fix bugs

app.py

@@ -3,7 +3,6 @@ from PIL import Image
 from docx import Document
 from io import BytesIO
 import os
-
 def merge_files(file_list, output_filename="merged.pdf"):
     writer = PdfWriter()
     
@@ -11,25 +10,31 @@ def merge_files(file_list, output_filename="merged.pdf"):
         ext = file.name.split('.')[-1].lower()
         
         if ext == 'pdf':
-            with open(file.name, 'rb') as f:
-                writer.append(f)
+            # Read PDF file from memory
+            writer.append(file)
         elif ext in ['jpg', 'jpeg', 'png']:
+            # Convert image to PDF
             img = Image.open(file)
             pdf_bytes = BytesIO()
             img.convert('RGB').save(pdf_bytes, format='PDF')
+            pdf_bytes.seek(0)
             writer.append(pdf_bytes)
         elif ext == 'docx':
+            # Convert DOCX to PDF-like content
             doc = Document(file)
             pdf_bytes = BytesIO()
             for paragraph in doc.paragraphs:
-                pdf_bytes.write(paragraph.text.encode('utf-8'))
+                pdf_bytes.write((paragraph.text + '\n').encode('utf-8'))
+            pdf_bytes.seek(0)
             writer.append(pdf_bytes)
         elif ext == 'txt':
-            with open(file.name, 'r') as f:
-                pdf_bytes = BytesIO()
-                pdf_bytes.write(f.read().encode('utf-8'))
-                writer.append(pdf_bytes)
+            # Convert TXT file to PDF-like content
+            pdf_bytes = BytesIO()
+            pdf_bytes.write(file.read())
+            pdf_bytes.seek(0)
+            writer.append(pdf_bytes)
     
+    # Save the final PDF
     with open(output_filename, 'wb') as output_pdf:
         writer.write(output_pdf)