fetch mod info from Nexus API if the web page is hidden due to adult content (#651)

2 files changed, 106 insertions, 30 deletions

diff --git a/src/SMAPI.Web/Framework/Clients/Nexus/NexusClient.cs b/src/SMAPI.Web/Framework/Clients/Nexus/NexusClient.cs
index 87393367..753d3b4f 100644
--- a/src/SMAPI.Web/Framework/Clients/Nexus/NexusClient.cs
+++ b/src/SMAPI.Web/Framework/Clients/Nexus/NexusClient.cs
@@ -4,8 +4,10 @@ using System.Linq;
 using System.Net;
 using System.Threading.Tasks;
 using HtmlAgilityPack;
+using Pathoschild.FluentNexus.Models;
 using Pathoschild.Http.Client;
 using StardewModdingAPI.Toolkit;
+using FluentNexusClient = Pathoschild.FluentNexus.NexusClient;
 
 namespace StardewModdingAPI.Web.Framework.Clients.Nexus
 {
@@ -16,28 +18,34 @@ namespace StardewModdingAPI.Web.Framework.Clients.Nexus
         ** 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 ModUrlFormat;
+        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 ModScrapeUrlFormat { get; set; }
+        public string WebModScrapeUrlFormat { get; set; }
 
-        /// <summary>The underlying HTTP client.</summary>
-        private readonly IClient Client;
+        /// <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;
 
 
         /*********
         ** Public methods
         *********/
         /// <summary>Construct an instance.</summary>
-        /// <param name="userAgent">The user agent for the Nexus Mods API client.</param>
-        /// <param name="baseUrl">The base URL for the Nexus Mods site.</param>
-        /// <param name="modUrlFormat">The URL for a Nexus Mods mod page for the user, excluding the <paramref name="baseUrl"/>, where {0} is the mod ID.</param>
-        /// <param name="modScrapeUrlFormat">The URL for a Nexus mod page to scrape for versions, excluding the base URL, where {0} is the mod ID.</param>
-        public NexusClient(string userAgent, string baseUrl, string modUrlFormat, string modScrapeUrlFormat)
+        /// <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.ModUrlFormat = modUrlFormat;
-            this.ModScrapeUrlFormat = modScrapeUrlFormat;
-            this.Client = new FluentClient(baseUrl).SetUserAgent(userAgent);
+            this.WebModUrlFormat = webModUrlFormat;
+            this.WebModScrapeUrlFormat = webModScrapeUrlFormat;
+            this.WebClient = new FluentClient(webBaseUrl).SetUserAgent(webUserAgent);
+            this.ApiClient = new FluentNexusClient(apiKey, "SMAPI", apiAppVersion);
         }
 
         /// <summary>Get metadata about a mod.</summary>
@@ -45,12 +53,38 @@ namespace StardewModdingAPI.Web.Framework.Clients.Nexus
         /// <returns>Returns the mod info if found, else <c>null</c>.</returns>
         public async Task<NexusMod> GetModAsync(uint 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(id);
+            if (mod?.Status == NexusModStatus.AdultContentForbidden)
+                mod = await this.GetModFromApiAsync(id);
+
+            return mod;
+        }
+
+        /// <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.Client
-                    .GetAsync(string.Format(this.ModScrapeUrlFormat, id))
+                html = await this.WebClient
+                    .GetAsync(string.Format(this.WebModScrapeUrlFormat, id))
                     .AsString();
             }
             catch (ApiException ex) when (ex.Status == HttpStatusCode.NotFound)
@@ -74,14 +108,8 @@ namespace StardewModdingAPI.Web.Framework.Clients.Nexus
                     case "not found":
                         return null;
 
-                    case "hidden mod":
-                        return new NexusMod { Error = $"Nexus error: {errorCode} ({errorText}).", Status = NexusModStatus.Hidden };
-
-                    case "not published":
-                        return new NexusMod { Error = $"Nexus error: {errorCode} ({errorText}).", Status = NexusModStatus.NotPublished };
-
                     default:
-                        return new NexusMod { Error = $"Nexus error: {errorCode} ({errorText}).", Status = NexusModStatus.Other };
+                        return new NexusMod { Error = $"Nexus error: {errorCode} ({errorText}).", Status = this.GetWebStatus(errorCode) };
                 }
             }
 
@@ -130,23 +158,68 @@ namespace StardewModdingAPI.Web.Framework.Clients.Nexus
             };
         }
 
-        /// <summary>Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.</summary>
-        public void Dispose()
+        /// <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)
         {
-            this.Client?.Dispose();
-        }
+            // 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);
+
+            // get versions
+            if (!SemanticVersion.TryParse(mod.Version, out ISemanticVersion mainVersion))
+                mainVersion = null;
+            ISemanticVersion latestFileVersion = null;
+            foreach (string rawVersion in files.Files.Select(p => p.FileVersion))
+            {
+                if (!SemanticVersion.TryParse(rawVersion, out ISemanticVersion cur))
+                    continue;
+                if (mainVersion != null && !cur.IsNewerThan(mainVersion))
+                    continue;
+                if (latestFileVersion != null && !cur.IsNewerThan(latestFileVersion))
+                    continue;
 
+                latestFileVersion = cur;
+            }
+
+            // yield info
+            return new NexusMod
+            {
+                Name = mod.Name,
+                Version = SemanticVersion.TryParse(mod.Version, out ISemanticVersion version) ? version?.ToString() : mod.Version,
+                LatestFileVersion = latestFileVersion,
+                Url = this.GetModUrl(id)
+            };
+        }
 
-        /*********
-        ** Private methods
-        *********/
         /// <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 UriBuilder(this.Client.BaseClient.BaseAddress);
-            builder.Path += string.Format(this.ModUrlFormat, id);
+            UriBuilder builder = new UriBuilder(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;
+            }
+        }
     }
 }
diff --git a/src/SMAPI.Web/Framework/Clients/Nexus/NexusModStatus.cs b/src/SMAPI.Web/Framework/Clients/Nexus/NexusModStatus.cs
index c5723093..9ef314cd 100644
--- a/src/SMAPI.Web/Framework/Clients/Nexus/NexusModStatus.cs
+++ b/src/SMAPI.Web/Framework/Clients/Nexus/NexusModStatus.cs
@@ -12,6 +12,9 @@ namespace StardewModdingAPI.Web.Framework.Clients.Nexus
         /// <summary>The mod hasn't been published yet.</summary>
         NotPublished,
 
+        /// <summary>The mod contains adult content which is hidden for anonymous web users.</summary>
+        AdultContentForbidden,
+
         /// <summary>The Nexus API returned an unhandled error.</summary>
         Other
     }