from fastapi import FastAPI
from pydantic import BaseModel
import torch
from transformers import AutoTokenizer, AutoModelForCausalLM

# Initialisera modellen och tokenizern
model_name = "AI-Sweden-Models/gpt-sw3-126m-instruct"
device = "cuda:0" if torch.cuda.is_available() else "cpu"

tokenizer = AutoTokenizer.from_pretrained(model_name)
model = AutoModelForCausalLM.from_pretrained(model_name)
model.to(device)
model.eval()

# FastAPI-applikationen
app = FastAPI()

class UserInput(BaseModel):
    prompt: str

@app.post("/generate/")
async def generate_response(user_input: UserInput):
    prompt = f"<|endoftext|><s>\nUser:\n{user_input.prompt}\n<s>\nBot:"
    input_ids = tokenizer(prompt, return_tensors="pt")["input_ids"].to(device)

    generated_token_ids = model.generate(
        inputs=input_ids,
        max_new_tokens=100,
        do_sample=True,
        temperature=0.6,
        top_p=1
    )[0]

    generated_text = tokenizer.decode(generated_token_ids[len(input_ids[0]):-1], skip_special_tokens=True)
    return {"response": generated_text.strip()}