using Chernobyl.Mathematics.Movement;
using NUnit.Framework;

namespace Chernobyl.Mathematics.Geometry
{
    /// <summary>
    /// A test fixture base helper class that is used to test types that 
    /// implement the <see cref="IShape"/> interface. This class also implements
    /// <see cref="TransformTests"/> so that the <see cref="ITransform"/> portion
    /// of the <see cref="IShape"/> interface can be tested as well.
    /// </summary>
    public abstract class ShapeTests : TransformTests
    {
        [Test, Description("Ensures the width of the IShape created by " +
            "CreateShape() is the width that was expected.")]
        public void WidthIsCorrect()
        {
            IShape shape = CreateShape();
            Assert.AreEqual(ExpectedWidth, shape.Width, "The width of the IShape " + 
                "is not correct.");
        }

        [Test, Description("Ensures the height of the IShape created by " +
                    "CreateShape() is the height that was expected.")]
        public void HeightIsCorrect()
        {
            IShape shape = CreateShape();
            Assert.AreEqual(ExpectedHeight, shape.Height, "The height of the " +
                "IShape is not correct.");
        }

        [Test, Description("Ensures the depth of the IShape created by " +
            "CreateShape() is the depth that was expected.")]
        public void DepthIsCorrect()
        {
            IShape shape = CreateShape();
            Assert.AreEqual(ExpectedDepth, shape.Depth, "The depth of the " +
                "IShape is not correct.");
        }

        [Test, Description("Ensures the IsConvex of the IShape created by " +
            "CreateShape() is the IsConvex that was expected.")]
        public void IsConvexIsCorrect()
        {
            IShape shape = CreateShape();
            Assert.AreEqual(ExpectedIsConvex, shape.IsConvex, "The IsConvex " + 
                "property of the IShape is not correct.");
        }

        [Test, Description("Ensures the area of the IShape created by " +
            "CreateShape() is the area that was expected.")]
        public void AreaIsCorrect()
        {
            IShape shape = CreateShape();
            Assert.AreEqual(ExpectedArea, shape.Area, "The area of the " +
                "IShape is not correct.");
        }

        [Test, Description("Ensures the volume of the IShape created by " +
            "CreateShape() is the volume that was expected.")]
        public void VolumeIsCorrect()
        {
            IShape shape = CreateShape();
            Assert.AreEqual(ExpectedVolume, shape.Volume, "The volume of the " +
                "IShape is not correct.");
        }

        [Test, Description("Ensures the perimeter of the IShape created by " +
            "CreateShape() is the perimeter that was expected.")]
        public void PerimeterIsCorrect()
        {
            IShape shape = CreateShape();
            Assert.AreEqual(ExpectedPerimeter, shape.Perimeter, "The perimeter" + 
                " of the IShape is not correct.");
        }

        [Test, Description("Ensures the dimensions of the IShape created by " +
            "CreateShape() is the dimensions that was expected.")]
        public void DimensionsIsCorrect()
        {
            IShape shape = CreateShape();
            Assert.AreEqual(ExpectedDimensions, shape.Dimensions, "The dimensions " + 
                " of the IShape is not correct.");
        }

        [Test, Description("Ensures the width is properly magnified after the " +
            "shape has been scaled in the X.")]
        public void ScalesWidthProperly()
        {
            const float scale = 2;

            IShape shape = CreateShape();
            float expectedWidth = shape.Width * scale;

            shape.ScaleX(scale);

            Assert.AreEqual(expectedWidth, shape.Width, "The shape's Width " + 
                "property does not report a value that has been scaled by 2 " + 
                "even though the Shape that has been scaled by 2 in the X.");
        }

        [Test, Description("Ensures the width is properly magnified after the " +
            "shape has been scaled in the Y.")]
        public void ScalesHeightProperly()
        {
            const float scale = 2;

            IShape shape = CreateShape();
            float expectedHeight = shape.Height * scale;

            shape.ScaleY(scale);

            Assert.AreEqual(expectedHeight, shape.Height, "The shape's Height " +
                "property does not report a value that has been scaled by 2 " +
                "even though the Shape that has been scaled by 2 in the Y.");
        }

        [Test, Description("Ensures the depth is properly magnified after the " +
            "shape has been scaled in the Z.")]
        public void ScalesDepthProperly()
        {
            const float scale = 2;

            IShape shape = CreateShape();
            float expectedDepth = shape.Depth * scale;

            shape.ScaleZ(scale);

            Assert.AreEqual(expectedDepth, shape.Depth, "The shape's Depth " +
                "property does not report a value that has been scaled by 2 " +
                "even though the Shape that has been scaled by 2 in the Z.");
        }

        /// <summary>
        /// Creates the <see cref="IShape"/> interface that is to be tested. 
        /// This method should always create a new instance and never reuse 
        /// instances.
        /// </summary>
        /// <returns>The <see cref="IShape"/> to test.</returns>
        protected abstract IShape CreateShape();

        /// <summary>
        /// The expected value of the <see cref="IShape.Width"/> property of 
        /// the <see cref="IShape"/> that is created by the
        ///  <see cref="CreateShape()"/> method.
        /// </summary>
        protected abstract float ExpectedWidth { get; }

        /// <summary>
        /// The expected value of the <see cref="IShape.Height"/> property of 
        /// the <see cref="IShape"/> that is created by the
        ///  <see cref="CreateShape()"/> method.
        /// </summary>
        protected abstract float ExpectedHeight { get; }

        /// <summary>
        /// The expected value of the <see cref="IShape.Depth"/> property of 
        /// the <see cref="IShape"/> that is created by the
        ///  <see cref="CreateShape()"/> method.
        /// </summary>
        protected abstract float ExpectedDepth { get; }

        /// <summary>
        /// The expected value of the <see cref="IShape.IsConvex"/> property of 
        /// the <see cref="IShape"/> that is created by the
        ///  <see cref="CreateShape()"/> method.
        /// </summary>
        protected abstract bool ExpectedIsConvex { get; }

        /// <summary>
        /// The expected value of the <see cref="IShape.Area"/> property of 
        /// the <see cref="IShape"/> that is created by the
        ///  <see cref="CreateShape()"/> method.
        /// </summary>
        protected abstract float ExpectedArea { get; }

        /// <summary>
        /// The expected value of the <see cref="IShape.Volume"/> property of 
        /// the <see cref="IShape"/> that is created by the
        ///  <see cref="CreateShape()"/> method.
        /// </summary>
        protected abstract float ExpectedVolume { get; }

        /// <summary>
        /// The expected value of the <see cref="IShape.Perimeter"/> property of 
        /// the <see cref="IShape"/> that is created by the
        ///  <see cref="CreateShape()"/> method.
        /// </summary>
        protected abstract float ExpectedPerimeter { get; }

        /// <summary>
        /// The expected value of the <see cref="IShape.Dimensions"/> property of 
        /// the <see cref="IShape"/> that is created by the
        ///  <see cref="CreateShape()"/> method.
        /// </summary>
        protected abstract uint ExpectedDimensions { get; }

        /// <summary>
        /// Creates the <see cref="ITransform"/> that is to be tested. This
        /// method should always be create a new <see cref="ITransform"/> when
        /// it is invoked and never reuse instances.
        /// </summary>
        /// <returns>
        /// The <see cref="ITransform"/> instance that is to be tested.
        /// </returns>
        protected override ITransform CreateTransform()
        {
            return CreateShape();
        }
    }
}