from transformers import AutoModelForCausalLM, AutoTokenizer
import torch
from vllm import LLM, SamplingParams
import os
from fastapi import FastAPI
from pydantic import BaseModel
from transformers import AutoTokenizer, AutoModelForCausalLM, LlamaTokenizer

os.environ["CUDA_DEVICE_ORDER"]="PCI_BUS_ID"
os.environ['CUDA_VISIBLE_DEVICES'] = "2"

MODEL_NAME = "RegularizedSelfPlay/sppo_forward1reverse5-0.1-PromptABC-Mistral-7B-Instruct-SPPO-Iter3"  # Example: "meta-llama/Llama-2-7b-chat-hf"
HF_TOKEN = os.getenv("HF_API_TOKEN")

# Load model and tokenizer
tokenizer = LlamaTokenizer.from_pretrained("mistralai/Mistral-7B-Instruct-v0.2", token=HF_TOKEN)
llm = LLM(
        model=MODEL_NAME, 
        # revision="1296dc8fd9b21e6424c9c305c06db9ae60c03ace",
        # tokenizer_revision="1296dc8fd9b21e6424c9c305c06db9ae60c03ace",
        tensor_parallel_size=1,
    )
tokenizer.pad_token = tokenizer.eos_token
sampling_params = SamplingParams(
    temperature=0.7,
    top_p=0.9,
    seed=2024,
    max_tokens=2048,
    #max_tokens=64, # set it to higher value like 2048 for proper test
)


def generate_response(prompt):
    # inputs = tokenizer(prompt, return_tensors="pt").to("cuda")  # Move to GPU

    inputs = tokenizer.apply_chat_template(
        [
            {"role": "user", "content": prompt}, 
            {"role": "assistant", "content": "None"}
        ],
        tokenize=False, add_generate_prompt=True
    ).split("None")[0]
    # outputs = model.generate(**inputs, max_length=512)

    response = llm.generate(
            inputs,
            sampling_params
        )[0].outputs[0].text

    # response = tokenizer.decode(outputs[0], skip_special_tokens=True)
    return response

app = FastAPI()

class PromptRequest(BaseModel):
    prompt: str

@app.post("/generate")
def generate_text(request: PromptRequest):
    response = generate_response(request.prompt)
    return {"response": response}

if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=8000)
    # print(generate_response('hi I like u'))