// Copyright (c) Six Labors.
// Licensed under the Apache License, Version 2.0.

using System.Numerics;
using SixLabors.ImageSharp.PixelFormats;
using Xunit;

namespace SixLabors.ImageSharp.Tests.PixelFormats
{
    [Trait("Category", "PixelFormats")]
    public class HalfVector4Tests
    {
        [Fact]
        public void HalfVector4_PackedValue()
        {
            Assert.Equal(0uL, new HalfVector4(Vector4.Zero).PackedValue);
            Assert.Equal(4323521613979991040uL, new HalfVector4(Vector4.One).PackedValue);
            Assert.Equal(13547034390470638592uL, new HalfVector4(-Vector4.One).PackedValue);
            Assert.Equal(15360uL, new HalfVector4(Vector4.UnitX).PackedValue);
            Assert.Equal(1006632960uL, new HalfVector4(Vector4.UnitY).PackedValue);
            Assert.Equal(65970697666560uL, new HalfVector4(Vector4.UnitZ).PackedValue);
            Assert.Equal(4323455642275676160uL, new HalfVector4(Vector4.UnitW).PackedValue);
            Assert.Equal(4035285078724390502uL, new HalfVector4(0.1f, 0.3f, 0.4f, 0.5f).PackedValue);
        }

        [Fact]
        public void HalfVector4_ToVector4()
        {
            Assert.Equal(Vector4.Zero, new HalfVector4(Vector4.Zero).ToVector4());
            Assert.Equal(Vector4.One, new HalfVector4(Vector4.One).ToVector4());
            Assert.Equal(-Vector4.One, new HalfVector4(-Vector4.One).ToVector4());
            Assert.Equal(Vector4.UnitX, new HalfVector4(Vector4.UnitX).ToVector4());
            Assert.Equal(Vector4.UnitY, new HalfVector4(Vector4.UnitY).ToVector4());
            Assert.Equal(Vector4.UnitZ, new HalfVector4(Vector4.UnitZ).ToVector4());
            Assert.Equal(Vector4.UnitW, new HalfVector4(Vector4.UnitW).ToVector4());
        }

        [Fact]
        public void HalfVector4_ToScaledVector4()
        {
            // arrange
            var halfVector4 = new HalfVector4(-Vector4.One);

            // act
            Vector4 actual = halfVector4.ToScaledVector4();

            // assert
            Assert.Equal(0, actual.X);
            Assert.Equal(0, actual.Y);
            Assert.Equal(0, actual.Z);
            Assert.Equal(0, actual.W);
        }

        [Fact]
        public void HalfVector4_FromScaledVector4()
        {
            // arrange
            var halfVector4 = default(HalfVector4);
            Vector4 scaled = new HalfVector4(-Vector4.One).ToScaledVector4();
            ulong expected = 13547034390470638592uL;

            // act
            halfVector4.FromScaledVector4(scaled);
            ulong actual = halfVector4.PackedValue;

            // assert
            Assert.Equal(expected, actual);
        }

        [Fact]
        public void HalfVector4_FromBgra5551()
        {
            // arrange
            var halfVector4 = default(HalfVector4);
            Vector4 expected = Vector4.One;

            // act
            halfVector4.FromBgra5551(new Bgra5551(1.0f, 1.0f, 1.0f, 1.0f));

            // assert
            Assert.Equal(expected, halfVector4.ToScaledVector4());
        }
    }
}