Update app.py

app.py

@@ -70,7 +70,9 @@ def zip_output_files():
     return ZIP_PATH
 
 # 主流程
-def process_pdf(pdf_file):
+def process_pdf(pdf_file, prefix="result_"):
+    if not prefix.strip():
+        prefix = "result_"
     try:
         progress = gr.Progress()
         progress(0, desc="準備中...")
@@ -107,7 +109,7 @@ def process_pdf(pdf_file):
                 result = overlay_image(bg.copy(), fg, *POS1)
                 result = overlay_image(result, fg, *POS2)
 
-                output_path = f"{OUTPUT_DIR}/result_{i:03d}.jpg"
+                output_path = f"{OUTPUT_DIR}/{prefix}{i:03d}.jpg"
                 cv2.imwrite(output_path, result)
                 results.append((output_path, f"Page {i:03d}"))
 
@@ -130,6 +132,7 @@ with gr.Blocks() as demo:
     gr.Markdown("## 📄 PDF頁面合成工具（背景固定為 7872x1200）")
 
     pdf_upload = gr.File(label="上傳PDF文件", file_types=[".pdf"])
+    prefix_input = gr.Textbox(label="輸出檔案前綴 (選填)", placeholder="例如：invoice_")
     btn_run = gr.Button("開始合成", variant="primary")
 
     with gr.Row():
@@ -138,10 +141,10 @@ with gr.Blocks() as demo:
         log_output = gr.Textbox(label="日誌", interactive=False)
 
     btn_run.click(
-        fn=process_pdf,
-        inputs=pdf_upload,
-        outputs=[gallery, zip_download, log_output],
-        concurrency_limit=4
+    fn=process_pdf,
+    inputs=[pdf_upload, prefix_input],
+    outputs=[gallery, zip_download, log_output],
+    concurrency_limit=4
     )
 
 if __name__ == "__main__":