using TriangleNet.Geometry;
using TriangleNet.Logging;
using TriangleNet.Topology;

namespace TriangleNet
{
	public static class MeshValidator
	{
		private static RobustPredicates predicates = RobustPredicates.Default;

		public static bool IsConsistent(Mesh mesh)
		{
			Otri otri = default(Otri);
			Otri ot = default(Otri);
			Otri ot2 = default(Otri);
			ILog<LogItem> instance = Log.Instance;
			bool noExact = Behavior.NoExact;
			Behavior.NoExact = false;
			int num = 0;
			foreach (Triangle triangle2 in mesh.triangles)
			{
				Triangle triangle = (otri.tri = triangle2);
				otri.orient = 0;
				while (otri.orient < 3)
				{
					Vertex vertex = otri.Org();
					Vertex vertex2 = otri.Dest();
					if (otri.orient == 0)
					{
						Vertex pc = otri.Apex();
						if (predicates.CounterClockwise(vertex, vertex2, pc) <= 0.0)
						{
							if (Log.Verbose)
							{
								instance.Warning($"Triangle is flat or inverted (ID {triangle.id}).", "MeshValidator.IsConsistent()");
							}
							num++;
						}
					}
					otri.Sym(ref ot);
					if (ot.tri.id != -1)
					{
						ot.Sym(ref ot2);
						if (otri.tri != ot2.tri || otri.orient != ot2.orient)
						{
							if (otri.tri == ot2.tri && Log.Verbose)
							{
								instance.Warning("Asymmetric triangle-triangle bond: (Right triangle, wrong orientation)", "MeshValidator.IsConsistent()");
							}
							num++;
						}
						Vertex vertex3 = ot.Org();
						Vertex vertex4 = ot.Dest();
						if (vertex != vertex4 || vertex2 != vertex3)
						{
							if (Log.Verbose)
							{
								instance.Warning("Mismatched edge coordinates between two triangles.", "MeshValidator.IsConsistent()");
							}
							num++;
						}
					}
					otri.orient++;
				}
			}
			mesh.MakeVertexMap();
			foreach (Vertex value in mesh.vertices.Values)
			{
				if (value.tri.tri == null && Log.Verbose)
				{
					instance.Warning("Vertex (ID " + value.id + ") not connected to mesh (duplicate input vertex?)", "MeshValidator.IsConsistent()");
				}
			}
			Behavior.NoExact = noExact;
			return num == 0;
		}

		public static bool IsDelaunay(Mesh mesh)
		{
			return IsDelaunay(mesh, constrained: false);
		}

		public static bool IsConstrainedDelaunay(Mesh mesh)
		{
			return IsDelaunay(mesh, constrained: true);
		}

		private static bool IsDelaunay(Mesh mesh, bool constrained)
		{
			Otri otri = default(Otri);
			Otri ot = default(Otri);
			Osub os = default(Osub);
			ILog<LogItem> instance = Log.Instance;
			bool noExact = Behavior.NoExact;
			Behavior.NoExact = false;
			int num = 0;
			Vertex infvertex = mesh.infvertex1;
			Vertex infvertex2 = mesh.infvertex2;
			Vertex infvertex3 = mesh.infvertex3;
			foreach (Triangle triangle in mesh.triangles)
			{
				otri.tri = triangle;
				otri.orient = 0;
				while (otri.orient < 3)
				{
					Vertex vertex = otri.Org();
					Vertex vertex2 = otri.Dest();
					Vertex vertex3 = otri.Apex();
					otri.Sym(ref ot);
					Vertex vertex4 = ot.Apex();
					bool flag = otri.tri.id < ot.tri.id && !Otri.IsDead(ot.tri) && ot.tri.id != -1 && vertex != infvertex && vertex != infvertex2 && vertex != infvertex3 && vertex2 != infvertex && vertex2 != infvertex2 && vertex2 != infvertex3 && vertex3 != infvertex && vertex3 != infvertex2 && vertex3 != infvertex3 && vertex4 != infvertex && vertex4 != infvertex2 && vertex4 != infvertex3;
					if (constrained && mesh.checksegments && flag)
					{
						otri.Pivot(ref os);
						if (os.seg.hash != -1)
						{
							flag = false;
						}
					}
					if (flag && predicates.NonRegular(vertex, vertex2, vertex3, vertex4) > 0.0)
					{
						if (Log.Verbose)
						{
							instance.Warning($"Non-regular pair of triangles found (IDs {otri.tri.id}/{ot.tri.id}).", "MeshValidator.IsDelaunay()");
						}
						num++;
					}
					otri.orient++;
				}
			}
			Behavior.NoExact = noExact;
			return num == 0;
		}
	}
}