fix(files): report success cancellation and errors with safe next actions (U02)

src/Duempelkas.Infrastructure/Services/BackupService.cs

@@ -1,3 +1,4 @@
+using Duempelkas.App.Services.Models;
 using System.Diagnostics;
 using System.Runtime.InteropServices;
 using Duempelkas.App.Services;
@@ -9,30 +10,35 @@ public class BackupService : IBackupService
 {
     private readonly DatabaseLocation location;
 
-    public BackupService(DatabaseLocation location) => this.location = location;
-
-    public async Task<string> CreateBackupAsync()
+    private readonly IFileDialogService dialogs;
+    public BackupService(DatabaseLocation location, IFileDialogService? dialogs = null)
     {
-        try
-        {
-            var path = await ShowSaveDialogAsync($"duempelkas-backup-{DateTime.Now:yyyyMMdd-HHmmss}.bak");
-            if (string.IsNullOrWhiteSpace(path)) return "Sicherung wurde abgebrochen.";
-            await CreateBackupToAsync(path);
-            return $"Sicherung gespeichert: {path}";
-        }
-        catch (Exception ex) { return $"Sicherung fehlgeschlagen: {ex.Message}"; }
+        this.location = location;
+        this.dialogs = dialogs ?? new FileDialogService();
     }
 
-    public async Task<string> RestoreBackupAsync()
+    public async Task<FileOperationResult> CreateBackupAsync()
     {
         try
         {
-            var path = await ShowOpenDialogAsync();
-            if (string.IsNullOrWhiteSpace(path)) return "Wiederherstellung wurde abgebrochen.";
-            var fallback = await RestoreFromAsync(path);
-            return $"Wiederherstellung erfolgreich. Rückfallsicherung: {fallback}";
+            var path = await dialogs.SaveAsync($"duempelkas-backup-{DateTime.Now:yyyyMMdd-HHmmss}.bak");
+            if (string.IsNullOrWhiteSpace(path)) return FileOperationResult.Cancelled();
+            await CreateBackupToAsync(path);
+            return new(FileOperationStatus.Success, "Sicherung gespeichert.", path);
         }
-        catch (Exception ex) { return $"Wiederherstellung fehlgeschlagen: {ex.Message}"; }
+        catch (Exception ex) { return FileOperationResult.Error(ex); }
+    }
+
+    public async Task<FileOperationResult> RestoreBackupAsync()
+    {
+        try
+        {
+            var path = await dialogs.OpenBackupAsync();
+            if (string.IsNullOrWhiteSpace(path)) return FileOperationResult.Cancelled();
+            var fallback = await RestoreFromAsync(path);
+            return new(FileOperationStatus.Success, "Sicherung zurückgespielt. Die bisherigen Daten liegen in der Rückfallsicherung:", fallback);
+        }
+        catch (Exception ex) { return FileOperationResult.Error(ex); }
     }
 
     public async Task CreateBackupToAsync(string path)
@@ -124,74 +130,4 @@ public class BackupService : IBackupService
         _ = db.TransferLinks.ToArray();
     }
 
-    private static Task<string?> ShowSaveDialogAsync(string suggestedFileName)
-    {
-        return Task.Run(() =>
-        {
-            if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
-            {
-                var documentsPath = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
-                return Path.Combine(documentsPath, suggestedFileName);
-            }
-
-            var script = $@"
-Add-Type -AssemblyName System.Windows.Forms
-$dialog = New-Object System.Windows.Forms.SaveFileDialog
-$dialog.Filter = 'Backup-Dateien (*.bak)|*.bak'
-$dialog.DefaultExt = 'bak'
-$dialog.AddExtension = $true
-$dialog.OverwritePrompt = $true
-$dialog.FileName = '{suggestedFileName.Replace("'", "''")}'
-$dialog.Title = 'Backup speichern'
-if ($dialog.ShowDialog() -eq 'OK') {{ $dialog.FileName }} else {{ '' }}
-";
-
-            return RunPowerShellDialog(script);
-        });
-    }
-
-    private static Task<string?> ShowOpenDialogAsync()
-    {
-        return Task.Run(() =>
-        {
-            if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
-            {
-                return null;
-            }
-
-            var script = @"
-Add-Type -AssemblyName System.Windows.Forms
-$dialog = New-Object System.Windows.Forms.OpenFileDialog
-$dialog.Filter = 'Backup-Dateien (*.bak)|*.bak'
-$dialog.Multiselect = $false
-$dialog.Title = 'Backup auswählen'
-if ($dialog.ShowDialog() -eq 'OK') { $dialog.FileName } else { '' }
-";
-
-            return RunPowerShellDialog(script);
-        });
-    }
-
-    private static string? RunPowerShellDialog(string script)
-    {
-        var psi = new ProcessStartInfo
-        {
-            FileName = "powershell",
-            Arguments = $"-NoProfile -Command \"{script.Replace("\"", "\\\"") }\"",
-            RedirectStandardOutput = true,
-            UseShellExecute = false,
-            CreateNoWindow = true
-        };
-
-        using var process = Process.Start(psi);
-        if (process == null)
-        {
-            return null;
-        }
-
-        var result = process.StandardOutput.ReadToEnd().Trim();
-        process.WaitForExit();
-
-        return string.IsNullOrWhiteSpace(result) ? null : result;
-    }
 }