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

 *

 * GEOS - Geometry Engine Open Source

 * http://geos.osgeo.org

 *

 * Copyright (C) 2023 Paul Ramsey <pramsey@cleverelephant.ca>

 * Copyright (c) 2023 Martin Davis.

 *

 * 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/geom/Coordinate.h>

#include <geos/geom/LineSegment.h>

#include <geos/coverage/CoverageEdge.h> // to materialize CoverageEdge

#include <set>

#include <map>

// Forward declarations

namespace geos {

namespace geom {

class CoordinateSequence;

class Geometry;

class LinearRing;

class MultiPolygon;

class Polygon;

}

namespace coverage {

class CoverageEdge;

}

}

namespace geos {     // geos

namespace coverage { // geos.coverage

/**

 * Models a polygonal coverage as a set of unique {@link CoverageEdge}s,

 * linked to the parent rings in the coverage polygons.

 * Each edge has either one or two parent rings, depending on whether

 * it is an inner or outer edge of the coverage.

 * The source coverage is represented as a array of polygonal geometries

 * (either {@link geos::geom::Polygon}s or {@link geos::geom::MultiPolygon}s).

 *

 * @author Martin Davis

 */

class GEOS_DLL CoverageRingEdges {

    using Coordinate = geos::geom::Coordinate;

    using CoordinateSequence = geos::geom::CoordinateSequence;

    using Geometry = geos::geom::Geometry;

    using LinearRing = geos::geom::LinearRing;

    using LineSegment = geos::geom::LineSegment;

    using MultiPolygon = geos::geom::MultiPolygon;

    using Polygon = geos::geom::Polygon;

private:

    // Members

    const std::vector<const Geometry*>& m_coverage;

    std::map<const LinearRing*, std::vector<CoverageEdge*>> m_ringEdgesMap;

    std::vector<CoverageEdge*> m_edges;

    std::vector<std::unique_ptr<CoverageEdge>> m_edgeStore;

    /* Turn off copy constructors for MSVC */

    CoverageRingEdges(const CoverageRingEdges&) = delete;

    CoverageRingEdges& operator=(const CoverageRingEdges&) = delete;

public:

    CoverageRingEdges(const std::vector<const Geometry*>& coverage)

        : m_coverage(coverage)

    {

        build();

    };

    std::vector<CoverageEdge*>& getEdges()

    {

        return m_edges;

    };

    /**

    * Selects the edges with a given ring count (which can be 1 or 2).

    *

    * @param ringCount the edge ring count to select (1 or 2)

    * @return the selected edges

    */

    std::vector<CoverageEdge*> selectEdges(

        std::size_t ringCount) const;

    /**

    * Recreates the polygon coverage from the current edge values.

    *

    * @return an array of polygonal geometries representing the coverage

    */

    std::vector<std::unique_ptr<Geometry>> buildCoverage() const;

private:

    void build();

    void addRingEdges(

        const LinearRing* ring,

        Coordinate::UnorderedSet& nodes,

        LineSegment::UnorderedSet& boundarySegs,

        std::map<LineSegment, CoverageEdge*>& uniqueEdgeMap);

    void addBoundaryInnerNodes(

        const LinearRing* ring,

        LineSegment::UnorderedSet& boundarySegs,

        Coordinate::UnorderedSet& nodes);

    std::vector<CoverageEdge*> extractRingEdges(

        const LinearRing* ring,

        std::map<LineSegment, CoverageEdge*>& uniqueEdgeMap,

        Coordinate::UnorderedSet& nodes);

    CoverageEdge* createEdge(

        const CoordinateSequence& ring,

        std::map<LineSegment, CoverageEdge*>& uniqueEdgeMap);

    CoverageEdge* createEdge(

        const CoordinateSequence& ring,

        std::size_t start, std::size_t end,

        std::map<LineSegment, CoverageEdge*>& uniqueEdgeMap);

    std::size_t findNextNodeIndex(

        const CoordinateSequence& ring,

        std::size_t start,

        Coordinate::UnorderedSet& nodes) const;

    static std::size_t next(

        std::size_t index,

        const CoordinateSequence& ring);

    Coordinate::UnorderedSet findMultiRingNodes(

        const std::vector<const Geometry*>& coverage);

    Coordinate::UnorderedSet findBoundaryNodes(

        LineSegment::UnorderedSet& lineSegments);

    std::unique_ptr<Geometry> buildPolygonal(

        const Geometry* geom) const;

    std::unique_ptr<Geometry> buildMultiPolygon(

        const MultiPolygon* geom) const;

    std::unique_ptr<Polygon> buildPolygon(

        const Polygon* polygon) const;

    std::unique_ptr<LinearRing> buildRing(

        const LinearRing* ring) const;

    bool isEdgeDirForward(

        const std::vector<CoverageEdge*>& ringEdges,

        std::size_t index,

        const Coordinate& prevPt) const;

};

} // namespace geos.coverage

} // namespace geos