/* -*-c++-*- */
/* osgEarth - Geospatial SDK for OpenSceneGraph
 * Copyright 2020 Pelican Mapping
 * http://osgearth.org
 *
 * osgEarth is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 */
#ifndef OSGEARTHSYMBOLOGY_STYLE_SELECTOR_H
#define OSGEARTHSYMBOLOGY_STYLE_SELECTOR_H 1

#include <osgEarth/Common>
#include <osgEarth/Style>
#include <osgEarth/Expression>

namespace osgEarth
{
    /**
     * A style selector lets you classify styles based on rules, such as a
     * feature query. By default the selector selects the style with the
     * same name as the selector, but you can override this by settings
     * the styleName property.
     */
    class OSGEARTH_EXPORT StyleSelector
    {
    public:
        /** Constructs a style selector */
        StyleSelector( const Config& conf =Config() );

        /** Constructs a style selector with a name and expression */
        StyleSelector(const std::string& name, const StringExpression& expr);

        virtual ~StyleSelector() { }

    public: // properties

        /** Name of this style class. */
        optional<std::string>& name() { return _name; }
        const optional<std::string>& name() const { return _name; }

        /** Name of the style to select */
        optional<std::string>& styleName() { return _styleName; }
        const optional<std::string>& styleName() const { return _styleName; }

        /** Script that returns the name of the style to select. */
        optional<StringExpression>& styleExpression() { return _styleExpression; }
        const optional<StringExpression>& styleExpression() const { return _styleExpression; }

        /** Expression/spatial filter used to select items to which the style will apply */
        optional<Query>& query() { return _query; }
        const optional<Query>& query() const { return _query; }

        /** Returns the styleClass() property, if set; otherwise returns the selector name. */
        std::string getSelectedStyleName() const;

        //Configurable
        virtual void mergeConfig( const Config& conf );
        virtual Config getConfig() const;

    protected:
        optional<std::string>      _name;
        optional<std::string>      _styleName;
        optional<StringExpression> _styleExpression;
        optional<Query>            _query;
    };

} // namespace osgEarth


#endif // OSGEARTHSYMBOLOGY_STYLE_SELECTOR_H