using System.Collections.Generic;
using System.Linq;
using Chernobyl.Mathematics.Movement;
using NUnit.Framework;

namespace Chernobyl.Mathematics.Geometry
{
    [TestFixture, Description("Tests for the ArcExtensions type.")]
    public class ArcExtensionsTests
    {
        [Test, Description("A test to ensure that ArcExtensions.ToLineSegments(IArc arc) " + 
            "returns one ILineSegment instance when two ITransform instances are " +
            "in the passed in IArc.")]
        public void ToLineSegmentTwoTransforms()
        {
            ITransform[] points = new ITransform[]
            {
                new MatrixTransform(),
                new MatrixTransform()
            };

            IArc arc = new Arc(points);
            IEnumerable<ILineSegment> lineSegments = arc.ToLineSegments();

            Assert.AreEqual(1, lineSegments.Count(), "Unexpected number of " +
                "ILineSegment instances in the returned IEnumerable{T}.");
        }

        [Test, Description("A test to ensure that ArcExtensions.ToLineSegments(IArc arc) " +
            "returns three ILineSegment instance when four ITransform instances are " +
            "in the passed in IArc.")]
        public void ToLineSegmentFourTransforms()
        {
            ITransform[] points = new ITransform[]
            {
                new MatrixTransform(),
                new MatrixTransform(),
                new MatrixTransform(),
                new MatrixTransform()
            };

            IArc arc = new Arc(points);
            IEnumerable<ILineSegment> lineSegments = arc.ToLineSegments();

            Assert.AreEqual(3, lineSegments.Count(), "Unexpected number of " +
                "ILineSegment instances in the returned IEnumerable{T}.");
        }
    }
}