Add file download button functionality

app.py

@@ -17,7 +17,7 @@ def generate_video(text, auth_openai, auth_elevenlabs, auth_replicate, auth_rev)
     return generated_video
 
 def download_video(video_path):
-    pass
+    return video_path
 
 with gr.Blocks() as demo:
     gr.Markdown("Generate a narrated horror story video from a text prompt.")
@@ -35,8 +35,10 @@ with gr.Blocks() as demo:
         with gr.Column():
             video_out = gr.Video(label="Output", interactive=False)
             download_button = gr.Button("Download")
+            output_file = gr.outputs.File(label="Video Output")
+            output_file.type = "video/mp4"
 
     generate_button.click(generate_video, inputs=[prompt_input, auth_openai_input, auth_eleven_input, auth_replicate_input, auth_rev_input], outputs=[video_out])
-    download_button.click(download_video, inputs=[video_out])
+    download_button.click(download_video, inputs=[video_out], outputs=[output_file])
 
 demo.launch(debug=True, enable_queue=True)