// SPDX-License-Identifier: LGPL-2.1-or-later

/***************************************************************************
 *   Copyright (c) 2008 Juergen Riegel <juergen.riegel@web.de>             *
 *                                                                         *
 *   This file is part of the FreeCAD CAx development system.              *
 *                                                                         *
 *   This library is free software; you can redistribute it and/or         *
 *   modify it under the terms of the GNU Library General Public           *
 *   License as published by the Free Software Foundation; either          *
 *   version 2 of the License, or (at your option) any later version.      *
 *                                                                         *
 *   This library  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 Library General Public License for more details.                  *
 *                                                                         *
 *   You should have received a copy of the GNU Library General Public     *
 *   License along with this library; see the file COPYING.LIB. If not,    *
 *   write to the Free Software Foundation, Inc., 59 Temple Place,         *
 *   Suite 330, Boston, MA  02111-1307, USA                                *
 *                                                                         *
 ***************************************************************************/

#ifndef _CurveProjector_h_
#define _CurveProjector_h_

#include <limits>

#include <TopoDS_Edge.hxx>

#include <Mod/Mesh/App/Mesh.h>
#include <Mod/MeshPart/MeshPartGlobal.h>

#include <Standard_Version.hxx>

namespace MeshCore
{
class MeshKernel;
class MeshGeomFacet;
class MeshFacetGrid;
}  // namespace MeshCore

using MeshCore::MeshGeomFacet;
using MeshCore::MeshKernel;

namespace MeshPart
{

/** The father of all projection algorithms
 */
class MeshPartExport CurveProjector
{
public:
    CurveProjector(const TopoDS_Shape& aShape, const MeshKernel& pMesh);
    virtual ~CurveProjector() = default;

    struct FaceSplitEdge
    {
        MeshCore::FacetIndex ulFaceIndex;
        Base::Vector3f p1, p2;
    };

    template<class T>
    struct TopoDSLess
    {
        bool operator()(const T& x, const T& y) const
        {
#if OCC_VERSION_HEX >= 0x070800
            std::hash<T> hasher;
            return hasher(x) < hasher(y);
#else
            constexpr int max = std::numeric_limits<int>::max();
            return x.HashCode(max - 1) < y.HashCode(max - 1);
#endif
        }
    };

    using result_type = std::map<TopoDS_Edge, std::vector<FaceSplitEdge>, TopoDSLess<TopoDS_Edge>>;


    result_type& result()
    {
        return mvEdgeSplitPoints;
    }

    void writeIntersectionPointsToFile(const char* name = "export_pts.asc");

protected:
    virtual void Do() = 0;
    const TopoDS_Shape& _Shape;
    const MeshKernel& _Mesh;
    result_type mvEdgeSplitPoints;
};


/** Project by intersection face planes with the curve
 */
class MeshPartExport CurveProjectorShape: public CurveProjector
{
public:
    CurveProjectorShape(const TopoDS_Shape& aShape, const MeshKernel& pMesh);
    ~CurveProjectorShape() override = default;

    void projectCurve(const TopoDS_Edge& aEdge, std::vector<FaceSplitEdge>& vSplitEdges);

    bool findStartPoint(
        const MeshKernel& MeshK,
        const Base::Vector3f& Pnt,
        Base::Vector3f& Rslt,
        MeshCore::FacetIndex& FaceIndex
    );


protected:
    void Do() override;
};


/** Project by projecting a sampled curve to the mesh
 */
class MeshPartExport CurveProjectorSimple: public CurveProjector
{
public:
    CurveProjectorSimple(const TopoDS_Shape& aShape, const MeshKernel& pMesh);
    ~CurveProjectorSimple() override = default;

    /// helper to discredicice a Edge...
    void GetSampledCurves(
        const TopoDS_Edge& aEdge,
        std::vector<Base::Vector3f>& rclPoints,
        unsigned long ulNbOfPoints = 30
    );


    void projectCurve(
        const TopoDS_Edge& aEdge,
        const std::vector<Base::Vector3f>& rclPoints,
        std::vector<FaceSplitEdge>& vSplitEdges
    );

    bool findStartPoint(
        const MeshKernel& MeshK,
        const Base::Vector3f& Pnt,
        Base::Vector3f& Rslt,
        MeshCore::FacetIndex& FaceIndex
    );


protected:
    void Do() override;
};

/** Project by projecting a sampled curve to the mesh
 */
class MeshPartExport CurveProjectorWithToolMesh: public CurveProjector
{
public:
    struct LineSeg
    {
        Base::Vector3f p;
        Base::Vector3f n;
    };

    CurveProjectorWithToolMesh(const TopoDS_Shape& aShape, const MeshKernel& pMesh, MeshKernel& rToolMesh);
    ~CurveProjectorWithToolMesh() override = default;


    void makeToolMesh(const TopoDS_Edge& aEdge, std::vector<MeshGeomFacet>& cVAry);


    MeshKernel& ToolMesh;

protected:
    void Do() override;
};

/**
 * The MeshProjection class projects a shape onto a mesh.
 * @author Werner Mayer
 */
class MeshPartExport MeshProjection
{
public:
    /// Helper class
    struct SplitEdge
    {
        MeshCore::PointIndex uE0, uE1; /**< start and endpoint of an edge */
        Base::Vector3f cPt;            /**< Point on edge (\a uE0, \a uE1) */
    };
    struct Edge
    {
        Base::Vector3f cPt1;
        Base::Vector3f cPt2;
    };
    struct PolyLine
    {
        std::vector<Base::Vector3f> points;
    };

    explicit MeshProjection(const MeshKernel& rMesh);

    /**
     * @brief findSectionParameters
     * Find the parameters of the edge where when projecting the corresponding point will lie
     * on an edge of the mesh.
     * @param edge
     * @param dir
     * @param parameters
     */
    void findSectionParameters(
        const TopoDS_Edge& edge,
        const Base::Vector3f& dir,
        std::set<double>& parameters
    ) const;
    void discretize(
        const TopoDS_Edge& aEdge,
        std::vector<Base::Vector3f>& polyline,
        std::size_t minPoints = 2
    ) const;
    /**
     * Searches all edges that intersect with the projected curve \a aShape. Therefore \a aShape
     * must contain shapes of type TopoDS_Edge, other shape types are ignored. A possible solution
     * is taken if the distance between the curve point and the projected point is <= \a fMaxDist.
     */
    void projectToMesh(const TopoDS_Shape& aShape, float fMaxDist, std::vector<PolyLine>& rPolyLines) const;
    /**
     * @brief projectOnMesh
     * Projects the given points onto the mesh along a given direction. The points can can be
     * projected will be saved to \a pointsOut
     * @brief projectOnMesh
     * @param pointsIn
     * @param dir
     * @param tolerance
     * @param pointsOut
     */
    void projectOnMesh(
        const std::vector<Base::Vector3f>& pointsIn,
        const Base::Vector3f& dir,
        float tolerance,
        std::vector<Base::Vector3f>& pointsOut
    ) const;
    /**
     * Project all edges of the shape onto the mesh using parallel projection.
     */
    void projectParallelToMesh(
        const TopoDS_Shape& aShape,
        const Base::Vector3f& dir,
        std::vector<PolyLine>& rPolyLines
    ) const;
    /**
     * Project all polylines onto the mesh using parallel projection.
     */
    void projectParallelToMesh(
        const std::vector<PolyLine>& aEdges,
        const Base::Vector3f& dir,
        std::vector<PolyLine>& rPolyLines
    ) const;
    /**
     * Cuts the mesh at the curve defined by \a aShape. This method call @ref projectToMesh() to get
     * the split the facet at the found points. @see projectToMesh() for more details.
     */
    void splitMeshByShape(const TopoDS_Shape& aShape, float fMaxDist) const;

protected:
    void projectEdgeToEdge(
        const TopoDS_Edge& aCurve,
        float fMaxDist,
        const MeshCore::MeshFacetGrid& rGrid,
        std::vector<SplitEdge>& rSplitEdges
    ) const;
    bool findIntersection(const Edge&, const Edge&, const Base::Vector3f& dir, Base::Vector3f& res) const;

private:
    const MeshKernel& _rcMesh;
};

}  // namespace MeshPart

#endif