1 files changed, 132 insertions, 0 deletions
diff --git a/src/StardewModdingAPI.Web/Controllers/ModsController.cs b/src/StardewModdingAPI.Web/Controllers/ModsController.cs
new file mode 100644
index 00000000..8fc2cb51
--- /dev/null
+++ b/src/StardewModdingAPI.Web/Controllers/ModsController.cs
@@ -0,0 +1,132 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.Options;
+using StardewModdingAPI.Web.Framework.ConfigModels;
+using StardewModdingAPI.Web.Framework.ModRepositories;
+using StardewModdingAPI.Models;
+
+namespace StardewModdingAPI.Web.Controllers
+{
+    /// <summary>Provides an API to perform mod update checks.</summary>
+    [Produces("application/json")]
+    internal class ModsController : Controller
+    {
+        /*********
+        ** Properties
+        *********/
+        /// <summary>The mod repositories which provide mod metadata.</summary>
+        private readonly IDictionary<string, IModRepository> Repositories;
+
+        /// <summary>The cache in which to store mod metadata.</summary>
+        private readonly IMemoryCache Cache;
+
+        /// <summary>The number of minutes update checks should be cached before refetching them.</summary>
+        private readonly int CacheMinutes;
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="cache">The cache in which to store mod metadata.</param>
+        /// <param name="configProvider">The config settings for mod update checks.</param>
+        public ModsController(IMemoryCache cache, IOptions<ModUpdateCheckConfig> configProvider)
+        {
+            ModUpdateCheckConfig config = configProvider.Value;
+
+            this.Cache = cache;
+            this.CacheMinutes = config.CacheMinutes;
+
+            this.Repositories =
+                new IModRepository[]
+                {
+                    new GitHubRepository(
+                        vendorKey: config.GitHubKey,
+                        baseUrl: config.GitHubBaseUrl,
+                        releaseUrlFormat: config.GitHubReleaseUrlFormat,
+                        userAgent: config.GitHubUserAgent,
+                        acceptHeader: config.GitHubAcceptHeader,
+                        username: config.GitHubUsername,
+                        password: config.GitHubPassword
+                    ),
+                    new NexusRepository(
+                        vendorKey: config.NexusKey,
+                        userAgent: config.NexusUserAgent,
+                        baseUrl: config.NexusBaseUrl,
+                        modUrlFormat: config.NexusModUrlFormat
+                    )
+                }
+                .ToDictionary(p => p.VendorKey, StringComparer.CurrentCultureIgnoreCase);
+        }
+
+        /// <summary>Fetch version metadata for the given mods.</summary>
+        /// <param name="modKeys">The namespaced mod keys to search as a comma-delimited array.</param>
+        [HttpGet]
+        public async Task<IDictionary<string, ModInfoModel>> GetAsync(string modKeys)
+        {
+            // sort & filter keys
+            string[] modKeysArray = (modKeys?.Split(',').Select(p => p.Trim()).ToArray() ?? new string[0])
+                .Distinct(StringComparer.CurrentCultureIgnoreCase)
+                .OrderBy(p => p, StringComparer.CurrentCultureIgnoreCase)
+                .ToArray();
+
+            // fetch mod info
+            IDictionary<string, ModInfoModel> result = new Dictionary<string, ModInfoModel>(StringComparer.CurrentCultureIgnoreCase);
+            foreach (string modKey in modKeysArray)
+            {
+                // parse mod key
+                if (!this.TryParseModKey(modKey, out string vendorKey, out string modID))
+                {
+                    result[modKey] = new ModInfoModel("The mod key isn't in a valid format. It should contain the mod repository key and mod ID like 'Nexus:541'.");
+                    continue;
+                }
+
+                // get matching repository
+                if (!this.Repositories.TryGetValue(vendorKey, out IModRepository repository))
+                {
+                    result[modKey] = new ModInfoModel("There's no mod repository matching this namespaced mod ID.");
+                    continue;
+                }
+
+                // fetch mod info
+                result[modKey] = await this.Cache.GetOrCreateAsync($"{repository.VendorKey}:{modID}".ToLower(), async entry =>
+                {
+                    entry.AbsoluteExpiration = DateTimeOffset.UtcNow.AddMinutes(this.CacheMinutes);
+                    return await repository.GetModInfoAsync(modID);
+                });
+            }
+
+            return result;
+        }
+
+
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>Parse a namespaced mod ID.</summary>
+        /// <param name="raw">The raw mod ID to parse.</param>
+        /// <param name="vendorKey">The parsed vendor key.</param>
+        /// <param name="modID">The parsed mod ID.</param>
+        /// <returns>Returns whether the value could be parsed.</returns>
+        private bool TryParseModKey(string raw, out string vendorKey, out string modID)
+        {
+            // split parts
+            string[] parts = raw?.Split(':');
+            if (parts == null || parts.Length != 2)
+            {
+                vendorKey = null;
+                modID = null;
+                return false;
+            }
+
+            // parse
+            vendorKey = parts[0];
+            modID = parts[1];
+            return true;
+        }
+    }
+}