using System;
using System.IO;
using TriangleNet.Geometry;
using TriangleNet.Meshing;

namespace TriangleNet.IO
{
	public class TriangleFormat : IPolygonFormat, IFileFormat, IMeshFormat
	{
		public bool IsSupported(string file)
		{
			switch (Path.GetExtension(file).ToLower())
			{
			case ".node":
			case ".poly":
			case ".ele":
				return true;
			default:
				return false;
			}
		}

		public IMesh Import(string filename)
		{
			switch (Path.GetExtension(filename))
			{
			case ".node":
			case ".poly":
			case ".ele":
			{
				new TriangleReader().Read(filename, out var geometry, out var triangles);
				if (geometry != null && triangles != null)
				{
					return Converter.ToMesh(geometry, triangles.ToArray());
				}
				break;
			}
			}
			throw new NotSupportedException("Could not load '" + filename + "' file.");
		}

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

		public void Write(IMesh mesh, Stream stream)
		{
			throw new NotImplementedException();
		}

		public IPolygon Read(string filename)
		{
			string extension = Path.GetExtension(filename);
			if (extension == ".node")
			{
				return new TriangleReader().ReadNodeFile(filename);
			}
			if (extension == ".poly")
			{
				return new TriangleReader().ReadPolyFile(filename);
			}
			throw new NotSupportedException("File format '" + extension + "' not supported.");
		}

		public void Write(IPolygon polygon, string filename)
		{
			new TriangleWriter().WritePoly(polygon, filename);
		}

		public void Write(IPolygon polygon, Stream stream)
		{
			throw new NotImplementedException();
		}
	}
}