import os
from threading import Thread
import bitsandbytes
from typing import Iterator

import gradio as gr
import spaces
import torch
from transformers import AutoModelForCausalLM, AutoTokenizer, TextIteratorStreamer


# Set the environment variable
os.environ['TF_ENABLE_ONEDNN_OPTS'] = '0'

DESCRIPTION = """\
# Llama 3.2 3B Instruct
Llama 3.2 3B is Meta's latest iteration of open LLMs.
This is a demo of [`meta-llama/Llama-3.2-3B-Instruct`](https://huggingface.co/meta-llama/Llama-3.2-3B-Instruct), fine-tuned for instruction following.
For more details, please check [our post](https://huggingface.co/blog/llama32).
"""

# Access token for the model (if required)
access_token = os.getenv('HF_TOKEN')
# Download the Base model
#model_id = "./models/Llama-32-3B-Instruct"
model_id = "nvidia/Llama-3_1-Nemotron-51B-Instruct"
MAX_MAX_NEW_TOKENS = 6144
DEFAULT_MAX_NEW_TOKENS = 6144
MAX_INPUT_TOKEN_LENGTH = int(os.getenv("MAX_INPUT_TOKEN_LENGTH", "6144"))

device = torch.device("cuda" if torch.cuda.is_available() else "cpu")

#model_id = "nltpt/Llama-3.2-3B-Instruct"
tokenizer = AutoTokenizer.from_pretrained(model_id,token=access_token)
#tokenizer.padding_side = 'right'
#tokenizer.eos_token_id = 107
#tokenizer.pad_token = tokenizer.eos_token
model = AutoModelForCausalLM.from_pretrained(
    model_id,
    device_map=device,
    trust_remote_code=True,
    #torch_dtype=torch.float8,
    load_in_8bit=True,
    token=access_token
)
model.eval()


@spaces.GPU(duration=90)
def generate(
    message: str,
    chat_history: list[tuple[str, str]],
    system_prompt: str,
    max_new_tokens: int = 1024,
    temperature: float = 0.6,
    top_p: float = 0.9,
    top_k: int = 50,
    repetition_penalty: float = 1.2,
) -> Iterator[str]:
    conversation = [{"role": "system", "content": system_prompt}]
    for user, assistant in chat_history:
        conversation.extend(
            [
                {"role": "user", "content": user},
                {"role": "assistant", "content": assistant},
            ]
        )
    conversation.append({"role": "user", "content": message})

    # Set pad_token_id if it's not already set
    if tokenizer.pad_token_id is None:
        tokenizer.padding_side = 'right'
        tokenizer.pad_token = tokenizer.eos_token

    input_ids = tokenizer.apply_chat_template(conversation, add_generation_prompt=True,add_special_tokens=True, return_tensors="pt",padding=True ,return_attention_mask=True)
    if input_ids.shape[1] > MAX_INPUT_TOKEN_LENGTH:
        input_ids = input_ids[:, -MAX_INPUT_TOKEN_LENGTH:]
        gr.Warning(f"Trimmed input from conversation as it was longer than {MAX_INPUT_TOKEN_LENGTH} tokens.")
    # Ensure attention mask is set
    #attention_mask = input_ids['attention_mask']

    input_ids = input_ids.to(model.device)
    #attention_mask = attention_mask.to(model.device)



    streamer = TextIteratorStreamer(tokenizer, timeout=2000.0, skip_prompt=True, skip_special_tokens=True)
    generate_kwargs = dict(
        input_ids=input_ids,
        streamer=streamer,
        max_new_tokens=max_new_tokens,
        do_sample=True,
        top_p=top_p,
        top_k=top_k,
        temperature=temperature,
        num_beams=1,
        repetition_penalty=repetition_penalty
    )
    t = Thread(target=model.generate, kwargs=generate_kwargs)
    t.start()

    outputs = []
    for text in streamer:
        outputs.append(text)
        yield "".join(outputs)


chat_interface = gr.ChatInterface(
    fn=generate,
    additional_inputs=[
        gr.Textbox(
            label="System Prompt",
            placeholder="Enter system prompt here...",
            lines=2,
        ),
        gr.Slider(
            label="Max new tokens",
            minimum=1,
            maximum=MAX_MAX_NEW_TOKENS,
            step=1,
            value=DEFAULT_MAX_NEW_TOKENS,
        ),
        gr.Slider(
            label="Temperature",
            minimum=0.1,
            maximum=4.0,
            step=0.1,
            value=0.6,
        ),
        gr.Slider(
            label="Top-p (nucleus sampling)",
            minimum=0.05,
            maximum=1.0,
            step=0.05,
            value=0.9,
        ),
        gr.Slider(
            label="Top-k",
            minimum=1,
            maximum=1000,
            step=1,
            value=50,
        ),
        gr.Slider(
            label="Repetition penalty",
            minimum=1.0,
            maximum=2.0,
            step=0.05,
            value=1.2,
        ),
    ],
    stop_btn=None,
    examples=[
        ["Hello there! How are you doing?"],
        ["Can you explain briefly to me what is the Python programming language?"],
        ["Explain the plot of Cinderella in a sentence."],
        ["How many hours does it take a man to eat a Helicopter?"],
        ["Write a 100-word article on 'Benefits of Open-Source in AI research'"],
    ],
    cache_examples=False,
)

with gr.Blocks(css="style.css", fill_height=True) as demo:
    gr.Markdown(DESCRIPTION)
    gr.DuplicateButton(value="Duplicate Space for private use", elem_id="duplicate-button")
    chat_interface.render()

if __name__ == "__main__":
    demo.queue(max_size=20).launch()