fix file download naming

app.py

@@ -244,29 +244,55 @@ with gr.Blocks(delete_cache=(86400, 86400)) as demo:
         dl_button = gr.Button("File download")
         dl_button.click(lambda: None, [chatbot], js="""
             (chat_history) => {
-                // Attempt to extract content enclosed in backticks with an optional filename
-                const contentRegex = /```(\\S*\\.(\\S+))?\\n?([\\s\\S]*?)```/;
+                // Only define exception mappings
+                const languageToExt = {
+                    'python': 'py',
+                    'javascript': 'js',
+                    'typescript': 'ts',
+                    'csharp': 'cs',
+                    'ruby': 'rb',
+                    'shell': 'sh',
+                    'bash': 'sh',
+                    'markdown': 'md',
+                    'yaml': 'yml',
+                    'rust': 'rs',
+                    'golang': 'go',
+                    'kotlin': 'kt'
+                };
+
+                const contentRegex = /```(?:([^\\n]+)?\\n)?([\\s\\S]*?)```/;
                 const match = contentRegex.exec(chat_history[chat_history.length - 1][1]);
-                if (match && match[3]) {
-                    // Extract the content and the file extension
-                    const content = match[3];
-                    const fileExtension = match[2] || 'txt'; // Default to .txt if extension is not found
-                    const filename = match[1] || `download.${fileExtension}`;
-                    // Create a Blob from the content
-                    const blob = new Blob([content], {type: `text/${fileExtension}`});
-                    // Create a download link for the Blob
+                
+                if (match && match[2]) {
+                    const specifier = match[1] ? match[1].trim() : '';
+                    const content = match[2];
+                    
+                    let filename = 'download';
+                    let fileExtension = 'txt'; // default
+
+                    if (specifier) {
+                        if (specifier.includes('.')) {
+                            // If specifier contains a dot, treat it as a filename
+                            const parts = specifier.split('.');
+                            filename = parts[0];
+                            fileExtension = parts[1];
+                        } else {
+                            // Use mapping if exists, otherwise use specifier itself
+                            const langLower = specifier.toLowerCase();
+                            fileExtension = languageToExt[langLower] || langLower;
+                            filename = 'code';
+                        }
+                    }
+
+                    const blob = new Blob([content], {type: 'text/plain'});
                     const url = URL.createObjectURL(blob);
                     const a = document.createElement('a');
                     a.href = url;
-                    // If the filename from the chat history doesn't have an extension, append the default
-                    a.download = filename.includes('.') ? filename : `${filename}.${fileExtension}`;
+                    a.download = `${filename}.${fileExtension}`;
                     document.body.appendChild(a);
                     a.click();
                     document.body.removeChild(a);
                     URL.revokeObjectURL(url);
-                } else {
-                    // Inform the user if the content is malformed or missing
-                    alert('Sorry, the file content could not be found or is in an unrecognized format.');
                 }
             }
         """)