using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Abstractions;
using System.IO.Compression;
using System.Linq;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;
using System.Xml;
using System.Xml.Serialization;
using API.Data;
using API.Data.Metadata;
using API.Data.Repositories;
using API.Entities;
using API.Entities.Enums;
using API.Extensions;
using API.Helpers;
using API.Helpers.Builders;
using API.Services;
using API.Services.Plus;
using API.Services.Tasks;
using API.Services.Tasks.Metadata;
using API.Services.Tasks.Scanner;
using API.Services.Tasks.Scanner.Parser;
using API.SignalR;
using API.Tests.Helpers;
using Hangfire;
using Microsoft.Extensions.Logging;
using NSubstitute;
using Xunit;
using Xunit.Abstractions;

namespace API.Tests.Services;

public class ScannerServiceTests : AbstractDbTest
{
    private readonly ITestOutputHelper _testOutputHelper;
    private readonly string _testDirectory = Path.Join(Directory.GetCurrentDirectory(), "../../../Services/Test Data/ScannerService/ScanTests");
    private readonly string _testcasesDirectory = Path.Join(Directory.GetCurrentDirectory(), "../../../Services/Test Data/ScannerService/TestCases");
    private readonly string _imagePath = Path.Join(Directory.GetCurrentDirectory(), "../../../Services/Test Data/ScannerService/1x1.png");
    private static readonly string[] ComicInfoExtensions = new[] { ".cbz", ".cbr", ".zip", ".rar" };

    public ScannerServiceTests(ITestOutputHelper testOutputHelper)
    {
        _testOutputHelper = testOutputHelper;

        // Set up Hangfire to use in-memory storage for testing
        GlobalConfiguration.Configuration.UseInMemoryStorage();
    }

    protected override async Task ResetDb()
    {
        _context.Library.RemoveRange(_context.Library);
        await _context.SaveChangesAsync();
    }

    [Fact]
    public async Task ScanLibrary_ComicVine_PublisherFolder()
    {
        var testcase = "Publisher - ComicVine.json";
        var library = await GenerateScannerData(testcase);
        var scanner = CreateServices();
        await scanner.ScanLibrary(library.Id);
        var postLib = await _unitOfWork.LibraryRepository.GetLibraryForIdAsync(library.Id, LibraryIncludes.Series);

        Assert.NotNull(postLib);
        Assert.Equal(4, postLib.Series.Count);
    }

    [Fact]
    public async Task ScanLibrary_ShouldCombineNestedFolder()
    {
        var testcase = "Series and Series-Series Combined - Manga.json";
        var library = await GenerateScannerData(testcase);
        var scanner = CreateServices();
        await scanner.ScanLibrary(library.Id);
        var postLib = await _unitOfWork.LibraryRepository.GetLibraryForIdAsync(library.Id, LibraryIncludes.Series);

        Assert.NotNull(postLib);
        Assert.Single(postLib.Series);
        Assert.Equal(2, postLib.Series.First().Volumes.Count);
    }


    [Fact]
    public async Task ScanLibrary_FlatSeries()
    {
        var testcase = "Flat Series - Manga.json";
        var library = await GenerateScannerData(testcase);
        var scanner = CreateServices();
        await scanner.ScanLibrary(library.Id);
        var postLib = await _unitOfWork.LibraryRepository.GetLibraryForIdAsync(library.Id, LibraryIncludes.Series);

        Assert.NotNull(postLib);
        Assert.Single(postLib.Series);
        Assert.Equal(3, postLib.Series.First().Volumes.Count);

        // TODO: Trigger a deletion of ch 10
    }

    [Fact]
    public async Task ScanLibrary_FlatSeriesWithSpecialFolder()
    {
        var testcase = "Flat Series with Specials Folder - Manga.json";
        var library = await GenerateScannerData(testcase);
        var scanner = CreateServices();
        await scanner.ScanLibrary(library.Id);
        var postLib = await _unitOfWork.LibraryRepository.GetLibraryForIdAsync(library.Id, LibraryIncludes.Series);

        Assert.NotNull(postLib);
        Assert.Single(postLib.Series);
        Assert.Equal(4, postLib.Series.First().Volumes.Count);
        Assert.NotNull(postLib.Series.First().Volumes.FirstOrDefault(v => v.Chapters.FirstOrDefault(c => c.IsSpecial) != null));
    }

    [Fact]
    public async Task ScanLibrary_FlatSeriesWithSpecial()
    {
        const string testcase = "Flat Special - Manga.json";

        var library = await GenerateScannerData(testcase);
        var scanner = CreateServices();
        await scanner.ScanLibrary(library.Id);
        var postLib = await _unitOfWork.LibraryRepository.GetLibraryForIdAsync(library.Id, LibraryIncludes.Series);

        Assert.NotNull(postLib);
        Assert.Single(postLib.Series);
        Assert.Equal(3, postLib.Series.First().Volumes.Count);
        Assert.NotNull(postLib.Series.First().Volumes.FirstOrDefault(v => v.Chapters.FirstOrDefault(c => c.IsSpecial) != null));
    }

    /// <summary>
    /// This is testing that if the first file is named A and has a localized name of B if all other files are named B, it should still group and name the series A
    /// </summary>
    [Fact]
    public async Task ScanLibrary_LocalizedSeries()
    {
        const string testcase = "Series with Localized - Manga.json";

        // Get the first file and generate a ComicInfo
        var infos = new Dictionary<string, ComicInfo>();
        infos.Add("My Dress-Up Darling v01.cbz", new ComicInfo()
        {
            Series = "My Dress-Up Darling",
            LocalizedSeries = "Sono Bisque Doll wa Koi wo Suru"
        });

        var library = await GenerateScannerData(testcase, infos);


        var scanner = CreateServices();
        await scanner.ScanLibrary(library.Id);
        var postLib = await _unitOfWork.LibraryRepository.GetLibraryForIdAsync(library.Id, LibraryIncludes.Series);

        Assert.NotNull(postLib);
        Assert.Single(postLib.Series);
        Assert.Equal(3, postLib.Series.First().Volumes.Count);
    }

    [Fact]
    public async Task ScanLibrary_LocalizedSeries2()
    {
        const string testcase = "Series with Localized 2 - Manga.json";

        // Get the first file and generate a ComicInfo
        var infos = new Dictionary<string, ComicInfo>();
        infos.Add("Immoral Guild v01.cbz", new ComicInfo()
        {
            Series = "Immoral Guild",
            LocalizedSeries = "Futoku no Guild" // Filename has a capital N and localizedSeries has lowercase
        });

        var library = await GenerateScannerData(testcase, infos);


        var scanner = CreateServices();
        await scanner.ScanLibrary(library.Id);
        var postLib = await _unitOfWork.LibraryRepository.GetLibraryForIdAsync(library.Id, LibraryIncludes.Series);

        Assert.NotNull(postLib);
        Assert.Single(postLib.Series);
        var s = postLib.Series.First();
        Assert.Equal("Immoral Guild", s.Name);
        Assert.Equal("Futoku no Guild", s.LocalizedName);
        Assert.Equal(3, s.Volumes.Count);
    }


    /// <summary>
    /// Special Keywords shouldn't be removed from the series name and thus these 2 should group
    /// </summary>
    [Fact]
    public async Task ScanLibrary_ExtraShouldNotAffect()
    {
        const string testcase = "Series with Extra - Manga.json";

        // Get the first file and generate a ComicInfo
        var infos = new Dictionary<string, ComicInfo>();
        infos.Add("Vol.01.cbz", new ComicInfo()
        {
            Series = "The Novel's Extra",
        });

        var library = await GenerateScannerData(testcase, infos);


        var scanner = CreateServices();
        await scanner.ScanLibrary(library.Id);
        var postLib = await _unitOfWork.LibraryRepository.GetLibraryForIdAsync(library.Id, LibraryIncludes.Series);

        Assert.NotNull(postLib);
        Assert.Single(postLib.Series);
        var s = postLib.Series.First();
        Assert.Equal("The Novel's Extra", s.Name);
        Assert.Equal(2, s.Volumes.Count);
    }


    /// <summary>
    /// Files under a folder with a SP marker should group into one issue
    /// </summary>
    /// <remarks>https://github.com/Kareadita/Kavita/issues/3299</remarks>
    [Fact]
    public async Task ScanLibrary_ImageSeries_SpecialGrouping()
    {
        const string testcase = "Image Series with SP Folder - Manga.json";

        var library = await GenerateScannerData(testcase);


        var scanner = CreateServices();
        await scanner.ScanLibrary(library.Id);
        var postLib = await _unitOfWork.LibraryRepository.GetLibraryForIdAsync(library.Id, LibraryIncludes.Series);

        Assert.NotNull(postLib);
        Assert.Single(postLib.Series);
        Assert.Equal(3, postLib.Series.First().Volumes.Count);
    }

    /// <summary>
    /// This test is currently disabled because the Image parser is unable to support multiple files mapping into one single Special.
    /// https://github.com/Kareadita/Kavita/issues/3299
    /// </summary>
    public async Task ScanLibrary_ImageSeries_SpecialGrouping_NonEnglish()
    {
        const string testcase = "Image Series with SP Folder (Non English) - Image.json";

        var library = await GenerateScannerData(testcase);


        var scanner = CreateServices();
        await scanner.ScanLibrary(library.Id);
        var postLib = await _unitOfWork.LibraryRepository.GetLibraryForIdAsync(library.Id, LibraryIncludes.Series);

        Assert.NotNull(postLib);
        Assert.Single(postLib.Series);
        var series = postLib.Series.First();
        Assert.Equal(3, series.Volumes.Count);
        var specialVolume = series.Volumes.FirstOrDefault(v => v.Name == Parser.SpecialVolume);
        Assert.NotNull(specialVolume);
        Assert.Single(specialVolume.Chapters);
        Assert.True(specialVolume.Chapters.First().IsSpecial);
        //Assert.Equal("葬送のフリーレン 公式ファンブック SP01", specialVolume.Chapters.First().Title);
    }


    [Fact]
    public async Task ScanLibrary_PublishersInheritFromChapters()
    {
        const string testcase = "Flat Special - Manga.json";

        var infos = new Dictionary<string, ComicInfo>();
        infos.Add("Uzaki-chan Wants to Hang Out! v01 (2019) (Digital) (danke-Empire).cbz", new ComicInfo()
        {
            Publisher = "Correct Publisher"
        });
        infos.Add("Uzaki-chan Wants to Hang Out! - 2022 New Years Special SP01.cbz", new ComicInfo()
        {
            Publisher = "Special Publisher"
        });
        infos.Add("Uzaki-chan Wants to Hang Out! - Ch. 103 - Kouhai and Control.cbz", new ComicInfo()
        {
            Publisher = "Chapter Publisher"
        });

        var library = await GenerateScannerData(testcase, infos);


        var scanner = CreateServices();
        await scanner.ScanLibrary(library.Id);
        var postLib = await _unitOfWork.LibraryRepository.GetLibraryForIdAsync(library.Id, LibraryIncludes.Series);

        Assert.NotNull(postLib);
        Assert.Single(postLib.Series);
        var publishers = postLib.Series.First().Metadata.People
            .Where(p => p.Role == PersonRole.Publisher);
        Assert.Equal(3, publishers.Count());
    }


    /// <summary>
    /// Tests that pdf parser handles the loose chapters correctly
    /// https://github.com/Kareadita/Kavita/issues/3148
    /// </summary>
    [Fact]
    public async Task ScanLibrary_LooseChapters_Pdf()
    {
        const string testcase = "PDF Comic Chapters - Comic.json";

        var library = await GenerateScannerData(testcase);


        var scanner = CreateServices();
        await scanner.ScanLibrary(library.Id);
        var postLib = await _unitOfWork.LibraryRepository.GetLibraryForIdAsync(library.Id, LibraryIncludes.Series);

        Assert.NotNull(postLib);
        Assert.Single(postLib.Series);
        var series = postLib.Series.First();
        Assert.Single(series.Volumes);
        Assert.Equal(4, series.Volumes.First().Chapters.Count);
    }

    [Fact]
    public async Task ScanLibrary_LooseChapters_Pdf_LN()
    {
        const string testcase = "PDF Comic Chapters - LightNovel.json";

        var library = await GenerateScannerData(testcase);


        var scanner = CreateServices();
        await scanner.ScanLibrary(library.Id);
        var postLib = await _unitOfWork.LibraryRepository.GetLibraryForIdAsync(library.Id, LibraryIncludes.Series);

        Assert.NotNull(postLib);
        Assert.Single(postLib.Series);
        var series = postLib.Series.First();
        Assert.Single(series.Volumes);
        Assert.Equal(4, series.Volumes.First().Chapters.Count);
    }


    #region Setup
    private async Task<Library> GenerateScannerData(string testcase, Dictionary<string, ComicInfo> comicInfos = null)
    {
        var testDirectoryPath = await GenerateTestDirectory(Path.Join(_testcasesDirectory, testcase), comicInfos);

        var (publisher, type) = SplitPublisherAndLibraryType(Path.GetFileNameWithoutExtension(testcase));

        var library = new LibraryBuilder(publisher, type)
            .WithFolders([new FolderPath() {Path = testDirectoryPath}])
            .Build();

        var admin = new AppUserBuilder("admin", "admin@kavita.com", Seed.DefaultThemes[0])
            .WithLibrary(library)
            .Build();

        _unitOfWork.UserRepository.Add(admin); // Admin is needed for generating collections/reading lists
        _unitOfWork.LibraryRepository.Add(library);
        await _unitOfWork.CommitAsync();

        return library;
    }

    private ScannerService CreateServices()
    {
        var fs = new FileSystem();
        var ds = new DirectoryService(Substitute.For<ILogger<DirectoryService>>(), fs);
        var archiveService = new ArchiveService(Substitute.For<ILogger<ArchiveService>>(), ds,
            Substitute.For<IImageService>(), Substitute.For<IMediaErrorService>());
        var readingItemService = new ReadingItemService(archiveService, Substitute.For<IBookService>(),
            Substitute.For<IImageService>(), ds, Substitute.For<ILogger<ReadingItemService>>());


        var processSeries = new ProcessSeries(_unitOfWork, Substitute.For<ILogger<ProcessSeries>>(),
            Substitute.For<IEventHub>(),
            ds, Substitute.For<ICacheHelper>(), readingItemService, new FileService(fs),
            Substitute.For<IMetadataService>(),
            Substitute.For<IWordCountAnalyzerService>(),
            Substitute.For<IReadingListService>(),
            Substitute.For<IExternalMetadataService>());

        var scanner = new ScannerService(_unitOfWork, Substitute.For<ILogger<ScannerService>>(),
            Substitute.For<IMetadataService>(),
            Substitute.For<ICacheService>(), Substitute.For<IEventHub>(), ds,
            readingItemService, processSeries, Substitute.For<IWordCountAnalyzerService>());
        return scanner;
    }

    private static (string Publisher, LibraryType Type) SplitPublisherAndLibraryType(string input)
    {
        // Split the input string based on " - "
        var parts = input.Split(" - ", StringSplitOptions.RemoveEmptyEntries);

        if (parts.Length != 2)
        {
            throw new ArgumentException("Input must be in the format 'Publisher - LibraryType'");
        }

        var publisher = parts[0].Trim();
        var libraryTypeString = parts[1].Trim();

        // Try to parse the right-hand side as a LibraryType enum
        if (!Enum.TryParse<LibraryType>(libraryTypeString, out var libraryType))
        {
            throw new ArgumentException($"'{libraryTypeString}' is not a valid LibraryType");
        }

        return (publisher, libraryType);
    }



    private async Task<string> GenerateTestDirectory(string mapPath, Dictionary<string, ComicInfo> comicInfos = null)
    {
        // Read the map file
        var mapContent = await File.ReadAllTextAsync(mapPath);

        // Deserialize the JSON content into a list of strings using System.Text.Json
        var filePaths = JsonSerializer.Deserialize<List<string>>(mapContent);

        // Create a test directory
        var testDirectory = Path.Combine(_testDirectory, Path.GetFileNameWithoutExtension(mapPath));
        if (Directory.Exists(testDirectory))
        {
            Directory.Delete(testDirectory, true);
        }
        Directory.CreateDirectory(testDirectory);

        // Generate the files and folders
        await Scaffold(testDirectory, filePaths, comicInfos);

        _testOutputHelper.WriteLine($"Test Directory Path: {testDirectory}");

        return testDirectory;
    }


    private async Task Scaffold(string testDirectory, List<string> filePaths, Dictionary<string, ComicInfo> comicInfos = null)
    {
        foreach (var relativePath in filePaths)
        {
            var fullPath = Path.Combine(testDirectory, relativePath);
            var fileDir = Path.GetDirectoryName(fullPath);

            // Create the directory if it doesn't exist
            if (!Directory.Exists(fileDir))
            {
                Directory.CreateDirectory(fileDir);
                Console.WriteLine($"Created directory: {fileDir}");
            }

            var ext = Path.GetExtension(fullPath).ToLower();
            if (ComicInfoExtensions.Contains(ext) && comicInfos != null && comicInfos.TryGetValue(Path.GetFileName(relativePath), out var info))
            {
                CreateMinimalCbz(fullPath, info);
            }
            else
            {
                // Create an empty file
                await File.Create(fullPath).DisposeAsync();
                Console.WriteLine($"Created empty file: {fullPath}");
            }
        }
    }

    private void CreateMinimalCbz(string filePath, ComicInfo? comicInfo = null)
    {
        using (var archive = ZipFile.Open(filePath, ZipArchiveMode.Create))
        {
            // Add the 1x1 image to the archive
            archive.CreateEntryFromFile(_imagePath, "1x1.png");

            if (comicInfo != null)
            {
                // Serialize ComicInfo object to XML
                var comicInfoXml = SerializeComicInfoToXml(comicInfo);

                // Create an entry for ComicInfo.xml in the archive
                var entry = archive.CreateEntry("ComicInfo.xml");
                using var entryStream = entry.Open();
                using var writer = new StreamWriter(entryStream, Encoding.UTF8);

                // Write the XML to the archive
                writer.Write(comicInfoXml);
            }

        }
        Console.WriteLine($"Created minimal CBZ archive: {filePath} with{(comicInfo != null ? "" : "out")} metadata.");
    }


    private static string SerializeComicInfoToXml(ComicInfo comicInfo)
    {
        var xmlSerializer = new XmlSerializer(typeof(ComicInfo));
        using var stringWriter = new StringWriter();
        using (var xmlWriter = XmlWriter.Create(stringWriter, new XmlWriterSettings { Indent = true, Encoding = new UTF8Encoding(false), OmitXmlDeclaration = false}))
        {
            xmlSerializer.Serialize(xmlWriter, comicInfo);
        }

        // For the love of god, I spent 2 hours trying to get utf-8 with no BOM
        return stringWriter.ToString().Replace("""<?xml version="1.0" encoding="utf-16"?>""",
            @"<?xml version='1.0' encoding='utf-8'?>");
    }
    #endregion
}