Update app.py

app.py

@@ -60,7 +60,15 @@ app.layout = dbc.Container([
     html.Div(id='log-output', style={'whiteSpace': 'pre-line'}),
 ], fluid=True)
 
-# ... (keep all other callbacks and functions as they were) ...
+@callback(
+    Output('split-button', 'disabled'),
+    Input('upload-pdf', 'contents')
+)
+def enable_split_button(contents):
+    if contents:
+        logger.info("PDF uploaded, enabling Split PDF button")
+        return False
+    return True
 
 @callback(
     Output('progress-bar', 'value'),
@@ -74,6 +82,7 @@ app.layout = dbc.Container([
     prevent_initial_call=True
 )
 def split_pdf(n_clicks, contents, filename, ranges):
+    global progress
     if not contents or not ranges:
         logger.warning("Split PDF clicked but no content or ranges provided")
         raise PreventUpdate
@@ -82,11 +91,49 @@ def split_pdf(n_clicks, contents, filename, ranges):
     ranges = [r for r in ranges if r]  # Filter out empty ranges
     logger.info(f"Processing {len(ranges)} ranges")
     
+    progress = 0  # Reset progress
+    
     thread = Thread(target=process_pdf, args=(contents, filename, ranges))
     thread.start()
     
     return 0, True, "PDF splitting process started. Check console for detailed logs.", "Processing..."
 
+def process_pdf(contents, filename, ranges):
+    global progress, generated_file
+    try:
+        # Decode PDF content
+        content_type, content_string = contents.split(',')
+        decoded = base64.b64decode(content_string)
+        
+        # Read the PDF
+        pdf = PdfReader(io.BytesIO(decoded))
+        total_pages = len(pdf.pages)
+        
+        # Create a ZIP file in memory
+        zip_buffer = io.BytesIO()
+        with zipfile.ZipFile(zip_buffer, 'w') as zf:
+            for i, page_range in enumerate(ranges):
+                start, end = map(int, page_range.split('-'))
+                writer = PdfWriter()
+                
+                for page_num in range(start - 1, min(end, total_pages)):
+                    writer.add_page(pdf.pages[page_num])
+                
+                # Save the split PDF to the ZIP file
+                output = io.BytesIO()
+                writer.write(output)
+                output.seek(0)
+                zf.writestr(f'split_{i+1}.pdf', output.getvalue())
+                
+                progress = (i + 1) / len(ranges) * 100
+        
+        zip_buffer.seek(0)
+        generated_file = zip_buffer.getvalue()
+        progress = 100
+    except Exception as e:
+        logger.error(f"Error processing PDF: {str(e)}")
+        progress = -1
+
 @callback(
     Output('progress-bar', 'value', allow_duplicate=True),
     Output('download-button', 'disabled', allow_duplicate=True),
@@ -102,7 +149,7 @@ def update_progress(value):
         return 100, False, "PDF splitting completed. Click 'Download ZIP' to get your files.", ""
     elif progress == -1:
         logger.error("PDF splitting failed")
-        return 0, False, "Error occurred during PDF splitting. Check console for details.", ""
+        return 0, True, "Error occurred during PDF splitting. Check console for details.", ""
     else:
         return progress, True, f"Processing... {progress:.0f}% complete", "Processing..."