using System;
using System.Linq;
using System.Utility;
using Chernobyl.Extensions;
using Chernobyl.Mathematics.Vectors;
using NUnit.Framework;

namespace Chernobyl.Mathematics.Geometry
{
    [TestFixture, Description("Tests for the Func type")]
    class PlaneTests
    {
        #region To1D

        [Test, Description(".To1D throws an exception when given a width or height less than 2")]
        public void To1DThrowsWhenGivenNegativeWidthHeight()
        {
            // ReSharper disable ReturnValueOfPureMethodIsNotUsed
            Assert.Throws<ArgumentOutOfRangeException>(() => Func.Passthrough<Vector2d>().To1D(1, 5).ToArray());
            Assert.Throws<ArgumentOutOfRangeException>(() => Func.Passthrough<Vector2d>().To1D(5, 1).ToArray());
            // ReSharper restore ReturnValueOfPureMethodIsNotUsed
        }

        [Test, Description(".To1D outputs data in the correct order.")]
        public void To1DCorrectOrder()
        {
            var dataset2D = Func.Counter().To2D().To1D(3, 3).ToArray();

            dataset2D.IsEqualTo(new[]
            {
                1, 2, 3,
                4, 5, 6,
                7, 8, 9,
            }, nameof(dataset2D));
        }

        [Test, Description(".To1D converts a 2D dataset method to 1D dataset method")]
        public void To1DCorrectConversion()
        {
            var dataset2D = Func.Passthrough<Vector2d>().To1D(5, 5).ToArray();

            dataset2D.IsEqualTo(new Vector2d[]
            {
                (0.0, 1.0),  (0.25, 1.0),  (0.5, 1.0),  (0.75, 1.0),  (1.0, 1.0),
                (0.0, 0.75), (0.25, 0.75), (0.5, 0.75), (0.75, 0.75), (1.0, 0.75),
                (0.0, 0.5),  (0.25, 0.5),  (0.5, 0.5),  (0.75, 0.5),  (1.0, 0.5),
                (0.0, 0.25), (0.25, 0.25), (0.5, 0.25), (0.75, 0.25), (1.0, 0.25),
                (0.0, 0.0),  (0.25, 0.0),  (0.5, 0.0),  (0.75, 0.0),  (1.0, 0.0),
            }, "To1D result");
        }

        #endregion // To1D

        #region SquarePredicate

        [Test, Description(".SquarePredicate throws when given bad arguments.")]
        public void SquarePredicateThrowsBadWidthHeight()
        {
            Assert.Throws<ArgumentOutOfRangeException>(() => Plane.Predicate.Square((3, 4), 0, 1), "bad width argument must cause exception");
            Assert.Throws<ArgumentOutOfRangeException>(() => Plane.Predicate.Square((3, 4), 1, 0), "bad height argument must cause exception");
        }

        [Test, Description(".SquarePredicate returns correct result based on position.")]
        public void SquarePredicateReturnsCorrectResults()
        {
            var predicate = Plane.Predicate.Square((3, 4), 5, 6);

            // Left test
            predicate((2, 5)).IsFalse("left outside");
            predicate((4, 5)).IsTrue("left inside");

            // Right test
            predicate((9, 5)).IsFalse("right outside");
            predicate((7, 5)).IsTrue("right inside");

            // Top test
            predicate((4, 11)).IsFalse("top outside");
            predicate((4, 9)).IsTrue("top inside");

            // Bottom test
            predicate((4, 3)).IsFalse("bottom outside");
            predicate((4, 5)).IsTrue("bottom inside");
        }

        #endregion // SquarePredicate
    }
}