1 files changed, 230 insertions, 0 deletions
diff --git a/src/StardewModdingAPI.Toolkit/Framework/Clients/Wiki/WikiClient.cs b/src/StardewModdingAPI.Toolkit/Framework/Clients/Wiki/WikiClient.cs
new file mode 100644
index 00000000..7197bf2c
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+++ b/src/StardewModdingAPI.Toolkit/Framework/Clients/Wiki/WikiClient.cs
@@ -0,0 +1,230 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.Linq;
+using System.Net;
+using System.Threading.Tasks;
+using HtmlAgilityPack;
+using Pathoschild.Http.Client;
+
+namespace StardewModdingAPI.Toolkit.Framework.Clients.Wiki
+{
+    /// <summary>An HTTP client for fetching mod metadata from the wiki.</summary>
+    public class WikiClient : IDisposable
+    {
+        /*********
+        ** Properties
+        *********/
+        /// <summary>The underlying HTTP client.</summary>
+        private readonly IClient Client;
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="userAgent">The user agent for the wiki API.</param>
+        /// <param name="baseUrl">The base URL for the wiki API.</param>
+        public WikiClient(string userAgent, string baseUrl = "https://stardewvalleywiki.com/mediawiki/api.php")
+        {
+            this.Client = new FluentClient(baseUrl).SetUserAgent(userAgent);
+        }
+
+        /// <summary>Fetch mods from the compatibility list.</summary>
+        public async Task<WikiModList> FetchModsAsync()
+        {
+            // fetch HTML
+            ResponseModel response = await this.Client
+                .GetAsync("")
+                .WithArguments(new
+                {
+                    action = "parse",
+                    page = "Modding:SMAPI_compatibility",
+                    format = "json"
+                })
+                .As<ResponseModel>();
+            string html = response.Parse.Text["*"];
+
+            // parse HTML
+            var doc = new HtmlDocument();
+            doc.LoadHtml(html);
+
+            // fetch game versions
+            string stableVersion = doc.DocumentNode.SelectSingleNode("div[@class='game-stable-version']")?.InnerText;
+            string betaVersion = doc.DocumentNode.SelectSingleNode("div[@class='game-beta-version']")?.InnerText;
+
+            // find mod entries
+            HtmlNodeCollection modNodes = doc.DocumentNode.SelectNodes("table[@id='mod-list']//tr[@class='mod']");
+            if (modNodes == null)
+                throw new InvalidOperationException("Can't parse wiki compatibility list, no mods found.");
+
+            // parse
+            WikiModEntry[] mods = this.ParseEntries(modNodes).ToArray();
+            return new WikiModList
+            {
+                StableVersion = stableVersion,
+                BetaVersion = betaVersion,
+                Mods = mods
+            };
+        }
+
+        /// <summary>Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.</summary>
+        public void Dispose()
+        {
+            this.Client?.Dispose();
+        }
+
+
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>Parse valid mod compatibility entries.</summary>
+        /// <param name="nodes">The HTML compatibility entries.</param>
+        private IEnumerable<WikiModEntry> ParseEntries(IEnumerable<HtmlNode> nodes)
+        {
+            foreach (HtmlNode node in nodes)
+            {
+                // extract fields
+                string[] names = this.GetAttributeAsCsv(node, "data-name");
+                string[] authors = this.GetAttributeAsCsv(node, "data-author");
+                string[] ids = this.GetAttributeAsCsv(node, "data-id");
+                string[] warnings = this.GetAttributeAsCsv(node, "data-warnings");
+                int? nexusID = this.GetAttributeAsNullableInt(node, "data-nexus-id");
+                int? chucklefishID = this.GetAttributeAsNullableInt(node, "data-cf-id");
+                string githubRepo = this.GetAttribute(node, "data-github");
+                string customSourceUrl = this.GetAttribute(node, "data-custom-source");
+                string customUrl = this.GetAttribute(node, "data-url");
+                string anchor = this.GetAttribute(node, "id");
+
+                // parse stable compatibility
+                WikiCompatibilityInfo compatibility = new WikiCompatibilityInfo
+                {
+                    Status = this.GetAttributeAsStatus(node, "data-status") ?? WikiCompatibilityStatus.Ok,
+                    BrokeIn = this.GetAttribute(node, "data-broke-in"),
+                    UnofficialVersion = this.GetAttributeAsSemanticVersion(node, "data-unofficial-version"),
+                    UnofficialUrl = this.GetAttribute(node, "data-unofficial-url"),
+                    Summary = this.GetInnerHtml(node, "mod-summary")?.Trim()
+                };
+
+                // parse beta compatibility
+                WikiCompatibilityInfo betaCompatibility = null;
+                {
+                    WikiCompatibilityStatus? betaStatus = this.GetAttributeAsStatus(node, "data-beta-status");
+                    if (betaStatus.HasValue)
+                    {
+                        betaCompatibility = new WikiCompatibilityInfo
+                        {
+                            Status = betaStatus.Value,
+                            BrokeIn = this.GetAttribute(node, "data-beta-broke-in"),
+                            UnofficialVersion = this.GetAttributeAsSemanticVersion(node, "data-beta-unofficial-version"),
+                            UnofficialUrl = this.GetAttribute(node, "data-beta-unofficial-url"),
+                            Summary = this.GetInnerHtml(node, "mod-beta-summary")
+                        };
+                    }
+                }
+
+                // yield model
+                yield return new WikiModEntry
+                {
+                    ID = ids,
+                    Name = names,
+                    Author = authors,
+                    NexusID = nexusID,
+                    ChucklefishID = chucklefishID,
+                    GitHubRepo = githubRepo,
+                    CustomSourceUrl = customSourceUrl,
+                    CustomUrl = customUrl,
+                    Compatibility = compatibility,
+                    BetaCompatibility = betaCompatibility,
+                    Warnings = warnings,
+                    Anchor = anchor
+                };
+            }
+        }
+
+        /// <summary>Get an attribute value.</summary>
+        /// <param name="element">The element whose attributes to read.</param>
+        /// <param name="name">The attribute name.</param>
+        private string GetAttribute(HtmlNode element, string name)
+        {
+            string value = element.GetAttributeValue(name, null);
+            if (string.IsNullOrWhiteSpace(value))
+                return null;
+
+            return WebUtility.HtmlDecode(value);
+        }
+
+        /// <summary>Get an attribute value and parse it as a comma-delimited list of strings.</summary>
+        /// <param name="element">The element whose attributes to read.</param>
+        /// <param name="name">The attribute name.</param>
+        private string[] GetAttributeAsCsv(HtmlNode element, string name)
+        {
+            string raw = this.GetAttribute(element, name);
+            return !string.IsNullOrWhiteSpace(raw)
+                ? raw.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries).Select(p => p.Trim()).ToArray()
+                : new string[0];
+        }
+
+        /// <summary>Get an attribute value and parse it as a compatibility status.</summary>
+        /// <param name="element">The element whose attributes to read.</param>
+        /// <param name="name">The attribute name.</param>
+        private WikiCompatibilityStatus? GetAttributeAsStatus(HtmlNode element, string name)
+        {
+            string raw = this.GetAttribute(element, name);
+            if (raw == null)
+                return null;
+            if (!Enum.TryParse(raw, true, out WikiCompatibilityStatus status))
+                throw new InvalidOperationException($"Unknown status '{raw}' when parsing compatibility list.");
+            return status;
+        }
+
+        /// <summary>Get an attribute value and parse it as a semantic version.</summary>
+        /// <param name="element">The element whose attributes to read.</param>
+        /// <param name="name">The attribute name.</param>
+        private ISemanticVersion GetAttributeAsSemanticVersion(HtmlNode element, string name)
+        {
+            string raw = this.GetAttribute(element, name);
+            return SemanticVersion.TryParse(raw, out ISemanticVersion version)
+                ? version
+                : null;
+        }
+
+        /// <summary>Get an attribute value and parse it as a nullable int.</summary>
+        /// <param name="element">The element whose attributes to read.</param>
+        /// <param name="name">The attribute name.</param>
+        private int? GetAttributeAsNullableInt(HtmlNode element, string name)
+        {
+            string raw = this.GetAttribute(element, name);
+            if (raw != null && int.TryParse(raw, out int value))
+                return value;
+            return null;
+        }
+
+        /// <summary>Get the text of an element with the given class name.</summary>
+        /// <param name="container">The metadata container.</param>
+        /// <param name="className">The field name.</param>
+        private string GetInnerHtml(HtmlNode container, string className)
+        {
+            return container.Descendants().FirstOrDefault(p => p.HasClass(className))?.InnerHtml;
+        }
+
+        /// <summary>The response model for the MediaWiki parse API.</summary>
+        [SuppressMessage("ReSharper", "ClassNeverInstantiated.Local")]
+        [SuppressMessage("ReSharper", "UnusedAutoPropertyAccessor.Local")]
+        private class ResponseModel
+        {
+            /// <summary>The parse API results.</summary>
+            public ResponseParseModel Parse { get; set; }
+        }
+
+        /// <summary>The inner response model for the MediaWiki parse API.</summary>
+        [SuppressMessage("ReSharper", "ClassNeverInstantiated.Local")]
+        [SuppressMessage("ReSharper", "CollectionNeverUpdated.Local")]
+        [SuppressMessage("ReSharper", "UnusedAutoPropertyAccessor.Local")]
+        private class ResponseParseModel
+        {
+            /// <summary>The parsed text.</summary>
+            public IDictionary<string, string> Text { get; set; }
+        }
+    }
+}