/* $Id$ */
/*
 * Cantus Tag Editor
 * Copyright © 2002-2004 by Samuel Abels <spam@debain.org>
 * Copyright © 2007 by Tim Huetz <tim.huetz@futures-net.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 3 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, see <http://www.gnu.org/licenses/>
 **/

#if !defined( _CANTUS_PLUGIN_H_ )
    #define _CANTUS_PLUGIN_H_

    /* if we have a config.h, include it */
    #ifdef HAVE_CONFIG_H
    #  include <config.h>
    #endif

    /* we need to tell that there will be a defition for "class Plugin" before we include */
    class CantusPlugin;

    /* some headers we need */
    #include <iostream>
    #include <dlfcn.h>
    #include <sigc++/object.h>
    #include <sigc++/signal.h>
    #include <cantus/shellpattern.h>
    #include <cantus/cantusplugin.h>
    #include <cantus/pluginwrappers.h>

    /**/
    #define PLUGIN_COMPAT_LEVEL 1

    /**
     * \brief
     * \author
     * \date
     */
    typedef struct {
        const gchar * name;      // A symbol name.
        const gchar * keyname;   // The plugindata hash key name.
        gboolean required;  // Whether or not the symbol is mandatory.
    } Symbol;


    /**
     * \brief
     * \author
     * \date
     */
    class CantusPlugin : public sigc::trackable {
        public:
            CantusPlugin();
            ~CantusPlugin();
  
            /* Triggered directly before the plugin will be deleted (= when the */
            /* refcounter has reached a value <= 0). */
            SigC::Signal1<void, CantusPlugin*> signalPluginDeleted;
  
            /* Loads a plugin and all its symbols into the object.
             */
            gint loadPlugin( const gchar * filename );
          
            /* Increase a plugin's refcounter. When the refcounter is <= 0 the plugin will
             * be unloaded. On object creation, the refcounter is 1.
             */
            void ref();
          
            /* Decrease a plugin's refcounter.
             */
            void unref();
          
            /* Define the plugin's priority.
             */
            void setPriority( gint priority );
          
            /* Returns the plugin's priority.
             */
            gint getPriority();
          
            /* Returns the plugin name.
             */
            const gchar * getName();
          
            /* Returns the name of the tags handled by this plugin.
             */
            const gchar * getTagname();
          
            /* Returns the title for the plugin's notebook tab label.
             */
            const gchar * getLabel();
          
            /* Returns the the plugin description (should be 200 chars max.).
             */
            const gchar * getDescription();
          
            /* Returns the plugin's major version number.
             */
            gint getMajorVersion();
          
            /* Returns the plugin's minor version number.
             */
            gint getMinorVersion();
          
            /* Returns a function pointer to the plugin's read() function.
             */
            const ReadFunc getReadFunction();
          
            /* Returns a function pointer to the plugin's write() function.
             */
            const WriteFunc getWriteFunction();
          
            /* Calls the plugin's uiwidget() function.
             */
            void * getUIWidget( gboolean vertical );
          
            /* Given a file name, this function returns TRUE if the plugin is responsible
             * for handling this filetype, otherwise FALSE.
             */
            gboolean isHandling( const gchar * filename );
          
        private:
            /* Checks, whether the plugin meets all mandatory requirements. Returns TRUE
             * if the plugin is valid, otherwise FALSE.
             */
            gboolean checkPlugin(void);
  
            void * m_dlHandle;    // The handle for dl_open.
            CantusHash * m_pluginData;  // A pointer to the C-compatible plugin data.
            gint m_refCounter;       // A refcounter indicating whether the plugin is
                           // still needed.
            gint m_pluginPriority;    // A priority, to be used by the backend only.
    };

#endif