinition::static_class_name())
      key.append(":").append(*pdef->name());
    
    searched_key_name_ret= key;

    const_iterator iter;
    if ((iter= find(key)) != end())
      return iter->second;
  }

  return grt::ValueRef();
}

void ArgumentPool::dump_keys(const boost::function<void (std::string)> &dump_function) const
{
  for (ArgumentPool::const_iterator i= begin(); i != end(); ++i)
  {
    if (dump_function)
      dump_function(i->first+"\n");
    else
      g_message("%s", i->first.c_str());
  }
}

void ArgumentPool::add_simple_value(const std::string &name, const grt::ValueRef &value)
{
  std::string prefix= "app.PluginInputDefinition:"+name;
  
  (*this)[prefix]= value;
}

void ArgumentPool::add_list_for_selection(const std::string &source_name,
                                          const grt::ObjectListRef &list)
{
  std::string prefix= "app.PluginSelectionInput:"+source_name+":";
  
  (*this)[prefix]= list;
}


void ArgumentPool::add_entries_for_object(const std::string &name,
                                          const grt::ObjectRef &object,
                                          const std::string &topmost_class_name)
{
  if (object.is_valid())
  {
    grt::GRT *grt= object.get_grt();
    std::string prefix= "app.PluginObjectInput:"+name+":";
    std::string class_name= object.class_name();
    bool done= false;
    for (;;)
    {
      grt::MetaClass *mc= grt->get_metaclass(class_name);
      (*this)[prefix+mc->name()]= object;

      class_name = mc->parent() ? mc->parent()->name() : "";
      if (topmost_class_name.empty() || class_name.empty() || done)
        break;
      if (topmost_class_name == class_name)
        done= true;
    }
  }
}

bool ArgumentPool::needs_simple_input(const app_PluginRef &plugin, const std::string &name)
{
  const size_t c= plugin->inputValues().count();
  for (size_t i= 0; i < c; i++)
  {
    app_PluginInputDefinitionRef pdef(plugin->inputValues().get(i));
    
    if (pdef.class_name() == app_PluginInputDefinition::static_class_name())
    {
      if (pdef->name() == name)
        return true;
    }
  }
  return false;
}

app_PluginFileInputRef ArgumentPool::needs_file_input(const app_PluginRef &plugin)
{
  const size_t c= plugin->inputValues().count();
  for (size_t i= 0; i < c; i++)
  {
    app_PluginInputDefinitionRef pdef(plugin->inputValues().get(i));
    
    if (pdef.is_instance(app_PluginFileInput::static_class_name()))
      return app_PluginFileInputRef::cast_from(pdef);
  }
  return app_PluginFileInputRef();
}

void ArgumentPool::add_file_input(const app_PluginFileInputRef &pdef,
                                  const std::string &value)
{
  std::string key = app_PluginFileInput::static_class_name();
  key.append(":").append(*pdef->name()).append(":").append(pdef->dialogType());
  
  (*this)[key]= grt::StringRef(value);
}

grt::BaseListRef ArgumentPool::build_argument_list(const app_PluginRef &plugin)
{
  // build the argument list
  grt::BaseListRef fargs(plugin->get_grt());
  
  const size_t c= plugin->inputValues().count();
  for (size_t i= 0; i < c; i++)
  {
    app_PluginInputDefinitionRef pdef(plugin->inputValues().get(i));
    std::string searched_key;
    grt::ValueRef argument= find_match(pdef, searched_key);
    if (!argument.is_valid())
    {
      g_message("Cannot satisfy plugin input for %s: %s", plugin->name().c_str(), searched_key.c_str());
      g_message("Missing input: %s", pdef.repr().c_str());
      
      throw grt::grt_runtime_error("Cannot execute "+*plugin->name(),
                                   "Plugin requires unavailable argument value.");
    }
    fargs.ginsert(argument);
  }  
  return fargs;
}
