Add basic support for prerelease versions

VersionInfo.cs

@@ -1,28 +1,35 @@
-using System.Xml.Linq;
+using System.Net.Http.Headers;
+using System.Xml.Linq;
 
 namespace ChrisKaczor.ApplicationUpdate;
 
 public class VersionInfo
 {
+    private static readonly HttpClient HttpClient = new() { DefaultRequestHeaders = { UserAgent = { ProductInfoHeaderValue.Parse(UpdateCheck.ApplicationName) } } };
+
     public Version? Version { get; set; }
     public string? InstallFile { get; set; }
     public DateTimeOffset? InstallCreated { get; set; }
+    public bool? Prerelease { get; set; }
 
-    public static async Task<VersionInfo?> Load(ServerType updateServerType, string server, string file)
+    public static async Task<VersionInfo?> Load(ServerType updateServerType, string url, string file, bool includePrerelease)
     {
         return updateServerType switch
         {
-            ServerType.Generic => LoadFile(server, file),
-            ServerType.GitHub => await LoadGitHub(server),
+            ServerType.Generic => LoadFile(url, file, includePrerelease),
+            ServerType.GitHub => await LoadGitHub(url, includePrerelease),
             _ => null
         };
     }
 
-    private static VersionInfo? LoadFile(string server, string file)
+    private static VersionInfo? LoadFile(string url, string file, bool includePrerelease)
     {
         try
         {
-            var document = XDocument.Load(server + file);
+            if (includePrerelease)
+                throw new NotSupportedException("Prerelease not currently supported for generic server type");
+
+            var document = XDocument.Load(url + file);
 
             var versionInformationElement = document.Element("versionInformation");
 
@@ -51,33 +58,26 @@ public class VersionInfo
         }
     }
 
-    private static async Task<VersionInfo?> LoadGitHub(string server)
+    private static async Task<VersionInfo?> LoadGitHub(string baseUrl, bool includePrerelease)
     {
-        try
-        {
-            var httpClient = new HttpClient();
+        var versionInfo = includePrerelease ? await GitHubRelease.GetLatestPrereleaseAsync(baseUrl) : await GitHubRelease.GetLatestAsync(baseUrl);
+        
+        return versionInfo;
+    }
 
-            httpClient.DefaultRequestHeaders.UserAgent.ParseAdd(UpdateCheck.ApplicationName);
-
-            var json = await httpClient.GetStringAsync(server);
-
-            var release = GitHubRelease.FromJson(json);
-
-            if (release?.TagName == null || release.Assets == null || release.Assets.Count == 0)
-                return null;
-
-            var versionInfo = new VersionInfo
-            {
-                Version = Version.Parse(release.TagName),
-                InstallFile = release.Assets[0].BrowserDownloadUrl,
-                InstallCreated = release.Assets[0].CreatedAt?.UtcDateTime
-            };
-
-            return versionInfo;
-        }
-        catch (Exception)
-        {
+    internal static VersionInfo? CreateFromGitHubRelease(GitHubRelease? release)
+    {
+        if (release?.TagName == null || release.Assets == null || release.Assets.Count == 0)
             return null;
-        }
+
+        var versionInfo = new VersionInfo
+        {
+            Version = Version.Parse(release.TagName),
+            InstallFile = release.Assets[0].BrowserDownloadUrl,
+            InstallCreated = release.Assets[0].CreatedAt?.UtcDateTime,
+            Prerelease = release.Prerelease
+        };
+
+        return versionInfo;
     }
 }