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

namespace Annulus.UnitTests.DiscreteCollisionDetection
{
    class PointToTriangleTests : TestFixture
    {
        public class ClosestPointOnTriangleToPoint : UnitTestSharp.TestFixture
        {
            public static readonly Vector a = new Vector(0, 1);
            public static readonly Vector b = new Vector(-1, 0);
            public static readonly Vector c = new Vector(1, 0);
            public static readonly Vector abMid = (a + b) / 2;

            Scalar wA, wB, wC;

            public void VertexA()
            {
                Vector p = a * 10;
                Vector pPrime = TrianglePoint.ClosestPointOnTriangleToPoint(a, b, c, p, out wA, out wB, out wC);

                CheckEqual(a, pPrime);
                CheckEqual(1, wA);
                CheckEqual(0, wB);
                CheckEqual(0, wC);
            }

            public void VertexB()
            {
                Vector p = a * 10;
                Vector pPrime = TrianglePoint.ClosestPointOnTriangleToPoint(b, a, c, p, out wA, out wB, out wC);

                CheckEqual(a, pPrime);
                CheckEqual(0, wA);
                CheckEqual(1, wB);
                CheckEqual(0, wC);
            }

            public void VertexC()
            {
                Vector p = a * 10;
                Vector pPrime = TrianglePoint.ClosestPointOnTriangleToPoint(c, b, a, p, out wA, out wB, out wC);

                CheckEqual(a, pPrime);
                CheckEqual(0, wA);
                CheckEqual(0, wB);
                CheckEqual(1, wC);
            }

            public void AB()
            {
                Vector p = abMid * 10;
                Vector pPrime = TrianglePoint.ClosestPointOnTriangleToPoint(a, b, c, p, out wA, out wB, out wC);

                CheckEqual(abMid, pPrime);
                CheckEqual(0.5, wA);
                CheckEqual(0.5, wB);
                CheckEqual(0, wC);
            }

            public void BC()
            {
                Vector p = abMid * 10;
                Vector pPrime = TrianglePoint.ClosestPointOnTriangleToPoint(c, b, a, p, out wA, out wB, out wC);

                CheckEqual(abMid, pPrime);
                CheckEqual(0, wA);
                CheckEqual(0.5, wB);
                CheckEqual(0.5, wC);
            }

            public void CA()
            {
                Vector p = abMid * 10;
                Vector pPrime = TrianglePoint.ClosestPointOnTriangleToPoint(a, c, b, p, out wA, out wB, out wC);

                CheckEqual(abMid, pPrime);
                CheckEqual(0.5, wA);
                CheckEqual(0, wB);
                CheckEqual(0.5, wC);
            }

            public void Inside()
            {
                Vector p = (a + b + c) / 3;
                Vector pPrime = TrianglePoint.ClosestPointOnTriangleToPoint(a, b, c, p, out wA, out wB, out wC);

                CheckEqual(p, pPrime);
                CheckEqual(1.0 / 3.0, wA);
                CheckEqual(1.0 / 3.0, wB);
                CheckEqual(1.0 / 3.0, wC);
            }

            public void Degenerate()
            {
                Vector p = a * 10;
                Vector pPrime = TrianglePoint.ClosestPointOnTriangleToPoint(a, a, a, p, out wA, out wB, out wC);

                CheckEqual(a, pPrime);
            }

            public void Colinear()
            {
                Vector a = new Vector(-1, 0);
                Vector b = new Vector(0, 0);
                Vector c = new Vector(1, 0);

                Vector p = new Vector(0.5, 10);
                Vector pPrime = TrianglePoint.ClosestPointOnTriangleToPoint(a, b, c, p, out wA, out wB, out wC);

                CheckEqual(new Vector(0.5, 0), pPrime);
            }
        }

        public class IsPointInsideTriangle : UnitTestSharp.TestFixture
        {
            IList<Vector> triangle = new Vector[]
            {
                new Vector(1, 0),
                new Vector(0, 1),
                new Vector(0, 0),
            };

            [IgnoreTest]
            public void Test(Vector pt, TrianglePoint.Status expected)
            {
                CheckEqual(expected, TrianglePoint.IsPointInsideTriangle(triangle[0], triangle[1], triangle[2], pt));
            }

            public void Left()
            {
                var pt = new Vector(-1, 0.5);

                Test(pt, TrianglePoint.Status.Outside);
            }

            public void Right()
            {
                var pt = new Vector(1, 1);

                Test(pt, TrianglePoint.Status.Outside);
            }

            public void Below()
            {
                var pt = new Vector(0.5, -1);

                Test(pt, TrianglePoint.Status.Outside);
            }

            public void TopVertexArea()
            {
                var pt = new Vector(-1, 7);

                Test(pt, TrianglePoint.Status.Outside);
            }

            public void BottomVertexArea()
            {
                var pt = new Vector(-1, -7);

                Test(pt, TrianglePoint.Status.Outside);
            }

            public void RightVertexArea()
            {
                var pt = new Vector(17, 1);

                Test(pt, TrianglePoint.Status.Outside);
            }

            public void Inside()
            {
                var pt = new Vector(0.25, 0.25);

                Test(pt, TrianglePoint.Status.Inside);
            }

            public void OnEdge_1()
            {
                var pt = new Vector(0.5, 0);

                Test(pt, TrianglePoint.Status.OnEdge);
            }

            public void OnEdge_2()
            {
                var pt = new Vector(0.5, 0.5);

                Test(pt, TrianglePoint.Status.OnEdge);
            }

            public void OnEdge_3()
            {
                var pt = new Vector(0, 0.5);

                Test(pt, TrianglePoint.Status.OnEdge);
            }

            public void onVertex()
            {
                for (int i = 0; i < triangle.Count(); ++i)
                {
                    Test(triangle[i], TrianglePoint.Status.OnEdge);
                }
            }

            IList<Vector> colinear = new Vector[]
            {
                new Vector(0, 0),
                new Vector(1, 0),
                new Vector(2, 0),
            };

            public void Degenerate_Colinear_On()
            {
                Test(new Vector(1.5, 0), TrianglePoint.Status.OnEdge);
            }

            public void Degenerate_Colinear_Outside()
            {
                Test(new Vector(1.5, 1), TrianglePoint.Status.Outside);
            }

            IList<Vector> point = new Vector[]
            {
                new Vector(1, 0),
                new Vector(1, 0),
                new Vector(1, 0),
            };

            public void SamePoint_On()
            {
                Test(new Vector(1, 0), TrianglePoint.Status.OnEdge);
            }

            public void SamePoint_Outside()
            {
                Test(new Vector(1, 1), TrianglePoint.Status.Outside);
            }
        }
    }
}