/**
 * \file
 * \copyright
 * Copyright (c) 2012-2021, OpenGeoSys Community (http://www.opengeosys.org)
 *            Distributed under a Modified BSD License.
 *              See accompanying file LICENSE.txt or
 *              http://www.opengeosys.org/project/license
 *
 */

#include "TriRule3.h"

#include "MathLib/GeometricBasics.h"
#include "MeshLib/Node.h"

namespace MeshLib
{
const unsigned TriRule3::edge_nodes[3][2] = {
    {0, 1},  // Edge 0
    {1, 2},  // Edge 1
    {2, 0},  // Edge 2
};

double TriRule3::computeVolume(Node const* const* _nodes)
{
    return MathLib::calcTriangleArea(*_nodes[0], *_nodes[1], *_nodes[2]);
}

bool TriRule3::isPntInElement(Node const* const* nodes,
                              MathLib::Point3d const& pnt, double eps)
{
    return MathLib::isPointInTriangle(pnt, *nodes[0], *nodes[1], *nodes[2],
                                      eps);
}

unsigned TriRule3::identifyFace(Node const* const* _nodes, Node* nodes[3])
{
    for (unsigned i = 0; i < 3; i++)
    {
        unsigned flag(0);
        for (unsigned j = 0; j < 2; j++)
        {
            for (unsigned k = 0; k < 2; k++)
            {
                if (_nodes[edge_nodes[i][j]] == nodes[k])
                {
                    flag++;
                }
            }
        }
        if (flag == 2)
        {
            return i;
        }
    }
    return std::numeric_limits<unsigned>::max();
}

ElementErrorCode TriRule3::validate(const Element* e)
{
    ElementErrorCode error_code;
    error_code[ElementErrorFlag::ZeroVolume] = hasZeroVolume(*e);
    error_code[ElementErrorFlag::NodeOrder] = !e->testElementNodeOrder();
    return error_code;
}

}  // end namespace MeshLib