using System.Collections.Generic;
using System.Globalization;
using System.IO;
using TriangleNet.Geometry;
using TriangleNet.Topology;

namespace TriangleNet.IO
{
	public class TriangleWriter
	{
		private static NumberFormatInfo nfi = NumberFormatInfo.InvariantInfo;

		public void Write(Mesh mesh, string filename)
		{
			WritePoly(mesh, Path.ChangeExtension(filename, ".poly"));
			WriteElements(mesh, Path.ChangeExtension(filename, ".ele"));
		}

		public void WriteNodes(Mesh mesh, string filename)
		{
			using StreamWriter writer = new StreamWriter(filename);
			WriteNodes(writer, mesh);
		}

		private void WriteNodes(StreamWriter writer, Mesh mesh)
		{
			int num = mesh.vertices.Count;
			int nextras = mesh.nextras;
			Behavior behavior = mesh.behavior;
			if (behavior.Jettison)
			{
				num = mesh.vertices.Count - mesh.undeads;
			}
			if (writer == null)
			{
				return;
			}
			writer.WriteLine("{0} {1} {2} {3}", num, mesh.mesh_dim, nextras, behavior.UseBoundaryMarkers ? "1" : "0");
			if (mesh.numbering == NodeNumbering.None)
			{
				mesh.Renumber();
			}
			if (mesh.numbering == NodeNumbering.Linear)
			{
				WriteNodes(writer, mesh.vertices.Values, behavior.UseBoundaryMarkers, nextras, behavior.Jettison);
				return;
			}
			Vertex[] array = new Vertex[mesh.vertices.Count];
			foreach (Vertex value in mesh.vertices.Values)
			{
				array[value.id] = value;
			}
			WriteNodes(writer, array, behavior.UseBoundaryMarkers, nextras, behavior.Jettison);
		}

		private void WriteNodes(StreamWriter writer, IEnumerable<Vertex> nodes, bool markers, int attribs, bool jettison)
		{
			int num = 0;
			foreach (Vertex node in nodes)
			{
				if (!jettison || node.type != VertexType.UndeadVertex)
				{
					writer.Write("{0} {1} {2}", num, node.x.ToString(nfi), node.y.ToString(nfi));
					if (markers)
					{
						writer.Write(" {0}", node.label);
					}
					writer.WriteLine();
					num++;
				}
			}
		}

		public void WriteElements(Mesh mesh, string filename)
		{
			Otri otri = default(Otri);
			bool useRegions = mesh.behavior.useRegions;
			int num = 0;
			otri.orient = 0;
			using StreamWriter streamWriter = new StreamWriter(filename);
			streamWriter.WriteLine("{0} 3 {1}", mesh.triangles.Count, useRegions ? 1 : 0);
			foreach (Triangle triangle2 in mesh.triangles)
			{
				Triangle triangle = (otri.tri = triangle2);
				Vertex vertex = otri.Org();
				Vertex vertex2 = otri.Dest();
				Vertex vertex3 = otri.Apex();
				streamWriter.Write("{0} {1} {2} {3}", num, vertex.id, vertex2.id, vertex3.id);
				if (useRegions)
				{
					streamWriter.Write(" {0}", otri.tri.label);
				}
				streamWriter.WriteLine();
				triangle.id = num++;
			}
		}

		public void WritePoly(IPolygon polygon, string filename)
		{
			bool hasSegmentMarkers = polygon.HasSegmentMarkers;
			using StreamWriter streamWriter = new StreamWriter(filename);
			streamWriter.WriteLine("{0} 2 0 {1}", polygon.Points.Count, polygon.HasPointMarkers ? "1" : "0");
			WriteNodes(streamWriter, polygon.Points, polygon.HasPointMarkers, 0, jettison: false);
			streamWriter.WriteLine("{0} {1}", polygon.Segments.Count, hasSegmentMarkers ? "1" : "0");
			int num = 0;
			foreach (ISegment segment in polygon.Segments)
			{
				Vertex vertex = segment.GetVertex(0);
				Vertex vertex2 = segment.GetVertex(1);
				if (hasSegmentMarkers)
				{
					streamWriter.WriteLine("{0} {1} {2} {3}", num, vertex.ID, vertex2.ID, segment.Label);
				}
				else
				{
					streamWriter.WriteLine("{0} {1} {2}", num, vertex.ID, vertex2.ID);
				}
				num++;
			}
			num = 0;
			streamWriter.WriteLine("{0}", polygon.Holes.Count);
			foreach (Point hole in polygon.Holes)
			{
				streamWriter.WriteLine("{0} {1} {2}", num++, hole.X.ToString(nfi), hole.Y.ToString(nfi));
			}
			if (polygon.Regions.Count <= 0)
			{
				return;
			}
			num = 0;
			streamWriter.WriteLine("{0}", polygon.Regions.Count);
			foreach (RegionPointer region in polygon.Regions)
			{
				streamWriter.WriteLine("{0} {1} {2} {3}", num, region.point.X.ToString(nfi), region.point.Y.ToString(nfi), region.id);
				num++;
			}
		}

		public void WritePoly(Mesh mesh, string filename)
		{
			WritePoly(mesh, filename, writeNodes: true);
		}

		public void WritePoly(Mesh mesh, string filename, bool writeNodes)
		{
			Osub osub = default(Osub);
			bool useBoundaryMarkers = mesh.behavior.UseBoundaryMarkers;
			using StreamWriter streamWriter = new StreamWriter(filename);
			if (writeNodes)
			{
				WriteNodes(streamWriter, mesh);
			}
			else
			{
				streamWriter.WriteLine("0 {0} {1} {2}", mesh.mesh_dim, mesh.nextras, useBoundaryMarkers ? "1" : "0");
			}
			streamWriter.WriteLine("{0} {1}", mesh.subsegs.Count, useBoundaryMarkers ? "1" : "0");
			osub.orient = 0;
			int num = 0;
			foreach (SubSegment value in mesh.subsegs.Values)
			{
				osub.seg = value;
				Vertex vertex = osub.Org();
				Vertex vertex2 = osub.Dest();
				if (useBoundaryMarkers)
				{
					streamWriter.WriteLine("{0} {1} {2} {3}", num, vertex.id, vertex2.id, osub.seg.boundary);
				}
				else
				{
					streamWriter.WriteLine("{0} {1} {2}", num, vertex.id, vertex2.id);
				}
				num++;
			}
			num = 0;
			streamWriter.WriteLine("{0}", mesh.holes.Count);
			foreach (Point hole in mesh.holes)
			{
				streamWriter.WriteLine("{0} {1} {2}", num++, hole.X.ToString(nfi), hole.Y.ToString(nfi));
			}
			if (mesh.regions.Count <= 0)
			{
				return;
			}
			num = 0;
			streamWriter.WriteLine("{0}", mesh.regions.Count);
			foreach (RegionPointer region in mesh.regions)
			{
				streamWriter.WriteLine("{0} {1} {2} {3}", num, region.point.X.ToString(nfi), region.point.Y.ToString(nfi), region.id);
				num++;
			}
		}

		public void WriteEdges(Mesh mesh, string filename)
		{
			Otri otri = default(Otri);
			Otri ot = default(Otri);
			Osub os = default(Osub);
			Behavior behavior = mesh.behavior;
			using StreamWriter streamWriter = new StreamWriter(filename);
			streamWriter.WriteLine("{0} {1}", mesh.NumberOfEdges, behavior.UseBoundaryMarkers ? "1" : "0");
			long num = 0L;
			foreach (Triangle triangle in mesh.triangles)
			{
				otri.tri = triangle;
				otri.orient = 0;
				while (otri.orient < 3)
				{
					otri.Sym(ref ot);
					if (otri.tri.id < ot.tri.id || ot.tri.id == -1)
					{
						Vertex vertex = otri.Org();
						Vertex vertex2 = otri.Dest();
						if (behavior.UseBoundaryMarkers)
						{
							if (behavior.useSegments)
							{
								otri.Pivot(ref os);
								if (os.seg.hash == -1)
								{
									streamWriter.WriteLine("{0} {1} {2} {3}", num, vertex.id, vertex2.id, 0);
								}
								else
								{
									streamWriter.WriteLine("{0} {1} {2} {3}", num, vertex.id, vertex2.id, os.seg.boundary);
								}
							}
							else
							{
								streamWriter.WriteLine("{0} {1} {2} {3}", num, vertex.id, vertex2.id, (ot.tri.id == -1) ? "1" : "0");
							}
						}
						else
						{
							streamWriter.WriteLine("{0} {1} {2}", num, vertex.id, vertex2.id);
						}
						num++;
					}
					otri.orient++;
				}
			}
		}

		public void WriteNeighbors(Mesh mesh, string filename)
		{
			Otri otri = default(Otri);
			Otri ot = default(Otri);
			int num = 0;
			using StreamWriter streamWriter = new StreamWriter(filename);
			streamWriter.WriteLine("{0} 3", mesh.triangles.Count);
			foreach (Triangle triangle in mesh.triangles)
			{
				otri.tri = triangle;
				otri.orient = 1;
				otri.Sym(ref ot);
				int id = ot.tri.id;
				otri.orient = 2;
				otri.Sym(ref ot);
				int id2 = ot.tri.id;
				otri.orient = 0;
				otri.Sym(ref ot);
				int id3 = ot.tri.id;
				streamWriter.WriteLine("{0} {1} {2} {3}", num++, id, id2, id3);
			}
		}
	}
}