/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2003 Robert Osfield 
 *
 * This library is open source and may be redistributed and/or modified under  
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 * 
 * This library 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 
 * OpenSceneGraph Public License for more details.
*/

#ifndef OSG_APPLICATIONUSAGE
#define OSG_APPLICATIONUSAGE 1

#include <osg/Export>

#include <map>
#include <string>
#include <iostream>

namespace osg {

class SG_EXPORT ApplicationUsage
{
    public:
        
        static ApplicationUsage* instance();

        ApplicationUsage() {}

        ApplicationUsage(const std::string& commandLineUsage);

        typedef std::map<std::string,std::string> UsageMap;
        
        enum Type
        {
            COMMAND_LINE_OPTION,
            ENVIRONMENTAL_VARIABLE,
            KEYBOARD_MOUSE_BINDING
        };
        
        void addUsageExplanation(Type type,const std::string& option,const std::string& explanation);
        
        void setCommandLineUsage(const std::string& explanation) { _commandLineUsage=explanation; }

        const std::string& getCommandLineUsage() const { return _commandLineUsage; }


        void addCommandLineOption(const std::string& option,const std::string& explanation);
        
        const UsageMap& getCommandLineOptions() const { return _commandLineOptions; }


        void addEnvironmentalVariable(const std::string& option,const std::string& explanation);
        
        const UsageMap& getEnvironmentalVariables() const { return _environmentalVariables; }


        void addKeyboardMouseBinding(const std::string& option,const std::string& explanation);

        const UsageMap& getKeyboardMouseBindings() const { return _keyboardMouse; }


        void write(std::ostream& output,const UsageMap& um,unsigned int widthOfOutput=80);
        
        void write(std::ostream& output,unsigned int widthOfOutput=80);

    protected:
    

        std::string _commandLineUsage;
        UsageMap    _commandLineOptions;
        UsageMap    _environmentalVariables;
        UsageMap    _keyboardMouse;
        
};

class ApplicationUsageProxy
{   
    public:

        /** register an explanation of commandline/evironmentalvaraible/keyboard mouse usage.*/
        ApplicationUsageProxy(ApplicationUsage::Type type,const std::string& option,const std::string& explanation)
        {
            ApplicationUsage::instance()->addUsageExplanation(type,option,explanation);
        }
};

}

#endif