changed.对启动器重构的尝试

LanMountainDesktop.Launcher/Update/RollbackStrategy.cs

@@ -0,0 +1,48 @@
+using LanMountainDesktop.Launcher.Models;
+
+namespace LanMountainDesktop.Launcher.Update;
+
+internal sealed class RollbackStrategy(
+    DeploymentLocator deploymentLocator,
+    UpdateSnapshotStore snapshotStore,
+    DeploymentActivator deploymentActivator)
+{
+    public LauncherResult RollbackLatest()
+    {
+        var latest = snapshotStore.LoadLatest();
+        if (latest is null)
+        {
+            return UpdateEngineResults.Failed("update.rollback", "no_snapshot", "No snapshot found.");
+        }
+
+        var (snapshotPath, snapshot) = latest.Value;
+        if (string.IsNullOrWhiteSpace(snapshot.SourceDirectory))
+        {
+            return UpdateEngineResults.Failed("update.rollback", "invalid_snapshot", "Invalid snapshot metadata.");
+        }
+
+        if (!Directory.Exists(snapshot.SourceDirectory))
+        {
+            return UpdateEngineResults.Failed("update.rollback", "source_missing", $"Rollback source deployment is missing: {snapshot.SourceDirectory}");
+        }
+
+        var currentDeployment = deploymentLocator.FindCurrentDeploymentDirectory();
+        if (string.IsNullOrWhiteSpace(currentDeployment))
+        {
+            return UpdateEngineResults.Failed("update.rollback", "no_current_deployment", "Current deployment not found.");
+        }
+
+        deploymentActivator.Activate(currentDeployment, snapshot.SourceDirectory);
+        snapshot.Status = "manual_rollback";
+        snapshotStore.Save(snapshotPath, snapshot);
+
+        return new LauncherResult
+        {
+            Success = true,
+            Stage = "update.rollback",
+            Code = "ok",
+            Message = $"Rolled back to {snapshot.SourceVersion}.",
+            RolledBackTo = snapshot.SourceVersion
+        };
+    }
+}