// expression_geo.h

/**
 *    Copyright (C) 2013 10gen Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
 *    as published by the Free Software Foundation.
 *
 *    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 Affero General Public License for more details.
 *
 *    You should have received a copy of the GNU Affero General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the GNU Affero General Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */


#pragma once

#include <boost/shared_ptr.hpp>

#include "mongo/db/geo/geometry_container.h"
#include "mongo/db/matcher/expression.h"
#include "mongo/db/matcher/expression_leaf.h"

namespace mongo {

    struct PointWithCRS;
    class GeometryContainer;

    // This represents either a $within or a $geoIntersects.
    class GeoExpression {
        MONGO_DISALLOW_COPYING(GeoExpression);

    public:
        GeoExpression();
        GeoExpression(const std::string& f);

        enum Predicate {
            WITHIN,
            INTERSECT,
            INVALID
        };

        // parseFrom() must be called before getGeometry() to ensure initialization of geoContainer
        Status parseFrom(const BSONObj &obj);

        std::string getField() const { return field; }
        Predicate getPred() const { return predicate; }
        const GeometryContainer& getGeometry() const { return *geoContainer; }

    private:
        // Parse geospatial query
        // e.g.
        // { "$intersect" : { "$geometry" : { "type" : "Point", "coordinates": [ 40, 5 ] } } }
        Status parseQuery(const BSONObj &obj);

        // Name of the field in the query.
        std::string field;
        std::unique_ptr<GeometryContainer> geoContainer;
        Predicate predicate;
    };

    class GeoMatchExpression : public LeafMatchExpression {
    public:
        GeoMatchExpression() : LeafMatchExpression( GEO ){}
        virtual ~GeoMatchExpression(){}

        /**
         * Takes ownership of the passed-in GeoExpression.
         */
        Status init( StringData path, const GeoExpression* query, const BSONObj& rawObj );

        virtual bool matchesSingleElement( const BSONElement& e ) const;

        virtual void debugString( StringBuilder& debug, int level = 0 ) const;

        virtual void toBSON(BSONObjBuilder* out) const;

        virtual bool equivalent( const MatchExpression* other ) const;

        virtual LeafMatchExpression* shallowClone() const;

        const GeoExpression& getGeoExpression() const { return *_query; }
        const BSONObj getRawObj() const { return _rawObj; }

    private:
        BSONObj _rawObj;
        // Share ownership of our query with all of our clones
        boost::shared_ptr<const GeoExpression> _query;
    };


    // TODO: Make a struct, turn parse stuff into something like
    // static Status parseNearQuery(const BSONObj& obj, NearQuery** out);
    class GeoNearExpression {
        MONGO_DISALLOW_COPYING(GeoNearExpression);

    public:
        GeoNearExpression();
        GeoNearExpression(const std::string& f);

        Status parseFrom(const BSONObj &obj);

        // The name of the field that contains the geometry.
        std::string field;

        // The starting point of the near search. Use forward declaration of geometries.
        std::unique_ptr<PointWithCRS> centroid;

        // Min and max distance from centroid that we're willing to search.
        // Distance is in units of the geometry's CRS, except SPHERE and isNearSphere => radians
        double minDistance;
        double maxDistance;

        // Is this a $nearSphere query
        bool isNearSphere;
        // $nearSphere with a legacy point implies units are radians
        bool unitsAreRadians;
        // $near with a non-legacy point implies a wrapping query, otherwise the query doesn't wrap
        bool isWrappingQuery;

        std::string toString() const {
            std::stringstream ss;
            ss << " field=" << field;
            ss << " maxdist=" << maxDistance;
            ss << " isNearSphere=" << isNearSphere;
            return ss.str();
        }

    private:
        bool parseLegacyQuery(const BSONObj &obj);
        Status parseNewQuery(const BSONObj &obj);
    };

    class GeoNearMatchExpression : public LeafMatchExpression {
    public:
        GeoNearMatchExpression() : LeafMatchExpression( GEO_NEAR ){}
        virtual ~GeoNearMatchExpression(){}

        Status init( StringData path, const GeoNearExpression* query, const BSONObj& rawObj );

        // This shouldn't be called and as such will crash.  GeoNear always requires an index.
        virtual bool matchesSingleElement( const BSONElement& e ) const;

        virtual void debugString( StringBuilder& debug, int level = 0 ) const;

        virtual void toBSON(BSONObjBuilder* out) const;

        virtual bool equivalent( const MatchExpression* other ) const;

        virtual LeafMatchExpression* shallowClone() const;

        const GeoNearExpression& getData() const { return *_query; }
        const BSONObj getRawObj() const { return _rawObj; }
    private:
        BSONObj _rawObj;
        // Share ownership of our query with all of our clones
        boost::shared_ptr<const GeoNearExpression> _query;
    };

}  // namespace mongo