Allow changing output directory

Closes #5

src/ViewModels/MainViewModel.cs

@@ -256,7 +256,7 @@ class MainViewModel : BaseViewModel, IFontResolver, ICanCheckShutdown
 
     public async Task ShowSettings()
     {
-        var updatedSettings = await DialogHost.Show(new SettingsViewModel(_settings));
+        var updatedSettings = await DialogHost.Show(new SettingsViewModel(_settings, TopLevelGrabber));
         if (updatedSettings != null)
         {
             _settings = (Settings)updatedSettings;
@@ -575,6 +575,14 @@ class MainViewModel : BaseViewModel, IFontResolver, ICanCheckShutdown
     {
         // TODO: calculate needed width for images based on page width and margins and all that?
         // TODO: resize (non-HEIC) images for smaller size...?
+        // safety checks
+        var outputDir = _settings.SaveOutputPdfInWorkingDir ? folderPath : _settings.OutputPdfDir;
+        if (!Directory.Exists(outputDir))
+        {
+            await DialogHost.Show(new WarningViewModel("Output directory not found! Please adjust your application Settings before continuing. Output directory: " + outputDir));
+            return;
+        }
+        // start making PDF!
         IsCreatingPDF = true;
         var pdfDoc = new Document();
         var outputFileName = ReportTitle + ".pdf";
@@ -828,15 +836,15 @@ class MainViewModel : BaseViewModel, IFontResolver, ICanCheckShutdown
         };
         LogInfo("Rendering document to PDF file...");
         pdfRenderer.RenderDocument();
-        string outputPDFFileName = Path.Join(folderPath, outputFileName);
+        string outputPDFFilePath = Path.Join(outputDir, outputFileName);
         LogInfo("Saving PDF document to disk...");
-        pdfRenderer.PdfDocument.Save(outputPDFFileName);
-        LogInfo("Finished saving PDF output to: " + outputPDFFileName);
+        pdfRenderer.PdfDocument.Save(outputPDFFilePath);
+        LogInfo("Finished saving PDF output to: " + outputPDFFilePath);
         await CreateAndSaveReportObjectAfterReportCreation();
         // clean up data dir
         Directory.Delete(convertedDir, true);
         // show output folder to user
-        OpenFolderForFileInFileViewer(outputPDFFileName);
+        OpenFolderForFileInFileViewer(outputPDFFilePath);
         IsCreatingPDF = false;
     }
 

src/ViewModels/SettingsViewModel.cs

@@ -25,15 +25,15 @@ class SettingsViewModel: ChangeNotifier
 {
     private Settings _previousSettings;
     private Settings _settings;
+    private string _errorMessage;
+    private ITopLevelGrabber? _topLevelGrabber;
 
-    public SettingsViewModel(Settings settingsToEdit)
+    public SettingsViewModel(Settings settingsToEdit, ITopLevelGrabber? topLevelGrabber)
     {
         _previousSettings = settingsToEdit;
-        _settings = new Settings
-        {
-            LastUsedPath = _previousSettings.LastUsedPath,
-            UseDocnetPDFImageRendering = _previousSettings.UseDocnetPDFImageRendering
-        };
+        _settings = new Settings(settingsToEdit); // clone it
+        _errorMessage = "";
+        _topLevelGrabber = topLevelGrabber;
     }
 
     public bool UseDocnetPDFImageRendering
@@ -46,6 +46,65 @@ class SettingsViewModel: ChangeNotifier
         }
     }
 
+    public bool SaveOutputPdfInWorkingDir
+    {
+        get => _settings.SaveOutputPdfInWorkingDir;
+        set
+        {
+            _settings.SaveOutputPdfInWorkingDir = value;
+            NotifyPropertyChanged();
+        }
+    }
+
+    public string OutputPdfDirPath
+    {
+        get => _settings.OutputPdfDir;
+        set
+        {
+            _settings.OutputPdfDir = value;
+            NotifyPropertyChanged();
+        }
+    }
+
+    public bool IsOutputPdfDirValid
+    {
+        get => SaveOutputPdfInWorkingDir || (!SaveOutputPdfInWorkingDir && Directory.Exists(OutputPdfDirPath));
+    }
+
+    public bool HasErrorMessage
+    {
+        get => !string.IsNullOrWhiteSpace(_errorMessage);
+    }
+
+    public string ErrorMessage
+    {
+        get => _errorMessage;
+        set
+        {
+            _errorMessage = value;
+            NotifyPropertyChanged();
+            NotifyPropertyChanged(nameof(HasErrorMessage));
+        }
+    }
+
+    public async void ChooseOutputFolder()
+    {
+        var topLevel = _topLevelGrabber?.GetTopLevel();
+        if (topLevel != null)
+        {
+            var folders = await topLevel.StorageProvider.OpenFolderPickerAsync(new FolderPickerOpenOptions()
+            {
+                Title = "Choose where to save your report file...",
+                AllowMultiple = false,
+            });
+            if (folders.Count == 1)
+            {
+                var folder = folders[0];
+                OutputPdfDirPath = folder.Path.LocalPath;
+            }
+        }
+    }
+
     public void Cancel()
     {
         DialogHost.Close("DialogHost", null);