import argparse
import torch
import gradio as gr
from threading import Thread
from transformers import TextIteratorStreamer, AutoTokenizer, AutoModelForCausalLM
from PIL import ImageDraw
import re
from torchvision.transforms.v2 import Resize

parser = argparse.ArgumentParser()
parser.add_argument("--cpu", action="store_true", help="Use CPU for computation")
args = parser.parse_args([])

DEVICE = "cuda" if torch.cuda.is_available() and not args.cpu else "cpu" # Determine device based on availability and argument
DTYPE = torch.float32 if DEVICE == "cpu" else torch.float16 # CPU doesn't support float16
LATEST_REVISION = "2024-05-20"
MODEL_ID = "yeshavyas27/moondream-ft"
tokenizer = AutoTokenizer.from_pretrained("vikhyatk/moondream2", revision=LATEST_REVISION)
moondream = AutoModelForCausalLM.from_pretrained(
    MODEL_ID, trust_remote_code=True, torch_dtype=DTYPE
).to(device=DEVICE)

moondream.eval()


def answer_question(img, prompt):
    image_embeds = moondream.encode_image(img)
    streamer = TextIteratorStreamer(tokenizer, skip_special_tokens=True)
    thread = Thread(
        target=moondream.answer_question,
        kwargs={
            "image_embeds": image_embeds,
            "question": prompt,
            "tokenizer": tokenizer,
            "streamer": streamer,
        },
    )
    thread.start()

    buffer = ""
    for new_text in streamer:
        buffer += new_text
        yield buffer


def extract_floats(text):
    # Regular expression to match an array of four floating point numbers
    pattern = r"\[\s*(-?\d+\.\d+)\s*,\s*(-?\d+\.\d+)\s*,\s*(-?\d+\.\d+)\s*,\s*(-?\d+\.\d+)\s*\]"
    match = re.search(pattern, text)
    if match:
        # Extract the numbers and convert them to floats
        return [float(num) for num in match.groups()]
    return None  # Return None if no match is found


def extract_bbox(text):
    bbox = None
    if extract_floats(text) is not None:
        x1, y1, x2, y2 = extract_floats(text)
        bbox = (x1, y1, x2, y2)
    return bbox


def process_answer(img, answer):
    if extract_bbox(answer) is not None:
        x1, y1, x2, y2 = extract_bbox(answer)
        draw_image = Resize(768)(img)
        width, height = draw_image.size
        x1, x2 = int(x1 * width), int(x2 * width)
        y1, y2 = int(y1 * height), int(y2 * height)
        bbox = (x1, y1, x2, y2)
        ImageDraw.Draw(draw_image).rectangle(bbox, outline="red", width=3)
        return gr.update(visible=True, value=draw_image)

    return gr.update(visible=False, value=None)


with gr.Blocks() as demo:
    gr.Markdown(
        """
        # 🌔 VQA Visual Question Answering 
        """
    )
    with gr.Row():
        prompt = gr.Textbox(label="Input Prompt", placeholder="Type here...", scale=4)
        submit = gr.Button("Submit")
    with gr.Row():
        img = gr.Image(type="pil", label="Upload an Image")
        with gr.Column():
            output = gr.Markdown(label="Response")
            ann = gr.Image(visible=False, label="Annotated Image")

    submit.click(answer_question, [img, prompt], output)
    prompt.submit(answer_question, [img, prompt], output)
    output.change(process_answer, [img, output], ann, show_progress=False)

demo.queue().launch(debug=True)