feat: implement rollback functionality with pre-update backup and recovery options | Rebase

src/EchoHub.Client/Program.cs

@@ -1,12 +1,58 @@
 using EchoHub.Client;
 using EchoHub.Client.Config;
+using EchoHub.Client.Services;
 using EchoHub.Client.Themes;
 using Microsoft.Extensions.Configuration;
 using Serilog;
 using Terminal.Gui.App;
-using Terminal.Gui.Drawing;
 
+// == CLI rollback: works without TUI, before anything else ================
+if (args.Contains("--rollback"))
+{
+    if (UpdateBackupService.BackupExists())
+    {
+        var info = UpdateBackupService.GetBackupInfo();
+        Console.WriteLine($"Rolling back to version {info?.Version ?? "unknown"}...");
+        try
+        {
+            UpdateBackupService.RestoreBackup();
+            // RestoreBackup calls Environment.Exit(0)
+        }
+        catch (Exception ex)
+        {
+            Console.Error.WriteLine($"Rollback failed: {ex.Message}");
+            Environment.Exit(1);
+        }
+    }
+    else
+    {
+        Console.Error.WriteLine("No backup available to restore.");
+        Environment.Exit(1);
+    }
+}
 
+// == Unix permission self-check (defense-in-depth after auto-update) ==
+if (!OperatingSystem.IsWindows())
+{
+    var exePath = Environment.ProcessPath;
+    if (!string.IsNullOrEmpty(exePath))
+    {
+        try
+        {
+            var mode = File.GetUnixFileMode(exePath);
+            if ((mode & UnixFileMode.UserExecute) == 0)
+            {
+                File.SetUnixFileMode(exePath, mode | UnixFileMode.UserExecute);
+            }
+        }
+        catch
+        {
+            // Best-effort; if we're running, we already have execute permission
+        }
+    }
+}
+
+// == Normal startup ==
 var appSettingsPath = Path.Combine(AppContext.BaseDirectory, "appsettings.json");
 if (!File.Exists(appSettingsPath))
 {
@@ -31,6 +77,38 @@ Log.Logger = new LoggerConfiguration()
 
 Log.Information("EchoHub client starting");
 
+// == Post-update detection: stale backup cleanup or flag for rollback menu ================
+if (UpdateBackupService.BackupExists())
+{
+    var backupInfo = UpdateBackupService.GetBackupInfo();
+    if (backupInfo is not null && DateTimeOffset.UtcNow - backupInfo.CreatedAt > TimeSpan.FromDays(7))
+    {
+        Log.Information("Deleting stale update backup from {Date}", backupInfo.CreatedAt);
+        UpdateBackupService.DeleteBackup();
+    }
+    else
+    {
+        Log.Information("Post-update: backup of v{OldVersion} available for rollback",
+            backupInfo?.Version ?? "unknown");
+        UpdateBackupService.IsPostUpdate = true;
+    }
+}
+
+// == Windows: clean up .old executable left by rollback restore ===========
+if (OperatingSystem.IsWindows())
+{
+    var currentExe = Environment.ProcessPath;
+    if (!string.IsNullOrEmpty(currentExe))
+    {
+        var oldExe = currentExe + ".old";
+        if (File.Exists(oldExe))
+        {
+            try { File.Delete(oldExe); }
+            catch { /* locked or permission issue — will be cleaned next launch */ }
+        }
+    }
+}
+
 try
 {
     var config = ConfigManager.Load();