// Copyright (c) Six Labors.
// Licensed under the Six Labors Split License.

using System.Numerics;
using System.Runtime.CompilerServices;
using SixLabors.ImageSharp.PixelFormats;

namespace SixLabors.ImageSharp.Tests.PixelFormats;

[Trait("Category", "PixelFormats")]
public class NormalizedShort2Tests
{
    [Fact]
    public void NormalizedShort2_PackedValue()
    {
        Assert.Equal(0xE6672CCC, new NormalizedShort2(0.35f, -0.2f).PackedValue);
        Assert.Equal(3650751693, new NormalizedShort2(0.1f, -0.3f).PackedValue);
        Assert.Equal(0x0U, new NormalizedShort2(Vector2.Zero).PackedValue);
        Assert.Equal(0x7FFF7FFFU, new NormalizedShort2(Vector2.One).PackedValue);
        Assert.Equal(0x80018001, new NormalizedShort2(-Vector2.One).PackedValue);

        // TODO: I don't think this can ever pass since the bytes are already truncated.
        // Assert.Equal(3650751693, n.PackedValue);
    }

    [Fact]
    public void NormalizedShort2_ToVector2()
    {
        Assert.Equal(Vector2.One, new NormalizedShort2(Vector2.One).ToVector2());
        Assert.Equal(Vector2.Zero, new NormalizedShort2(Vector2.Zero).ToVector2());
        Assert.Equal(-Vector2.One, new NormalizedShort2(-Vector2.One).ToVector2());
        Assert.Equal(Vector2.One, new NormalizedShort2(Vector2.One * 1234.0f).ToVector2());
        Assert.Equal(-Vector2.One, new NormalizedShort2(Vector2.One * -1234.0f).ToVector2());
    }

    [Fact]
    public void NormalizedShort2_ToVector4()
    {
        Assert.Equal(new Vector4(1, 1, 0, 1), new NormalizedShort2(Vector2.One).ToVector4());
        Assert.Equal(new Vector4(0, 0, 0, 1), new NormalizedShort2(Vector2.Zero).ToVector4());
    }

    [Fact]
    public void NormalizedShort2_ToScaledVector4()
    {
        // arrange
        NormalizedShort2 short2 = new(-Vector2.One);

        // act
        Vector4 actual = short2.ToScaledVector4();

        // assert
        Assert.Equal(0, actual.X);
        Assert.Equal(0, actual.Y);
        Assert.Equal(0, actual.Z);
        Assert.Equal(1, actual.W);
    }

    [Fact]
    public void NormalizedShort2_FromScaledVector4()
    {
        // arrange
        Vector4 scaled = new NormalizedShort2(-Vector2.One).ToScaledVector4();
        const uint expected = 0x80018001;

        // act
        NormalizedShort2 short2 = NormalizedShort2.FromScaledVector4(scaled);
        uint actual = short2.PackedValue;

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

    [Fact]
    public void NormalizedShort2_FromBgra5551()
    {
        // arrange
        Vector4 expected = new(1, 1, 0, 1);

        // act
        NormalizedShort2 normalizedShort2 = NormalizedShort2.FromBgra5551(new Bgra5551(1f, 1f, 1f, 1f));

        // assert
        Assert.Equal(expected, normalizedShort2.ToVector4());
    }

    [Fact]
    public void NormalizedShort2_PixelInformation()
    {
        PixelTypeInfo info = NormalizedShort2.GetPixelTypeInfo();
        Assert.Equal(Unsafe.SizeOf<NormalizedShort2>() * 8, info.BitsPerPixel);
        Assert.Equal(PixelAlphaRepresentation.None, info.AlphaRepresentation);
        Assert.Equal(PixelColorType.Red | PixelColorType.Green, info.ColorType);

        PixelComponentInfo componentInfo = info.ComponentInfo.Value;
        Assert.Equal(2, componentInfo.ComponentCount);
        Assert.Equal(0, componentInfo.Padding);
        Assert.Equal(16, componentInfo.GetComponentPrecision(0));
        Assert.Equal(16, componentInfo.GetComponentPrecision(1));
        Assert.Equal(16, componentInfo.GetMaximumComponentPrecision());
    }
}