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

using System;
using SixLabors.ImageSharp.Metadata.Profiles.Exif;
using SixLabors.ImageSharp.PixelFormats;
using SixLabors.ImageSharp.Processing;
using SixLabors.ImageSharp.Tests.TestUtilities.ImageComparison;

using Xunit;

namespace SixLabors.ImageSharp.Tests.Processing.Processors.Transforms
{
    [GroupOutput("Transforms")]
    public class AutoOrientTests
    {
        public const string FlipTestFile = TestImages.Bmp.F;

        public static readonly TheoryData<ExifDataType, byte[]> InvalidOrientationValues
            = new TheoryData<ExifDataType, byte[]>
        {
            { ExifDataType.Byte, new byte[] { 1 } },
            { ExifDataType.SignedByte, new byte[] { 2 } },
            { ExifDataType.SignedShort, BitConverter.GetBytes((short) 3) },
            { ExifDataType.Long, BitConverter.GetBytes((uint) 4) },
            { ExifDataType.SignedLong, BitConverter.GetBytes((int) 5) }
        };

        public static readonly TheoryData<ushort> ExifOrientationValues = new TheoryData<ushort>()
                                                                              {
                                                                                  0,
                                                                                  1,
                                                                                  2,
                                                                                  3,
                                                                                  4,
                                                                                  5,
                                                                                  6,
                                                                                  7,
                                                                                  8
                                                                              };

        [Theory]
        [WithFile(FlipTestFile, nameof(ExifOrientationValues), PixelTypes.Rgba32)]
        public void AutoOrient_WorksForAllExifOrientations<TPixel>(TestImageProvider<TPixel> provider, ushort orientation)
            where TPixel : struct, IPixel<TPixel>
        {
            using (Image<TPixel> image = provider.GetImage())
            {
                image.Metadata.ExifProfile = new ExifProfile();
                image.Metadata.ExifProfile.SetValue(ExifTag.Orientation, orientation);
                
                image.Mutate(x => x.AutoOrient());
                image.DebugSave(provider, orientation, appendPixelTypeToFileName: false);
                image.CompareToReferenceOutput(provider, orientation, appendPixelTypeToFileName: false);
            }
        }

        [Theory]
        [WithFile(FlipTestFile, nameof(InvalidOrientationValues), PixelTypes.Rgba32)]
        public void AutoOrient_WorksWithCorruptExifData<TPixel>(TestImageProvider<TPixel> provider, ExifDataType dataType, byte[] orientation)
            where TPixel : struct, IPixel<TPixel>
        {
            var profile = new ExifProfile();
            profile.SetValue(ExifTag.JPEGTables, orientation);

            byte[] bytes = profile.ToByteArray();
            // Change the tag into ExifTag.Orientation
            bytes[16] = 18;
            bytes[17] = 1;
            // Change the data type
            bytes[18] = (byte)dataType;
            // Change the number of components
            bytes[20] = 1;
            
            byte[] orientationCodeData = new byte[8];
            Array.Copy(orientation, orientationCodeData, orientation.Length);

            ulong orientationCode = BitConverter.ToUInt64(orientationCodeData, 0);

            using (Image<TPixel> image = provider.GetImage())
            using (Image<TPixel> reference = image.Clone())
            {
                image.Metadata.ExifProfile = new ExifProfile(bytes);
                image.Mutate(x => x.AutoOrient());
                image.DebugSave(provider, $"{dataType}-{orientationCode}", appendPixelTypeToFileName: false);
                ImageComparer.Exact.VerifySimilarity(image, reference);
            }
        }
    }
}