from fastapi import FastAPI
from pydantic import BaseModel
import uvicorn
import prompt_style
import os
from huggingface_hub import hf_hub_download
# from llama_cpp import Llama
import time


# model_id = "failspy/Meta-Llama-3-8B-Instruct-abliterated-v3-GGUF"
# filename="Meta-Llama-3-8B-Instruct-abliterated-v3_q6.gguf"
# model_path = hf_hub_download(repo_id=model_id, filename="Meta-Llama-3-8B-Instruct-abliterated-v3_q6.gguf", token=os.environ['HF_TOKEN'])
# model = Llama(model_path=model_path, n_gpu_layers=-1, n_ctx=4096, verbose=False)

# model = Llama.from_pretrained(repo_id=model_id, filename=filename, n_gpu_layers=-1, token=os.environ['HF_TOKEN'], 
#                               n_ctx=4096, verbose=False, attn_implementation="flash_attention_2")

from transformers import AutoModelForCausalLM, BitsAndBytesConfig, AutoTokenizer

model_id = "failspy/Meta-Llama-3-8B-Instruct-abliterated-v3"
model_8bit = AutoModelForCausalLM.from_pretrained(model_id, quantization_config=BitsAndBytesConfig(load_in_8bit=True), 
                                                  token=os.environ['HF_TOKEN'], attn_implementation="flash_attention_2")


class Item(BaseModel):
    prompt: str
    history: list
    system_prompt: str
    temperature: float = 0.8
    max_new_tokens: int = 1024
    top_p: float = 0.95
    repetition_penalty: float = 1.0
    seed : int = 42
    
app = FastAPI()

def format_prompt(item: Item):
    messages = [
        {"role": "system", "content": prompt_style.data},
    ]
    for it in item.history:
        messages.append({"role" : "user", "content": it[0]})
        messages.append({"role" : "assistant", "content": it[1]})
    messages.append({"role" : "user", "content": item.prompt})
    return messages

def generate(item: Item):
    formatted_prompt = format_prompt(item)
    # output = model.create_chat_completion(messages=formatted_prompt, seed=item.seed,  
    #                                       temperature=item.temperature, max_tokens=item.max_new_tokens)
    # out = output['choices'][0]['message']['content']
    # return out
    
    input_ids = tokenizer.apply_chat_template(
        formatted_prompt,
        add_generation_prompt=True,
        return_tensors="pt"
    ).to("cuda")
    
    terminators = [
        tokenizer.eos_token_id,
        tokenizer.convert_tokens_to_ids("<|eot_id|>")
    ]
    
    outputs = model_8bit.generate(
        input_ids,
        max_new_tokens=item.max_new_tokens,
        eos_token_id=terminators,
        do_sample=True,
        temperature=item.temperature,
        top_p=item.top_p,
    )
    response = outputs[0][input_ids.shape[-1]:]
    return tokenizer.decode(response, skip_special_tokens=True)

    # inputs = tokenizer(prompt, return_tensors="pt").to("cuda")
    # generated_ids = model.generate(**inputs)
    # outputs = tokenizer.batch_decode(generated_ids, skip_special_tokens=True)

@app.post("/generate/")
async def generate_text(item: Item):
    t1 = time.time()
    ans = generate(item)
    print(ans)
    print(f"time: {str(time.time() - t1)}")
    return {"response": ans}


@app.get("/")
def read_root():
    
    return {"Hello": "Worlds"}