text: // 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 "mongol/db/geo/geometry_container.h"
  #include "mongol/db/matcher/expression.h"
  #include "mongol/db/matcher/expression_leaf.h"
  
  namespace mongol {
  
  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), _canSkipValidation(false) {}
  
      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 std::unique_ptr<MatchExpression> shallowClone() const;
  
      void setCanSkipValidation(bool val) {
          _canSkipValidation = val;
      }
  
      bool getCanSkipValidation() const {
          return _canSkipValidation;
      }
  
      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
      std::shared_ptr<const GeoExpression> _query;
      bool _canSkipValidation;
  };
  
  
  // 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 std::unique_ptr<MatchExpression> 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
      std::shared_ptr<const GeoNearExpression> _query;
  };
  
  }  // namespace mongol
  