add update check (#154)

2 files changed, 55 insertions, 0 deletions

diff --git a/src/StardewModdingAPI/Framework/GitRelease.cs b/src/StardewModdingAPI/Framework/GitRelease.cs
new file mode 100644
index 00000000..0da57efd
--- /dev/null
+++ b/src/StardewModdingAPI/Framework/GitRelease.cs
@@ -0,0 +1,19 @@
+using Newtonsoft.Json;
+
+namespace StardewModdingAPI.Framework
+{
+    /// <summary>Metadata about a GitHub release tag.</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; }
+    }
+}
\ No newline at end of file
diff --git a/src/StardewModdingAPI/Framework/UpdateHelper.cs b/src/StardewModdingAPI/Framework/UpdateHelper.cs
new file mode 100644
index 00000000..ddd1d840
--- /dev/null
+++ b/src/StardewModdingAPI/Framework/UpdateHelper.cs
@@ -0,0 +1,36 @@
+using System.IO;
+using System.Net;
+using System.Reflection;
+using System.Threading.Tasks;
+using Newtonsoft.Json;
+
+namespace StardewModdingAPI.Framework
+{
+    /// <summary>Provides utility methods for mod updates.</summary>
+    internal class UpdateHelper
+    {
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Get the latest release from a GitHub repository.</summary>
+        /// <param name="repository">The name of the repository from which to fetch releases (like "cjsu/SMAPI").</param>
+        public static async Task<GitRelease> GetLatestVersionAsync(string repository)
+        {
+            // build request
+            // (avoid HttpClient for Mac compatibility)
+            HttpWebRequest request = WebRequest.CreateHttp($"https://api.github.com/repos/{repository}/releases/latest");
+            AssemblyName assembly = typeof(UpdateHelper).Assembly.GetName();
+            request.UserAgent = $"{assembly.Name}/{assembly.Version}";
+            request.Accept = "application/vnd.github.v3+json";
+
+            // fetch data 
+            using (WebResponse response = await request.GetResponseAsync())
+            using (Stream responseStream = response.GetResponseStream())
+            using (StreamReader reader = new StreamReader(responseStream))
+            {
+                string responseText = reader.ReadToEnd();
+                return JsonConvert.DeserializeObject<GitRelease>(responseText);
+            }
+        }
+    }
+}