/**********************************************************************

 *

 * GEOS - Geometry Engine Open Source

 * http://geos.osgeo.org

 *

 * Copyright (C) 2020 Paul Ramsey <pramsey@cleverelephant.ca>

 *

 * This is free software; you can redistribute and/or modify it under

 * the terms of the GNU Lesser General Public Licence as published

 * by the Free Software Foundation.

 * See the COPYING file for more information.

 *

 **********************************************************************/

#pragma once

#include <geos/export.h>

#include <geos/geom/Envelope.h>

#include <geos/index/kdtree/KdNodeVisitor.h>

#include <geos/index/kdtree/KdNode.h>

#include <memory>

#include <vector>

#include <string>

#include <deque>

#ifdef _MSC_VER

#pragma warning(push)

#pragma warning(disable: 4251) // warning C4251: needs to have dll-interface to be used by clients of class

#endif

namespace geos {

namespace index { // geos::index

namespace kdtree { // geos::index::kdtree

/**

 * An implementation of a 2-D KD-Tree. KD-trees provide fast range searching on

 * point data.

 * <p>

 * This implementation supports detecting and snapping points which are closer

 * than a given distance tolerance.

 * If the same point (up to tolerance) is inserted

 * more than once, it is snapped to the existing node.

 * In other words, if a point is inserted which lies within the tolerance of a node already in the index,

 * it is snapped to that node.

 * When a point is snapped to a node then a new node is not created but the count of the existing node

 * is incremented.

 * If more than one node in the tree is within tolerance of an inserted point,

 * the closest and then lowest node is snapped to.

 *

 * @author David Skea

 * @author Martin Davis

 */

class GEOS_DLL KdTree {

private:

    std::deque<KdNode> nodeQue;

    KdNode *root;

    std::size_t numberOfNodes;

    double tolerance;

    KdNode* findBestMatchNode(const geom::Coordinate& p);

    KdNode* insertExact(const geom::Coordinate& p, void* data);

    void queryNode(KdNode* currentNode, const geom::Envelope& queryEnv, bool odd, KdNodeVisitor& visitor);

    KdNode* queryNodePoint(KdNode* currentNode, const geom::Coordinate& queryPt, bool odd);

    /**

    * Create a node on a locally managed deque to allow easy

    * disposal and hopefully faster allocation as well.

    */

    KdNode* createNode(const geom::Coordinate& p, void* data);

    /**

    * BestMatchVisitor used to query the tree for a match

    * within tolerance.

    */

    class BestMatchVisitor : public KdNodeVisitor {

    public:

        BestMatchVisitor(const geom::Coordinate& p_p, double p_tolerance);

        geom::Envelope queryEnvelope();

        KdNode* getNode();

        void visit(KdNode* node) override;

    private:

        // Members

        double tolerance;

        KdNode* matchNode;

        double matchDist;

        const geom::Coordinate& p;

        // Declare type as noncopyable

        BestMatchVisitor(const BestMatchVisitor& other);

        BestMatchVisitor& operator=(const BestMatchVisitor& rhs);

    };

    /**

    * AccumulatingVisitor used to query the tree and get list

    * of matching nodes.

    */

    class AccumulatingVisitor : public KdNodeVisitor {

    public:

        AccumulatingVisitor(std::vector<KdNode*>& p_nodeList) :

            nodeList(p_nodeList) {};

        void visit(KdNode* node) override { nodeList.push_back(node); }

    private:

        // Members

        std::vector<KdNode*>& nodeList;

        // Declare type as noncopyable

        AccumulatingVisitor(const AccumulatingVisitor& other);

        AccumulatingVisitor& operator=(const AccumulatingVisitor& rhs);

    };

public:

    /**

    * Converts a collection of {@link KdNode}s to an vector of {@link geom::Coordinate}s.

    *

    * @param kdnodes a collection of nodes

    * @return an vector of the coordinates represented by the nodes

    */

    static std::unique_ptr<std::vector<geom::Coordinate>> toCoordinates(std::vector<KdNode*>& kdnodes);

    /**

    * Converts a collection of {@link KdNode}s

    * to an vector of {@link geom::Coordinate}s,

    * specifying whether repeated nodes should be represented

    * by multiple coordinates.

    *

    * @param kdnodes a collection of nodes

    * @param includeRepeated true if repeated nodes should

    *   be included multiple times

    * @return an vector of the coordinates represented by the nodes

    */

    static std::unique_ptr<std::vector<geom::Coordinate>> toCoordinates(std::vector<KdNode*>& kdnodes, bool includeRepeated);

    KdTree() :

        root(nullptr),

        numberOfNodes(0),

        tolerance(0.0)

        {};

    KdTree(double p_tolerance) :

        root(nullptr),

        numberOfNodes(0),

        tolerance(p_tolerance)

        {};

    bool isEmpty() { return root == nullptr; }

    /**

    * Inserts a new point in the kd-tree.

    */

    KdNode* insert(const geom::Coordinate& p);

    KdNode* insert(const geom::Coordinate& p, void* data);

    /**

    * Performs a range search of the points in the index and visits all nodes found.

    */

    void query(const geom::Envelope& queryEnv, KdNodeVisitor& visitor);

    /**

    * Performs a range search of the points in the index.

    */

    std::unique_ptr<std::vector<KdNode*>> query(const geom::Envelope& queryEnv);

    /**

    * Performs a range search of the points in the index.

    */

    void query(const geom::Envelope& queryEnv, std::vector<KdNode*>& result);

    /**

    * Searches for a given point in the index and returns its node if found.

    */

    KdNode* query(const geom::Coordinate& queryPt);

};

} // namespace geos::index::kdtree

} // namespace geos::index

} // namespace geos

#ifdef _MSC_VER

#pragma warning(pop)

#endif