/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 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/Referenced>

#include <map>
#include <string>
#include <ostream>

namespace osg {

class OSG_EXPORT ApplicationUsage : public osg::Referenced
{
    public:

        static ApplicationUsage* instance();

        ApplicationUsage() {}

        ApplicationUsage(const std::string& commandLineUsage);

        typedef std::map<std::string,std::string> UsageMap;


        /** The ApplicationName is often displayed when logging errors, and frequently incorporated into the Description (below). */
        void setApplicationName(const std::string& name) { _applicationName = name; }
        const std::string& getApplicationName() const { return _applicationName; }

        /** If non-empty, the Description is typically shown by the Help Handler
          * as text on the Help display (which also lists keyboard abbreviations. */
        void setDescription(const std::string& desc) { _description = desc; }
        const std::string& getDescription() const { return _description; }

        enum Type
        {
            NO_HELP = 0x0,
            COMMAND_LINE_OPTION = 0x1,
            ENVIRONMENTAL_VARIABLE = 0x2,
            KEYBOARD_MOUSE_BINDING = 0x4,
            HELP_ALL = KEYBOARD_MOUSE_BINDING|ENVIRONMENTAL_VARIABLE|COMMAND_LINE_OPTION
        };

        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 std::string &defaultValue = "");

        void setCommandLineOptions(const UsageMap& usageMap) { _commandLineOptions=usageMap; }
        const UsageMap& getCommandLineOptions() const { return _commandLineOptions; }

        void setCommandLineOptionsDefaults(const UsageMap& usageMap) { _commandLineOptionsDefaults=usageMap; }
        const UsageMap& getCommandLineOptionsDefaults() const { return _commandLineOptionsDefaults; }


        void addEnvironmentalVariable(const std::string& option,const std::string& explanation, const std::string& defaultValue = "");

        void setEnvironmentalVariables(const UsageMap& usageMap) { _environmentalVariables=usageMap; }
        const UsageMap& getEnvironmentalVariables() const { return _environmentalVariables; }

        void setEnvironmentalVariablesDefaults(const UsageMap& usageMap) { _environmentalVariablesDefaults=usageMap; }
        const UsageMap& getEnvironmentalVariablesDefaults() const { return _environmentalVariablesDefaults; }


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

        void setKeyboardMouseBindings(const UsageMap& usageMap) { _keyboardMouse=usageMap; }
        const UsageMap& getKeyboardMouseBindings() const { return _keyboardMouse; }


        void getFormattedString(std::string& str, const UsageMap& um,unsigned int widthOfOutput=80,bool showDefaults=false,const UsageMap& ud=UsageMap());

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

        void write(std::ostream& output,unsigned int type=COMMAND_LINE_OPTION, unsigned int widthOfOutput=80,bool showDefaults=false);

        void writeEnvironmentSettings(std::ostream& output);

    protected:

        virtual ~ApplicationUsage() {}

        std::string _applicationName;
        std::string _description;
        std::string _commandLineUsage;
        UsageMap    _commandLineOptions;
        UsageMap    _environmentalVariables;
        UsageMap    _keyboardMouse;
        UsageMap    _environmentalVariablesDefaults;
        UsageMap    _commandLineOptionsDefaults;

};

class ApplicationUsageProxy
{
    public:

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

}

#endif
