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

 *

 * GEOS - Geometry Engine Open Source

 * http://geos.osgeo.org

 *

 * Copyright (C) 2011 Sandro Santilli <strk@kbt.io>

 * Copyright (C) 2007 Refractions Research Inc.

 *

 * 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.

 *

 **********************************************************************

 *

 * Last port: operation/buffer/OffsetSegmentString.java r378 (JTS-1.12)

 *

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

#pragma once

#include <geos/geom/Coordinate.h> // for inlines

#include <geos/geom/CoordinateSequence.h> // for inlines

#include <geos/geom/PrecisionModel.h> // for inlines

#include <vector>

#include <memory>

#include <cassert>

namespace geos {

namespace operation { // geos.operation

namespace buffer { // geos.operation.buffer

/// A dynamic list of the vertices in a constructed offset curve.

///

/// Automatically removes close vertices

/// which are closer than a given tolerance.

///

/// @author Martin Davis

///

class OffsetSegmentString {

private:

    geom::CoordinateSequence* ptList;

    const geom::PrecisionModel* precisionModel;

    /** \brief

     * The distance below which two adjacent points on the curve

     * are considered to be coincident.

     *

     * This is chosen to be a small fraction of the offset distance.

     */

    double minimumVertexDistance;

    /** \brief

     * Tests whether the given point is redundant relative to the previous

     * point in the list (up to tolerance)

     *

     * @param pt

     * @return true if the point is redundant

     */

    bool

    isRedundant(const geom::Coordinate& pt) const

    {

        if(ptList->size() < 1) {

            return false;

        }

        const geom::Coordinate& lastPt = ptList->back();

        double ptDist = pt.distance(lastPt);

        if(ptDist < minimumVertexDistance) {

            return true;

        }

        return false;

    }

    OffsetSegmentString(const OffsetSegmentString&) = delete;

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

public:

    friend std::ostream& operator<< (std::ostream& os, const OffsetSegmentString& node);

    OffsetSegmentString()

        :

        ptList(new geom::CoordinateSequence()),

        precisionModel(nullptr),

        minimumVertexDistance(0.0)

    {

    }

    ~OffsetSegmentString()

    {

        delete ptList;

    }

    void

    reset()

    {

        if(ptList) {

            ptList->clear();

        }

        else {

            ptList = new geom::CoordinateSequence();

        }

        precisionModel = nullptr;

        minimumVertexDistance = 0.0;

    }

    void

    setPrecisionModel(const geom::PrecisionModel* nPrecisionModel)

    {

        precisionModel = nPrecisionModel;

    }

    void

    setMinimumVertexDistance(double nMinVertexDistance)

    {

        minimumVertexDistance = nMinVertexDistance;

    }

    void

    addPt(const geom::Coordinate& pt)

    {

        assert(precisionModel);

        geom::Coordinate bufPt = pt;

        precisionModel->makePrecise(bufPt);

        // don't add duplicate (or near-duplicate) points

        if(isRedundant(bufPt)) {

            return;

        }

        // we ask to allow repeated as we checked this ourself

        // (JTS uses a vector for ptList, not a CoordinateSequence,

        // we should do the same)

        ptList->add(bufPt, true);

    }

    void

    addPts(const geom::CoordinateSequence& pts, bool isForward)

    {

        if(isForward) {

            for(std::size_t i = 0, n = pts.size(); i < n; ++i) {

                addPt(pts[i]);

            }

        }

        else {

            for(std::size_t i = pts.size(); i > 0; --i) {

                addPt(pts[i - 1]);

            }

        }

    }

    /// Check that points are a ring

    ///

    /// add the startpoint again if they are not

    void

    closeRing()

    {

        if(ptList->size() < 1) {

            return;

        }

        const geom::Coordinate& startPt = ptList->front();

        const geom::Coordinate& lastPt = ptList->back();

        if(startPt.equals(lastPt)) {

            return;

        }

        // we ask to allow repeated as we checked this ourself

        ptList->add(startPt, true);

    }

    /// Get coordinates by taking ownership of them

    ///

    /// After this call, the coordinates reference in

    /// this object are dropped. Calling twice will

    /// segfault...

    ///

    /// FIXME: refactor memory management of this

    ///

    geom::CoordinateSequence*

    getCoordinates()

    {

        closeRing();

        geom::CoordinateSequence* ret = ptList;

        ptList = nullptr;

        return ret;

    }

    inline size_t

    size() const

    {

        return ptList ? ptList->size() : 0 ;

    }

};

inline std::ostream&

operator<< (std::ostream& os,

            const OffsetSegmentString& lst)

{

    if(lst.ptList) {

        os << *(lst.ptList);

    }

    else {

        os << "empty (consumed?)";

    }

    return os;

}

} // namespace geos.operation.buffer

} // namespace geos.operation

} // namespace geos