FictionArchive/FictionArchive.Service.NovelService/Services/NovelUpdateService.cs

using FictionArchive.Service.FileService.IntegrationEvents;
using FictionArchive.Service.NovelService.Models.Configuration;
using FictionArchive.Service.NovelService.Models.Enums;
using FictionArchive.Service.NovelService.Models.Images;
using FictionArchive.Service.NovelService.Models.Localization;
using FictionArchive.Service.NovelService.Models.Novels;
using FictionArchive.Service.NovelService.Models.SourceAdapters;
using FictionArchive.Service.NovelService.Services.SourceAdapters;
using FictionArchive.Service.Shared.Services.EventBus;
using HtmlAgilityPack;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Options;

namespace FictionArchive.Service.NovelService.Services;

public class NovelUpdateService
{
    private readonly NovelServiceDbContext _dbContext;
    private readonly ILogger<NovelUpdateService> _logger;
    private readonly IEnumerable<ISourceAdapter> _sourceAdapters;
    private readonly IEventBus _eventBus;
    private readonly NovelUpdateServiceConfiguration _novelUpdateServiceConfiguration;

    public NovelUpdateService(NovelServiceDbContext dbContext, ILogger<NovelUpdateService> logger, IEnumerable<ISourceAdapter> sourceAdapters, IEventBus eventBus, IOptions<NovelUpdateServiceConfiguration> novelUpdateServiceConfiguration)
    {
        _dbContext = dbContext;
        _logger = logger;
        _sourceAdapters = sourceAdapters;
        _eventBus = eventBus;
        _novelUpdateServiceConfiguration = novelUpdateServiceConfiguration.Value;
    }

    public async Task<Novel> ImportNovel(string novelUrl)
    {
        NovelMetadata? metadata = null;
        foreach (ISourceAdapter sourceAdapter in _sourceAdapters)
        {
            if (await sourceAdapter.CanProcessNovel(novelUrl))
            {
                metadata = await sourceAdapter.GetMetadata(novelUrl);
            }
        }

        if (metadata == null)
        {
            throw new NotSupportedException("The provided novel url is currently unsupported.");
        }

        var systemTags = metadata.SystemTags.Select(tag => new NovelTag()
        {
            Key = tag,
            DisplayName = LocalizationKey.CreateFromText(tag, metadata.RawLanguage),
            TagType = TagType.System
        });
        var sourceTags = metadata.SourceTags.Select(tag => new NovelTag()
        {
            Key = tag,
            DisplayName = LocalizationKey.CreateFromText(tag, metadata.RawLanguage),
            TagType = TagType.External
        });

        var addedNovel = _dbContext.Novels.Add(new Novel()
        {
            Author = new Person()
            {
                Name = LocalizationKey.CreateFromText(metadata.AuthorName, metadata.RawLanguage),
                ExternalUrl = metadata.AuthorUrl,
            },
            RawLanguage = metadata.RawLanguage,
            Url = metadata.Url,
            ExternalId = metadata.ExternalId,
            CoverImage = metadata.CoverImage != null ? new Image()
            {
                OriginalPath = metadata.CoverImage.Url,
            } : null,
            Chapters = metadata.Chapters.Select(chapter =>
            {
                return new Chapter()
                {
                    Order = chapter.Order,
                    Url = chapter.Url,
                    Revision = chapter.Revision,
                    Name = LocalizationKey.CreateFromText(chapter.Name, metadata.RawLanguage),
                    Body = new LocalizationKey()
                    {
                        Texts = new List<LocalizationText>()
                    }
                };
            }).ToList(),
            Description = LocalizationKey.CreateFromText(metadata.Description, metadata.RawLanguage),
            Name = LocalizationKey.CreateFromText(metadata.Name, metadata.RawLanguage),
            RawStatus = metadata.RawStatus,
            Tags = sourceTags.Concat(systemTags).ToList(),
            Source = new Source()
            {
                Name = metadata.SourceDescriptor.Name,
                Url = metadata.SourceDescriptor.Url,
                Key = metadata.SourceDescriptor.Key,
            }
        });
        await _dbContext.SaveChangesAsync();
        
        // Signal request for cover image if present
        if (addedNovel.Entity.CoverImage != null)
        {
            await _eventBus.Publish(new FileUploadRequestCreatedEvent()
            {
                RequestId = addedNovel.Entity.CoverImage.Id,
                FileData = metadata.CoverImage.Data,
                FilePath = $"Novels/{addedNovel.Entity.Id}/Images/cover.jpg"
            });
        }
        
        return addedNovel.Entity;
    }

    public async Task<Chapter> PullChapterContents(uint novelId, uint chapterNumber)
    {
        var novel = await _dbContext.Novels.Where(novel => novel.Id == novelId)
            .Include(novel => novel.Chapters)
            .ThenInclude(chapter => chapter.Body)
            .ThenInclude(body => body.Texts)
            .Include(novel => novel.Source).Include(novel => novel.Chapters).ThenInclude(chapter => chapter.Images)
            .FirstOrDefaultAsync();
        var chapter = novel.Chapters.Where(chapter => chapter.Order == chapterNumber).FirstOrDefault();
        var adapter = _sourceAdapters.FirstOrDefault(adapter => adapter.SourceDescriptor.Key == novel.Source.Key);
        var rawChapter = await adapter.GetRawChapter(chapter.Url);
        var localizationText = new LocalizationText()
        {
            Text = rawChapter.Text,
            Language = novel.RawLanguage
        };
        chapter.Body.Texts.Add(localizationText);
        chapter.Images = rawChapter.ImageData.Select(img => new Image()
        {
            OriginalPath = img.Url
        }).ToList();
        await _dbContext.SaveChangesAsync();
        
        // Images are saved and have ids, update the chapter body to replace image tags
        var chapterDoc = new HtmlDocument();
        chapterDoc.LoadHtml(rawChapter.Text);
        foreach (var image in chapter.Images)
        {
            var match = chapterDoc.DocumentNode.SelectSingleNode(@$"//img[@src='{image.OriginalPath}']");
            if (match != null)
            {
                match.Attributes["src"].Value = _novelUpdateServiceConfiguration.PendingImageUrl;
                if (match.Attributes.Contains("alt"))
                {
                    match.Attributes["alt"].Value = image.Id.ToString();
                }
                else
                {
                    match.Attributes.Add("alt", image.Id.ToString());
                }
            }
        }
        localizationText.Text = chapterDoc.DocumentNode.OuterHtml;
        await _dbContext.SaveChangesAsync();
        
        // Body was updated, raise image request
        int imgCount = 0;
        foreach (var image in chapter.Images)
        {
            var data = rawChapter.ImageData.FirstOrDefault(img => img.Url == image.OriginalPath);
            await _eventBus.Publish(new FileUploadRequestCreatedEvent()
            {
                FileData = data.Data,
                FilePath = $"{novel.Id}/Images/Chapter-{chapter.Id}/{imgCount++}.jpg",
                RequestId = image.Id
            });
        }

        return chapter;
    }

    public async Task UpdateImage(Guid imageId, string newUrl)
    {
        var image = await _dbContext.Images
            .Include(img => img.Chapter)
            .ThenInclude(chapter => chapter.Body)
            .ThenInclude(body => body.Texts)
            .FirstOrDefaultAsync(image => image.Id == imageId);
        image.NewPath = newUrl;
        
        // If this is an image from a chapter, let's update the chapter body(s)
        if (image.Chapter != null)
        {
            foreach (var bodyText in image.Chapter.Body.Texts)
            {
                var chapterDoc = new HtmlDocument();
                chapterDoc.LoadHtml(bodyText.Text);
                var match = chapterDoc.DocumentNode.SelectSingleNode(@$"//img[@alt='{image.Id}']");
                if (match != null)
                {
                    match.Attributes["src"].Value = newUrl;
                }
            }
        }
        
        await _dbContext.SaveChangesAsync();
    }
}