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

using System;

using SixLabors.ImageSharp.Formats.Png;
using SixLabors.ImageSharp.PixelFormats;
using SixLabors.ImageSharp.Processing;
using SixLabors.ImageSharp.Tests.TestUtilities.ImageComparison;
using SixLabors.Primitives;

using Xunit;

namespace SixLabors.ImageSharp.Tests.Drawing
{
    [GroupOutput("Drawing")]
    public class DrawImageTests
    {
        public static readonly TheoryData<PixelColorBlendingMode> BlendingModes = new TheoryData<PixelColorBlendingMode>
            {
                PixelColorBlendingMode.Normal,
                PixelColorBlendingMode.Multiply,
                PixelColorBlendingMode.Add,
                PixelColorBlendingMode.Subtract,
                PixelColorBlendingMode.Screen,
                PixelColorBlendingMode.Darken,
                PixelColorBlendingMode.Lighten,
                PixelColorBlendingMode.Overlay,
                PixelColorBlendingMode.HardLight,
            };

        [Theory]
        [WithFile(TestImages.Png.Rainbow, nameof(BlendingModes), PixelTypes.Rgba32)]
        public void ImageBlendingMatchesSvgSpecExamples<TPixel>(TestImageProvider<TPixel> provider, PixelColorBlendingMode mode)
            where TPixel : struct, IPixel<TPixel>
        {
            using (Image<TPixel> background = provider.GetImage())
            using (var source = Image.Load<TPixel>(TestFile.Create(TestImages.Png.Ducky).Bytes))
            {
                background.Mutate(x => x.DrawImage(source, mode, 1F));
                background.DebugSave(
                    provider,
                    new { mode = mode },
                    appendPixelTypeToFileName: false,
                    appendSourceFileOrDescription: false);

                var comparer = ImageComparer.TolerantPercentage(0.01F);
                background.CompareToReferenceOutput(comparer,
                    provider,
                    new { mode = mode },
                    appendPixelTypeToFileName: false,
                    appendSourceFileOrDescription: false);
            }
        }

        [Theory]
        [WithFile(TestImages.Png.CalliphoraPartial, PixelTypes.Rgba32, TestImages.Png.Splash, PixelColorBlendingMode.Normal, 1f)]
        [WithFile(TestImages.Png.CalliphoraPartial, PixelTypes.Bgr24, TestImages.Png.Bike, PixelColorBlendingMode.Normal, 1f)]
        [WithFile(TestImages.Png.CalliphoraPartial, PixelTypes.Rgba32, TestImages.Png.Splash, PixelColorBlendingMode.Normal, 0.75f)]
        [WithFile(TestImages.Png.CalliphoraPartial, PixelTypes.Rgba32, TestImages.Png.Splash, PixelColorBlendingMode.Normal, 0.25f)]

        [WithTestPatternImages(400, 400, PixelTypes.Rgba32, TestImages.Png.Splash, PixelColorBlendingMode.Multiply, 0.5f)]
        [WithTestPatternImages(400, 400, PixelTypes.Rgba32, TestImages.Png.Splash, PixelColorBlendingMode.Add, 0.5f)]
        [WithTestPatternImages(400, 400, PixelTypes.Rgba32, TestImages.Png.Splash, PixelColorBlendingMode.Subtract, 0.5f)]

        [WithFile(TestImages.Png.Rgb48Bpp, PixelTypes.Rgba64, TestImages.Png.Splash, PixelColorBlendingMode.Normal, 1f)]
        [WithFile(TestImages.Png.Rgb48Bpp, PixelTypes.Rgba64, TestImages.Png.Splash, PixelColorBlendingMode.Normal, 0.25f)]
        public void WorksWithDifferentConfigurations<TPixel>(
            TestImageProvider<TPixel> provider,
            string brushImage,
            PixelColorBlendingMode mode,
            float opacity)
            where TPixel : struct, IPixel<TPixel>
        {
            using (Image<TPixel> image = provider.GetImage())
            using (var blend = Image.Load<TPixel>(TestFile.Create(brushImage).Bytes))
            {
                Size size = new Size(image.Width * 3 / 4, image.Height * 3 / 4);
                Point position = new Point(image.Width / 8, image.Height / 8);
                blend.Mutate(x => x.Resize(size.Width, size.Height, KnownResamplers.Bicubic));
                image.Mutate(x => x.DrawImage(blend, position, mode, opacity));
                FormattableString testInfo = $"{System.IO.Path.GetFileNameWithoutExtension(brushImage)}-{mode}-{opacity}";

                PngEncoder encoder = new PngEncoder();

                if (provider.PixelType == PixelTypes.Rgba64)
                {
                    encoder.BitDepth = PngBitDepth.Bit16;
                }

                image.DebugSave(provider, testInfo, encoder: encoder);
                image.CompareToReferenceOutput(ImageComparer.TolerantPercentage(0.01f),
                    provider,
                    testInfo);
            }
        }

        [Theory]
        [WithTestPatternImages(200, 200, PixelTypes.Rgba32 | PixelTypes.Bgra32)]
        public void DrawImageOfDifferentPixelType<TPixel>(TestImageProvider<TPixel> provider)
            where TPixel : struct, IPixel<TPixel>
        {
            byte[] brushData = TestFile.Create(TestImages.Png.Ducky).Bytes;

            using (Image<TPixel> image = provider.GetImage())
            using (Image brushImage = provider.PixelType == PixelTypes.Rgba32
                                          ? (Image)Image.Load<Bgra32>(brushData)
                                          : Image.Load<Rgba32>(brushData))
            {
                image.Mutate(c => c.DrawImage(brushImage, 0.5f));

                image.DebugSave(provider, appendSourceFileOrDescription: false);
                image.CompareToReferenceOutput(
                    ImageComparer.TolerantPercentage(0.01f),
                    provider,
                    appendSourceFileOrDescription: false);
            }
        }

        [Theory]
        [WithSolidFilledImages(100, 100, "White", PixelTypes.Rgba32, 0, 0)]
        [WithSolidFilledImages(100, 100, "White", PixelTypes.Rgba32, 25, 25)]
        [WithSolidFilledImages(100, 100, "White", PixelTypes.Rgba32, 75, 50)]
        [WithSolidFilledImages(100, 100, "White", PixelTypes.Rgba32, -25, -30)]
        public void WorksWithDifferentLocations(TestImageProvider<Rgba32> provider, int x, int y)
        {
            using (Image<Rgba32> background = provider.GetImage())
            using (var overlay = new Image<Rgba32>(50, 50))
            {
                overlay.Mutate(c => c.Fill(Rgba32.Black));

                background.Mutate(c => c.DrawImage(overlay, new Point(x, y), PixelColorBlendingMode.Normal, 1F));

                background.DebugSave(
                    provider,
                    testOutputDetails: $"{x}_{y}",
                    appendPixelTypeToFileName: false,
                    appendSourceFileOrDescription: false);

                background.CompareToReferenceOutput(
                    provider,
                    testOutputDetails: $"{x}_{y}",
                    appendPixelTypeToFileName: false,
                    appendSourceFileOrDescription: false);
            }
        }

        [Theory]
        [WithFile(TestImages.Png.Splash, PixelTypes.Rgba32)]
        public void DrawTransformed<TPixel>(TestImageProvider<TPixel> provider)
            where TPixel : struct, IPixel<TPixel>
        {
            using (Image<TPixel> image = provider.GetImage())
            using (var blend = Image.Load<TPixel>(TestFile.Create(TestImages.Bmp.Car).Bytes))
            {
                AffineTransformBuilder builder = new AffineTransformBuilder()
                    .AppendRotationDegrees(45F)
                    .AppendScale(new SizeF(.25F, .25F))
                    .AppendTranslation(new PointF(10, 10));

                // Apply a background color so we can see the translation.
                blend.Mutate(x => x.Transform(builder));
                blend.Mutate(x => x.BackgroundColor(Color.HotPink));

                // Lets center the matrix so we can tell whether any cut-off issues we may have belong to the drawing processor
                var position = new Point((image.Width - blend.Width) / 2, (image.Height - blend.Height) / 2);
                image.Mutate(x => x.DrawImage(blend, position, .75F));

                image.DebugSave(provider, appendSourceFileOrDescription: false, appendPixelTypeToFileName: false);
                image.CompareToReferenceOutput(ImageComparer.TolerantPercentage(0.002f),
                    provider,
                    appendSourceFileOrDescription: false,
                    appendPixelTypeToFileName: false);
            }
        }

        [Theory]
        [WithSolidFilledImages(100, 100, 255, 255, 255, PixelTypes.Rgba32, -30, -30)]
        [WithSolidFilledImages(100, 100, 255, 255, 255, PixelTypes.Rgba32, 130, -30)]
        [WithSolidFilledImages(100, 100, 255, 255, 255, PixelTypes.Rgba32, 130, 130)]
        [WithSolidFilledImages(100, 100, 255, 255, 255, PixelTypes.Rgba32, -30, 130)]
        public void NonOverlappingImageThrows(TestImageProvider<Rgba32> provider, int x, int y)
        {
            using (Image<Rgba32> background = provider.GetImage())
            using (var overlay = new Image<Rgba32>(Configuration.Default, 10, 10, Rgba32.Black))
            {
                ImageProcessingException ex = Assert.Throws<ImageProcessingException>(Test);

                Assert.Contains("does not overlap", ex.ToString());

                void Test()
                {
                    background.Mutate(context => context.DrawImage(overlay, new Point(x, y), GraphicsOptions.Default));
                }
            }
        }


    }
}