from fastapi import FastAPI, HTTPException
from pydantic import BaseModel
import transformers

app = FastAPI()

model_name = 'Intel/neural-chat-7b-v3-1'
model = transformers.AutoModelForCausalLM.from_pretrained(model_name)
tokenizer = transformers.AutoTokenizer.from_pretrained(model_name)

class ChatInput(BaseModel):
    system_input: str
    user_input: str

@app.post("/generate-response")
async def generate_response(chat_input: ChatInput):
    try:
        # Format the input using the provided template
        prompt = f"### System:\n{chat_input.system_input}\n### User:\n{chat_input.user_input}\n### Assistant:\n"

        # Tokenize and encode the prompt
        inputs = tokenizer.encode(prompt, return_tensors="pt", add_special_tokens=False)

        # Generate a response
        outputs = model.generate(inputs, max_length=1000, num_return_sequences=1)
        response = tokenizer.decode(outputs[0], skip_special_tokens=True)

        # Extract only the assistant's response
        return {"response": response.split("### Assistant:\n")[-1]}

    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))