using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;

namespace CaeMesh
{
    [Serializable]
    public class ParabolicHexaElement : FeElement3D
    {
        // Variables                                                                                                                
        private static int vtkCellTypeInt = (int)vtkCellType.VTK_QUADRATIC_HEXAHEDRON;
        private static double a = 1.0 / 3.0;
        private static double b = -a / 4;


        // Properties                                                                                                               


        // Constructors                                                                                                             
        public ParabolicHexaElement(int id, int[] nodeIds)
          : base(id, nodeIds)
        {
        }
        public ParabolicHexaElement(int id, int partId, int[] nodeIds)
            : base(id, partId, nodeIds)
        {
        }


        // Methods                                                                                                                  
        public override int[] GetVtkNodeIds()
        {
            // return a copy -> ToArray
            return NodeIds.ToArray();
        }
        public override int[] GetGmshNodeIds()
        {
            int[] nodeIds = new int[NodeIds.Length];
            Array.Copy(NodeIds, nodeIds, 8);
            //
            nodeIds[8] = NodeIds[8];
            nodeIds[9] = NodeIds[11];
            nodeIds[10] = NodeIds[16];
            nodeIds[11] = NodeIds[9];
            //
            nodeIds[12] = NodeIds[17];
            nodeIds[13] = NodeIds[10];
            nodeIds[14] = NodeIds[18];
            nodeIds[15] = NodeIds[19];
            //
            nodeIds[16] = NodeIds[12];
            nodeIds[17] = NodeIds[15];
            nodeIds[18] = NodeIds[13];
            nodeIds[19] = NodeIds[14];
            //
            return nodeIds;
        }
        public override int GetVtkCellType()
        {
            return vtkCellTypeInt;
        }
        public override FeFaceName GetFaceNameFromSortedNodeIds(int[] nodeIds)
        {
            // the node ids are sorted 
            // S1 = 1-2-3-4 . 0-1-2-3 . 0-1-2-3
            // S2 = 5-8-7-6 . 4-7-6-5 . 4-5-6-7
            // S3 = 1-5-6-2 . 0-4-5-1 . 0-1-4-5
            // S4 = 2-6-7-3 . 1-5-6-2 . 1-2-5-6
            // S5 = 3-7-8-4 . 2-6-7-3 . 2-3-6-7
            // S6 = 4-8-5-1 . 3-7-4-0 . 0-3-4-7
            if (nodeIds[2] == 2) return FeFaceName.S1;
            else if (nodeIds[0] == 4) return FeFaceName.S2;
            else if (nodeIds[1] == 1) return FeFaceName.S3;
            else if (nodeIds[0] == 1) return FeFaceName.S4;
            else if (nodeIds[0] == 2) return FeFaceName.S5;
            else if (nodeIds[0] == 0) return FeFaceName.S6;
            else throw new NotSupportedException();
        }
        public override int[] GetNodeIdsFromFaceName(FeFaceName faceName)
        {
            // S1 = 1-2-3-4-9-10-11-12  . 0-1-2-3-8-9-10-11
            // S2 = 5-8-7-6-16-15-14-13 . 4-7-6-5-15-14-13-12
            // S3 = 1-5-6-2-17-13-18-9  . 0-4-5-1-16-12-17-8
            // S4 = 2-6-7-3-18-14-19-10 . 1-5-6-2-17-13-18-9
            // S5 = 3-7-8-4-19-15-20-11 . 2-6-7-3-18-14-19-10
            // S6 = 4-8-5-1-20-16-17-12 . 3-7-4-0-19-15-16-11
            switch (faceName)
            {
                case FeFaceName.S1:
                    return new int[] { NodeIds[0], NodeIds[1], NodeIds[2], NodeIds[3],
                                       NodeIds[8], NodeIds[9], NodeIds[10], NodeIds[11] };
                case FeFaceName.S2:
                    return new int[] { NodeIds[4], NodeIds[7], NodeIds[6], NodeIds[5],
                                       NodeIds[15], NodeIds[14], NodeIds[13], NodeIds[12] };
                case FeFaceName.S3:
                    return new int[] { NodeIds[0], NodeIds[4], NodeIds[5], NodeIds[1],
                                       NodeIds[16], NodeIds[12], NodeIds[17], NodeIds[8] };
                case FeFaceName.S4:
                    return new int[] { NodeIds[1], NodeIds[5], NodeIds[6], NodeIds[2],
                                       NodeIds[17], NodeIds[13], NodeIds[18], NodeIds[9] };
                case FeFaceName.S5:
                    return new int[] { NodeIds[2], NodeIds[6], NodeIds[7], NodeIds[3],
                                       NodeIds[18], NodeIds[14], NodeIds[19], NodeIds[10] };
                case FeFaceName.S6:
                    return new int[] { NodeIds[3], NodeIds[7], NodeIds[4], NodeIds[0],
                                       NodeIds[19], NodeIds[15], NodeIds[16], NodeIds[11] };
                default:
                    throw new NotSupportedException();
            }
        }
        public override int[] GetVtkCellFromFaceName(FeFaceName faceName)
        {
            // invert the surface normal to point outwards
            // S1 = 1-2-3-4-9-10-11-12  . 0-1-2-3-8-9-10-11   . 0-3-2-1-11-10-9-8
            // S2 = 5-8-7-6-16-15-14-13 . 4-7-6-5-15-14-13-12 . 4-5-6-7-12-13-14-15
            // S3 = 1-5-6-2-17-13-18-9  . 0-4-5-1-16-12-17-8  . 0-1-5-4-8-17-12-16
            // S4 = 2-6-7-3-18-14-19-10 . 1-5-6-2-17-13-18-9  . 1-2-6-5-9-18-13-17
            // S5 = 3-7-8-4-19-15-20-11 . 2-6-7-3-18-14-19-10 . 2-3-7-6-10-19-14-18
            // S6 = 4-8-5-1-20-16-17-12 . 3-7-4-0-19-15-16-11 . 3-0-4-7-11-16-15-19
            switch (faceName)
            {
                case FeFaceName.S1:
                    return new int[] { NodeIds[0], NodeIds[3], NodeIds[2], NodeIds[1],
                                       NodeIds[11], NodeIds[10], NodeIds[9], NodeIds[8] };
                case FeFaceName.S2:
                    return new int[] { NodeIds[4], NodeIds[5], NodeIds[6], NodeIds[7],
                                       NodeIds[12], NodeIds[13], NodeIds[14], NodeIds[15] };
                case FeFaceName.S3:
                    return new int[] { NodeIds[0], NodeIds[1], NodeIds[5], NodeIds[4],
                                       NodeIds[8], NodeIds[17], NodeIds[12], NodeIds[16] };
                case FeFaceName.S4:
                    return new int[] { NodeIds[1], NodeIds[2], NodeIds[6], NodeIds[5],
                                       NodeIds[9], NodeIds[18], NodeIds[13], NodeIds[17] };
                case FeFaceName.S5:
                    return new int[] { NodeIds[2], NodeIds[3], NodeIds[7], NodeIds[6],
                                       NodeIds[10], NodeIds[19], NodeIds[14], NodeIds[18] };
                case FeFaceName.S6:
                    return new int[] { NodeIds[3], NodeIds[0], NodeIds[4], NodeIds[7],
                                       NodeIds[11], NodeIds[16], NodeIds[15], NodeIds[19] };
                default:
                    throw new NotSupportedException();
            }
        }
        public override int GetVtkCellIdFromCell(int[] cell)
        {
            if (cell[0] == NodeIds[0] && cell[1] == NodeIds[3] && cell[2] == NodeIds[2] && cell[3] == NodeIds[1] &&
                cell[4] == NodeIds[11] && cell[5] == NodeIds[10] && cell[6] == NodeIds[9] && cell[7] == NodeIds[8]) return 0;
            else if (cell[0] == NodeIds[4] && cell[1] == NodeIds[5] && cell[2] == NodeIds[6] && cell[3] == NodeIds[7] &&
                     cell[4] == NodeIds[12] && cell[5] == NodeIds[13] && cell[6] == NodeIds[14] && cell[7] == NodeIds[15]) return 1;
            else if (cell[0] == NodeIds[0] && cell[1] == NodeIds[1] && cell[2] == NodeIds[5] && cell[3] == NodeIds[4] &&
                     cell[4] == NodeIds[8] && cell[5] == NodeIds[17] && cell[6] == NodeIds[12] && cell[7] == NodeIds[16]) return 2;
            else if (cell[0] == NodeIds[1] && cell[1] == NodeIds[2] && cell[2] == NodeIds[6] && cell[3] == NodeIds[5] &&
                     cell[4] == NodeIds[9] && cell[5] == NodeIds[18] && cell[6] == NodeIds[13] && cell[7] == NodeIds[17]) return 3;
            else if (cell[0] == NodeIds[2] && cell[1] == NodeIds[3] && cell[2] == NodeIds[7] && cell[3] == NodeIds[6] &&
                     cell[4] == NodeIds[10] && cell[5] == NodeIds[19] && cell[6] == NodeIds[14] && cell[7] == NodeIds[18]) return 4;
            else if (cell[0] == NodeIds[3] && cell[1] == NodeIds[0] && cell[2] == NodeIds[4] && cell[3] == NodeIds[7] &&
                     cell[4] == NodeIds[11] && cell[5] == NodeIds[16] && cell[6] == NodeIds[15] && cell[7] == NodeIds[19]) return 5;
            return -1;
        }
        public override int[][] GetAllVtkCells()
        {
            // use Method: GetVtkCellFromFaceName(FeFaceName faceName)
            int[][] cells = new int[6][];
            //
            cells[0] = new int[] { NodeIds[0], NodeIds[3], NodeIds[2], NodeIds[1],
                                   NodeIds[11], NodeIds[10], NodeIds[9], NodeIds[8] };
            cells[1] = new int[] { NodeIds[4], NodeIds[5], NodeIds[6], NodeIds[7],
                                   NodeIds[12], NodeIds[13], NodeIds[14], NodeIds[15] };
            cells[2] = new int[] { NodeIds[0], NodeIds[1], NodeIds[5], NodeIds[4],
                                   NodeIds[8], NodeIds[17], NodeIds[12], NodeIds[16] };
            cells[3] = new int[] { NodeIds[1], NodeIds[2], NodeIds[6], NodeIds[5],
                                   NodeIds[9], NodeIds[18], NodeIds[13], NodeIds[17] };
            cells[4] = new int[] { NodeIds[2], NodeIds[3], NodeIds[7], NodeIds[6],
                                   NodeIds[10], NodeIds[19], NodeIds[14], NodeIds[18] };
            cells[5] = new int[] { NodeIds[3], NodeIds[0], NodeIds[4], NodeIds[7],
                                   NodeIds[11], NodeIds[16], NodeIds[15], NodeIds[19] };
            //
            return cells;
        }
        public override Dictionary<FeFaceName, double> GetFaceNamesAndAreasFromNodeSet(HashSet<int> nodeSet,
                                                                                       Dictionary<int, FeNode> nodes,
                                                                                       bool edgeFaces)
        {
            // Check only first 8 nodes (as in linear element)
            int significantNodes = 8;
            bool[] faceNodeIds = new bool[significantNodes];
            //
            int count = 0;
            for (int i = 0; i < significantNodes; i++)
            {
                if (nodeSet.Contains(NodeIds[i]))
                {
                    faceNodeIds[i] = true;
                    count++;
                }
                // If five or more nodes were missed: break
                if (i + 1 - count >= 5) break;
            }
            // S1 = 1-2-3-4 . 0-1-2-3
            // S2 = 5-8-7-6 . 4-7-6-5
            // S3 = 1-5-6-2 . 0-4-5-1
            // S4 = 2-6-7-3 . 1-5-6-2
            // S5 = 3-7-8-4 . 2-6-7-3
            // S6 = 4-8-5-1 . 3-7-4-0
            Dictionary<FeFaceName, double> faces = new Dictionary<FeFaceName, double>();
            //
            if (faceNodeIds[0] && faceNodeIds[1] && faceNodeIds[2] && faceNodeIds[3])
                faces.Add(FeFaceName.S1, GetArea(FeFaceName.S1, nodes));
            if (faceNodeIds[4] && faceNodeIds[7] && faceNodeIds[6] && faceNodeIds[5])
                faces.Add(FeFaceName.S2, GetArea(FeFaceName.S2, nodes));
            if (faceNodeIds[0] && faceNodeIds[4] && faceNodeIds[5] && faceNodeIds[1])
                faces.Add(FeFaceName.S3, GetArea(FeFaceName.S3, nodes));
            if (faceNodeIds[1] && faceNodeIds[5] && faceNodeIds[6] && faceNodeIds[2])
                faces.Add(FeFaceName.S4, GetArea(FeFaceName.S4, nodes));
            if (faceNodeIds[2] && faceNodeIds[6] && faceNodeIds[7] && faceNodeIds[3])
                faces.Add(FeFaceName.S5, GetArea(FeFaceName.S5, nodes));
            if (faceNodeIds[3] && faceNodeIds[7] && faceNodeIds[4] && faceNodeIds[0])
                faces.Add(FeFaceName.S6, GetArea(FeFaceName.S6, nodes));
            //
            return faces;
        }
        public override double[] GetEquivalentForcesFromFaceName(FeFaceName faceName)
        {
            return new double[] { b, b, b, b, a, a, a, a };
        }
        public override double[] GetEquivalentForcesFromFaceName(FeFaceName faceName, double[] nodalValues)
        {
            return GetEquivalentForces(typeof(ParabolicQuadrilateralElement), nodalValues);
        }
        public override double GetArea(FeFaceName faceName, Dictionary<int, FeNode> nodes)
        {
            int[] cell = GetVtkCellFromFaceName(faceName);
            return GeometryTools.RectangleArea(nodes[cell[0]], nodes[cell[1]], nodes[cell[2]], nodes[cell[3]],
                                               nodes[cell[4]], nodes[cell[5]], nodes[cell[6]], nodes[cell[7]]);
        }
        public override double[] GetFaceCG(FeFaceName faceName, Dictionary<int, FeNode> nodes, out double area)
        {
            int[] cell = GetVtkCellFromFaceName(faceName);
            double[] cg = GeometryTools.QuadrilateralCG(nodes[cell[0]], nodes[cell[1]], nodes[cell[2]], nodes[cell[3]],
                                                    nodes[cell[4]], nodes[cell[5]], nodes[cell[6]], nodes[cell[7]], out area);
            return cg;
        }
        public override double GetVolume(Dictionary<int, FeNode> nodes)
        {
            return GeometryTools.HexahedronVolume(nodes[NodeIds[0]], nodes[NodeIds[1]],
                                                  nodes[NodeIds[2]], nodes[NodeIds[3]],
                                                  nodes[NodeIds[4]], nodes[NodeIds[5]],
                                                  nodes[NodeIds[6]], nodes[NodeIds[7]],
                                                  nodes[NodeIds[8]], nodes[NodeIds[9]],
                                                  nodes[NodeIds[10]], nodes[NodeIds[11]],
                                                  nodes[NodeIds[12]], nodes[NodeIds[13]],
                                                  nodes[NodeIds[14]], nodes[NodeIds[15]],
                                                  nodes[NodeIds[16]], nodes[NodeIds[17]],
                                                  nodes[NodeIds[18]], nodes[NodeIds[19]]);
        }
        public override double[] GetCG(Dictionary<int, FeNode> nodes, out double volume)
        {
            return GeometryTools.HexahedronCG(nodes[NodeIds[0]], nodes[NodeIds[1]],
                                              nodes[NodeIds[2]], nodes[NodeIds[3]],
                                              nodes[NodeIds[4]], nodes[NodeIds[5]],
                                              nodes[NodeIds[6]], nodes[NodeIds[7]],
                                              nodes[NodeIds[8]], nodes[NodeIds[9]],
                                              nodes[NodeIds[10]], nodes[NodeIds[11]],
                                              nodes[NodeIds[12]], nodes[NodeIds[13]],
                                              nodes[NodeIds[14]], nodes[NodeIds[15]],
                                              nodes[NodeIds[16]], nodes[NodeIds[17]],
                                              nodes[NodeIds[18]], nodes[NodeIds[19]], out volume);
        }
        public override FeElement DeepCopy()
        {
            return new ParabolicHexaElement(Id, PartId, NodeIds.ToArray());
        }
    }
}