nadekobot/src/NadekoBot/Modules/Nsfw/Nhentai/NhentaiScraperService.cs

using AngleSharp.Html.Dom;
using AngleSharp.Html.Parser;
using NadekoBot.Modules.Searches.Common;

namespace NadekoBot.Modules.Nsfw;

public sealed class NhentaiScraperService : INhentaiService, INService
{
    private readonly IHttpClientFactory _httpFactory;

    private static readonly HtmlParser _htmlParser = new(new()
    {
        IsScripting = false,
        IsEmbedded = false,
        IsSupportingProcessingInstructions = false,
        IsKeepingSourceReferences = false,
        IsNotSupportingFrames = true
    });

    public NhentaiScraperService(IHttpClientFactory httpFactory)
    {
        _httpFactory = httpFactory;
    }

    private HttpClient GetHttpClient()
    {
        var http = _httpFactory.CreateClient();
        http.DefaultRequestHeaders.Add("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.5060.114 Safari/537.36");
        http.DefaultRequestHeaders.Add("Cookie", "cf_clearance=I5pR71P4wJkRBFTLFjBndI.GwfKwT.Gx06uS8XNmRJo-1657214595-0-150; csrftoken=WMWRLtsQtBVQYvYkbqXKJHI9T1JwWCdd3tNhoxHn7aHLUYHAqe60XFUKAoWsJtda");
        return http;
    }
    
    public async Task<Gallery?> GetAsync(uint id)
    {
        using var http = GetHttpClient();
        try
        {
            var url = $"https://nhentai.net/g/{id}/";
            var strRes = await http.GetStringAsync(url);
            var doc = await _htmlParser.ParseDocumentAsync(strRes);

            var title = doc.QuerySelector("#info .title")?.TextContent;
            var fullTitle = doc.QuerySelector("meta[itemprop=\"name\"]")?.Attributes["content"]?.Value
                            ?? title;
            var thumb = (doc.QuerySelector("#cover a img") as IHtmlImageElement)?.Dataset["src"];

            var tagsElem = doc.QuerySelector("#tags");
            
            var pageCount = tagsElem?.QuerySelector("a.tag[href^=\"/search/?q=pages\"] span")?.TextContent;
            var likes = doc.QuerySelector(".buttons .btn-disabled.btn.tooltip span span")?.TextContent?.Trim('(', ')');
            var uploadedAt = (tagsElem?.QuerySelector(".tag-container .tags time.nobold") as IHtmlTimeElement)?.DateTime;

            var tags = tagsElem?.QuerySelectorAll(".tag-container .tags > a.tag[href^=\"/tag\"]")
                .Cast<IHtmlAnchorElement>()
                .Select(x => new Tag()
                {
                    Name = x.QuerySelector("span:first-child")?.TextContent,
                    Url = $"https://nhentai.net{x.PathName}"
                })
                .ToArray();

            if (string.IsNullOrWhiteSpace(fullTitle))
                return null;

            if (!int.TryParse(pageCount, out var pc))
                return null;

            if (!int.TryParse(likes, out var lc))
                return null;

            if (!DateTime.TryParse(uploadedAt, out var ua))
                return null;

            return new Gallery(id,
                url,
                fullTitle,
                title,
                thumb,
                pc,
                lc,
                ua,
                tags);
        }
        catch (HttpRequestException)
        {
            Log.Warning("Nhentai with id {NhentaiId} not found", id);
            return null;
        }
    }

    public async Task<IReadOnlyList<uint>> GetIdsBySearchAsync(string search)
    {
        using var http = GetHttpClient();
        try
        {
            var url = $"https://nhentai.net/search/?q={Uri.EscapeDataString(search)}&sort=popular-today";
            var strRes = await http.GetStringAsync(url);
            var doc = await _htmlParser.ParseDocumentAsync(strRes);

            var elems = doc.QuerySelectorAll(".container .gallery a")
                .Cast<IHtmlAnchorElement>()
                .Where(x => x.PathName.StartsWith("/g/"))
                .Select(x => x.PathName[3..^1])
                .Select(uint.Parse)
                .ToArray();
            
            return elems;
        }
        catch (HttpRequestException)
        {
            Log.Warning("Nhentai search for {NhentaiSearch} failed", search);
            return Array.Empty<uint>();
        }
    }
}