using System.Collections.Generic;
using global::System.Numerics;

namespace Pilz.S3DFileParser
{
    public class Object3D
    {
        public List<Mesh> Meshes { get; private set; } = new List<Mesh>();
        public Dictionary<string, Material> Materials { get; private set; } = new Dictionary<string, Material>();
        public Shading Shading { get; set; } = new Shading();

        public void ScaleModel(float factor)
        {
            foreach (Mesh m in Meshes)
            {
                foreach (Vertex v in m.Vertices)
                {
                    v.X *= factor;
                    v.Y *= factor;
                    v.Z *= factor;
                }
            }
        }

        public void OffsetModel(Vector3 off)
        {
            foreach (Mesh m in Meshes)
            {
                foreach (Vertex v in m.Vertices)
                {
                    v.X += off.X;
                    v.Y += off.Y;
                    v.Z += off.Z;
                }
            }
        }

        public ModelBoundaries GetBoundaries()
        {
            float? maxX = default;
            float? maxY = default;
            float? maxZ = default;
            float? minX = default;
            float? minY = default;
            float? minZ = default;
            foreach (Mesh m in Meshes)
            {
                foreach (Vertex vert in m.Vertices)
                {
                    if (maxX is null || vert.X > maxX)
                        maxX = (float?)vert.X;
                    if (maxY is null || vert.Y > maxY)
                        maxY = (float?)vert.Y;
                    if (maxZ is null || vert.Z > maxZ)
                        maxZ = (float?)vert.Z;
                    if (minX is null || vert.X < minX)
                        minX = (float?)vert.X;
                    if (minY is null || vert.Y < minY)
                        minY = (float?)vert.Y;
                    if (minZ is null || vert.Z < minZ)
                        minZ = (float?)vert.Z;
                }
            }

            if (maxX is null)
                maxX = 0;
            if (maxY is null)
                maxY = 0;
            if (maxZ is null)
                maxZ = 0;
            if (minX is null)
                minX = 0;
            if (minY is null)
                minY = 0;
            if (minZ is null)
                minZ = 0;
            return new ModelBoundaries(new Vector3((float)maxX, (float)maxY, (float)maxZ), new Vector3((float)minX, (float)minY, (float)minZ));
        }

        public void SetNullVertices()
        {
            var newVert = new Vertex() { X = 0d, Y = 0d, Z = 0d };
            int nullCounter;
            foreach (Mesh m in Meshes)
            {
                nullCounter = 0;
                foreach (Face f in m.Faces)
                {
                    foreach (Point p in f.Points)
                    {
                        if (p.Vertex is null)
                        {
                            p.Vertex = newVert;
                            nullCounter += 1;
                        }
                    }
                }

                if (nullCounter > 0)
                {
                    m.Vertices.Add(newVert);
                }
            }
        }

        public void SetNullUVs()
        {
            var newUV = new UV() { U = 0f, V = 0f };
            int nullCounter;
            foreach (Mesh m in Meshes)
            {
                nullCounter = 0;
                foreach (Face f in m.Faces)
                {
                    foreach (Point p in f.Points)
                    {
                        if (p.UV is null)
                        {
                            p.UV = newUV;
                            nullCounter += 1;
                        }
                    }
                }

                if (nullCounter > 0)
                {
                    m.UVs.Add(newUV);
                }
            }
        }

        public void SetNullNormals()
        {
            var newNormal = new Normal() { X = 0f, Y = 0f, Z = 1f };
            int nullCounter;
            foreach (Mesh m in Meshes)
            {
                nullCounter = 0;
                foreach (Face f in m.Faces)
                {
                    foreach (Point p in f.Points)
                    {
                        if (p.Normal is null)
                        {
                            p.Normal = newNormal;
                            nullCounter += 1;
                        }
                    }
                }

                if (nullCounter > 0)
                {
                    m.Normals.Add(newNormal);
                }
            }
        }

        public void RemoveUnusedMaterials()
        {
            // Dim usedMats As New List(Of Material)
            // Dim unusedMats As New List(Of String)

            // For Each f As Face In Faces
            // If Not usedMats.Contains(f.Material) Then
            // usedMats.Add(f.Material)
            // End If
            // Next

            // For Each kvp As KeyValuePair(Of String, Material) In Materials
            // If Not usedMats.Contains(kvp.Value) Then
            // unusedMats.Add(kvp.Key)
            // End If
            // Next

            // For Each k As String In unusedMats
            // Materials.Remove(k)
            // Next
        }

        public Object3D ToOneMesh()
        {
            var newObject3D = new Object3D();
            var newMesh = new Mesh();
            foreach (KeyValuePair<string, Material> mat in Materials)
                newObject3D.Materials.Add(mat.Key, mat.Value);
            foreach (Mesh m in Meshes)
            {
                foreach (Vertex v in m.Vertices)
                    newMesh.Vertices.Add(v);
                foreach (VertexColor vc in m.VertexColors)
                    newMesh.VertexColors.Add(vc);
                foreach (Normal n in m.Normals)
                    newMesh.Normals.Add(n);
                foreach (UV uv in m.UVs)
                    newMesh.UVs.Add(uv);
                foreach (Face f in m.Faces)
                    newMesh.Faces.Add(f);
            }

            newObject3D.Meshes.Add(newMesh);
            return newObject3D;
        }

        public void CenterModel()
        {
            Mesh.CenterModel(Meshes);
        }

        public static void CenterModel(IEnumerable<Object3D> objs)
        {
            var meshes = new List<Mesh>();
            foreach (Object3D obj in objs)
                meshes.AddRange(obj.Meshes);
            Mesh.CenterModel(meshes);
        }
    }
}