using Azimuth;
using System;
using UnitTestSharp;

namespace Susurrus.UnitTests
{
    public class ViewTests : TestFixture
    {
        public static View Standard()
        {
            return new View(new Vector(100, 50), 10);
        }

        public class CtorTests : TestFixture
        {
            public void KeepsTheCenterAndHalfWidth()
            {
                View view = Standard();

                CheckEqual(100.0, view.Center.X.Value);
                CheckEqual(50.0, view.Center.Y.Value);
                CheckEqual(10.0, view.HalfWidth.Value);
            }

            public void AHalfWidthOfZero_Throws()
            {
                CheckThrow(typeof(ArgumentOutOfRangeException));
                new View(Vector.Zero, 0);
            }

            public void ANegativeHalfWidth_Throws()
            {
                CheckThrow(typeof(ArgumentOutOfRangeException));
                new View(Vector.Zero, -1);
            }

            public void AnInfiniteHalfWidth_Throws()
            {
                CheckThrow(typeof(ArgumentOutOfRangeException));
                new View(Vector.Zero, double.PositiveInfinity);
            }

            public void ACenterThatIsNotANumber_Throws()
            {
                CheckThrow(typeof(ArgumentOutOfRangeException));
                new View(Vector.NaN, 10);
            }
        }

        public class CheckPositionTests : TestFixture
        {
            public void AFinitePosition_Passes()
            {
                View.CheckPosition(new Vector(-5, 1e9), "position");
            }

            public void ANaNCoordinate_Throws()
            {
                CheckThrow(typeof(ArgumentOutOfRangeException));
                View.CheckPosition(new Vector(0, double.NaN), "position");
            }

            public void AnInfiniteCoordinate_Throws()
            {
                CheckThrow(typeof(ArgumentOutOfRangeException));
                View.CheckPosition(new Vector(double.NegativeInfinity, 0), "position");
            }
        }

        public class PanOfTests : TestFixture
        {
            public void TheCenter_IsInTheMiddle()
            {
                CheckEqual(0.0, Standard().PanOf(new Vector(100, 50)).Value);
            }

            public void HalfAHalfWidthToTheRight_IsHalfwayRight()
            {
                CheckEqual(0.5, Standard().PanOf(new Vector(105, 50)).Value);
            }

            public void HalfAHalfWidthToTheLeft_IsHalfwayLeft()
            {
                CheckEqual(-0.5, Standard().PanOf(new Vector(95, 50)).Value);
            }

            public void TheRightEdge_IsAllTheWayRight()
            {
                CheckEqual(1.0, Standard().PanOf(new Vector(110, 50)).Value);
            }

            public void BeyondTheRightEdge_StaysAllTheWayRight()
            {
                CheckEqual(1.0, Standard().PanOf(new Vector(1000, 50)).Value);
            }

            public void BeyondTheLeftEdge_StaysAllTheWayLeft()
            {
                CheckEqual(-1.0, Standard().PanOf(new Vector(-1000, 50)).Value);
            }

            public void Height_MakesNoDifference()
            {
                CheckEqual(0.0, Standard().PanOf(new Vector(100, 5000)).Value);
            }

            public void APositionThatIsNotANumber_Throws()
            {
                CheckThrow(typeof(ArgumentOutOfRangeException));
                Standard().PanOf(Vector.NaN);
            }
        }

        public class DistanceToTests : TestFixture
        {
            public void TheCenter_IsZero()
            {
                CheckEqual(0.0, Standard().DistanceTo(new Vector(100, 50)).Value);
            }

            public void IsStraightLine_AcrossBothAxes()
            {
                CheckEqual(5.0, Standard().DistanceTo(new Vector(103, 54)).Value);
            }

            public void APositionThatIsNotANumber_Throws()
            {
                CheckThrow(typeof(ArgumentOutOfRangeException));
                Standard().DistanceTo(Vector.NaN);
            }
        }
    }
}