import gradio as gr
from transformers import AutoProcessor, Idefics3ForConditionalGeneration
import re
import time
from PIL import Image
import torch
import spaces
import subprocess
subprocess.run('pip install flash-attn --no-build-isolation', env={'FLASH_ATTENTION_SKIP_CUDA_BUILD': "TRUE"}, shell=True)


processor = AutoProcessor.from_pretrained("HuggingFaceTB/SmolVLM_converted_4")

model = Idefics3ForConditionalGeneration.from_pretrained("HuggingFaceTB/SmolVLM_converted_4", 
        torch_dtype=torch.bfloat16,
        _attn_implementation="flash_attention_2").to("cuda")

@spaces.GPU
def model_inference(
    images, text, assistant_prefix, decoding_strategy, temperature, max_new_tokens,
    repetition_penalty, top_p
):
    if text == "" and not images:
        gr.Error("Please input a query and optionally image(s).")

    if text == "" and images:
        gr.Error("Please input a text query along the image(s).")

    if isinstance(images, Image.Image):
        images = [images]


    resulting_messages = [
                {
                    "role": "user",
                    "content": [{"type": "image"}] + [
                        {"type": "text", "text": text}
                    ]
                }
            ]

    if assistant_prefix:
      text = f"{assistant_prefix} {text}"


    prompt = processor.apply_chat_template(resulting_messages, add_generation_prompt=True)
    inputs = processor(text=prompt, images=[images], return_tensors="pt")
    inputs = {k: v.to("cuda") for k, v in inputs.items()}

    generation_args = {
        "max_new_tokens": max_new_tokens,
        "repetition_penalty": repetition_penalty,

    }

    assert decoding_strategy in [
        "Greedy",
        "Top P Sampling",
    ]
    if decoding_strategy == "Greedy":
        generation_args["do_sample"] = False
    elif decoding_strategy == "Top P Sampling":
        generation_args["temperature"] = temperature
        generation_args["do_sample"] = True
        generation_args["top_p"] = top_p

    generation_args.update(inputs)

    # Generate
    generated_ids = model.generate(**generation_args)

    generated_texts = processor.batch_decode(generated_ids[:, generation_args["input_ids"].size(1):], skip_special_tokens=True)
    return generated_texts[0]


with gr.Blocks(fill_height=True) as demo:
    gr.Markdown("## SmolVLM 🐶")
    gr.Markdown("Play with [HuggingFaceTB/SmolVLM](https://huggingface.co/HuggingFaceTB/SmolVLM) in this demo. To get started, upload an image and text or try one of the examples.")
    gr.Markdown("**Disclaimer:** SmolVLM does not include an RLHF alignment stage, so it may not consistently follow prompts or handle complex tasks. However, this doesn't mean it is incapable of doing so. Adding a prefix to the assistant's response, such as Let's think step for a reasoning question or `<html>` for HTML code generation, can significantly improve the output in practice. You could also play with the parameters such as the temperature in non-greedy mode.")
    with gr.Column():
        image_input = gr.Image(label="Upload your Image", type="pil", scale=1)
        query_input = gr.Textbox(label="Prompt")
        assistant_prefix = gr.Textbox(label="Assistant Prefix", placeholder="Let's think step by step.")

        submit_btn = gr.Button("Submit")
        output = gr.Textbox(label="Output")

    with gr.Accordion(label="Example Inputs and Advanced Generation Parameters"):
        examples=[
                    ["example_images/mmmu_example.jpeg", "Chase wants to buy 4 kilograms of oval beads and 5 kilograms of star-shaped beads. How much will he spend?", "Let's think step by step.", "Greedy", 0.4, 512, 1.2, 0.8],
                    ["example_images/rococo_1.jpg", "What art era is this?", None, "Greedy", 0.4, 512, 1.2, 0.8],
                    ["example_images/paper_with_text.png", "Read what's written on the paper", None, "Greedy", 0.4, 512, 1.2, 0.8],
                    ["example_images/dragons_playing.png","What's unusual about this image?",None,  "Greedy", 0.4, 512, 1.2, 0.8],
                    ["example_images/example_images_ai2d_example_2.jpeg", "What happens to fish if pelicans increase?", None, "Greedy", 0.4, 512, 1.2, 0.8],
                    ["example_images/travel_tips.jpg", "I want to go somewhere similar to the one in the photo. Give me destinations and travel tips.", None, "Greedy", 0.4, 512, 1.2, 0.8],
                    ["example_images/dummy_pdf.png", "How much percent is the order status?", None, "Greedy", 0.4, 512, 1.2, 0.8],
                    ["example_images/art_critic.png", "As an art critic AI assistant, could you describe this painting in details and make a thorough critic?.",None,  "Greedy", 0.4, 512, 1.2, 0.8],
                    ["example_images/s2w_example.png",  "What is this UI about?", None,"Greedy", 0.4, 512, 1.2, 0.8]]

        # Hyper-parameters for generation
        max_new_tokens = gr.Slider(
              minimum=8,
              maximum=1024,
              value=512,
              step=1,
              interactive=True,
              label="Maximum number of new tokens to generate",
          )
        repetition_penalty = gr.Slider(
              minimum=0.01,
              maximum=5.0,
              value=1.2,
              step=0.01,
              interactive=True,
              label="Repetition penalty",
              info="1.0 is equivalent to no penalty",
          )
        temperature = gr.Slider(
              minimum=0.0,
              maximum=5.0,
              value=0.4,
              step=0.1,
              interactive=True,
              label="Sampling temperature",
              info="Higher values will produce more diverse outputs.",
          )
        top_p = gr.Slider(
              minimum=0.01,
              maximum=0.99,
              value=0.8,
              step=0.01,
              interactive=True,
              label="Top P",
              info="Higher values is equivalent to sampling more low-probability tokens.",
          )
        decoding_strategy = gr.Radio(
              [
                  "Greedy",
                  "Top P Sampling",
              ],
              value="Greedy",
              label="Decoding strategy",
              interactive=True,
              info="Higher values is equivalent to sampling more low-probability tokens.",
          )
        decoding_strategy.change(
              fn=lambda selection: gr.Slider(
                  visible=(
                      selection in ["contrastive_sampling", "beam_sampling", "Top P Sampling", "sampling_top_k"]
                  )
              ),
              inputs=decoding_strategy,
              outputs=temperature,
          )

        decoding_strategy.change(
              fn=lambda selection: gr.Slider(
                  visible=(
                      selection in ["contrastive_sampling", "beam_sampling", "Top P Sampling", "sampling_top_k"]
                  )
              ),
              inputs=decoding_strategy,
              outputs=repetition_penalty,
          )
        decoding_strategy.change(
              fn=lambda selection: gr.Slider(visible=(selection in ["Top P Sampling"])),
              inputs=decoding_strategy,
              outputs=top_p,
          )
        gr.Examples(
                        examples = examples,
                        inputs=[image_input, query_input, assistant_prefix, decoding_strategy, temperature,
                                                              max_new_tokens, repetition_penalty, top_p],
                        outputs=output,
                        fn=model_inference
                    )

        submit_btn.click(model_inference, inputs = [image_input, query_input, assistant_prefix, decoding_strategy, temperature,
                                                      max_new_tokens, repetition_penalty, top_p], outputs=output)


demo.launch(debug=True)