3 files changed, 106 insertions, 0 deletions
diff --git a/src/SMAPI.Web/Framework/Clients/GitHub/GitHubClient.cs b/src/SMAPI.Web/Framework/Clients/GitHub/GitHubClient.cs
new file mode 100644
index 00000000..0b205660
--- /dev/null
+++ b/src/SMAPI.Web/Framework/Clients/GitHub/GitHubClient.cs
@@ -0,0 +1,70 @@
+using System;
+using System.Net;
+using System.Threading.Tasks;
+using Pathoschild.Http.Client;
+
+namespace StardewModdingAPI.Web.Framework.Clients.GitHub
+{
+    /// <summary>An HTTP client for fetching metadata from GitHub.</summary>
+    internal class GitHubClient : IGitHubClient
+    {
+        /*********
+        ** Properties
+        *********/
+        /// <summary>The URL for a GitHub releases API query excluding the base URL, where {0} is the repository owner and name.</summary>
+        private readonly string ReleaseUrlFormat;
+
+        /// <summary>The underlying HTTP client.</summary>
+        private readonly IClient Client;
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="baseUrl">The base URL for the GitHub API.</param>
+        /// <param name="releaseUrlFormat">The URL for a GitHub releases API query excluding the <paramref name="baseUrl"/>, where {0} is the repository owner and name.</param>
+        /// <param name="userAgent">The user agent for the API client.</param>
+        /// <param name="acceptHeader">The Accept header value expected by the GitHub API.</param>
+        /// <param name="username">The username with which to authenticate to the GitHub API.</param>
+        /// <param name="password">The password with which to authenticate to the GitHub API.</param>
+        public GitHubClient(string baseUrl, string releaseUrlFormat, string userAgent, string acceptHeader, string username, string password)
+        {
+            this.ReleaseUrlFormat = releaseUrlFormat;
+
+            this.Client = new FluentClient(baseUrl)
+                .SetUserAgent(userAgent)
+                .AddDefault(req => req.WithHeader("Accept", acceptHeader));
+            if (!string.IsNullOrWhiteSpace(username))
+                this.Client = this.Client.SetBasicAuthentication(username, password);
+        }
+
+        /// <summary>Get the latest release for a GitHub repository.</summary>
+        /// <param name="repo">The repository key (like <c>Pathoschild/SMAPI</c>).</param>
+        /// <returns>Returns the latest release if found, else <c>null</c>.</returns>
+        public async Task<GitRelease> GetLatestReleaseAsync(string repo)
+        {
+            // validate key format
+            if (!repo.Contains("/") || repo.IndexOf("/", StringComparison.InvariantCultureIgnoreCase) != repo.LastIndexOf("/", StringComparison.InvariantCultureIgnoreCase))
+                throw new ArgumentException($"The value '{repo}' isn't a valid GitHub repository key, must be a username and project name like 'Pathoschild/SMAPI'.", nameof(repo));
+
+            // fetch info
+            try
+            {
+                return await this.Client
+                    .GetAsync(string.Format(this.ReleaseUrlFormat, repo))
+                    .As<GitRelease>();
+            }
+            catch (ApiException ex) when (ex.Status == HttpStatusCode.NotFound)
+            {
+                return null;
+            }
+        }
+
+        /// <summary>Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.</summary>
+        public void Dispose()
+        {
+            this.Client?.Dispose();
+        }
+    }
+}
diff --git a/src/SMAPI.Web/Framework/Clients/GitHub/GitRelease.cs b/src/SMAPI.Web/Framework/Clients/GitHub/GitRelease.cs
new file mode 100644
index 00000000..0a47f3b4
--- /dev/null
+++ b/src/SMAPI.Web/Framework/Clients/GitHub/GitRelease.cs
@@ -0,0 +1,19 @@
+using Newtonsoft.Json;
+
+namespace StardewModdingAPI.Web.Framework.Clients.GitHub
+{
+    /// <summary>A GitHub project release.</summary>
+    internal class GitRelease
+    {
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>The display name.</summary>
+        [JsonProperty("name")]
+        public string Name { get; set; }
+
+        /// <summary>The semantic version string.</summary>
+        [JsonProperty("tag_name")]
+        public string Tag { get; set; }
+    }
+}
diff --git a/src/SMAPI.Web/Framework/Clients/GitHub/IGitHubClient.cs b/src/SMAPI.Web/Framework/Clients/GitHub/IGitHubClient.cs
new file mode 100644
index 00000000..6e8eadff
--- /dev/null
+++ b/src/SMAPI.Web/Framework/Clients/GitHub/IGitHubClient.cs
@@ -0,0 +1,17 @@
+using System;
+using System.Threading.Tasks;
+
+namespace StardewModdingAPI.Web.Framework.Clients.GitHub
+{
+    /// <summary>An HTTP client for fetching metadata from GitHub.</summary>
+    internal interface IGitHubClient : IDisposable
+    {
+        /*********
+        ** Methods
+        *********/
+        /// <summary>Get the latest release for a GitHub repository.</summary>
+        /// <param name="repo">The repository key (like <c>Pathoschild/SMAPI</c>).</param>
+        /// <returns>Returns the latest release if found, else <c>null</c>.</returns>
+        Task<GitRelease> GetLatestReleaseAsync(string repo);
+    }
+}