add support for CurseForge update keys (#605)

12 files changed, 268 insertions, 1 deletions

diff --git a/docs/release-notes.md b/docs/release-notes.md
index 1d933f96..5c12c4cc 100644
--- a/docs/release-notes.md
+++ b/docs/release-notes.md
@@ -47,6 +47,7 @@ For modders:
     * Now ignores metadata files and folders (like `__MACOSX` and `__folder_managed_by_vortex`) and content files (like `.txt` or `.png`), which avoids missing-manifest errors in some common cases.
     * Now detects XNB mods more accurately, and consolidates multi-folder XNB mods in logged messages.
   * SMAPI now automatically removes invalid content when loading a save to prevent crashes. A warning is shown in-game when this happens. This applies for locations and NPCs.
+  * Added update checks for CurseForge mods.
   * Added support for configuring console colors via `smapi-internal/config.json` (intended for players with unusual consoles).
   * Added support for specifying SMAPI command-line arguments as environment variables for Linux/Mac compatibility.
   * Improved launch script compatibility on Linux (thanks to kurumushi and toastal!).
diff --git a/src/SMAPI.Toolkit/Framework/UpdateData/ModRepositoryKey.cs b/src/SMAPI.Toolkit/Framework/UpdateData/ModRepositoryKey.cs
index f6c402d5..765ca334 100644
--- a/src/SMAPI.Toolkit/Framework/UpdateData/ModRepositoryKey.cs
+++ b/src/SMAPI.Toolkit/Framework/UpdateData/ModRepositoryKey.cs
@@ -9,6 +9,9 @@ namespace StardewModdingAPI.Toolkit.Framework.UpdateData
         /// <summary>The Chucklefish mod repository.</summary>
         Chucklefish,
 
+        /// <summary>The CurseForge mod repository.</summary>
+        CurseForge,
+
         /// <summary>A GitHub project containing releases.</summary>
         GitHub,
 
diff --git a/src/SMAPI.Web/Controllers/ModsApiController.cs b/src/SMAPI.Web/Controllers/ModsApiController.cs
index 8419b220..1412105a 100644
--- a/src/SMAPI.Web/Controllers/ModsApiController.cs
+++ b/src/SMAPI.Web/Controllers/ModsApiController.cs
@@ -14,6 +14,7 @@ using StardewModdingAPI.Toolkit.Framework.UpdateData;
 using StardewModdingAPI.Web.Framework.Caching.Mods;
 using StardewModdingAPI.Web.Framework.Caching.Wiki;
 using StardewModdingAPI.Web.Framework.Clients.Chucklefish;
+using StardewModdingAPI.Web.Framework.Clients.CurseForge;
 using StardewModdingAPI.Web.Framework.Clients.GitHub;
 using StardewModdingAPI.Web.Framework.Clients.ModDrop;
 using StardewModdingAPI.Web.Framework.Clients.Nexus;
@@ -61,10 +62,11 @@ namespace StardewModdingAPI.Web.Controllers
         /// <param name="modCache">The cache in which to store mod metadata.</param>
         /// <param name="configProvider">The config settings for mod update checks.</param>
         /// <param name="chucklefish">The Chucklefish API client.</param>
+        /// <param name="curseForge">The CurseForge API client.</param>
         /// <param name="github">The GitHub API client.</param>
         /// <param name="modDrop">The ModDrop API client.</param>
         /// <param name="nexus">The Nexus API client.</param>
-        public ModsApiController(IHostingEnvironment environment, IWikiCacheRepository wikiCache, IModCacheRepository modCache, IOptions<ModUpdateCheckConfig> configProvider, IChucklefishClient chucklefish, IGitHubClient github, IModDropClient modDrop, INexusClient nexus)
+        public ModsApiController(IHostingEnvironment environment, IWikiCacheRepository wikiCache, IModCacheRepository modCache, IOptions<ModUpdateCheckConfig> configProvider, IChucklefishClient chucklefish, ICurseForgeClient curseForge, IGitHubClient github, IModDropClient modDrop, INexusClient nexus)
         {
             this.ModDatabase = new ModToolkit().GetModDatabase(Path.Combine(environment.WebRootPath, "SMAPI.metadata.json"));
             ModUpdateCheckConfig config = configProvider.Value;
@@ -78,6 +80,7 @@ namespace StardewModdingAPI.Web.Controllers
                 new IModRepository[]
                 {
                     new ChucklefishRepository(chucklefish),
+                    new CurseForgeRepository(curseForge), 
                     new GitHubRepository(github),
                     new ModDropRepository(modDrop),
                     new NexusRepository(nexus)
diff --git a/src/SMAPI.Web/Framework/Clients/CurseForge/CurseForgeClient.cs b/src/SMAPI.Web/Framework/Clients/CurseForge/CurseForgeClient.cs
new file mode 100644
index 00000000..140b854e
--- /dev/null
+++ b/src/SMAPI.Web/Framework/Clients/CurseForge/CurseForgeClient.cs
@@ -0,0 +1,113 @@
+using System.Linq;
+using System.Text.RegularExpressions;
+using System.Threading.Tasks;
+using Pathoschild.Http.Client;
+using StardewModdingAPI.Toolkit;
+using StardewModdingAPI.Web.Framework.Clients.CurseForge.ResponseModels;
+
+namespace StardewModdingAPI.Web.Framework.Clients.CurseForge
+{
+    /// <summary>An HTTP client for fetching mod metadata from the CurseForge API.</summary>
+    internal class CurseForgeClient : ICurseForgeClient
+    {
+        /*********
+        ** Fields
+        *********/
+        /// <summary>The underlying HTTP client.</summary>
+        private readonly IClient Client;
+
+        /// <summary>A regex pattern which matches a version number in a CurseForge mod file name.</summary>
+        private readonly Regex VersionInNamePattern = new Regex(@"^(?:.+? | *)v?(\d+\.\d+(?:\.\d+)?(?:-.+?)?) *(?:\.(?:zip|rar|7z))?$", RegexOptions.Compiled);
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="userAgent">The user agent for the API client.</param>
+        /// <param name="apiUrl">The base URL for the CurseForge API.</param>
+        public CurseForgeClient(string userAgent, string apiUrl)
+        {
+            this.Client = new FluentClient(apiUrl).SetUserAgent(userAgent);
+        }
+
+        /// <summary>Get metadata about a mod.</summary>
+        /// <param name="id">The CurseForge mod ID.</param>
+        /// <returns>Returns the mod info if found, else <c>null</c>.</returns>
+        public async Task<CurseForgeMod> GetModAsync(long id)
+        {
+            // get raw data
+            ModModel mod = await this.Client
+                .GetAsync($"addon/{id}")
+                .As<ModModel>();
+            if (mod == null)
+                return null;
+
+            // get latest versions
+            string invalidVersion = null;
+            ISemanticVersion latest = null;
+            foreach (ModFileModel file in mod.LatestFiles)
+            {
+                // extract version
+                ISemanticVersion version;
+                {
+                    string raw = this.GetRawVersion(file);
+                    if (raw == null)
+                        continue;
+
+                    if (!SemanticVersion.TryParse(raw, out version))
+                    {
+                        if (invalidVersion == null)
+                            invalidVersion = raw;
+                        continue;
+                    }
+                }
+
+                // track latest version
+                if (latest == null || version.IsNewerThan(latest))
+                    latest = version;
+            }
+
+            // get error
+            string error = null;
+            if (latest == null && invalidVersion == null)
+            {
+                error = mod.LatestFiles.Any()
+                    ? $"CurseForge mod {id} has no downloads which specify the version in a recognised format."
+                    : $"CurseForge mod {id} has no downloads.";
+            }
+
+            // generate result
+            return new CurseForgeMod
+            {
+                Name = mod.Name,
+                LatestVersion = latest?.ToString() ?? invalidVersion,
+                Url = mod.WebsiteUrl,
+                Error = error
+            };
+        }
+
+        /// <summary>Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.</summary>
+        public void Dispose()
+        {
+            this.Client?.Dispose();
+        }
+
+
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>Get a raw version string for a mod file, if available.</summary>
+        /// <param name="file">The file whose version to get.</param>
+        private string GetRawVersion(ModFileModel file)
+        {
+            Match match = this.VersionInNamePattern.Match(file.DisplayName);
+            if (!match.Success)
+                match = this.VersionInNamePattern.Match(file.FileName);
+
+            return match.Success
+                ? match.Groups[1].Value
+                : null;
+        }
+    }
+}
diff --git a/src/SMAPI.Web/Framework/Clients/CurseForge/CurseForgeMod.cs b/src/SMAPI.Web/Framework/Clients/CurseForge/CurseForgeMod.cs
new file mode 100644
index 00000000..e5bb8cf1
--- /dev/null
+++ b/src/SMAPI.Web/Framework/Clients/CurseForge/CurseForgeMod.cs
@@ -0,0 +1,23 @@
+using Newtonsoft.Json;
+
+namespace StardewModdingAPI.Web.Framework.Clients.CurseForge
+{
+    /// <summary>Mod metadata from the CurseForge API.</summary>
+    internal class CurseForgeMod
+    {
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>The mod name.</summary>
+        public string Name { get; set; }
+
+        /// <summary>The latest file version.</summary>
+        public string LatestVersion { get; set; }
+
+        /// <summary>The mod's web URL.</summary>
+        public string Url { get; set; }
+
+        /// <summary>A user-friendly error which indicates why fetching the mod info failed (if applicable).</summary>
+        public string Error { get; set; }
+    }
+}
diff --git a/src/SMAPI.Web/Framework/Clients/CurseForge/ICurseForgeClient.cs b/src/SMAPI.Web/Framework/Clients/CurseForge/ICurseForgeClient.cs
new file mode 100644
index 00000000..907b4087
--- /dev/null
+++ b/src/SMAPI.Web/Framework/Clients/CurseForge/ICurseForgeClient.cs
@@ -0,0 +1,17 @@
+using System;
+using System.Threading.Tasks;
+
+namespace StardewModdingAPI.Web.Framework.Clients.CurseForge
+{
+    /// <summary>An HTTP client for fetching mod metadata from the CurseForge API.</summary>
+    internal interface ICurseForgeClient : IDisposable
+    {
+        /*********
+        ** Methods
+        *********/
+        /// <summary>Get metadata about a mod.</summary>
+        /// <param name="id">The CurseForge mod ID.</param>
+        /// <returns>Returns the mod info if found, else <c>null</c>.</returns>
+        Task<CurseForgeMod> GetModAsync(long id);
+    }
+}
diff --git a/src/SMAPI.Web/Framework/Clients/CurseForge/ResponseModels/ModFileModel.cs b/src/SMAPI.Web/Framework/Clients/CurseForge/ResponseModels/ModFileModel.cs
new file mode 100644
index 00000000..9de74847
--- /dev/null
+++ b/src/SMAPI.Web/Framework/Clients/CurseForge/ResponseModels/ModFileModel.cs
@@ -0,0 +1,12 @@
+namespace StardewModdingAPI.Web.Framework.Clients.CurseForge.ResponseModels
+{
+    /// <summary>Metadata from the CurseForge API about a mod file.</summary>
+    public class ModFileModel
+    {
+        /// <summary>The file name as downloaded.</summary>
+        public string FileName { get; set; }
+
+        /// <summary>The file display name.</summary>
+        public string DisplayName { get; set; }
+    }
+}
diff --git a/src/SMAPI.Web/Framework/Clients/CurseForge/ResponseModels/ModModel.cs b/src/SMAPI.Web/Framework/Clients/CurseForge/ResponseModels/ModModel.cs
new file mode 100644
index 00000000..48cd185b
--- /dev/null
+++ b/src/SMAPI.Web/Framework/Clients/CurseForge/ResponseModels/ModModel.cs
@@ -0,0 +1,18 @@
+namespace StardewModdingAPI.Web.Framework.Clients.CurseForge.ResponseModels
+{
+    /// <summary>An mod from the CurseForge API.</summary>
+    public class ModModel
+    {
+        /// <summary>The mod's unique ID on CurseForge.</summary>
+        public int ID { get; set; }
+
+        /// <summary>The mod name.</summary>
+        public string Name { get; set; }
+
+        /// <summary>The web URL for the mod page.</summary>
+        public string WebsiteUrl { get; set; }
+
+        /// <summary>The available file downloads.</summary>
+        public ModFileModel[] LatestFiles { get; set; }
+    }
+}
diff --git a/src/SMAPI.Web/Framework/ConfigModels/ApiClientsConfig.cs b/src/SMAPI.Web/Framework/ConfigModels/ApiClientsConfig.cs
index a0a1f42a..121690c5 100644
--- a/src/SMAPI.Web/Framework/ConfigModels/ApiClientsConfig.cs
+++ b/src/SMAPI.Web/Framework/ConfigModels/ApiClientsConfig.cs
@@ -24,6 +24,13 @@ namespace StardewModdingAPI.Web.Framework.ConfigModels
 
 
         /****
+        ** CurseForge
+        ****/
+        /// <summary>The base URL for the CurseForge API.</summary>
+        public string CurseForgeBaseUrl { get; set; }
+
+
+        /****
         ** GitHub
         ****/
         /// <summary>The base URL for the GitHub API.</summary>
diff --git a/src/SMAPI.Web/Framework/ModRepositories/CurseForgeRepository.cs b/src/SMAPI.Web/Framework/ModRepositories/CurseForgeRepository.cs
new file mode 100644
index 00000000..93ddc1eb
--- /dev/null
+++ b/src/SMAPI.Web/Framework/ModRepositories/CurseForgeRepository.cs
@@ -0,0 +1,63 @@
+using System;
+using System.Threading.Tasks;
+using StardewModdingAPI.Toolkit.Framework.UpdateData;
+using StardewModdingAPI.Web.Framework.Clients.CurseForge;
+
+namespace StardewModdingAPI.Web.Framework.ModRepositories
+{
+    /// <summary>An HTTP client for fetching mod metadata from CurseForge.</summary>
+    internal class CurseForgeRepository : RepositoryBase
+    {
+        /*********
+        ** Fields
+        *********/
+        /// <summary>The underlying CurseForge API client.</summary>
+        private readonly ICurseForgeClient Client;
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="client">The underlying CurseForge API client.</param>
+        public CurseForgeRepository(ICurseForgeClient client)
+            : base(ModRepositoryKey.CurseForge)
+        {
+            this.Client = client;
+        }
+
+        /// <summary>Get metadata about a mod in the repository.</summary>
+        /// <param name="id">The mod ID in this repository.</param>
+        public override async Task<ModInfoModel> GetModInfoAsync(string id)
+        {
+            // validate ID format
+            if (!uint.TryParse(id, out uint curseID))
+                return new ModInfoModel().SetError(RemoteModStatus.DoesNotExist, $"The value '{id}' isn't a valid CurseForge mod ID, must be an integer ID.");
+
+            // fetch info
+            try
+            {
+                CurseForgeMod mod = await this.Client.GetModAsync(curseID);
+                if (mod == null)
+                    return new ModInfoModel().SetError(RemoteModStatus.DoesNotExist, "Found no CurseForge mod with this ID.");
+                if (mod.Error != null)
+                {
+                    RemoteModStatus remoteStatus = RemoteModStatus.InvalidData;
+                    return new ModInfoModel().SetError(remoteStatus, mod.Error);
+                }
+
+                return new ModInfoModel(name: mod.Name, version: this.NormalizeVersion(mod.LatestVersion), url: mod.Url);
+            }
+            catch (Exception ex)
+            {
+                return new ModInfoModel().SetError(RemoteModStatus.TemporaryError, ex.ToString());
+            }
+        }
+
+        /// <summary>Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.</summary>
+        public override void Dispose()
+        {
+            this.Client.Dispose();
+        }
+    }
+}
diff --git a/src/SMAPI.Web/Startup.cs b/src/SMAPI.Web/Startup.cs
index bf69d543..8110b696 100644
--- a/src/SMAPI.Web/Startup.cs
+++ b/src/SMAPI.Web/Startup.cs
@@ -16,6 +16,7 @@ using StardewModdingAPI.Web.Framework.Caching;
 using StardewModdingAPI.Web.Framework.Caching.Mods;
 using StardewModdingAPI.Web.Framework.Caching.Wiki;
 using StardewModdingAPI.Web.Framework.Clients.Chucklefish;
+using StardewModdingAPI.Web.Framework.Clients.CurseForge;
 using StardewModdingAPI.Web.Framework.Clients.GitHub;
 using StardewModdingAPI.Web.Framework.Clients.ModDrop;
 using StardewModdingAPI.Web.Framework.Clients.Nexus;
@@ -119,6 +120,10 @@ namespace StardewModdingAPI.Web
                     baseUrl: api.ChucklefishBaseUrl,
                     modPageUrlFormat: api.ChucklefishModPageUrlFormat
                 ));
+                services.AddSingleton<ICurseForgeClient>(new CurseForgeClient(
+                    userAgent: userAgent,
+                    apiUrl: api.CurseForgeBaseUrl
+                ));
 
                 services.AddSingleton<IGitHubClient>(new GitHubClient(
                     baseUrl: api.GitHubBaseUrl,
diff --git a/src/SMAPI.Web/appsettings.json b/src/SMAPI.Web/appsettings.json
index a440cf42..674bb672 100644
--- a/src/SMAPI.Web/appsettings.json
+++ b/src/SMAPI.Web/appsettings.json
@@ -30,6 +30,8 @@
         "ChucklefishBaseUrl": "https://community.playstarbound.com",
         "ChucklefishModPageUrlFormat": "resources/{0}",
 
+        "CurseForgeBaseUrl": "https://addons-ecs.forgesvc.net/api/v2/",
+
         "GitHubBaseUrl": "https://api.github.com",
         "GitHubAcceptHeader": "application/vnd.github.v3+json",
         "GitHubUsername": null, // see top note