import torch
import spaces
import gradio as gr
from transformers import Pix2StructForConditionalGeneration, Pix2StructProcessor
from PIL import Image

# Load model and processor
model = Pix2StructForConditionalGeneration.from_pretrained(
    "google/pix2struct-screen2words-large", dtype=torch.bfloat16
).to("cuda")
model.eval()
processor = Pix2StructProcessor.from_pretrained("google/pix2struct-screen2words-large")

# Define the function
@spaces.GPU
def describe_ui(image, text):
    # text 為使用者輸入的 prompt，可為空字串
    inputs = processor(images=image, text=text or "", return_tensors="pt").to(
        dtype=torch.bfloat16, device="cuda"
    )
    predictions = model.generate(**inputs)
    return processor.decode(predictions[0], skip_special_tokens=False)

# Launch the Gradio interface
gr.Interface(
    fn=describe_ui,
    inputs=[
        gr.Image(type="pil", label="Upload UI Screenshot"),
        gr.Textbox(label="Optional prompt / instruction", placeholder="e.g. Describe layout and buttons"),
    ],
    outputs=gr.Textbox(label="Model Output"),
    title="UI Screen Describer (Pix2Struct)",
    description="Upload a screenshot or UI image and optionally enter a text prompt. The model (Google Pix2Struct) will generate a detailed description.",
).launch()