using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using UnitTestSharp;
using Lodestone;
using Microsoft.Xna.Framework;

namespace Lodestone.UnitTests
{
    class PolygonTests : TestFixture
    {
        Polygon polygon;
        Vector2[] points;

        public void TestConcaveFails()
        {
            var points = new Vector2[10];
            points[0] = new Vector2(0, -10);
            points[1] = new Vector2(2, -8);
            points[2] = new Vector2(4, -7);
            points[3] = new Vector2(3, -5);
            points[4] = new Vector2(5, -3);
            points[5] = new Vector2(3, -1);
            points[6] = new Vector2(1, -5);
            points[7] = new Vector2(2, -6);
            points[8] = new Vector2(1, -8);
            points[9] = new Vector2(0, -9);

            CheckThrow(typeof(Exception));
            new Polygon(points);
        }

        public void TestComplexFails()
        {
            var points = new Vector2[10];
            points[0] = new Vector2(0, 0);
            points[1] = new Vector2(2, 0);
            points[2] = new Vector2(2, 1);
            points[3] = new Vector2(1, 1);
            points[4] = new Vector2(1, -2);
            points[5] = new Vector2(2, -2);
            points[6] = new Vector2(2, -1);
            points[7] = new Vector2(-2, -1);
            points[8] = new Vector2(-2, -2);
            points[9] = new Vector2(1, 0);

            CheckThrow(typeof(Exception));
            new Polygon(points);
        }

        
        public void TestConvexPasses()
        {
            var points = new Vector2[8];
            points[0] = new Vector2(0, 0);
            points[1] = new Vector2(0, 1);
            points[2] = new Vector2(1, 2);
            points[3] = new Vector2(2, 2);
            points[4] = new Vector2(3, 1);
            points[5] = new Vector2(3, 0);
            points[6] = new Vector2(2, -1);
            points[7] = new Vector2(1, -1);

            new Polygon(points);
        }
        
        public void TestDirectionCorrect()
        {
            var points = new Vector2[8];
            points[0] = new Vector2(0, 0);
            points[1] = new Vector2(0, 1);
            points[2] = new Vector2(1, 2);
            points[3] = new Vector2(2, 2);
            points[4] = new Vector2(3, 1);
            points[5] = new Vector2(3, 0);
            points[6] = new Vector2(2, -1);
            points[7] = new Vector2(1, -1);

            var polygon = new Polygon(points);

            CheckTrue(polygon.Clockwise);
        }

        
        public void TestProjectToNormal()
        {
            var points = new Vector2[8];
            points[0] = new Vector2(0, 0);
            points[1] = new Vector2(0, 1);
            points[2] = new Vector2(1, 2);
            points[3] = new Vector2(2, 2);
            points[4] = new Vector2(3, 1);
            points[5] = new Vector2(3, 0);
            points[6] = new Vector2(2, -1);
            points[7] = new Vector2(1, -1);

            var polygon = new Polygon(points);

            Interval expected = new Interval(0, 4);
            Vector2 vector = new Vector2(1, -1);

            CheckEqual(expected, polygon.ProjectToNormal(vector));
        }

        
        public void TestCenterOfMass_Clockwise()
        {
            var points = new Vector2[4];
            points[0] = new Vector2(0, 0);
            points[1] = new Vector2(0, 1);
            points[2] = new Vector2(1, 1);
            points[3] = new Vector2(1, 0);

            var polygon = new Polygon(points);

            CheckEqual(Vector2.Zero, polygon.CenterOfMass);
        }

        public void TestCenterOfMass_CCW()
        {
            var points = new Vector2[4];
            points[3] = new Vector2(0, 0);
            points[2] = new Vector2(0, 1);
            points[1] = new Vector2(1, 1);
            points[0] = new Vector2(1, 0);

            var polygon = new Polygon(points);

            CheckEqual(Vector2.Zero, polygon.CenterOfMass);
        }
        
        public void TestArea_Clockwise()
        {
            var points = new Vector2[4];
            points[0] = new Vector2(0, 0);
            points[1] = new Vector2(0, 1);
            points[2] = new Vector2(1, 1);
            points[3] = new Vector2(1, 0);

            var polygon = new Polygon(points);

            Scalar expected = 1;

            CheckEqual(expected, polygon.Area);
        }

        public void TestArea_CCW()
        {
            var points = new Vector2[4];
            points[3] = new Vector2(0, 0);
            points[2] = new Vector2(0, 1);
            points[1] = new Vector2(1, 1);
            points[0] = new Vector2(1, 0);

            var polygon = new Polygon(points);

            var expected = 1;

            CheckEqual((Scalar)expected, polygon.Area);
        }

        public void TestArea()
        {
            var points = new Vector2[6];
            points[0] = new Vector2(0, 0);
            points[1] = new Vector2(1, 0);
            points[2] = new Vector2(2, 1);
            points[3] = new Vector2(2, 2);
            points[4] = new Vector2(1, 3);
            points[5] = new Vector2(0, 3);

            var polygon = new Polygon(points);

            CheckEqual((Scalar)5, polygon.Area);
        }
        
        public void TestPerimeter()
        {
            points = new Vector2[4];
            points[0] = new Vector2(0, 0);
            points[1] = new Vector2(0, 1);
            points[2] = new Vector2(1, 1);
            points[3] = new Vector2(1, 0);

            polygon = new Polygon(points);

            Scalar expected = 4;

            CheckEqual(expected, polygon.Perimeter);
        }

        public void TestClone()
        {
            var points = new Vector2[8];
            points[0] = new Vector2(0, 0);
            points[1] = new Vector2(0, 1);
            points[2] = new Vector2(1, 2);
            points[3] = new Vector2(2, 2);
            points[4] = new Vector2(3, 1);
            points[5] = new Vector2(3, 0);
            points[6] = new Vector2(2, -1);
            points[7] = new Vector2(1, -1);
            var polygon = new Polygon(points);
            var clone = (Polygon)polygon.Clone();

            CheckEqual(polygon.Clockwise, clone.Clockwise);
            CheckEqual(polygon.Perimeter, clone.Perimeter);
            CheckEqual(polygon.Area, clone.Area);
        }

        public void TestClone2()
        {
            var points = new Vector2[6];
            points[0] = new Vector2(0, 0);
            points[1] = new Vector2(1, 0);
            points[2] = new Vector2(2, 1);
            points[3] = new Vector2(2, 2);
            points[4] = new Vector2(1, 3);
            points[5] = new Vector2(0, 3);

            var polygon = new Polygon(points);

            Scalar expected = 5;
            var clone = polygon.Clone();

            CheckEqual(expected, polygon.Area);

            CheckEqual(expected, polygon.Clone().Area);
            Check(Scalar.FuzzyEquality(expected, polygon.Clone().Area));
        }

        public void TestCache()
        {
            var points = new Vector2[6];
            points[0] = new Vector2(0, 0);
            points[1] = new Vector2(1, 0);
            points[2] = new Vector2(2, 1);
            points[3] = new Vector2(2, 2);
            points[4] = new Vector2(1, 3);
            points[5] = new Vector2(0, 3);

            var polygon = new Polygon(points);

            //try and time getting 100 random normals
            var vector = new Vector2((float)0.103, (float)-1.009);
            var timer = new System.Diagnostics.Stopwatch();
            timer.Reset();
            timer.Start();
            for (int i = 0; i < 1000; i++)
            {
                polygon.ProjectToNormal(vector);
            }
            timer.Stop();

            //try and time getting 100 common normals
            vector = polygon.CommonNormals.Keys.ElementAt(1);
            var timer2 = new System.Diagnostics.Stopwatch();
            timer2.Reset();
            timer2.Start();
            for (int i = 0; i < 1000; i++)
            {
                polygon.ProjectToNormal(vector);
            }
            timer2.Stop();

            //Check the timing
            CheckTrue(timer.ElapsedTicks > timer2.ElapsedTicks);

        }

        public void TestBoundingCircle()
        {
            points = new Vector2[4];
            points[0] = new Vector2(1, 1);
            points[1] = new Vector2(-1, 1);
            points[2] = new Vector2(-1, -1);
            points[3] = new Vector2(1, -1);

            polygon = new Polygon(points);

            CheckEqual(Math.Truncate(100*(2*Math.Sqrt(.5))), Math.Truncate(100*(polygon.BoundingCircle.Radius)));
        }
    }
}