using System;

namespace TriangleNet.Geometry
{
	public class Segment : ISegment, IEdge
	{
		private Vertex v0;

		private Vertex v1;

		private int label;

		public int Label
		{
			get
			{
				return label;
			}
			set
			{
				label = value;
			}
		}

		public int P0 => v0.id;

		public int P1 => v1.id;

		public Segment(Vertex v0, Vertex v1)
			: this(v0, v1, 0)
		{
		}

		public Segment(Vertex v0, Vertex v1, int label)
		{
			this.v0 = v0;
			this.v1 = v1;
			this.label = label;
		}

		public Vertex GetVertex(int index)
		{
			return index switch
			{
				0 => v0, 
				1 => v1, 
				_ => throw new IndexOutOfRangeException(), 
			};
		}

		public ITriangle GetTriangle(int index)
		{
			throw new NotImplementedException();
		}
	}
}