added a RegexGenerator to find the first markdown code fence with a csv attribute

app/MindWork AI Studio/Tools/PlainFileExport.cs

@@ -1,28 +1,67 @@
-using System.Diagnostics;
+using System.Text.RegularExpressions;
 using AIStudio.Chat;
-using AIStudio.Dialogs;
 using AIStudio.Tools.PluginSystem;
 using AIStudio.Tools.Rust;
 using AIStudio.Tools.Services;
-using DialogOptions = MudBlazor.DialogOptions;
 
 namespace AIStudio.Tools;
 
-public static class PlainFileExport
+public static partial class PlainFileExport
 {
     private static readonly ILogger LOGGER = Program.LOGGER_FACTORY.CreateLogger(nameof(PlainFileExport)); 
     
     private sealed record ExportTarget(string DisplayName, FileTypeFilter FileType);
     
     private static readonly ExportTarget MARKDOWN = new("Markdown (.md)", FileTypes.MARKDOWN);
+    private static readonly ExportTarget CSV = new("CSV (.csv)", FileTypes.CSV);
     
     private static string TB(string fallbackEn) => I18N.I.T(fallbackEn, typeof(PlainFileExport).Namespace, nameof(PlainFileExport));
+
+    /// <summary>
+    /// Extracts the content of the first complete Markdown code block marked as CSV.
+    /// </summary>
+    public static bool TryExtractCsvContent(IContent content, out string csvContent)
+    {
+        if (content is ContentText text)
+        {
+            var match = CsvCodeFenceRegex().Match(text.Text);
+            if (match.Success)
+            {
+                csvContent = match.Groups["content"].Value;
+                return true;
+            }
+        }
+
+        csvContent = string.Empty;
+        return false;
+    }
+
+    [GeneratedRegex(
+        """
+        # Matches an opening Markdown code fence and captures its delimiter.
+        ^(?<fence>`{3,}|~{3,})
+
+        # Matches the csv language identifier and the end of the opening fence line.
+        # Also allow tab-separated, pipe-separated and semicolon separated values at the code fence
+        [ \t]*(csv|tsv|psv|ssv)[ \t]*\r?\n
+
+        # Captures the content of the first matching fenced code block.
+        (?<content>[\s\S]*?)
+
+        # Matches the corresponding closing fence followed by a line ending or end of input.
+        ^\k<fence>[ \t]*(?=\r?\n|$)
+        """,
+        RegexOptions.IgnoreCase |
+        RegexOptions.Multiline |
+        RegexOptions.IgnorePatternWhitespace)]
+    private static partial Regex CsvCodeFenceRegex();
     
     public static async Task<bool> ToFile(RustService rustService, FileExportFormat format, IContent markdownContent)
     {
         var exportTarget = format switch
         {
             FileExportFormat.MARKDOWN => MARKDOWN,
+            FileExportFormat.CSV => CSV,
             _ => throw new ArgumentOutOfRangeException(nameof(format), format, null),
         };
         
@@ -37,14 +76,19 @@ public static class PlainFileExport
 
         try
         {
-            var markdownText = markdownContent switch
+            var fileContent = format switch
             {
-                ContentText text => text.Text,
+                FileExportFormat.MARKDOWN => markdownContent switch
-                ContentImage _ => "Image export is not yet possible.",
+                {
-                _ => "Unknown content type. Cannot export document."
+                    ContentText text => text.Text,
+                    ContentImage _ => "Image export is not yet possible.",
+                    _ => "Unknown content type. Cannot export document."
+                },
+                FileExportFormat.CSV when TryExtractCsvContent(markdownContent, out var csvContent) => csvContent,
+                _ => throw new ArgumentOutOfRangeException(nameof(format), format, null),
             };
 
-            await File.WriteAllTextAsync(response.SaveFilePath, markdownText);
+            await File.WriteAllTextAsync(response.SaveFilePath, fileContent);
             await MessageBus.INSTANCE.SendSuccess(new(Icons.Material.Filled.CheckCircle, TB("Document export successful")));
             
             return true;