using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Threading.Tasks; using HtmlAgilityPack; using Pathoschild.FluentNexus.Models; using Pathoschild.Http.Client; using StardewModdingAPI.Toolkit; using StardewModdingAPI.Toolkit.Framework.UpdateData; using StardewModdingAPI.Web.Framework.Clients.Nexus.ResponseModels; using FluentNexusClient = Pathoschild.FluentNexus.NexusClient; namespace StardewModdingAPI.Web.Framework.Clients.Nexus { /// <summary>An HTTP client for fetching mod metadata from the Nexus website.</summary> internal class NexusClient : INexusClient { /********* ** Fields *********/ /// <summary>The URL for a Nexus mod page for the user, excluding the base URL, where {0} is the mod ID.</summary> private readonly string WebModUrlFormat; /// <summary>The URL for a Nexus mod page to scrape for versions, excluding the base URL, where {0} is the mod ID.</summary> public string WebModScrapeUrlFormat { get; set; } /// <summary>The underlying HTTP client for the Nexus Mods website.</summary> private readonly IClient WebClient; /// <summary>The underlying HTTP client for the Nexus API.</summary> private readonly FluentNexusClient ApiClient; /********* ** Accessors *********/ /// <summary>The unique key for the mod site.</summary> public ModSiteKey SiteKey => ModSiteKey.Nexus; /********* ** Public methods *********/ /// <summary>Construct an instance.</summary> /// <param name="webUserAgent">The user agent for the Nexus Mods web client.</param> /// <param name="webBaseUrl">The base URL for the Nexus Mods site.</param> /// <param name="webModUrlFormat">The URL for a Nexus Mods mod page for the user, excluding the <paramref name="webBaseUrl"/>, where {0} is the mod ID.</param> /// <param name="webModScrapeUrlFormat">The URL for a Nexus mod page to scrape for versions, excluding the base URL, where {0} is the mod ID.</param> /// <param name="apiAppVersion">The app version to show in API user agents.</param> /// <param name="apiKey">The Nexus API authentication key.</param> public NexusClient(string webUserAgent, string webBaseUrl, string webModUrlFormat, string webModScrapeUrlFormat, string apiAppVersion, string apiKey) { this.WebModUrlFormat = webModUrlFormat; this.WebModScrapeUrlFormat = webModScrapeUrlFormat; this.WebClient = new FluentClient(webBaseUrl).SetUserAgent(webUserAgent); this.ApiClient = new FluentNexusClient(apiKey, "SMAPI", apiAppVersion); } /// <summary>Get update check info about a mod.</summary> /// <param name="id">The mod ID.</param> public async Task<IModPage?> GetModData(string id) { IModPage page = new GenericModPage(this.SiteKey, id); if (!uint.TryParse(id, out uint parsedId)) return page.SetError(RemoteModStatus.DoesNotExist, $"The value '{id}' isn't a valid Nexus mod ID, must be an integer ID."); // Fetch from the Nexus website when possible, since it has no rate limits. Mods with // adult content are hidden for anonymous users, so fall back to the API in that case. // Note that the API has very restrictive rate limits which means we can't just use it // for all cases. NexusMod? mod = await this.GetModFromWebsiteAsync(parsedId); if (mod?.Status == NexusModStatus.AdultContentForbidden) mod = await this.GetModFromApiAsync(parsedId); // page doesn't exist if (mod == null || mod.Status is NexusModStatus.Hidden or NexusModStatus.NotPublished) return page.SetError(RemoteModStatus.DoesNotExist, "Found no Nexus mod with this ID."); // return info page.SetInfo(name: mod.Name ?? parsedId.ToString(), url: mod.Url ?? this.GetModUrl(parsedId), version: mod.Version, downloads: mod.Downloads); if (mod.Status != NexusModStatus.Ok) page.SetError(RemoteModStatus.TemporaryError, mod.Error!); return page; } /// <summary>Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.</summary> public void Dispose() { this.WebClient.Dispose(); } /********* ** Private methods *********/ /// <summary>Get metadata about a mod by scraping the Nexus website.</summary> /// <param name="id">The Nexus mod ID.</param> /// <returns>Returns the mod info if found, else <c>null</c>.</returns> private async Task<NexusMod?> GetModFromWebsiteAsync(uint id) { // fetch HTML string html; try { html = await this.WebClient .GetAsync(string.Format(this.WebModScrapeUrlFormat, id)) .AsString(); } catch (ApiException ex) when (ex.Status == HttpStatusCode.NotFound) { return null; } // parse HTML HtmlDocument doc = new(); doc.LoadHtml(html); // handle Nexus error message HtmlNode? node = doc.DocumentNode.SelectSingleNode("//div[contains(@class, 'site-notice')][contains(@class, 'warning')]"); if (node != null) { string[] errorParts = node.InnerText.Trim().Split(new[] { '\n' }, 2, System.StringSplitOptions.RemoveEmptyEntries); string errorCode = errorParts[0]; string? errorText = errorParts.Length > 1 ? errorParts[1] : null; switch (errorCode.Trim().ToLower()) { case "not found": return null; default: return new NexusMod( status: this.GetWebStatus(errorCode), error: $"Nexus error: {errorCode} ({errorText})." ); } } // extract mod info string url = this.GetModUrl(id); string? name = doc.DocumentNode.SelectSingleNode("//div[@id='pagetitle']//h1")?.InnerText.Trim(); string? version = doc.DocumentNode.SelectSingleNode("//ul[contains(@class, 'stats')]//li[@class='stat-version']//div[@class='stat']")?.InnerText.Trim(); SemanticVersion.TryParse(version, out ISemanticVersion? parsedVersion); // extract files var downloads = new List<IModDownload>(); foreach (HtmlNode fileSection in doc.DocumentNode.SelectNodes("//div[contains(@class, 'files-tabs')]")) { string sectionName = fileSection.Descendants("h2").First().InnerText; if (sectionName != "Main files" && sectionName != "Optional files") continue; foreach (var container in fileSection.Descendants("dt")) { string fileName = container.GetDataAttribute("name").Value; string fileVersion = container.GetDataAttribute("version").Value; string? description = container.SelectSingleNode("following-sibling::*[1][self::dd]//div").InnerText?.Trim(); // get text of next <dd> tag; derived from https://stackoverflow.com/a/25535623/262123 downloads.Add( new GenericModDownload(fileName, description, fileVersion) ); } } // yield info return new NexusMod( name: name ?? id.ToString(), version: parsedVersion?.ToString() ?? version, url: url, downloads: downloads.ToArray() ); } /// <summary>Get metadata about a mod from the Nexus API.</summary> /// <param name="id">The Nexus mod ID.</param> /// <returns>Returns the mod info if found, else <c>null</c>.</returns> private async Task<NexusMod> GetModFromApiAsync(uint id) { // fetch mod Mod mod = await this.ApiClient.Mods.GetMod("stardewvalley", (int)id); ModFileList files = await this.ApiClient.ModFiles.GetModFiles("stardewvalley", (int)id, FileCategory.Main, FileCategory.Optional); // yield info return new NexusMod( name: mod.Name, version: SemanticVersion.TryParse(mod.Version, out ISemanticVersion? version) ? version.ToString() : mod.Version, url: this.GetModUrl(id), downloads: files.Files .Select(file => (IModDownload)new GenericModDownload(file.Name, file.Description, file.FileVersion)) .ToArray() ); } /// <summary>Get the full mod page URL for a given ID.</summary> /// <param name="id">The mod ID.</param> private string GetModUrl(uint id) { UriBuilder builder = new(this.WebClient.BaseClient.BaseAddress!); builder.Path += string.Format(this.WebModUrlFormat, id); return builder.Uri.ToString(); } /// <summary>Get the mod status for a web error code.</summary> /// <param name="errorCode">The Nexus error code.</param> private NexusModStatus GetWebStatus(string errorCode) { switch (errorCode.Trim().ToLower()) { case "adult content": return NexusModStatus.AdultContentForbidden; case "hidden mod": return NexusModStatus.Hidden; case "not published": return NexusModStatus.NotPublished; default: return NexusModStatus.Other; } } } }