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

using System;
using System.IO;
using System.Linq;
using Moq;
using SixLabors.ImageSharp.Formats;
using SixLabors.ImageSharp.Formats.Bmp;
using SixLabors.ImageSharp.Formats.Gif;
using SixLabors.ImageSharp.Formats.Jpeg;
using SixLabors.ImageSharp.Formats.Png;
using SixLabors.ImageSharp.Formats.Tga;
using SixLabors.ImageSharp.Formats.Tiff;
using SixLabors.ImageSharp.Formats.Webp;
using SixLabors.ImageSharp.PixelFormats;
using Xunit;

namespace SixLabors.ImageSharp.Tests.Formats
{
    public class ImageFormatManagerTests
    {
        public ImageFormatManager FormatsManagerEmpty { get; }

        public ImageFormatManager DefaultFormatsManager { get; }

        public ImageFormatManagerTests()
        {
            this.DefaultFormatsManager = Configuration.CreateDefaultInstance().ImageFormatsManager;
            this.FormatsManagerEmpty = new ImageFormatManager();
        }

        [Fact]
        public void IfAutoLoadWellKnownFormatsIsTrueAllFormatsAreLoaded()
        {
            Assert.Equal(1, this.DefaultFormatsManager.ImageEncoders.Select(item => item.Value).OfType<PngEncoder>().Count());
            Assert.Equal(1, this.DefaultFormatsManager.ImageEncoders.Select(item => item.Value).OfType<BmpEncoder>().Count());
            Assert.Equal(1, this.DefaultFormatsManager.ImageEncoders.Select(item => item.Value).OfType<JpegEncoder>().Count());
            Assert.Equal(1, this.DefaultFormatsManager.ImageEncoders.Select(item => item.Value).OfType<GifEncoder>().Count());
            Assert.Equal(1, this.DefaultFormatsManager.ImageEncoders.Select(item => item.Value).OfType<TgaEncoder>().Count());
            Assert.Equal(1, this.DefaultFormatsManager.ImageEncoders.Select(item => item.Value).OfType<TiffEncoder>().Count());
            Assert.Equal(1, this.DefaultFormatsManager.ImageEncoders.Select(item => item.Value).OfType<WebpEncoder>().Count());

            Assert.Equal(1, this.DefaultFormatsManager.ImageDecoders.Select(item => item.Value).OfType<PngDecoder>().Count());
            Assert.Equal(1, this.DefaultFormatsManager.ImageDecoders.Select(item => item.Value).OfType<BmpDecoder>().Count());
            Assert.Equal(1, this.DefaultFormatsManager.ImageDecoders.Select(item => item.Value).OfType<JpegDecoder>().Count());
            Assert.Equal(1, this.DefaultFormatsManager.ImageDecoders.Select(item => item.Value).OfType<BmpDecoder>().Count());
            Assert.Equal(1, this.DefaultFormatsManager.ImageDecoders.Select(item => item.Value).OfType<TgaDecoder>().Count());
            Assert.Equal(1, this.DefaultFormatsManager.ImageDecoders.Select(item => item.Value).OfType<TiffDecoder>().Count());
            Assert.Equal(1, this.DefaultFormatsManager.ImageDecoders.Select(item => item.Value).OfType<WebpDecoder>().Count());
        }

        [Fact]
        public void AddImageFormatDetectorNullThrows()
            => Assert.Throws<ArgumentNullException>(() => this.DefaultFormatsManager.AddImageFormatDetector(null));

        [Fact]
        public void RegisterNullMimeTypeEncoder()
        {
            Assert.Throws<ArgumentNullException>(() => this.DefaultFormatsManager.SetEncoder(null, new Mock<IImageEncoder>().Object));
            Assert.Throws<ArgumentNullException>(() => this.DefaultFormatsManager.SetEncoder(BmpFormat.Instance, null));
            Assert.Throws<ArgumentNullException>(() => this.DefaultFormatsManager.SetEncoder(null, null));
        }

        [Fact]
        public void RegisterNullSetDecoder()
        {
            Assert.Throws<ArgumentNullException>(() => this.DefaultFormatsManager.SetDecoder(null, new Mock<IImageDecoder>().Object));
            Assert.Throws<ArgumentNullException>(() => this.DefaultFormatsManager.SetDecoder(BmpFormat.Instance, null));
            Assert.Throws<ArgumentNullException>(() => this.DefaultFormatsManager.SetDecoder(null, null));
        }

        [Fact]
        public void RegisterMimeTypeEncoderReplacesLast()
        {
            IImageEncoder encoder1 = new Mock<IImageEncoder>().Object;
            this.FormatsManagerEmpty.SetEncoder(TestFormat.GlobalTestFormat, encoder1);
            IImageEncoder found = this.FormatsManagerEmpty.FindEncoder(TestFormat.GlobalTestFormat);
            Assert.Equal(encoder1, found);

            IImageEncoder encoder2 = new Mock<IImageEncoder>().Object;
            this.FormatsManagerEmpty.SetEncoder(TestFormat.GlobalTestFormat, encoder2);
            IImageEncoder found2 = this.FormatsManagerEmpty.FindEncoder(TestFormat.GlobalTestFormat);
            Assert.Equal(encoder2, found2);
            Assert.NotEqual(found, found2);
        }

        [Fact]
        public void RegisterMimeTypeDecoderReplacesLast()
        {
            IImageDecoder decoder1 = new Mock<IImageDecoder>().Object;
            this.FormatsManagerEmpty.SetDecoder(TestFormat.GlobalTestFormat, decoder1);
            IImageDecoder found = this.FormatsManagerEmpty.FindDecoder(TestFormat.GlobalTestFormat);
            Assert.Equal(decoder1, found);

            IImageDecoder decoder2 = new Mock<IImageDecoder>().Object;
            this.FormatsManagerEmpty.SetDecoder(TestFormat.GlobalTestFormat, decoder2);
            IImageDecoder found2 = this.FormatsManagerEmpty.FindDecoder(TestFormat.GlobalTestFormat);
            Assert.Equal(decoder2, found2);
            Assert.NotEqual(found, found2);
        }

        [Fact]
        public void AddFormatCallsConfig()
        {
            var provider = new Mock<IConfigurationModule>();
            var config = new Configuration();
            config.Configure(provider.Object);

            provider.Verify(x => x.Configure(config));
        }

        [Fact]
        public void DetectFormatAllocatesCleanBuffer()
        {
            byte[] jpegImage;
            using (var buffer = new MemoryStream())
            {
                using var image = new Image<Rgba32>(100, 100);
                image.SaveAsJpeg(buffer);
                jpegImage = buffer.ToArray();
            }

            byte[] invalidImage = { 1, 2, 3 };

            Assert.Equal(Image.DetectFormat(jpegImage), JpegFormat.Instance);
            Assert.True(Image.DetectFormat(invalidImage) is null);
        }
    }
}