changed.对启动器重构的尝试

LanMountainDesktop.Launcher/Update/DeploymentActivator.cs

@@ -0,0 +1,73 @@
+using LanMountainDesktop.Launcher.Models;
+
+namespace LanMountainDesktop.Launcher.Update;
+
+internal sealed class DeploymentActivator(DeploymentLocator deploymentLocator)
+{
+    public void Activate(string fromDeployment, string toDeployment)
+    {
+        var toCurrent = Path.Combine(toDeployment, ".current");
+        var fromCurrent = Path.Combine(fromDeployment, ".current");
+        var fromDestroy = Path.Combine(fromDeployment, ".destroy");
+        var toDestroy = Path.Combine(toDeployment, ".destroy");
+        var toPartial = Path.Combine(toDeployment, ".partial");
+
+        File.WriteAllText(toCurrent, string.Empty);
+        if (File.Exists(toDestroy))
+        {
+            File.Delete(toDestroy);
+        }
+
+        if (File.Exists(fromCurrent))
+        {
+            File.Delete(fromCurrent);
+        }
+
+        File.WriteAllText(fromDestroy, string.Empty);
+        if (File.Exists(toPartial))
+        {
+            File.Delete(toPartial);
+        }
+    }
+
+    public RollbackAttemptResult TryRollbackOnFailure(SnapshotMetadata snapshot)
+    {
+        try
+        {
+            if (!string.IsNullOrWhiteSpace(snapshot.TargetDirectory) && Directory.Exists(snapshot.TargetDirectory))
+            {
+                Directory.Delete(snapshot.TargetDirectory, true);
+            }
+
+            if (string.IsNullOrWhiteSpace(snapshot.SourceDirectory) || !Directory.Exists(snapshot.SourceDirectory))
+            {
+                return new RollbackAttemptResult(false, "Source deployment is missing.");
+            }
+
+            var destroyMarker = Path.Combine(snapshot.SourceDirectory, ".destroy");
+            if (File.Exists(destroyMarker))
+            {
+                File.Delete(destroyMarker);
+            }
+
+            var currentMarker = Path.Combine(snapshot.SourceDirectory, ".current");
+            if (!File.Exists(currentMarker))
+            {
+                File.WriteAllText(currentMarker, string.Empty);
+            }
+
+            return new RollbackAttemptResult(true, null);
+        }
+        catch (Exception ex)
+        {
+            return new RollbackAttemptResult(false, ex.Message);
+        }
+    }
+
+    public void RetainDeploymentsForRollback()
+    {
+        deploymentLocator.CleanupOldDeployments(minVersionsToKeep: 3);
+    }
+}
+
+internal sealed record RollbackAttemptResult(bool Success, string? ErrorMessage);