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

using System.Linq;
using SixLabors.ImageSharp.Formats.Webp.Lossy;
using SixLabors.ImageSharp.Tests.TestUtilities;
using Xunit;

namespace SixLabors.ImageSharp.Tests.Formats.WebP
{
    [Trait("Format", "Webp")]
    public class LossyUtilsTests
    {
        private static void RunVp8Sse4X4Test()
        {
            byte[] a =
            {
                27, 27, 28, 29, 29, 28, 27, 27, 27, 28, 28, 29, 29, 28, 28, 27, 129, 129, 129, 129, 129, 129, 129,
                129, 128, 128, 128, 128, 128, 128, 128, 128, 27, 27, 27, 27, 27, 27, 27, 27, 27, 28, 28, 29, 29, 28,
                28, 27, 129, 129, 129, 129, 129, 129, 129, 129, 128, 128, 128, 128, 128, 128, 128, 128, 27, 27, 26,
                26, 26, 26, 27, 27, 27, 28, 28, 29, 29, 28, 28, 27, 129, 129, 129, 129, 129, 129, 129, 129, 128,
                128, 128, 128, 128, 128, 128, 128, 28, 27, 27, 26, 26, 27, 27, 28, 27, 28, 28, 29, 29, 28, 28, 27,
                129, 129, 129, 129, 129, 129, 129, 129, 128, 128, 128, 128, 128, 128, 128, 128
            };

            byte[] b =
            {
                26, 26, 26, 26, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 204, 204, 204, 204, 204, 204, 204,
                204, 204, 204, 204, 204, 204, 204, 204, 204, 26, 26, 26, 26, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
                28, 28, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 26, 26, 26,
                26, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 204, 204, 204, 204, 204, 204, 204, 204, 204,
                204, 204, 204, 204, 204, 204, 204, 26, 26, 26, 26, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
                204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204
            };

            int expected = 27;

            int actual = LossyUtils.Vp8_Sse4X4(a, b);

            Assert.Equal(expected, actual);
		}

        private static void RunMean16x4Test()
        {
            // arrange
            byte[] input =
            {
                154, 145, 102, 115, 127, 129, 126, 125, 126, 120, 133, 152, 157, 153, 119, 94, 104, 116, 111, 113,
                113, 109, 105, 124, 173, 175, 177, 170, 175, 172, 166, 164, 151, 141, 99, 114, 125, 126, 135, 150,
                133, 115, 127, 149, 141, 168, 100, 54, 110, 117, 115, 116, 119, 115, 117, 130, 174, 174, 174, 157,
                146, 171, 166, 158, 117, 140, 96, 111, 119, 119, 136, 171, 188, 134, 121, 126, 136, 119, 59, 77,
                109, 115, 113, 120, 120, 117, 128, 115, 174, 173, 173, 161, 152, 148, 153, 162, 105, 140, 96, 114,
                115, 122, 141, 173, 190, 190, 142, 106, 151, 78, 66, 141, 110, 117, 123, 136, 118, 124, 127, 114,
                173, 175, 166, 155, 155, 159, 159, 158
            };
            uint[] dc = new uint[4];
            uint[] expectedDc = { 1940, 2139, 2252, 1813 };

            // act
            LossyUtils.Mean16x4(input, dc);

            // assert
            Assert.True(dc.SequenceEqual(expectedDc));
        }

        private static void RunHadamardTransformTest()
        {
            byte[] a =
            {
                27, 27, 28, 29, 29, 28, 27, 27, 27, 28, 28, 29, 29, 28, 28, 27, 129, 129, 129, 129, 129, 129, 129,
                129, 128, 128, 128, 128, 128, 128, 128, 128, 27, 27, 27, 27, 27, 27, 27, 27, 27, 28, 28, 29, 29, 28,
                28, 27, 129, 129, 129, 129, 129, 129, 129, 129, 128, 128, 128, 128, 128, 128, 128, 128, 27, 27, 26,
                26, 26, 26, 27, 27, 27, 28, 28, 29, 29, 28, 28, 27, 129, 129, 129, 129, 129, 129, 129, 129, 128,
                128, 128, 128, 128, 128, 128, 128, 28, 27, 27, 26, 26, 27, 27, 28, 27, 28, 28, 29, 29, 28, 28, 27
            };

            byte[] b =
            {
                28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 204, 204, 204, 204, 204, 204, 204,
                204, 204, 204, 204, 204, 204, 204, 204, 204, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
                28, 28, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 204, 28, 28, 28,
                28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 204, 204, 204, 204, 204, 204, 204, 204, 204,
                204, 204, 204, 204, 204, 204, 204, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28
            };

            ushort[] w = { 38, 32, 20, 9, 32, 28, 17, 7, 20, 17, 10, 4, 9, 7, 4, 2 };
            int expected = 2;

            int actual = LossyUtils.Vp8Disto4X4(a, b, w, new int[16]);
            Assert.Equal(expected, actual);
        }

        [Fact]
        public void Vp8Sse4X4_Works() => RunVp8Sse4X4Test();

        [Fact]
        public void Mean16x4_Works() => RunMean16x4Test();

        [Fact]
        public void HadamardTransform_Works() => RunHadamardTransformTest();

#if SUPPORTS_RUNTIME_INTRINSICS
        [Fact]
        public void Vp8Sse4X4_WithHardwareIntrinsics_Works() => FeatureTestRunner.RunWithHwIntrinsicsFeature(RunVp8Sse4X4Test, HwIntrinsics.AllowAll);

        [Fact]
        public void Vp8Sse4X4_WithoutHardwareIntrinsics_Works() => FeatureTestRunner.RunWithHwIntrinsicsFeature(RunVp8Sse4X4Test, HwIntrinsics.DisableHWIntrinsic);

        [Fact]
        public void Mean16x4_WithHardwareIntrinsics_Works() => FeatureTestRunner.RunWithHwIntrinsicsFeature(RunMean16x4Test, HwIntrinsics.AllowAll);

        [Fact]
        public void Mean16x4_WithoutHardwareIntrinsics_Works() => FeatureTestRunner.RunWithHwIntrinsicsFeature(RunMean16x4Test, HwIntrinsics.DisableHWIntrinsic);

        [Fact]
        public void HadamardTransform_WithHardwareIntrinsics_Works() => FeatureTestRunner.RunWithHwIntrinsicsFeature(RunHadamardTransformTest, HwIntrinsics.AllowAll);

        [Fact]
        public void HadamardTransform_WithoutHardwareIntrinsics_Works() => FeatureTestRunner.RunWithHwIntrinsicsFeature(RunHadamardTransformTest, HwIntrinsics.DisableHWIntrinsic);
#endif
    }
}