using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Annulus.DiscreteCollisionDetection;
using Azimuth;

namespace Annulus.UnitTests.DiscreteCollisionDetection
{
    public class ConnectingSegmentvsRayTests : UnitTestSharp.TestFixture
    {
        public void Basic()
        {
            var edge1 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(-1, 0),
            };

            var edge2 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(1, 0),
            };

            var ray = new Ray
            {
                Direction = new Vector(0, -1),
                From = new Vector(0, 4),
            };

            Scalar TOI, fraction;
            var result = ConnectingSegmentvsRay.FindIntersection(edge1, edge2, ray, out TOI, out fraction);

            CheckEqual(true, result);
            CheckEqual(2, TOI);
            CheckEqual(0.5, fraction);
        }

        public void Miss_Left()
        {
            var edge1 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(-1, 0),
            };

            var edge2 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(1, 0),
            };

            var ray = new Ray
            {
                Direction = new Vector(0, -1),
                From = new Vector(-2, 4),
            };

            Scalar TOI, fraction;
            var result = ConnectingSegmentvsRay.FindIntersection(edge1, edge2, ray, out TOI, out fraction);

            CheckEqual(false, result);
            Check(Scalar.IsNaN(TOI));
            Check(Scalar.IsNaN(fraction));
        }

        public void Miss_Right()
        {
            var edge1 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(-1, 0),
            };

            var edge2 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(1, 0),
            };

            var ray = new Ray
            {
                Direction = new Vector(0, -1),
                From = new Vector(2, 4),
            };

            Scalar TOI, fraction;
            var result = ConnectingSegmentvsRay.FindIntersection(edge1, edge2, ray, out TOI, out fraction);

            CheckEqual(false, result);
            Check(Scalar.IsNaN(TOI));
            Check(Scalar.IsNaN(fraction));
        }

        public void WrongDirection()
        {
            var edge1 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(-1, 0),
            };

            var edge2 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(1, 0),
            };

            var ray = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(0, 4),
            };

            Scalar TOI, fraction;
            var result = ConnectingSegmentvsRay.FindIntersection(edge1, edge2, ray, out TOI, out fraction);

            CheckEqual(false, result);
            Check(Scalar.IsNaN(TOI));
            Check(Scalar.IsNaN(fraction));
        }

        public void Stationary()
        {
            var edge1 = new Ray
            {
                Direction = new Vector(0, 0),
                From = new Vector(-1, 0),
            };

            var edge2 = new Ray
            {
                Direction = new Vector(0, 0),
                From = new Vector(1, 0),
            };

            var ray = new Ray
            {
                Direction = new Vector(0, 0),
                From = new Vector(2, 4),
            };

            Scalar TOI, fraction;
            var result = ConnectingSegmentvsRay.FindIntersection(edge1, edge2, ray, out TOI, out fraction);

            CheckEqual(false, result);
            Check(Scalar.IsNaN(TOI));
            Check(Scalar.IsNaN(fraction));
        }

        public void Overlapping_Miss()
        {
            var edge1 = new Ray
            {
                Direction = new Vector(0, -1),
                From = new Vector(0, 0),
            };

            var edge2 = new Ray
            {
                Direction = new Vector(0, -1),
                From = new Vector(0, 0),
            };

            var ray = new Ray
            {
                Direction = new Vector(0, -1),
                From = new Vector(0, 4),
            };

            Scalar TOI, fraction;
            var result = ConnectingSegmentvsRay.FindIntersection(edge1, edge2, ray, out TOI, out fraction);

            CheckEqual(false, result);
            Check(Scalar.IsNaN(TOI));
            Check(Scalar.IsNaN(fraction));
        }

        public void Overlapping_Hit()
        {
            var edge1 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(0, 0),
            };

            var edge2 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(0, 0),
            };

            var ray = new Ray
            {
                Direction = new Vector(0, -1),
                From = new Vector(0, 4),
            };

            Scalar TOI, fraction;
            var result = ConnectingSegmentvsRay.FindIntersection(edge1, edge2, ray, out TOI, out fraction);

            CheckEqual(true, result);
            CheckEqual(2, TOI);
            CheckEqual(0, fraction);
        }

        public void RayEdge1_Converge()
        {
            var edge1 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(0, 0),
            };

            var edge2 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(1, 0),
            };

            var ray = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(0, 0),
            };

            Scalar TOI, fraction;
            var result = ConnectingSegmentvsRay.FindIntersection(edge1, edge2, ray, out TOI, out fraction);

            CheckEqual(true, result);
            CheckEqual(0, TOI);
            CheckEqual(0, fraction);
        }

        public void RayEdge1_Diverge()
        {
            var edge1 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(0, 0),
            };

            var edge2 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(1, 0),
            };

            var ray = new Ray
            {
                Direction = new Vector(0, -1),
                From = new Vector(0, 0),
            };

            Scalar TOI, fraction;
            var result = ConnectingSegmentvsRay.FindIntersection(edge1, edge2, ray, out TOI, out fraction);

            CheckEqual(true, result);
            CheckEqual(0, TOI);
            CheckEqual(0, fraction);
        }

        public void RayEdge2_Converge()
        {
            var edge1 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(1, 0),
            };

            var edge2 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(0, 0),
            };

            var ray = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(0, 0),
            };

            Scalar TOI, fraction;
            var result = ConnectingSegmentvsRay.FindIntersection(edge1, edge2, ray, out TOI, out fraction);

            CheckEqual(true, result);
            CheckEqual(0, TOI);
            CheckEqual(1, fraction);
        }

        public void RayEdge2_Diverge()
        {
            var edge1 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(1, 0),
            };

            var edge2 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(0, 0),
            };

            var ray = new Ray
            {
                Direction = new Vector(0, -1),
                From = new Vector(0, 0),
            };

            Scalar TOI, fraction;
            var result = ConnectingSegmentvsRay.FindIntersection(edge1, edge2, ray, out TOI, out fraction);

            CheckEqual(true, result);
            CheckEqual(0, TOI);
            CheckEqual(1, fraction);
        }

        public void RayMid_Converge()
        {
            var edge1 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(1, 0),
            };

            var edge2 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(0, 0),
            };

            var ray = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(0.5, 0),
            };

            Scalar TOI, fraction;
            var result = ConnectingSegmentvsRay.FindIntersection(edge1, edge2, ray, out TOI, out fraction);

            CheckEqual(true, result);
            CheckEqual(0, TOI);
            CheckEqual(0.5, fraction);
        }

        public void RayMid_Diverge()
        {
            var edge1 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(1, 0),
            };

            var edge2 = new Ray
            {
                Direction = new Vector(0, 1),
                From = new Vector(0, 0),
            };

            var ray = new Ray
            {
                Direction = new Vector(0, -1),
                From = new Vector(0.5, 0),
            };

            Scalar TOI, fraction;
            var result = ConnectingSegmentvsRay.FindIntersection(edge1, edge2, ray, out TOI, out fraction);

            CheckEqual(true, result);
            CheckEqual(0, TOI);
            CheckEqual(0.5, fraction);
        }

        public void InvertedCone()
        {
            var edge1 = new Ray
            {
                Direction = new Vector(1, -1),
                From = new Vector(1, -2),
            };

            var edge2 = new Ray
            {
                Direction = new Vector(1, 1),
                From = new Vector(1, -1),
            };

            var ray = new Ray
            {
                Direction = new Vector(1, -1),
                From = new Vector(1, 1),
            };

            Scalar TOI, fraction;
            var result = ConnectingSegmentvsRay.FindIntersection(edge1, edge2, ray, out TOI, out fraction);

            CheckEqual(true, result);
            CheckEqual(1, TOI);
            CheckEqual(1, fraction);
        }

        public void CollapseThenHit()
        {
            var edge1 = new Ray
            {
                Direction = new Vector(0, 0),
                From = new Vector(0, 0),
            };

            var edge2 = new Ray
            {
                Direction = new Vector(0, -1),
                From = new Vector(0, 1),
            };

            var ray = new Ray
            {
                Direction = new Vector(-1, 0),
                From = new Vector(2, -1),
            };

            Scalar TOI, fraction;
            var result = ConnectingSegmentvsRay.FindIntersection(edge1, edge2, ray, out TOI, out fraction);

            CheckEqual(true, result);
            CheckEqual(2, TOI);
            CheckEqual(1, fraction);
        }
    }
}